- earlier capabilities are accessible from Python

- MultiStreamReceiver and SampleWriter cleaned - AcquisitionFormat introduced - Logger created - MultiStreamProcessor idea introduced, MultiStreamToFile introduced - MATLAB scripts have been modified to load new capture folder structure - began implementing MultiStreamOscilloscope
2022-05-05 00:11:48 +02:00 · 2022-05-05 00:11:48 +02:00 · 22233ce62d
commit 22233ce62d
parent cff343e959
42 changed files with 1962 additions and 495 deletions
--- a/.gitignore
+++ b/.gitignore
@ -0,0 +1 @@
+*.bkup
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@ -1,13 +1,18 @@
-cmake_minimum_required(VERSION 3.20)
+cmake_minimum_required(VERSION 3.16)

-SET(APP_NAME wfr)
+SET(APP_NAME wfr_app)

 project(${APP_NAME})
 set(CMAKE_CXX_STANDARD 17)

-add_executable(${APP_NAME} main.cpp src/ALSADevice.cpp src/ALSADevice.h src/MemoryPool.cpp src/MemoryPool.h utils/Semaphore.h utils/Semaphore.cpp src/SampleWriter.h src/Timestamp.h
-        #src/SampleReceiver.h
-        src/audio_types.h src/ServerBeacon.cpp src/ServerBeacon.h src/GUI.h src/globals.h src/Callback.h src/MultiStreamReceiver.cpp src/MultiStreamReceiver.h)
+add_executable(${APP_NAME}
+        main.cpp
+        src/ALSADevice.cpp
+        src/ALSADevice.h
+        src/MemoryPool.cpp
+        src/MemoryPool.h
+        utils/Semaphore.h
+        utils/Semaphore.cpp)

 find_package(Threads REQUIRED)
 if (THREADS_FOUND)
@ -36,6 +41,12 @@ if (GTKMM_FOUND)
    target_link_libraries(${APP_NAME} ${GTKMM_LIBRARIES})
 endif(GTKMM_FOUND)

+add_dependencies(${APP_NAME} wfr)
+target_link_libraries(${APP_NAME} wfr)
+
 install(TARGETS ${APP_NAME} RUNTIME DESTINATION ${PROJECT_SOURCE_DIR}/runtime ARCHIVE DESTINATION ${PROJECT_SOURCE_DIR}/runtime)

-set(CMAKE_CXX_FLAGS ${CMAKE_CXX_FLAGS} "-rdynamic")
+set(CMAKE_CXX_FLAGS ${CMAKE_CXX_FLAGS} "-rdynamic")
+
+add_subdirectory(libwfr)
+add_subdirectory(python)
--- a/MATLAB/read_multistream_dir.m
+++ b/MATLAB/read_multistream_dir.m
@ -2,14 +2,14 @@ function read_multistream_dir(d, prefix, plotrange, onlydata)
  % get directories containing samples
  hint_file_name = strcat('./runtime/', d, '/node_dir_hint.txt');
  hint_file = fopen(hint_file_name);
-  node_dirs = textscan(hint_file, '%s');
+  node_files = textscan(hint_file, '%s');
  fclose(hint_file);
  
-  node_names = strrep(node_dirs{1,1}, prefix, "");
+  node_names = strrep(node_files{1,1}, prefix, "");
  
-  node_dirs = strcat('./runtime/', d, '/', node_dirs{1,1});
+  node_files = strcat('./runtime/', d, '/', node_files{1,1});
  
-  sync_datasets(node_dirs, node_names, plotrange, onlydata);
+  sync_datasets(node_files, node_names, plotrange, onlydata);
  
-  print(strcat('./runtime/', d, '/figure.svg'), '-dsvg');
+  %print(strcat('./runtime/', d, '/figure.svg'), '-dsvg');
 end
--- a/MATLAB/read_syncdata.m
+++ b/MATLAB/read_syncdata.m
@ -1,42 +1,46 @@
-function ds = read_syncdata(DATASET_DIR)
+function ds = read_syncdata(data_files)
  % settings
  %DATASET_DIR = 'test_20221';
-  TS_FILE = 'ts';
-  SAMPLE_FILE_PREFIX = 'ch_';
-  FILE_EXT = 'dat';
-  CHANNELS = 2;
+  TS_FILE_EXT = 'ts';
+  %SAMPLE_FILE_PREFIX = 'ch_';
+  SAMPLE_FILE_EXT = 'dat';
+  %CHANNELS = 2;

-  % computed values
-  FN_TS = strcat(DATASET_DIR, '/', TS_FILE, '.', FILE_EXT);
+  %for ch=0:1:(CHANNELS-1)
+  %  FN_SAMPLE{ch+1} = strcat(data_files, '/', SAMPLE_FILE_PREFIX, num2str(ch), '.', SAMPLE_FILE_EXT);
+  %end

-  for ch=0:1:(CHANNELS-1)
-    FN_SAMPLE{ch+1} = strcat(DATASET_DIR, '/', SAMPLE_FILE_PREFIX, num2str(ch), '.', FILE_EXT);
-  end
+  [files_n,~] = size(data_files);
+  
+  s = [];
+  ts = [];
+  
+  for i=1:files_n
+    
+    data_file = data_files(i,:);
+    
+    % load timestamps
+    FN_TS = strcat(data_file, '.', TS_FILE_EXT);
+    f = fopen(FN_TS ,'r');
+    d = fread(f,[2,Inf],'uint32');
+    fclose(f);

+    % create fractional timestamp
+    d = d(1,:) + d(2,:) / 1E+09;
+    
+    ts = [ts; d];

-  % load timestamps
-  f = fopen(FN_TS ,'r');
-  ts = fread(f,[2,Inf],'uint32');
-  fclose(f);
+    % get sample count
+    %sample_cnt = length(ts);

-  % take first element as t0
-  %ts(1,:) = ts(1,:) - 1636036145;
-
-  % create fractional timestamp
-  ts = ts(1,:) + ts(2,:) / 1E+09;
-
-  % get sample count
-  sample_cnt = length(ts);
-
-  % load samples
-  s = zeros(CHANNELS, sample_cnt);
-  for ch=1:CHANNELS
-    f = fopen(FN_SAMPLE{ch},'r');
+    % load samples
+    FN_SAMPLE = strcat(data_file, '.', SAMPLE_FILE_EXT);
+    f = fopen(FN_SAMPLE,'r');
    d = fread(f, [1,Inf],'int16');
-    s(ch,:) = d;
+    s = [s; d];
    fclose(f);
  end
-
+  
  %figure(1)
  %plot(ts(1,1:100), s(1,1:100), 'x')
  %xlim([ts(1) ts(100)])
--- a/MATLAB/sync_datasets.m
+++ b/MATLAB/sync_datasets.m
@ -68,18 +68,18 @@ function sds = sync_datasets(dss, node_names, PLOTRANGE, ONLYDATA)
  grid on
  
  if (ONLYDATA)
-    xlabel("Idő [s]");
+    %xlabel("Idő [s]");
+    xlabel("Time [s]")
  end
  
-  ylabel("Feszültség [V]");
+  %ylabel("Feszültség [V]");
+  ylabel("Voltage [V]");
  xlim([ts_ref(PLOTRANGE(1)) ts_ref(PLOTRANGE(end))]);
    
  legend_lines = {};
  
  for i=1:length(node_names)
-    for ch=1:2 
-      legend_lines{2 * (i - 1) + ch, 1} = strcat(node_names{i,1}, " CH", num2str(ch));
-    end
+    legend_lines{i,1} = node_names{i,1};
  end
  
  legend(legend_lines);
@ -116,9 +116,12 @@ function sds = sync_datasets(dss, node_names, PLOTRANGE, ONLYDATA)
  end
  
  legend(legend_lines);
-  ylabel("Erősítéshibával kompenzált különbség")
+  %ylabel("Erősítéshibával kompenzált különbség")
+  ylabel("Gain error compensated difference")
  xlim([ts_ref(PLOTRANGE(1)) ts_ref(PLOTRANGE(end))]);
  
+  grid on
+  
  % plot timestamp errors
  subplot(3,1,3);
  
@ -133,8 +136,10 @@ function sds = sync_datasets(dss, node_names, PLOTRANGE, ONLYDATA)
  end
  
  grid on
-  xlabel("Idő [s]");
-  ylabel("Időhiba [ns]");
+  xlabel("Time [s]")
+  %xlabel("Idő [s]");
+  ylabel("Time error [ns]")
+  %ylabel("Időhiba [ns]");
  legend(legend_lines);
  xlim([ts_ref(PLOTRANGE(1)) ts_ref(PLOTRANGE(end))]);
  
--- a/libwfr/CMakeLists.txt
+++ b/libwfr/CMakeLists.txt
@ -0,0 +1,44 @@
+cmake_minimum_required(VERSION 3.16)
+project(libwfr)
+
+set(CMAKE_CXX_STANDARD 20)
+
+# Threads
+find_package(Threads REQUIRED)
+
+set(SOURCES
+        src/audio_types.h
+        src/Callback.h
+        src/MultiStreamReceiver.cpp
+        src/MultiStreamReceiver.h
+        src/SampleWriter.cpp
+        src/SampleWriter.h
+        src/ServerBeacon.cpp
+        src/ServerBeacon.h
+        src/Timestamp.h
+        src/Logger.cpp
+        src/Logger.h
+        src/AcquisitionFormat.cpp
+        src/AcquisitionFormat.h
+        src/ChannelBuffer.cpp
+        src/ChannelBuffer.h
+        src/MultiStreamProcessor.cpp
+        src/MultiStreamProcessor.h
+        src/MultiStreamToFile.cpp
+        src/MultiStreamToFile.h
+        src/ICreatable.h
+        src/MultiStreamOscilloscope.cpp
+        src/MultiStreamOscilloscope.h
+        src/Trigger.cpp
+        src/Trigger.h)
+
+###
+
+add_library(wfr ${SOURCES})
+target_link_libraries(wfr Threads::Threads)
+target_include_directories(wfr PUBLIC ${PROJECT_SOURCE_DIR}/../utils)
+install(TARGETS wfr
+        LIBRARY DESTINATION ${PROJECT_SOURCE_DIR}/bin
+        ARCHIVE DESTINATION ${PROJECT_SOURCE_DIR}/bin)
+
+set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fPIC")
--- a/libwfr/src/AcquisitionFormat.cpp
+++ b/libwfr/src/AcquisitionFormat.cpp
@ -0,0 +1,101 @@
+//
+// Created by epagris on 2022.05.03..
+//
+
+#include <sstream>
+#include <cstring>
+#include <set>
+#include <list>
+#include <vector>
+#include "AcquisitionFormat.h"
+#include "Logger.h"
+
+AcquisitionFormat::AcquisitionFormat() {
+    memset(this, 0, sizeof(AcquisitionFormat)); // clear every field
+}
+
+
+AcquisitionFormat::AcquisitionFormat(const std::string &acqFormatStr) {
+    std::stringstream sstream(acqFormatStr);
+
+    // fill the input
+    sstream >> sampling_rate_Hz;
+    sstream >> sample_size_b;
+    sstream >> channel_count;
+    sstream >> mch_samples_per_packet;
+
+    // fill the rest...
+    fillDerivedFields();
+}
+
+AcquisitionFormat::AcquisitionFormat(size_t sampling_rate_Hz, size_t sample_size_b, size_t channel_count, size_t mch_samples_per_packet) {
+    // fill the input
+    this->sampling_rate_Hz = sampling_rate_Hz;
+    this->sample_size_b = sample_size_b;
+    this->channel_count = channel_count;
+    this->mch_samples_per_packet = mch_samples_per_packet;
+
+    // fill the rest...
+    fillDerivedFields();
+}
+
+void AcquisitionFormat::fillDerivedFields() {
+    mSettingsValid = true;
+
+    // validate sampling rate
+    std::set<size_t> validSamplingRates = {8000, 8021, 32000, 44100, 48000, 88200, 96000};
+    if (!validSamplingRates.contains(sampling_rate_Hz)) {
+        Logger::logLine("INVALID sampling rate of " + std::to_string(sampling_rate_Hz) + " Hz.");
+        mSettingsValid &= false;
+    }
+
+    // validate sample size
+    struct SampleSizeStorageSizeAssignment {
+        size_t sample_size_b;
+        size_t storage_size_B;
+    };
+
+    std::vector<SampleSizeStorageSizeAssignment> validSampleSizes = {
+            {8,  1},
+            {12, 2},
+            {16, 2},
+            {24, 4},
+            {32, 4}
+    };
+
+    // look for storage size
+    sample_storage_size_B = 0;
+    for (const auto& s: validSampleSizes) {
+        if (s.sample_size_b == sample_size_b) {
+            sample_storage_size_B = s.storage_size_B;
+            break;
+        }
+    }
+
+    if (sample_storage_size_B == 0) {
+        Logger::logLine("INVALID sample size of " + std::to_string(sample_size_b) + "bits.");
+        mSettingsValid &= false;
+    }
+
+    // validate channel count
+    if (channel_count > 8) {
+        Logger::logLine("WARNING Channel count of " + std::to_string(channel_count) + " is likely too large.");
+    }
+
+    // validate packet size
+    if ((sampling_rate_Hz % mch_samples_per_packet) != 0) {
+        Logger::logLine("INVALID multichannel sample count (now " + std::to_string(mch_samples_per_packet) +
+                        "), this must be an integer divisor of sampling rate (" + std::to_string(sampling_rate_Hz) + " Hz)!");
+        mSettingsValid &= false;
+    }
+
+    distinct_samples_per_packet = mch_samples_per_packet * channel_count;
+    sample_data_size_per_packet_B = sample_storage_size_B * distinct_samples_per_packet;
+    single_channel_data_size_per_packet_B = mch_samples_per_packet * sample_storage_size_B;
+    all_channel_sample_size_B = channel_count * sample_storage_size_B;
+    packet_period_ns = 1E+09 * mch_samples_per_packet / (double) sampling_rate_Hz;
+}
+
+bool AcquisitionFormat::isValid() const {
+    return mSettingsValid;
+}
--- a/libwfr/src/AcquisitionFormat.h
+++ b/libwfr/src/AcquisitionFormat.h
@ -0,0 +1,34 @@
+//
+// Created by epagris on 2022.05.03..
+//
+
+#ifndef WFR_APP_ACQUISITIONFORMAT_H
+#define WFR_APP_ACQUISITIONFORMAT_H
+
+
+#include <string>
+
+class AcquisitionFormat {
+public:
+    size_t sampling_rate_Hz; // sampling rate
+    size_t sample_size_b; // sample size in bits
+    size_t sample_storage_size_B; // sample storage size in bytes
+    size_t channel_count; // number of channels
+    size_t mch_samples_per_packet; // number of all-channel samples per packet
+    size_t distinct_samples_per_packet; // number of samples summed across all channel
+    size_t sample_data_size_per_packet_B; // data size summed across the full packet
+    size_t single_channel_data_size_per_packet_B; // data size of a single channel in the packet
+    size_t all_channel_sample_size_B; // sample size of a full, all-channel sample
+    double packet_period_ns; // time period encapsulated by a full packet
+private:
+    bool mSettingsValid; // indicate if current settings are valid
+    void fillDerivedFields(); // fill fields with values derived from the input data
+public:
+    AcquisitionFormat(); // default contr.
+    explicit AcquisitionFormat(const std::string& acqFormatStr); // constr. from formatt string
+    AcquisitionFormat(size_t sampling_rate_Hz, size_t sample_size_b, size_t channel_count, size_t mch_samples_per_packet); // constr. from fields
+    bool isValid() const; // are the fields represent a valid set of settings
+};
+
+
+#endif //WFR_APP_ACQUISITIONFORMAT_H
--- a/libwfr/src/Callback.h
+++ b/libwfr/src/Callback.h
--- a/libwfr/src/ChannelBuffer.cpp
+++ b/libwfr/src/ChannelBuffer.cpp
@ -0,0 +1,239 @@
+//
+// Created by epagris on 2022.05.03..
+//
+
+#include <cstring>
+#include "ChannelBuffer.h"
+#include "Logger.h"
+
+ChannelBuffer::ChannelBuffer(size_t blockSize, size_t blockCount, size_t elementSize) {
+    // check if blockSize is divisible by 4
+    if ((blockSize % 4) != 0) {
+        throw std::runtime_error(std::string("Block size must be an integral multiple of 4! ") + __FUNCTION__);
+    }
+
+    // fill-in parameters
+    mBlockSize = blockSize;
+    mBlockCount = blockCount;
+    mFullMemSize = blockSize * blockCount;
+    mElementSize = elementSize;
+    mElementsPerBlock = blockSize / elementSize;
+
+    // allocate memory
+    mpMem = std::shared_ptr<uint8_t>(new uint8_t[mFullMemSize]); // exception is thrown if this fails...
+
+    // clear and fill-in memory blocks
+    clear();
+
+    // no reader is waiting
+    mReaderWaiting = false;
+}
+
+void ChannelBuffer::store(const void *pSrc) {
+    mStoreFetch_mtx.lock(); // MUTEX!!!
+
+    BlockDescriptor bd;
+
+    if (mFreeBlocks.empty()) { // if there're no more free blocks to allocate, then drop the eldest one and shift the queue
+        // release block
+        bd = mOccupiedBlocks.front();
+        mOccupiedBlocks.pop_front();
+
+        // log buffer overrun
+        //Logger::logLine("ChannelBuffer overrun!");
+
+    } else { // if there's at least a single free block
+        // acquire the free block
+        bd = mFreeBlocks.front();
+
+        // remove from the free queue
+        mFreeBlocks.pop_front();
+
+        // put into the queue of occupied blocks
+        //mOccupiedBlocks.push(bd);
+    }
+
+    // store tag
+    mLastTag += mElementsPerBlock;
+    bd.tag = mLastTag;
+
+    // push back onto the queue ("move to the end of the queue")
+    mOccupiedBlocks.push_back(bd);
+
+    // copy content
+    void *pDest = bd.p;
+    memcpy(pDest, pSrc, mBlockSize);
+
+    // handle waiting readers
+    if (mReaderWaiting) {
+        mReaderWaiting = false;
+        mStoreFetch_mtx.unlock();
+        mReadSem.post();
+    } else {
+        mStoreFetch_mtx.unlock();
+    }
+}
+
+uint64_t ChannelBuffer::fetch(void *pDst, ssize_t size) {
+    mStoreFetch_mtx.lock(); // MUTEX!!!
+
+    // if there're no data to copy, then block
+    if (mOccupiedBlocks.empty()) {
+        mReaderWaiting = true; // signal that reader is waiting
+        mStoreFetch_mtx.unlock(); // release lock
+        mReadSem.wait(); // wait on data to become available
+        mStoreFetch_mtx.lock(); // re-lock mutex
+    }
+
+    BlockDescriptor bd;
+
+    // if there're data to copy
+    if (!mOccupiedBlocks.empty()) {
+        // get block
+        bd = mOccupiedBlocks.front();
+
+        void *pSrc = bd.p;
+
+        // copy content to given memory area
+        if (size == 0) {
+            memcpy(pDst, pSrc, mBlockSize);
+        } else if (size > 0) { // copy from the beginning of the block
+            memcpy(pDst, pSrc, std::min((size_t) size, mBlockSize));
+        } else if (size < 0) { // copy from the end of the block
+            size_t copySize = std::min((size_t) (labs(size)), mBlockSize); // determine copy size
+            uint8_t *pSrcStart = (uint8_t *) pSrc + mBlockSize - copySize; // determine beginning of area to copy
+            memcpy(pDst, pSrcStart, copySize); // copy
+        }
+
+        // remove from the queue of occupied blocks
+        mOccupiedBlocks.pop_front();
+
+        // add to the queue of free blocks
+        mFreeBlocks.push_back(bd);
+    } else {
+        throw std::runtime_error("Error, this mustn't be hit!");
+    }
+
+    mStoreFetch_mtx.unlock(); // release semaphore
+
+    return bd.tag;
+}
+
+void ChannelBuffer::clear() {
+    std::unique_lock<std::mutex> lock(mStoreFetch_mtx); // MUTEX!
+
+    // fill-in free blocks
+    mOccupiedBlocks.clear();
+    mFreeBlocks.clear();
+    for (size_t i = 0; i < mBlockCount; i++) {
+        BlockDescriptor bd = {.p = mpMem.get() + i * mBlockSize, .tag = -1};
+        mFreeBlocks.push_back(bd);
+    }
+}
+
+std::shared_ptr<const uint8_t> ChannelBuffer::fullBuffer() const {
+    return mpMem;
+}
+
+int64_t ChannelBuffer::getEldestTag() {
+    std::unique_lock<std::mutex> lock(mStoreFetch_mtx);
+
+    if (!mOccupiedBlocks.empty()) {
+        return mOccupiedBlocks.front().tag;
+    } else {
+        return -1;
+    }
+}
+
+size_t ChannelBuffer::copyBetweenTags(void *pDst, int64_t start, int64_t end) {
+    std::unique_lock<std::mutex> lock(mStoreFetch_mtx);
+
+    if (mOccupiedBlocks.empty() || (end < start)) {
+        return 0;
+    }
+
+    uint8_t * pDstByte = (uint8_t *) pDst;
+
+    // get eldest and youngest tag
+    int64_t eldestTag = mOccupiedBlocks.front().tag;
+    int64_t youngestTag = mOccupiedBlocks.back().tag;
+
+    // clip tags falling out of valid range
+    start = std::max(start, eldestTag);
+    end = std::min(end, youngestTag);
+
+    // iterators
+    std::list<BlockDescriptor>::iterator startIter, endIter;
+    bool startIterFound = false, endIterFound = false;
+
+    // find starting block
+    for (auto iter = mOccupiedBlocks.begin(); iter != mOccupiedBlocks.end() && (!startIterFound && !endIterFound); iter++) {
+        // select start iter
+        if ((iter->tag <= start) && ((iter->tag + mElementsPerBlock - 1) >= start)) {
+            startIter = iter;
+            startIterFound = true;
+        }
+        if ((iter->tag <= end) && ((iter->tag + mElementsPerBlock - 1) >= end)) {
+            endIter = iter;
+            endIterFound = true;
+        }
+    }
+
+    uint8_t *pStart;
+    size_t sizeCopied = 0;
+
+    // IF range resides in a single block
+    if (startIter == endIter) {
+        pStart = startIter->p + (start - startIter->tag) * mElementSize;
+        sizeCopied = end - start + 1;
+        memcpy(pDst, pStart, sizeCopied);
+    } else { // IF range spans across multiple blocks
+        auto iterAfterEnd = endIter;
+        iterAfterEnd++;
+
+        size_t copySize = 0;
+        for (auto iter = startIter; iter != iterAfterEnd; iter++) {
+            if (iter == startIter) { // START
+                pStart = iter->p + (start - iter->tag) * mElementSize;
+                copySize = mBlockSize - (start - iter->tag) + 1;
+                memcpy(pDstByte + sizeCopied, pStart, copySize);
+                sizeCopied += copySize;
+            } else if (iter == endIter) { // END
+                pStart = iter->p;
+                copySize = (end - iter->tag) + 1;
+                memcpy(pDstByte + sizeCopied, pStart, copySize);
+                sizeCopied += copySize;
+            } else { // INBETWEEN
+                pStart = iter->p;
+                copySize = mBlockSize;
+                memcpy(pDstByte + sizeCopied, pStart, copySize);
+                sizeCopied += copySize;
+            }
+        }
+    }
+
+    return sizeCopied;
+}
+
+size_t ChannelBuffer::getFreeBlockCnt() {
+    std::unique_lock<std::mutex> lock(mStoreFetch_mtx);
+    return mFreeBlocks.size();
+}
+
+int64_t ChannelBuffer::copyBlock(size_t n, void * pDst) {
+    std::unique_lock<std::mutex> lock(mStoreFetch_mtx);
+
+    // block not found
+    if ((n + 1) > mOccupiedBlocks.size()) {
+        return -1;
+    }
+
+    // block found
+    auto iter = mOccupiedBlocks.begin();
+    std::advance(iter, n);
+
+    // copy block contents
+    memcpy(pDst, iter->p, mBlockSize);
+
+    return iter->tag;
+}
--- a/libwfr/src/ChannelBuffer.h
+++ b/libwfr/src/ChannelBuffer.h
@ -0,0 +1,53 @@
+//
+// Created by epagris on 2022.05.03..
+//
+
+#ifndef WFR_APP_CHANNELBUFFER_H
+#define WFR_APP_CHANNELBUFFER_H
+
+
+#include <cstddef>
+#include <queue>
+#include <cstdint>
+#include <memory>
+#include <mutex>
+#include <list>
+#include <Semaphore.h>
+
+/*
+ * Finite-length, automatically dropping channel buffer designed for exactly one reader
+ */
+
+class ChannelBuffer {
+public:
+    struct BlockDescriptor {
+        uint8_t * p;
+        int64_t tag;
+    };
+private:
+    size_t mBlockSize; // size of a block
+    size_t mBlockCount; // number of blocks
+    size_t mFullMemSize; // allocate memory block size derived from block size and block count
+    size_t mElementSize; // size of a single element
+    size_t mElementsPerBlock; // number of elements per block
+    uint64_t mLastTag; // last assigned tag
+    std::list<BlockDescriptor> mOccupiedBlocks; // occupied blocks
+    std::list<BlockDescriptor> mFreeBlocks; // free blocks
+    std::shared_ptr<uint8_t> mpMem; // memory holding buffers (free and occupied also)
+    std::mutex mStoreFetch_mtx; // mutex for concurrent fetching and storing
+    bool mReaderWaiting; // indicates, that a reader is waiting for new data
+    Semaphore mReadSem; // read semaphore for blocking reader
+public:
+    ChannelBuffer(size_t blockSize, size_t blockCount, size_t elementSize); // constr.
+    void store(const void *pSrc); // store into a new data block by copying from pSrc
+    uint64_t fetch(void * pDst, ssize_t size = 0); // fetch eldest data block and copy to pDst
+    std::shared_ptr<const uint8_t> fullBuffer() const; // get full buffer
+    void clear(); // clear block occupancies
+    int64_t getEldestTag(); // get the tag residing the longest in the buffer
+    size_t copyBetweenTags(void *pDst, int64_t start, int64_t end); // copy data to external buffer between tags (return: number of bytes copied)
+    size_t getFreeBlockCnt(); // get number of free blocks
+    int64_t copyBlock(size_t n, void * pDst); // get block (nth eldest)
+};
+
+
+#endif //WFR_APP_CHANNELBUFFER_H
--- a/libwfr/src/ICreatable.h
+++ b/libwfr/src/ICreatable.h
@ -0,0 +1,19 @@
+//
+// Created by epagris on 2022.05.04..
+//
+
+#ifndef WFR_APP_ICREATABLE_H
+#define WFR_APP_ICREATABLE_H
+
+#include <memory>
+
+template <typename T, typename... ParamTypes>
+class ICreatable {
+public:
+    static std::shared_ptr<T> create(ParamTypes... params) {
+        return std::shared_ptr<T>((T *) new T(params...));
+    }
+};
+
+
+#endif //WFR_APP_ICREATABLE_H
--- a/libwfr/src/Logger.cpp
+++ b/libwfr/src/Logger.cpp
@ -0,0 +1,50 @@
+//
+// Created by epagris on 2022.05.03..
+//
+
+#include <unistd.h>
+#include <fcntl.h>
+#include <iostream>
+#include "Logger.h"
+
+bool Logger::mLogEn = false;
+int Logger::mLogFD = -1;
+bool Logger::mCloseOnStop = false;
+
+void Logger::log(const std::string &str) {
+    if (mLogEn) {
+        write(mLogFD, str.c_str(), str.size());
+    }
+}
+
+void Logger::logLine(const std::string &str) {
+    std::string line = str + "\n";
+    log(line);
+}
+
+void Logger::startLogging(int fd) {
+    mLogFD = fd;
+    mLogEn = true;
+}
+
+void Logger::startLogging(const std::string &filename) {
+    mLogFD = open(filename.c_str(), O_WRONLY);
+
+    if (mLogFD < 0) {
+        std::cerr << "Could not open log output file! (" + filename + ")" << std::endl;
+        return;
+    }
+
+    mCloseOnStop = true; // close file when abandoning logging session, since we have opened it
+    mLogEn = true;
+}
+
+void Logger::stopLogging() {
+    if (mLogEn) {
+        mLogEn = false;
+
+        if (mCloseOnStop) { // close file belonging to us
+            close(mLogFD);
+        }
+    }
+}
--- a/libwfr/src/Logger.h
+++ b/libwfr/src/Logger.h
@ -0,0 +1,33 @@
+//
+// Created by epagris on 2022.05.03..
+//
+
+#ifndef WFR_APP_LOGGER_H
+#define WFR_APP_LOGGER_H
+
+
+#include <string>
+#include <unistd.h>
+
+class Logger {
+public:
+    static constexpr int LOG_FD_DEF = STDOUT_FILENO; // default log file descriptor
+private:
+    static bool mLogEn; // enable logging
+    static int mLogFD; // file descriptor for logging
+    static bool mCloseOnStop; // close file when stopping logging
+private:
+    Logger() = default; // constr.
+public:
+    static void startLogging(int fd = STDOUT_FILENO); // start logging on given file descriptor
+    static void startLogging(const std::string &filename); // start logging using a filename
+    static void stopLogging(); // stop logging
+
+    // logging functions
+    static void log(const std::string &str);
+    static void logLine(const std::string &str);
+
+};
+
+
+#endif //WFR_APP_LOGGER_H
--- a/libwfr/src/MultiStreamOscilloscope.cpp
+++ b/libwfr/src/MultiStreamOscilloscope.cpp
@ -0,0 +1,100 @@
+//
+// Created by epagris on 2022.05.04..
+//
+
+#include <cmath>
+#include "MultiStreamOscilloscope.h"
+
+MultiStreamOscilloscope::MultiStreamOscilloscope() {
+    mCapturePeriod_ns = DRAW_WINDOW_PERIOD_NS_DEF;
+    verticalScale = VOLT_PER_BIN_DEF;
+    mTrigState = {false, false};
+}
+
+void MultiStreamOscilloscope::setup(const std::vector<in_addr_t> &nodes, const AcquisitionFormat &acqFmt) {
+    MultiStreamProcessor::setup(nodes, acqFmt);
+
+    // calculate buffer parameters
+    mCaptureLength = ceil(mCapturePeriod_ns / 1E+09 * acqFmt.sampling_rate_Hz); // calculate draw window period in samples
+    mFIFOBlockCnt = 2 * floor(mCaptureLength / acqFmt.mch_samples_per_packet); // TODO: 2x: pretrigger...
+    mFIFOBlockSize = mAcqFmt.mch_samples_per_packet * sizeof(SamplePoint);
+
+    // setup channel buffers
+    mpChBufs.resize(mChCnt);
+    for (auto chBuf: mpChBufs) {
+        chBuf.reset(new ChannelBuffer(mFIFOBlockSize, mFIFOBlockCnt, 0));
+    }
+
+    // setup sample assembly buffer
+    mpAssemblyBuffer.reset(new SamplePoint[mAcqFmt.mch_samples_per_packet]);
+
+    // setup trigger buffer
+    mpTriggerBuffer.reset(new SamplePoint[mAcqFmt.mch_samples_per_packet]);
+}
+
+bool MultiStreamOscilloscope::input(size_t ch, const std::shared_ptr<Timestamp> &pTime, const void *pData, size_t size) {
+    if (!MultiStreamProcessor::input(ch, pTime, pData, size)) {
+        return false;
+    }
+
+    // assemble sample points
+    double sample;
+    for (size_t i = 0; i < mAcqFmt.mch_samples_per_packet; i++) {
+        uint8_t *pSample = ((uint8_t *) pData) + i * mAcqFmt.sample_storage_size_B; // generate sample pointer
+
+        // fetch value
+        switch (mAcqFmt.sample_storage_size_B) {
+            case 1:
+                sample = *((int8_t *) pSample);
+                break;
+            case 2:
+                sample = *((int16_t *) pSample);
+                break;
+            case 4:
+                sample = *((int32_t *) pSample);
+                break;
+        }
+
+        // infer vertical gain
+        sample *= verticalScale;
+
+        // save sample point
+        mpAssemblyBuffer.get()[i] = {.t = pTime.get()[i].to_ns(), .x = sample};
+    }
+
+    // push new block of samples onto the FIFO
+    mpChBufs[ch]->store(mpAssemblyBuffer.get());
+
+    // if a sufficient collection of samples are available (the FIFO is full)
+    // and the trigger is armed, and the trigger channel is the curent one,
+    // then probe samples to trigger
+    if (trigSettings.ch == ch && mTrigState.armed && mpChBufs[ch]->getFreeBlockCnt() == 0) {
+        int64_t tag = mpChBufs[ch]->copyBlock(2, mpTriggerBuffer.get()); // TODO magic constant!...
+        for (size_t i = 0; i < mAcqFmt.mch_samples_per_packet; i++) {
+            const SamplePoint& samplePoint = mpTriggerBuffer.get()[i]; // get sample
+            mTrigState.trigd = trigSettings.sample(samplePoint.x); // probe if causes a trigger
+
+            // triggered?
+            if (mTrigState.trigd) {
+                mTrigState.armed = false; // disable trigger system until arming
+                mTrigState.triggerSampleTag = tag + i; // store the sample the trigger fired on
+
+                // copy captured data
+                size_t preTriggerSamples = mAcqFmt.mch_samples_per_packet;
+                int64_t captureStart = mTrigState.triggerSampleTag - preTriggerSamples;
+                int64_t captureEnd = captureStart + mCaptureLength;
+                mpChBufs[ch]->copyBetweenTags(mpTriggerBuffer.get(), captureStart, captureEnd);
+            }
+        }
+    }
+
+    return true;
+}
+
+void MultiStreamOscilloscope::triggerNow() {
+
+}
+
+void MultiStreamOscilloscope::armTrigger() {
+
+}
--- a/libwfr/src/MultiStreamOscilloscope.h
+++ b/libwfr/src/MultiStreamOscilloscope.h
@ -0,0 +1,51 @@
+//
+// Created by epagris on 2022.05.04..
+//
+
+#ifndef WFR_APP_MULTISTREAMOSCILLOSCOPE_H
+#define WFR_APP_MULTISTREAMOSCILLOSCOPE_H
+
+
+#include "ICreatable.h"
+#include "MultiStreamProcessor.h"
+#include "ChannelBuffer.h"
+#include "Trigger.h"
+
+class MultiStreamOscilloscope : public MultiStreamProcessor, public ICreatable<MultiStreamOscilloscope> {
+public:
+    static constexpr size_t DRAW_WINDOW_PERIOD_NS_DEF = 50E+06; // default window length (50ms)
+    static constexpr double VOLT_PER_BIN_DEF = 42.80E-06; // default vertical resolution
+public:
+    struct SamplePoint {
+        int64_t t; // time
+        double x; // sample data
+    };
+private:
+    std::vector<std::shared_ptr<ChannelBuffer>> mpChBufs; // channel buffers
+    size_t mCapturePeriod_ns; // drawing window period
+    size_t mCaptureLength; // length of drawing sliding window in SAMPLES
+    size_t mFIFOBlockCnt; // number of blocks the FIFO consists of
+    size_t mFIFOBlockSize; // FIFO block size in bytes
+    std::shared_ptr<SamplePoint> mpAssemblyBuffer; // buffer for assembling sample points
+    std::shared_ptr<SamplePoint> mpTriggerBuffer; // buffer for probing against trigger conditions
+    std::shared_ptr<SamplePoint> mpCaptureBuffer; // buffer for last capture
+public:
+    TriggerSettings trigSettings; // trigger settings
+    double verticalScale; // vertical resolution
+private:
+    struct {
+        bool armed; // indicates wheter trigger is armed or not
+        bool trigd; // indicates if trigger has fired
+        int64_t triggerSampleTag;
+    } mTrigState;
+public:
+    MultiStreamOscilloscope();
+    void triggerNow(); // make the scope trigger regardless conditions
+    void armTrigger(); // arm trigger for next acquisition
+
+    void setup(const std::vector<in_addr_t> &nodes, const AcquisitionFormat &acqFmt) override;
+    bool input(size_t ch, const std::shared_ptr<Timestamp> &pTime, const void *pData, size_t size) override;
+};
+
+
+#endif //WFR_APP_MULTISTREAMOSCILLOSCOPE_H
--- a/libwfr/src/MultiStreamProcessor.cpp
+++ b/libwfr/src/MultiStreamProcessor.cpp
@ -0,0 +1,29 @@
+//
+// Created by epagris on 2022.05.04..
+//
+
+#include "MultiStreamProcessor.h"
+#include "Logger.h"
+
+void MultiStreamProcessor::setup(const std::vector<in_addr_t> &nodes, const AcquisitionFormat &acqFmt) {
+    // get parameters
+    mNodes = nodes;
+    mChCnt = nodes.size() * acqFmt.channel_count;
+    mAcqFmt = acqFmt;
+}
+
+bool MultiStreamProcessor::input(size_t ch, const std::shared_ptr<Timestamp> &pTime, const void *pData, size_t size) {
+    // check input validity
+    if (ch >= mChCnt) {
+        Logger::logLine("INVALID channel index (" + std::to_string(ch) + ") in " + __FUNCTION__);
+        return false;
+    }
+
+    if (size > mAcqFmt.single_channel_data_size_per_packet_B) {
+        Logger::logLine("INVALID data size (" + std::to_string(size) + " bytes) in " + __FUNCTION__ +
+                        ". Predefined single-channel all-data size (" +
+                        std::to_string(mAcqFmt.single_channel_data_size_per_packet_B) + " bytes) exceeded, tail clipped!");
+    }
+
+    return true;
+}
--- a/libwfr/src/MultiStreamProcessor.h
+++ b/libwfr/src/MultiStreamProcessor.h
@ -0,0 +1,28 @@
+//
+// Created by epagris on 2022.05.04..
+//
+
+#ifndef WFR_APP_MULTISTREAMPROCESSOR_H
+#define WFR_APP_MULTISTREAMPROCESSOR_H
+
+
+#include <netinet/in.h>
+#include <vector>
+#include <memory>
+#include "AcquisitionFormat.h"
+#include "Timestamp.h"
+
+class MultiStreamProcessor {
+protected:
+    std::vector<in_addr_t> mNodes; // client node addresses
+    size_t mChCnt; // channel count
+    AcquisitionFormat mAcqFmt; // acquisition format
+protected:
+    MultiStreamProcessor() = default;
+public:
+    virtual void setup(const std::vector<in_addr_t> &nodes, const AcquisitionFormat &acqFmt); // setup function for adapting to data streams
+    virtual bool input(size_t ch, const std::shared_ptr<Timestamp> &pTime, const void *pData, size_t size); // input data for a channel
+};
+
+
+#endif //WFR_APP_MULTISTREAMPROCESSOR_H
--- a/libwfr/src/MultiStreamReceiver.cpp
+++ b/libwfr/src/MultiStreamReceiver.cpp
@ -0,0 +1,247 @@
+//
+// Created by epagris on 2021. 11. 22..
+//
+
+#include <arpa/inet.h>
+
+#include <memory>
+#include <thread>
+#include <unistd.h>
+#include <cstring>
+
+#include "MultiStreamReceiver.h"
+#include "audio_types.h"
+#include "Logger.h"
+
+MultiStreamReceiver::MultiStreamReceiver(const std::vector<in_addr_t> &nodes, size_t samplingRate, size_t sampleSize, size_t channelCount, size_t mchSampPerPckt, unsigned short port)
+        : MultiStreamReceiver(nodes, AcquisitionFormat(samplingRate, sampleSize, channelCount, mchSampPerPckt), port) {
+}
+
+MultiStreamReceiver::MultiStreamReceiver(const std::vector<in_addr_t> &nodes, const std::string &acqFormat_str, unsigned short port)
+        : MultiStreamReceiver(nodes, AcquisitionFormat(acqFormat_str), port) {
+}
+
+MultiStreamReceiver::MultiStreamReceiver(const std::vector<in_addr_t> &nodes, const AcquisitionFormat &acqFormat, unsigned short port)
+        : port(port), mAcqFmt(acqFormat) {
+    mRunning = false;
+    mClientNodes = nodes;
+    mSoc = -1; // some dummy initial value
+}
+
+MultiStreamReceiver::MultiStreamReceiver(const std::vector<std::string> &nodes_str, const AcquisitionFormat &acqFormat, unsigned short port)
+        : port(port), mAcqFmt(acqFormat) {
+    mRunning = false;
+    mSoc = -1;
+
+    for (auto &node_addr: nodes_str) {
+        mClientNodes.push_back({ inet_addr(node_addr.c_str()) });
+    }
+}
+
+MultiStreamReceiver::MultiStreamReceiver(const std::vector<std::string> &nodes_str, const std::string &acqFormat_str, unsigned short port)
+        : MultiStreamReceiver(nodes_str, AcquisitionFormat(acqFormat_str), port) {
+}
+
+MultiStreamReceiver::~MultiStreamReceiver() {
+    stop();
+}
+
+void MultiStreamReceiver::startNetworking() {
+    // open socket
+    mSoc = socket(AF_INET, SOCK_DGRAM, 0);
+    if (mSoc == -1) {
+        throw std::runtime_error(std::string("Could not create UDP-socket in ") + __FUNCTION__ + "!");
+    }
+
+    int opt = 1;
+    if (setsockopt(mSoc, SOL_SOCKET, SO_REUSEADDR | SO_REUSEPORT, &opt, sizeof(opt)) == -1) {
+        throw std::runtime_error(std::string("Could not set socket options in ") + __FUNCTION__ + "!");
+    }
+
+    sockaddr_in addr;
+    addr.sin_family = AF_INET;
+    addr.sin_addr.s_addr = INADDR_ANY;
+    addr.sin_port = htons(port);
+
+    // bind
+    if (bind(mSoc, (const sockaddr *) &addr, sizeof(addr)) == -1) {
+        throw std::runtime_error(std::string("Could not bind socket options in ") + __FUNCTION__ + "!");
+    }
+}
+
+void MultiStreamReceiver::start(const std::shared_ptr<MultiStreamProcessor> &pMSP) {
+    if (mRunning) {
+        return;
+    }
+
+    // store multistream processor
+    mpMSP = pMSP;
+    mpMSP->setup(mClientNodes, mAcqFmt);
+
+    if (mpMSP == nullptr) {
+        Logger::logLine(std::string("ERROR MultiStreamProcessor is NULL in ") + __FUNCTION__ + ", cannot start MultiStreamReceiver!");
+        return;
+    }
+
+    // ----------------------------
+
+    //createSampleWriters(); // TODO
+    startNetworking();
+
+    // ----------------------------
+
+    mRunning = true;
+    mRecvThread = std::make_shared<std::thread>(fnRecv, this);
+}
+
+void MultiStreamReceiver::stop() {
+    if (!mRunning) {
+        return;
+    }
+
+    mRunning = false;
+    mRecvThread->join();
+    close(mSoc);
+    mpSampleWriters.clear();
+}
+
+// --------------------------------------
+
+void MultiStreamReceiver::fnRecv(MultiStreamReceiver *pMSR) {
+    // select-related structures
+    fd_set read_fds;
+    timeval tv;
+
+    // allocate receive buffer based on sample size
+    size_t expected_receive_size = pMSR->mAcqFmt.sample_data_size_per_packet_B + sizeof(AudioPayloadHeader);
+    std::shared_ptr<uint8_t> pRecvBuf(new uint8_t[expected_receive_size]);
+
+    // allocate buffers for extracted channels
+    std::shared_ptr<uint8_t> pChannelBuf(new uint8_t[pMSR->mAcqFmt.sample_data_size_per_packet_B]);
+
+//    if (pMSR->mSampleSize == 16) {
+//        pRecvBuf.reset(new uint8_t[pMSR->mStereoBufLen * 2 + sizeof(AudioPayloadHeader)]);
+//    } else if (pMSR->mSampleSize == 24 || pMSR->mSampleSize == 32) {
+//        pRecvBuf.reset(new uint8_t[pMSR->mStereoBufLen * 4 + sizeof(AudioPayloadHeader)]);
+//    }
+
+    // audio payload header
+    AudioPayloadHeader aph;
+
+    // packet timestamps
+    Timestamp ts[2]; // current and previous timestamp
+
+    // limit on time difference variation
+    double timeDiffVariation_ns = 1E+09 / pMSR->mAcqFmt.sampling_rate_Hz * TS_VALIDITY_RANGE;
+
+    // allocate buffer for interpolated timestamps
+    std::shared_ptr<Timestamp> pTSBuf(new Timestamp[pMSR->mAcqFmt.mch_samples_per_packet]);
+
+    while (pMSR->mRunning) {
+        // fd-set
+        FD_ZERO(&read_fds);
+        FD_SET(pMSR->mSoc, &read_fds);
+
+        // timeout
+        tv.tv_sec = 0;
+        tv.tv_usec = 1E+06 / 4;
+
+        // wait for data
+        int fd_cnt = select(pMSR->mSoc + 1, &read_fds, nullptr, nullptr, &tv);
+
+        // if data is available on the socket
+        if ((fd_cnt > 0) && FD_ISSET(pMSR->mSoc, &read_fds)) {
+
+            /* // read just the header
+             * if (read(pMSR->mSoc, (&aph), sizeof(AudioPayloadHeader)) < sizeof(AudioPayloadHeader)) {
+                throw std::runtime_error("Receive error!");
+            }
+
+            // read the rest
+            if ((recv_size = read(pMSR->mSoc, pRecvBuf.get(), aph.sample_cnt * aph.channel_count * pMSR->mSampleStorageSizeByte)) <= 0) {
+                throw std::runtime_error("Receive error!");
+                // TODO check buffer size equivalence
+            }*/
+
+            size_t recv_size;
+            if ((recv_size = recv(pMSR->mSoc, pRecvBuf.get(), expected_receive_size, 0)) <= 0) {
+                throw std::runtime_error("Receive error!");
+            }
+
+            // get header
+            memcpy(&aph, pRecvBuf.get(), sizeof(AudioPayloadHeader));
+
+            // ----------- TIME PROCESSING ---------------
+
+            // store timestamp
+            ts[1] = ts[0]; // shift FIFO
+            ts[0] = {(int64_t) aph.timestamp_s, (int64_t) aph.timestamp_ns}; // store new timestamp
+
+            // if previous timestamp is empty, then don't store samples since time interpolation can not be done
+            if (ts[1].empty()) {
+                continue;
+            }
+
+            // calculate step size
+            Timestamp d = (ts[0] - ts[1]) / (double) pMSR->mAcqFmt.mch_samples_per_packet;
+
+            // validity check on time step size
+            if (llabs(d.to_ns() - ((int64_t) (1E+09 / pMSR->mAcqFmt.sampling_rate_Hz))) > timeDiffVariation_ns) {
+                Logger::logLine("SKIPPED packet due to large packet period variation!");
+                continue; // skip this packet if time step is outside the valid range
+            }
+
+            // prepare time interpolation
+            Timestamp ts_interp = ts[1]; // start from the oldest one
+
+            // ------------- SAMPLE PROCESSING -------------
+
+            // decompose data into distinct channels ("transpose matrix")
+            uint8_t *pSampleData = pRecvBuf.get() + sizeof(AudioPayloadHeader); // get pointer on the data block
+
+            for (size_t i = 0; i < pMSR->mAcqFmt.mch_samples_per_packet; i++) { // iterate on all samples
+                for (size_t ch = 0; ch < pMSR->mAcqFmt.channel_count; ch++) {
+                    // calculate source and destination indices
+                    size_t dstIndex = pMSR->mAcqFmt.single_channel_data_size_per_packet_B * ch + // channel offset ("select column")
+                                      pMSR->mAcqFmt.sample_storage_size_B * i; // destination sample index ("select row")
+
+                    size_t srcIndex = pMSR->mAcqFmt.all_channel_sample_size_B * i + // sample offset ("select row")
+                                      ch * pMSR->mAcqFmt.sample_storage_size_B; // channel offset ("select column")
+
+                    // copy sample
+                    memcpy(pChannelBuf.get() + dstIndex, pSampleData + srcIndex, pMSR->mAcqFmt.sample_storage_size_B);
+                }
+
+                // TIME INTERPOLATION [optimizing loops] (interpolate time for each sample)
+                ts_interp += d;
+                pTSBuf.get()[i] = ts_interp;
+            }
+
+            // get sample writer for the specific address
+//            std::shared_ptr<SampleWriter> pSampleWriter = nullptr;
+            for (size_t i = 0; i < pMSR->mClientNodes.size(); i++) {
+                if (pMSR->mClientNodes[i] == aph.addr) {
+                    size_t ch0 = i * pMSR->mAcqFmt.channel_count; // get "first channel" of that node
+
+                    // transfer channel data
+                    for (size_t ch = 0; ch < pMSR->mAcqFmt.channel_count; ch++) {
+                        size_t dataSize = pMSR->mAcqFmt.single_channel_data_size_per_packet_B;
+                        uint8_t *pChData = pChannelBuf.get() + ch * dataSize; // get channel data
+
+                        // pass data
+                        pMSR->mpMSP->input(ch + ch0, pTSBuf, pChData, dataSize);
+                    }
+
+//                    pSampleWriter = pMSR->mpSampleWriters[i];
+                    break;
+                }
+            }
+
+            // if sample writer is found
+//            if (pSampleWriter != nullptr) {
+//                std::unique_lock<std::mutex> lock(pMSR->mSampleInsertMtx);
+//                pSampleWriter->addSamples(pRecvBuf.get() + sizeof(AudioPayloadHeader), {aph.timestamp_s, aph.timestamp_ns}); // get sample data
+//            }
+        }
+    }
+}
--- a/libwfr/src/MultiStreamReceiver.h
+++ b/libwfr/src/MultiStreamReceiver.h
@ -0,0 +1,51 @@
+//
+// Created by epagris on 2021. 11. 22..
+//
+
+#ifndef WFR_MULTISTREAMRECEIVER_H
+#define WFR_MULTISTREAMRECEIVER_H
+
+
+#include <netinet/in.h>
+#include <vector>
+#include <memory>
+#include <thread>
+#include <mutex>
+#include "SampleWriter.h"
+#include "AcquisitionFormat.h"
+#include "MultiStreamProcessor.h"
+
+class MultiStreamReceiver {
+public:
+    static constexpr unsigned short DEFAULT_PORT = 20220; // default port
+    static constexpr double TS_VALIDITY_RANGE = 0.1; // maximal variation of packet length considered valid
+private:
+    std::vector<in_addr_t> mClientNodes; // client node addresses
+    int mSoc; // UDP-socket for receiving samples
+    std::shared_ptr<std::thread> mRecvThread; // thread for reception
+    static void fnRecv(MultiStreamReceiver *pMSR); // routine function running in separate thread
+    bool mRunning;
+    std::vector<std::shared_ptr<SampleWriter>> mpSampleWriters; // sample writers for streams
+    //std::mutex mSampleInsertMtx; // mutex protecting against sample insertion collision when calling  pSampleWriter->addSamples(...)
+    std::shared_ptr<MultiStreamProcessor> mpMSP; // multistream processor INSTANCE (pointer to...)
+private:
+    AcquisitionFormat mAcqFmt; // acquisition format
+private:
+    void startNetworking(); // start networking
+public:
+    const unsigned short port; // port
+public:
+    MultiStreamReceiver(const std::vector<in_addr_t> &nodes, size_t samplingRate, size_t sampleSize, size_t channelCount, size_t mchSampPerPckt, unsigned short port = DEFAULT_PORT);
+    MultiStreamReceiver(const std::vector<in_addr_t> &nodes, const AcquisitionFormat &acqFormat, unsigned short port = DEFAULT_PORT);
+    MultiStreamReceiver(const std::vector<in_addr_t> &nodes, const std::string &acqFormat_str, unsigned short port = DEFAULT_PORT);
+    MultiStreamReceiver(const std::vector<std::string> &nodes_str, const AcquisitionFormat &acqFormat, unsigned short port = DEFAULT_PORT);
+    MultiStreamReceiver(const std::vector<std::string> &nodes_str, const std::string &acqFormat_str, unsigned short port = DEFAULT_PORT);
+
+    void start(const std::shared_ptr<MultiStreamProcessor> &pMSP); // start reception
+    void stop();  // stop reception
+
+    virtual ~MultiStreamReceiver();
+};
+
+
+#endif //WFR_MULTISTREAMRECEIVER_H
--- a/libwfr/src/MultiStreamToFile.cpp
+++ b/libwfr/src/MultiStreamToFile.cpp
@ -0,0 +1,71 @@
+//
+// Created by epagris on 2022.05.04..
+//
+
+#include <stdexcept>
+#include <unistd.h>
+#include <arpa/inet.h>
+#include "MultiStreamToFile.h"
+#include "Logger.h"
+
+MultiStreamToFile::MultiStreamToFile(const std::string &targetDir) {
+    mTargetDir = targetDir;
+}
+
+void MultiStreamToFile::createSampleWriters() {
+    struct stat sb;
+    if (stat(mTargetDir.c_str(), &sb) == 0 && S_ISDIR(sb.st_mode)) { // if directory exists then leave it as it is
+        //unlink(datasetName.c_str()); FIXME
+    } else if (mkdir(mTargetDir.c_str(), 0777) == -1) { // else: create directory for dataset
+        throw std::runtime_error("Could not create directory " + mTargetDir + "!");
+    }
+
+    if (chdir(mTargetDir.c_str()) == -1) {
+        throw std::runtime_error("Could not change to target directory!");
+    }
+
+    std::string nodeDirHint = "";
+
+    // create sample writers, ONE-PER-CHANNEL
+    size_t acc_ch = 0; // accumulative channel index (across all preceding nodes)
+    for (unsigned int &mClientNode: mNodes) {
+        for (size_t ch = 0; ch < mAcqFmt.channel_count; ch++) {
+            // create sample writer
+            std::string datasetName = std::string("node_") + inet_ntoa({mClientNode}) + "ch" + std::to_string(acc_ch);
+            mpSampleWriters.emplace_back(std::make_shared<SampleWriter>(datasetName, mAcqFmt));
+
+            // create hint
+            nodeDirHint += datasetName + "\n";
+
+            // increase accumulative channel count
+            acc_ch++;
+        }
+    }
+
+    // save hint
+    std::ofstream hintFile("node_dir_hint.txt", std::ios_base::out);
+    hintFile << nodeDirHint;
+    hintFile.close();
+
+    if (chdir("..") == -1) {
+        throw std::runtime_error("Could not change to target directory!");
+    }
+}
+
+void MultiStreamToFile::setup(const std::vector<in_addr_t> &nodes, const AcquisitionFormat &acqFmt) {
+    MultiStreamProcessor::setup(nodes, acqFmt);
+
+    // prepare for receiving data
+    createSampleWriters();
+}
+
+bool MultiStreamToFile::input(size_t ch, const std::shared_ptr<Timestamp> &pTime, const void *pData, size_t size) {
+    if (!MultiStreamProcessor::input(ch, pTime, pData, size)) {
+        return false;
+    }
+
+    // store new data
+    mpSampleWriters[ch]->addSamples((const uint8_t *) pData, pTime);
+
+    return true;
+}
--- a/libwfr/src/MultiStreamToFile.h
+++ b/libwfr/src/MultiStreamToFile.h
@ -0,0 +1,29 @@
+//
+// Created by epagris on 2022.05.04..
+//
+
+#ifndef WFR_APP_MULTISTREAMTOFILE_H
+#define WFR_APP_MULTISTREAMTOFILE_H
+
+
+#include <memory>
+#include "MultiStreamProcessor.h"
+#include "SampleWriter.h"
+#include "ICreatable.h"
+
+class MultiStreamToFile : public MultiStreamProcessor, public ICreatable<MultiStreamToFile, const std::string&> {
+private:
+    std::string mTargetDir; // target directory
+    std::vector<std::shared_ptr<SampleWriter>> mpSampleWriters; // sample writers for streams
+private:
+    void createSampleWriters(); // create sample writers
+public:
+    MultiStreamToFile(const std::string& targetDir); // constr.
+
+public:
+    void setup(const std::vector<in_addr_t> &nodes, const AcquisitionFormat &acqFmt) override;
+    bool input(size_t ch, const std::shared_ptr<Timestamp> &pTime, const void *pData, size_t size) override;
+};
+
+
+#endif //WFR_APP_MULTISTREAMTOFILE_H
--- a/libwfr/src/SampleWriter.cpp
+++ b/libwfr/src/SampleWriter.cpp
@ -0,0 +1,136 @@
+#include "SampleWriter.h"
+#include "AcquisitionFormat.h"
+
+SampleWriter::SampleWriter(const std::string &datasetName, const AcquisitionFormat &acqFmt, bool withoutTSFile)
+        : mAcqFmt(acqFmt), mWithoutTSFile(withoutTSFile) { // constr.
+    prepareBuffers();
+    prepareOutputFiles(datasetName);
+}
+
+SampleWriter::~SampleWriter() {
+    closeFiles();
+}
+
+void SampleWriter::prepareBuffers() {
+    // allocate timestamp data buffer
+    mpTs = std::shared_ptr<TimestampRecord>(new TimestampRecord[mAcqFmt.mch_samples_per_packet]);
+
+    // allocate buffer based on sample size
+    mpSamples = std::shared_ptr<uint8_t>(new uint8_t[mAcqFmt.single_channel_data_size_per_packet_B]);
+}
+
+void SampleWriter::prepareOutputFiles(const std::string &datasetName) {
+//    struct stat sb;
+//    if (stat(datasetName.c_str(), &sb) == 0 && S_ISDIR(sb.st_mode)) { // if directory exists then leave it as it is
+//        //unlink(datasetName.c_str()); FIXME
+//    } else if (mkdir(datasetName.c_str(), 0777) == -1) { // else: create directory for dataset
+//        throw std::runtime_error("Could not create directory " + datasetName + "!");
+//    }
+//
+//    std::string datadir_dirsep = datasetName + DIRSEP;
+
+    // timestamps
+    if (!mWithoutTSFile) {
+        mTsFileName = datasetName + '.' + TS_EXT; // timestamp
+
+        // open timestamp file
+        mTsFile.open(mTsFileName, std::ios_base::binary);
+        if (!mTsFile.is_open()) {
+            throw std::runtime_error("Could not open timestamp file " + mTsFileName + "!");
+        }
+    }
+
+    // data samples
+    mSampleFileName = datasetName + '.' + SAMPLE_EXT;
+    mSampleFile.open(mSampleFileName, std::ios_base::binary);
+    if (!mSampleFile.is_open()) {
+        throw std::runtime_error("Could not open sample file " + mSampleFileName + "!");
+    }
+}
+
+void SampleWriter::closeFiles() {
+    // close file storing timestamp files
+    if (!mWithoutTSFile) {
+        mTsFile.close();
+    }
+
+    // close files stroring samples
+    mSampleFile.close();
+}
+
+void SampleWriter::addSamples(const uint8_t *pSamples, const std::shared_ptr<Timestamp> &pTime) {
+/*    // shift FIFO and store new timestamp
+    mTs[1] = mTs[0];
+    mTs[0] = ts;
+
+    // if previous timestamp is empty, then don't store samples since time interpolation can not be done
+    if (mTs[1].empty()) {
+        return;
+    }
+
+    // calculate time step size
+    Timestamp d = (mTs[0] - mTs[1]) / (double) mBlockSize;
+
+    // validity check on time step size
+    if (d.to_ns() > mSamplingPeriod_ns_UB || d.to_ns() < mSamplingPeriod_ns_LB) {
+        return; // skip this packet if time step is outside the valid range
+    }
+
+    // timestamp for time interpolation
+    Timestamp ts_interp = mTs[1];
+
+    // get channel pointers
+    int8_t *ppCh[mChN];
+    for (size_t i = 0; i < mChN; i++) {
+        ppCh[i] = mpSamples[i].get();
+    }
+
+    // extract samples
+    for (size_t i = 0; i < mBlockSize; i++) {
+        // select record
+        auto *pRawSamples = (int8_t *) (pSamples + i * mSampleDisposition);
+
+        // store sample for a channel
+        for (size_t ch = 0; ch < mChN; ch++) {
+            if (mSampleStorageSizeByte == 2) {
+                *((int16_t*)(ppCh[ch] + (i * mSampleStorageSizeByte))) = *((int16_t*)(pRawSamples + (ch * mSampleStorageSizeByte)));
+            } else if (mSampleStorageSizeByte == 4) {
+                *((int32_t*)(ppCh[ch] + (i * mSampleStorageSizeByte))) = *((int32_t*)(pRawSamples + (ch * mSampleStorageSizeByte)));
+            }
+        }
+
+        // step time
+        ts_interp += d;
+
+        // store timestamp
+        mpTs.get()[i] = ts_interp;
+    }
+
+        // write to file newly created records
+    */
+    // write timestamps
+    if (!mWithoutTSFile) {
+        // convert timestamp
+        for (size_t i = 0; i < mAcqFmt.mch_samples_per_packet; i++) {
+            mpTs.get()[i] = pTime.get()[i];
+        }
+
+        // write...
+        mTsFile.write((const char *) mpTs.get(), mAcqFmt.mch_samples_per_packet * sizeof(TimestampRecord));
+    }
+
+    // write samples
+    mSampleFile.write((const char *) pSamples, mAcqFmt.single_channel_data_size_per_packet_B);
+
+    // increment counter
+    mSamplesN += mAcqFmt.mch_samples_per_packet;
+}
+
+unsigned long long SampleWriter::getSampleCnt() const {
+    return mSamplesN;
+}
+
+// static fields
+const std::string SampleWriter::TS_EXT = "ts";
+//const std::string SampleWriter::SAMPLE_FILENAME_PREFIX = "ch_";
+const std::string SampleWriter::SAMPLE_EXT = "dat";
--- a/libwfr/src/SampleWriter.h
+++ b/libwfr/src/SampleWriter.h
@ -0,0 +1,65 @@
+//
+// Created by epagris on 2021. 11. 01..
+//
+
+#ifndef WFR_SAMPLEWRITER_H
+#define WFR_SAMPLEWRITER_H
+
+#include <fstream>
+#include <string>
+#include <memory>
+#include <iostream>
+#include <sys/stat.h>
+#include <vector>
+#include <set>
+#include <queue>
+#include "Timestamp.h"
+#include "AcquisitionFormat.h"
+
+#define DIRSEP '/'
+
+class SampleWriter {
+public:
+    static const std::string TS_EXT; // filename for timestamp file
+    //static const std::string SAMPLE_FILENAME_PREFIX; // filename prefix for sample file
+    static const std::string SAMPLE_EXT; // datafile extensions
+public:
+    // timestamp record
+    struct TimestampRecord {
+    public:
+        uint32_t ts_s, ts_ns; // timestamp
+    public:
+        TimestampRecord &operator=(const Timestamp &ts) {
+            ts_s = (uint32_t) ts.s;
+            ts_ns = (uint32_t) ts.ns;
+            return *this;
+        }
+    };
+
+private:
+    AcquisitionFormat mAcqFmt;
+    bool mWithoutTSFile; // does sample writer omit timestamp outputting?
+private:
+    std::shared_ptr<TimestampRecord> mpTs; // timestamp records
+    std::shared_ptr<uint8_t> mpSamples; // sample buffer
+
+    std::string mTsFileName; // timestamp filename
+    std::ofstream mTsFile; // timestamp file
+    std::string mSampleFileName; // sample file name
+    std::ofstream mSampleFile; // sample output file
+private:
+    unsigned long long mSamplesN; // number of samples written until now
+private:
+    void prepareBuffers(); // resize sample and record buffers
+    void prepareOutputFiles(const std::string &datasetName); // prepare dataset environment
+    void closeFiles(); // close files
+public:
+    SampleWriter(const std::string &datasetName, const AcquisitionFormat &acqFmt, bool withoutTSFile = false);
+    ~SampleWriter();
+
+    void addSamples(const uint8_t *pSamples, const std::shared_ptr<Timestamp> &pTime); // add n samples to file
+    unsigned long long getSampleCnt() const; // get number of samples written out
+};
+
+
+#endif //WFR_SAMPLEWRITER_H
--- a/libwfr/src/ServerBeacon.cpp
+++ b/libwfr/src/ServerBeacon.cpp
@ -6,17 +6,27 @@
 #include <memory>
 #include <unistd.h>
 #include <cstring>
+#include <cmath>
 #include "ServerBeacon.h"

 const in_addr ServerBeacon::DEFAULT_MULTICAST_ADDR = {inet_addr("224.0.2.21")};

-ServerBeacon::ServerBeacon() : mRunning(false), mScanCallback(nullptr) {
+ServerBeacon::ServerBeacon() :
+        mRunning(false), mScanCallback(nullptr) {
    setMulticastAddr(DEFAULT_MULTICAST_ADDR);
    setPort(DEFAULT_PORT);
    setAnnouncePeriod(DEFAULT_ANNOUNCE_PERIOD_MS);
 }

-ServerBeacon::ServerBeacon(const in_addr &addr, unsigned short port, size_t announcePeriod_ms) : mRunning(false), mScanCallback(nullptr) {
+ServerBeacon::ServerBeacon(const in_addr &addr, unsigned short port, size_t announcePeriod_ms) :
+        mRunning(false), mScanCallback(nullptr) {
+    setMulticastAddr(addr);
+    setPort(port);
+    setAnnouncePeriod(announcePeriod_ms);
+}
+
+ServerBeacon::ServerBeacon(const std::string &addr, unsigned short port, size_t announcePeriod_ms) :
+        mRunning(false), mScanCallback(nullptr) {
    setMulticastAddr(addr);
    setPort(port);
    setAnnouncePeriod(announcePeriod_ms);
@ -26,6 +36,11 @@ void ServerBeacon::setMulticastAddr(const in_addr &addr) {
    mAddr = addr;
 }

+void ServerBeacon::setMulticastAddr(const std::string &addr_s) {
+    mAddr = {inet_addr(addr_s.c_str())};
+}
+
+
 in_addr ServerBeacon::getMulticastAddr() const {
    return mAddr;
 }
@ -93,7 +108,7 @@ void ServerBeacon::startBeacon() {
 }

 void ServerBeacon::stopBeacon() {
-    if (!mRunning){
+    if (!mRunning) {
        return;
    }

@ -102,12 +117,27 @@ void ServerBeacon::stopBeacon() {
    close(mBeaconSoc);
 }

+void ServerBeacon::singleScan() {
+    if (mRunning) {
+        return;
+    }
+
+    // start the beacon
+    startBeacon();
+
+    // wait for nodes to respond
+    std::this_thread::sleep_for(std::chrono::milliseconds((size_t) (mAnnPeriod_ms * 0.75)));
+
+    // stop the beacon
+    stopBeacon();
+}
+
 std::list<in_addr> ServerBeacon::getNodesOnNetwork() {
    std::list<in_addr> nodeAddrs;

    mBeaconMtx.lock();

-    for (auto nodeInfo : mNodes) {
+    for (auto nodeInfo: mNodes) {
        nodeAddrs.push_back(nodeInfo.addr);
    }

@ -116,10 +146,22 @@ std::list<in_addr> ServerBeacon::getNodesOnNetwork() {
    return nodeAddrs;
 }

+std::list<std::string> ServerBeacon::getNodesOnNetwork_str() {
+    std::list<std::string> nodeAddrs;
+
+    for (auto nodeInfo: getNodesOnNetwork()) {
+        nodeAddrs.emplace_back(inet_ntoa(nodeInfo));
+    }
+
+    return nodeAddrs;
+}

 // -------------------------------------------

 void ServerBeacon::fn_BeaconThread(ServerBeacon *pSB) {
+    // log
+    Logger::logLine("START beacon");
+
    // beacon message used to send and receive information
    BeaconMsg msg;

@ -163,6 +205,9 @@ void ServerBeacon::fn_BeaconThread(ServerBeacon *pSB) {

                clNodes.push_back(clInfo);

+                // log
+                Logger::logLine(std::string("FOUND NODE ") + inet_ntoa(clInfo.addr));
+
                //std::cout << inet_ntoa(clInfo.addr) << std::endl;
            }

@ -189,9 +234,12 @@ void ServerBeacon::fn_BeaconThread(ServerBeacon *pSB) {
            (*pSB->mScanCallback)(pSB);
        }
    }
+
+    // log
+    Logger::logLine("STOP beacon");
 }

-void ServerBeacon::setScanCallback(const std::shared_ptr<CallbackBase<ServerBeacon *>>& scanCB) {
+void ServerBeacon::setScanCallback(const std::shared_ptr<CallbackBase<ServerBeacon *>> &scanCB) {
    mScanCallback = scanCB;
 }

@ -208,7 +256,7 @@ unsigned short ServerBeacon::getNodeNettermPort(in_addr addr) {

    int nettermPort = -1;

-    for (const auto& nodeInfo : mNodes) {
+    for (const auto &nodeInfo: mNodes) {
        if (nodeInfo.addr.s_addr == addr.s_addr) {
            nettermPort = nodeInfo.terminalPort;
            break;
@ -221,45 +269,142 @@ unsigned short ServerBeacon::getNodeNettermPort(in_addr addr) {
        throw std::runtime_error(std::string("Node not found in database! (") + inet_ntoa(addr) + ")!");
    }

-    return (unsigned short)nettermPort;
+    return (unsigned short) nettermPort;
 }

-void ServerBeacon::sendNettermCmd(in_addr addr, unsigned short port, const std::string &cmd) {
+#define MAX_TERM_LINE_LENGTH (127)
+
+std::string ServerBeacon::sendNettermCmd(in_addr addr, unsigned short port, const std::string &cmd, bool expectResp) {
    int soc = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
    if (soc == -1) {
        throw std::runtime_error("Could not create TCP socket to execute netterm commands!");
    }

+    // return value
+    std::string ret_resp;
+
+    // connect to server
    sockaddr_in serverAddr;
    memset(&serverAddr, 0, sizeof(sockaddr_in));
    serverAddr.sin_addr = addr;
    serverAddr.sin_port = htons(port);
    serverAddr.sin_family = AF_INET;

-    if (connect(soc, (const sockaddr *)&serverAddr, sizeof(sockaddr_in)) == -1) {
+    if (connect(soc, (const sockaddr *) &serverAddr, sizeof(sockaddr_in)) == -1) {
        throw std::runtime_error(std::string("Could not connect to netterm! (") + inet_ntoa(addr) + ":" + std::to_string(port) + ")");
    }

-    static std::string nodeftty_cmd = "nodeftty";
-    send(soc, "nodeftty", nodeftty_cmd.size(), 0);
+    static std::string nodeftty_cmd = "nodeftty\n";
+    send(soc, nodeftty_cmd.c_str(), nodeftty_cmd.size(), 0);

    // send command
-    send(soc, cmd.c_str(), cmd.size(), 0);
+    std::string cmd_nl = cmd + "\n";
+    send(soc, cmd_nl.c_str(), cmd_nl.size(), 0);

+    // log
+    Logger::logLine(std::string("CMD '") + cmd + "' ON " + inet_ntoa(addr));
+
+    if (expectResp) {
+        // wait for response
+        fd_set read_fds;
+        timeval tv = {1, 0}; // 1s timeout
+        FD_ZERO(&read_fds);
+        FD_SET(soc, &read_fds);
+
+        if (select(soc + 1, &read_fds, nullptr, nullptr, &tv) <= 0) { // if we have NO response
+            Logger::logLine(std::string("  -->NO RESPONSE"));
+
+        } else if(FD_ISSET(soc, &read_fds)) { // if we have response
+            char sResp[MAX_TERM_LINE_LENGTH + 1];
+            size_t resp_len = recv(soc, sResp, MAX_TERM_LINE_LENGTH, 0);
+            sResp[resp_len] = '\0';
+
+            ret_resp = std::string(sResp);
+
+            // clip trailing \r\n to [r][n]
+            if (ret_resp.ends_with("\r\n")) {
+                ret_resp = ret_resp.substr(0, ret_resp.size() - 2);
+            }
+
+            // log
+            Logger::logLine(std::string("  -->RESP '") + ret_resp + "'");
+        }
+    }
+
+    // close connection gracefully
+    std::string cmdExit = "exit\n";
+    send(soc, cmdExit.c_str(), cmdExit.size(), 0);
+
+    // wait for response
+    fd_set read_fds;
+    timeval tv = {1, 0}; // 1s timeout
+    FD_ZERO(&read_fds);
+    FD_SET(soc, &read_fds);
+
+    if (select(soc + 1, &read_fds, nullptr, nullptr, &tv) <= 0) {
+        Logger::logLine(std::string("  -->FORCED CLOSE")); // log
+    }
+
+    // close the connection finally
    close(soc);
+
+    return ret_resp;
 }

 void ServerBeacon::execCmdOnNode(in_addr addr, const std::string &cmd) {
    unsigned short port = getNodeNettermPort(addr);
-    sendNettermCmd(addr, port, cmd);
+    sendNettermCmd(addr, port, cmd, false);
 }

-void ServerBeacon::execCmdOnAllTerms(const std::string &cmd) {
+void ServerBeacon::execCmdOnNode(const std::string &addr_str, const std::string &cmd) {
+    in_addr node_addr = {inet_addr(addr_str.c_str())};
+    execCmdOnNode(node_addr, cmd);
+}
+
+void ServerBeacon::execCmdOnAllNodes(const std::string &cmd) {
    mBeaconMtx.lock();

-    for (const auto& nodeInfo : mNodes) {
-        sendNettermCmd(nodeInfo.addr, nodeInfo.terminalPort, cmd);
+    for (const auto &nodeInfo: mNodes) {
+        sendNettermCmd(nodeInfo.addr, nodeInfo.terminalPort, cmd, false);
    }

    mBeaconMtx.unlock();
-}
+}
+
+std::string ServerBeacon::queryFromNode(in_addr addr, const std::string &cmd) {
+    unsigned short port = getNodeNettermPort(addr);
+    return sendNettermCmd(addr, port, cmd, true);
+}
+
+std::string ServerBeacon::queryFromNode(const std::string &addr_str, const std::string &cmd) {
+    in_addr node_addr = {inet_addr(addr_str.c_str())};
+    return queryFromNode(node_addr, cmd);
+}
+
+std::map<in_addr_t, std::string> ServerBeacon::queryFromAllNodes(const std::string &cmd) {
+    std::map<in_addr_t, std::string> res;
+
+    mBeaconMtx.lock();
+
+    for (const auto &nodeInfo: mNodes) {
+        res[nodeInfo.addr.s_addr] = sendNettermCmd(nodeInfo.addr, nodeInfo.terminalPort, cmd, true);
+    }
+
+    mBeaconMtx.unlock();
+
+    return res;
+}
+
+std::map<std::string, std::string> ServerBeacon::queryFromAllNodes_str(const std::string &cmd) {
+    std::map<std::string, std::string> res;
+
+    mBeaconMtx.lock();
+
+    for (const auto &nodeInfo: mNodes) {
+        res[inet_ntoa(nodeInfo.addr)] = sendNettermCmd(nodeInfo.addr, nodeInfo.terminalPort, cmd, true);
+    }
+
+    mBeaconMtx.unlock();
+
+    return res;
+}
--- a/libwfr/src/ServerBeacon.h
+++ b/libwfr/src/ServerBeacon.h
@ -11,7 +11,9 @@
 #include <arpa/inet.h>
 #include <thread>
 #include <mutex>
+#include <map>
 #include "Callback.h"
+#include "Logger.h"

 class ServerBeacon {
 public:
@ -47,11 +49,13 @@ private:
        uint8_t server_nClient; // server or client
    };
 private:
-    void sendNettermCmd(in_addr addr, unsigned short port, const std::string& cmd); // send netterm cmd
+    std::string sendNettermCmd(in_addr addr, unsigned short port, const std::string &cmd, bool expectResp); // send netterm cmd
 public:
    ServerBeacon(); // constr.
-    explicit ServerBeacon(const in_addr& addr, unsigned short port, size_t announcePeriod_ms); // constr. with beacon port and announce period
+    ServerBeacon(const in_addr& addr, unsigned short port, size_t announcePeriod_ms); // constr. with beacon port and announce period
+    ServerBeacon(const std::string& addr, unsigned short port, size_t announcePeriod_ms); // constr. with beacon port and announce period
    void setMulticastAddr(const in_addr& addr); // set multicasting address
+    void setMulticastAddr(const std::string& addr_s); // set multicast address (string)
    in_addr getMulticastAddr() const; // set multicasting address
    void setPort(unsigned short port); // set port BEFORE starting beacon
    unsigned short getPort() const; // get beacon port
@ -61,11 +65,18 @@ public:
    std::string getInterfaceAddr() const; // get multicast interface address
    void startBeacon(); // start the beacon
    void stopBeacon(); // stop the beacon
+    void singleScan(); // initiate a single scan
    std::list<in_addr> getNodesOnNetwork(); // get nodes connected to the same network
-    unsigned short getNodeNettermPort(in_addr addr); // get network terminal port of ndoe
+    std::list<std::string> getNodesOnNetwork_str(); // get nodes connected to the same network (list of string)
+    unsigned short getNodeNettermPort(in_addr addr); // get network terminal port of node
    void setScanCallback(const std::shared_ptr<CallbackBase<ServerBeacon *>>& scanCB); // set scan callback
-    void execCmdOnNode(in_addr addr, const std::string& cmd); // execute command on a node through netterm
-    void execCmdOnAllTerms(const std::string& cmd); // multicast command to all netterms
+    void execCmdOnNode(in_addr addr, const std::string& cmd); // execute command on a node through netterm AND DON'T expect a response
+    void execCmdOnNode(const std::string& addr_str, const std::string& cmd);
+    std::string queryFromNode(in_addr addr, const std::string& cmd); // --- " ---- AND expect a response
+    std::string queryFromNode(const std::string& addr_str, const std::string& cmd);
+    void execCmdOnAllNodes(const std::string& cmd); // multicast command to all netterms
+    std::map<in_addr_t, std::string> queryFromAllNodes(const std::string& cmd); // --- " ---- AND expect a response
+    std::map<std::string, std::string> queryFromAllNodes_str(const std::string& cmd); // (string address)
 };


--- a/libwfr/src/Timestamp.h
+++ b/libwfr/src/Timestamp.h
--- a/libwfr/src/Trigger.cpp
+++ b/libwfr/src/Trigger.cpp
@ -0,0 +1,55 @@
+//
+// Created by epagris on 2022.05.04..
+//
+
+#include "Trigger.h"
+
+TriggerSettings::TriggerSettings() {
+    TriggerSettings::reset();
+}
+
+void TriggerSettings::reset() {
+    mFirstSample = true;
+    ch = 0;
+}
+
+bool TriggerSettings::sample(double x) {
+    return false; // never trigger
+}
+
+// ------------------------
+
+SlopeTrigger::SlopeTrigger() {
+    level = 0;
+    slope = RISING;
+    SlopeTrigger::reset();
+}
+
+void SlopeTrigger::reset() {
+    TriggerSettings::reset();
+
+    x_prev = 0;
+}
+
+bool SlopeTrigger::sample(double x) {
+    // do not act on first sample
+    if (mFirstSample) {
+        mFirstSample = false;
+        x_prev = x;
+        return false;
+    }
+
+    bool trig = false;
+
+    // on every other sample...
+    if (((slope == RISING) && (x_prev < level && x > level)) ||
+        ((slope == FALLING) && (x_prev > level && x < level))) {
+        trig = true;
+    }
+
+    x_prev = x;
+
+    return trig;
+}
+
+
--- a/libwfr/src/Trigger.h
+++ b/libwfr/src/Trigger.h
@ -0,0 +1,38 @@
+//
+// Created by epagris on 2022.05.04..
+//
+
+#ifndef WFR_APP_TRIGGER_H
+#define WFR_APP_TRIGGER_H
+
+#include <cstddef>
+
+// Dummy trigger base
+struct TriggerSettings {
+protected:
+    bool mFirstSample; // indicates the latest sample was the first since the last reset
+public:
+    size_t ch; // channel to probe
+public:
+    TriggerSettings();
+
+    virtual void reset(); // reset trigger internal state
+    virtual bool sample(double x); // insert sample into the trigger
+};
+
+// Simple slope trigger
+struct SlopeTrigger : public TriggerSettings {
+public:
+    enum SlopeType { RISING, FALLING };
+private:
+    double x_prev; // previous sample
+public:
+    double level; // trigger level
+    SlopeType slope; // slope direction
+public:
+    SlopeTrigger(); // constr.
+    void reset() override;
+    bool sample(double x) override;
+};
+
+#endif //WFR_APP_TRIGGER_H
--- a/libwfr/src/audio_types.h
+++ b/libwfr/src/audio_types.h
@ -0,0 +1,28 @@
+//
+// Created by epagris on 2021. 11. 02..
+//
+
+#ifndef WFR_AUDIO_TYPES_H
+#define WFR_AUDIO_TYPES_H
+
+#include <cstdint>
+
+#define PERIOD_LEN_DEF (STEREO_BUF_LEN / 2)
+
+#define MCH_SAMP_PER_PCKT_DEF (192)
+#define SAMPLE_RATE_DEF (48000)
+#define SAMPLE_SIZE_DEF (16)
+#define CHANNEL_COUNT_DEF (2)
+
+//typedef int16_t AudioSampleType16_DEF;
+
+typedef struct {
+    uint32_t timestamp_s, timestamp_ns; // timestamp
+    uint32_t sample_cnt; // count of all-channel samples in packet
+    uint16_t sample_size; // size of a single (mono) sample
+    uint16_t channel_count; // number of channels
+    in_addr_t addr; // client node address
+    //AudioSampleType16_DEF pData[MCH_SAMP_PER_PCKT_DEF]; // buffer for stereo data
+} AudioPayloadHeader;
+
+#endif //WFR_AUDIO_TYPES_H
--- a/main.cpp
+++ b/main.cpp
@ -10,9 +10,9 @@
 #include <sys/socket.h>
 #include <netinet/in.h>
 #include "src/ALSADevice.h"
-#include "src/SampleWriter.h"
-#include "src/audio_types.h"
-#include "src/ServerBeacon.h"
+#include "libwfr/src/SampleWriter.h"
+#include "libwfr/src/audio_types.h"
+#include "libwfr/src/ServerBeacon.h"
 #include "src/GUI.h"

 //uint8_t pRecvBuf[8096] __attribute__ ((aligned (32)));
@ -28,6 +28,10 @@ int main(int argc, char * argv[]) {
    std::string mcastIFAddr = argv[2];
    unsigned short beaconPort = atoi(argv[1]);

+    Logger::startLogging();
+
+    auto a = MultiStreamToFile::create("asd");
+
    // -----------------

    //ALSADevice dev(PERIOD_LEN, SAMPLE_RATE);
--- a/python/CMakeLists.txt
+++ b/python/CMakeLists.txt
@ -0,0 +1,30 @@
+cmake_minimum_required(VERSION 3.16)
+
+project(wfr-python-extension)
+
+set(Python_ADDITIONAL_VERSIONS 3.8)
+
+find_package(Python3 COMPONENTS Interpreter Development)
+find_package(PythonLibs REQUIRED)
+
+#list(APPEND CMAKE_MODULE_PATH "/home/epagris/.local/lib/python3.8/site-packages/skbuild/resources/cmake/")
+
+#find_package(PythonExtensions REQUIRED)
+
+find_package(pybind11 REQUIRED)
+
+set(CMAKE_CXX_STANDARD 17)
+set(SRC
+        src/wfsmodule.cpp)
+
+pybind11_add_module(pywfs src/wfsmodule.cpp)
+target_include_directories(pywfs PUBLIC ${PROJECT_SOURCE_DIR}/../libwfr/src)
+add_dependencies(pywfs wfr)
+
+target_compile_definitions(pywfs PRIVATE VERSION_INFO=${EXAMPLE_VERSION_INFO})
+target_include_directories(pywfs PUBLIC ${PYTHON_INCLUDE_DIRS})
+target_link_libraries(pywfs PUBLIC wfr)
+
+set_target_properties(pywfs PROPERTIES SUFFIX ".so")
+
+install(TARGETS pywfs DESTINATION ${PROJECT_SOURCE_DIR}/module)
--- a/python/src/wfsmodule.cpp
+++ b/python/src/wfsmodule.cpp
@ -0,0 +1,90 @@
+#include <pybind11/pybind11.h>
+#include <pybind11/stl.h>
+
+#include <ServerBeacon.h>
+#include "AcquisitionFormat.h"
+#include "MultiStreamToFile.h"
+#include "MultiStreamReceiver.h"
+
+#define STRINGIFY(x) #x
+#define MACRO_STRINGIFY(x) STRINGIFY(x)
+
+
+int add(int i, int j) {
+    return i + j;
+}
+
+namespace py = pybind11;
+using namespace py::literals;
+
+PYBIND11_MODULE(pywfs, m) {
+    m.doc() = R"pbdoc(
+        WaveFormStream extension
+        -----------------------
+
+    )pbdoc";
+
+//    py::class_<in_addr>(m, "in_addr")
+//            .def(py::init<>())
+//            .def_readwrite("s_addr", &in_addr::s_addr);
+
+    // Logger
+    py::class_<Logger>(m, "Logger")
+            .def_static("start", static_cast<void (*)(int)>(&Logger::startLogging), py::arg("fd") = STDOUT_FILENO)
+            .def_static("stop", &Logger::stopLogging);
+
+    // ServerBeacon
+    py::class_<ServerBeacon>(m, "ServerBeacon")
+            .def(py::init<>())
+            .def("setMulticastAddr", static_cast<void (ServerBeacon::*)(const std::string &)>(&ServerBeacon::setMulticastAddr))
+            .def("setInterfaceAddr", static_cast<void (ServerBeacon::*)(const std::string &)>(&ServerBeacon::setInterfaceAddr))
+            .def("singleScan", &ServerBeacon::singleScan)
+            .def("getNodesOnNetwork", &ServerBeacon::getNodesOnNetwork_str)
+            .def("execCmdOnNode", static_cast<void (ServerBeacon::*)(const std::string &, const std::string &)>(&ServerBeacon::execCmdOnNode))
+            .def("queryFromNode", static_cast<std::string (ServerBeacon::*)(const std::string &, const std::string &)>(&ServerBeacon::queryFromNode))
+            .def("execCmdOnAllNodes", &ServerBeacon::execCmdOnAllNodes)
+            .def("queryFromAllNodes", &ServerBeacon::queryFromAllNodes_str);
+
+    // AquisitionFormat
+    py::class_<AcquisitionFormat>(m, "AcquisitionFormat")
+            .def(py::init<const std::string>())
+            .def(py::init<size_t, size_t, size_t, size_t>())
+            .def_readonly("sampling_rate_Hz", &AcquisitionFormat::sampling_rate_Hz)
+            .def_readonly("sample_size_b", &AcquisitionFormat::sample_size_b)
+            .def_readonly("sameple_storage_size_B", &AcquisitionFormat::sample_storage_size_B)
+            .def_readonly("channel_count", &AcquisitionFormat::channel_count)
+            .def_readonly("mch_sample_per_packet", &AcquisitionFormat::mch_samples_per_packet)
+            .def_readonly("distinct_samples_per_packet", &AcquisitionFormat::distinct_samples_per_packet)
+            .def_readonly("sample_data_size_per_packet", &AcquisitionFormat::sample_data_size_per_packet_B)
+            .def_readonly("single_channel_data_size_per_packet_B", &AcquisitionFormat::single_channel_data_size_per_packet_B)
+            .def_readonly("all_channel_sample_size_B", &AcquisitionFormat::all_channel_sample_size_B)
+            .def_readonly("packet_period_ns", &AcquisitionFormat::packet_period_ns)
+            .def("isValid", &AcquisitionFormat::isValid);
+
+    // MultiStreamReceiver
+    py::class_<MultiStreamReceiver>(m, "MultiStreamReceiver")
+            .def(py::init<std::vector<std::string>, const AcquisitionFormat &, unsigned short>(), "nodes_str"_a, "acqFormat"_a, "port"_a = MultiStreamReceiver::DEFAULT_PORT)
+            .def(py::init<std::vector<std::string>, const std::string &, unsigned short>(), "nodes_str"_a, "acqFormat_str"_a, "port"_a = MultiStreamReceiver::DEFAULT_PORT)
+            .def("listen", &MultiStreamReceiver::start)
+            .def("close", &MultiStreamReceiver::stop);
+
+    // MultiStreamProcessor (abstract class)
+    py::class_<MultiStreamProcessor, std::shared_ptr<MultiStreamProcessor>> MSP(m, "MultiStreamProcessor");
+
+    // MultiStreamToFile
+    py::class_<MultiStreamToFile, std::shared_ptr<MultiStreamToFile>, MultiStreamProcessor>(m, "MultiStreamToFile")
+            .def_static("create", &MultiStreamToFile::create);
+
+//
+//    m.def("subtract", [](int i, int j) { return i - j; }, R"pbdoc(
+//        Subtract two numbers
+//        Some other explanation about the subtract function.
+//    )pbdoc");
+
+#ifdef VERSION_INFO
+    m.attr("__version__") = MACRO_STRINGIFY(VERSION_INFO);
+#else
+    m.attr("__version__") = "dev";
+#endif
+}
+
--- a/python/src/wfsmodule.h
+++ b/python/src/wfsmodule.h
@ -0,0 +1,8 @@
+//
+// Created by epagris on 2022.05.01..
+//
+
+#ifndef WFR_APP_WFSMODULE_H
+#define WFR_APP_WFSMODULE_H
+
+#endif //WFR_APP_WFSMODULE_H
--- a/src/GUI.h
+++ b/src/GUI.h
@ -11,10 +11,11 @@
 #include <gtk/gtk.h>
 #include <gtkmm-3.0/gtkmm.h>

-#include "ServerBeacon.h"
+#include "../libwfr/src/ServerBeacon.h"
 #include "globals.h"
-#include "Callback.h"
-#include "MultiStreamReceiver.h"
+#include "../libwfr/src/Callback.h"
+#include "../libwfr/src/MultiStreamReceiver.h"
+#include "../libwfr/src/MultiStreamToFile.h"

 class GUI : public Gtk::Application {
 public:
@ -261,11 +262,12 @@ public:
            wStartStopCaptureBtn->set_label("Stop capture");
            mFlags.captureRunning = true;

-            mpMSR = std::make_shared<MultiStreamReceiver>(mClNodeTW->getSelectedLines(), wFolderChooser->get_filename());
-            mpMSR->start();
-            mGlobs->beacon->execCmdOnAllTerms(std::string("snd connect ") + mGlobs->beacon->getInterfaceAddr() + " " + std::to_string(mpMSR->port));
+            mpMSR = std::make_shared<MultiStreamReceiver>(mClNodeTW->getSelectedLines(), SAMPLE_RATE_DEF, SAMPLE_SIZE_DEF, CHANNEL_COUNT_DEF, MCH_SAMP_PER_PCKT_DEF);
+            mpMSR->start(std::make_shared<MultiStreamToFile>(wFolderChooser->get_filename()));
+            //mpMSR->start(std::shared_ptr<MultiStreamProcessor>((MultiStreamProcessor*) new MultiStreamToFile(wFolderChooser->get_filename())));
+            mGlobs->beacon->execCmdOnAllNodes(std::string("snd connect ") + mGlobs->beacon->getInterfaceAddr() + " " + std::to_string(mpMSR->port));
        } else {
-            mGlobs->beacon->execCmdOnAllTerms("snd disconnect");
+            mGlobs->beacon->execCmdOnAllNodes("snd disconnect");
            mpMSR = nullptr;

            wFolderChooser->set_sensitive(true);
--- a/src/MultiStreamReceiver.cpp
+++ b/src/MultiStreamReceiver.cpp
@ -1,154 +0,0 @@
-//
-// Created by epagris on 2021. 11. 22..
-//
-
-#include <arpa/inet.h>
-
-#include <memory>
-#include <thread>
-#include <unistd.h>
-
-#include "MultiStreamReceiver.h"
-#include "audio_types.h"
-
-MultiStreamReceiver::MultiStreamReceiver(const std::vector<in_addr_t> &nodes, const std::string& targetDir, unsigned short port) : port(port) {
-    mTargetDir = targetDir;
-    mRunning = false;
-    mClientNodes = nodes;
-}
-
-MultiStreamReceiver::~MultiStreamReceiver() {
-    stop();
-}
-
-void MultiStreamReceiver::startNetworking() {
-    // open socket
-    mSoc = socket(AF_INET, SOCK_DGRAM, 0);
-    if (mSoc == -1) {
-        throw std::runtime_error(std::string("Could not create UDP-socket in ") + __FUNCTION__ + "!");
-    }
-
-    int opt = 1;
-    if (setsockopt(mSoc, SOL_SOCKET, SO_REUSEADDR | SO_REUSEPORT, &opt, sizeof(opt)) == -1) {
-        throw std::runtime_error(std::string("Could not set socket options in ") + __FUNCTION__ + "!");
-    }
-
-    sockaddr_in addr;
-    addr.sin_family = AF_INET;
-    addr.sin_addr.s_addr = INADDR_ANY;
-    addr.sin_port = htons(port);
-
-    // bind
-    if (bind(mSoc, (const sockaddr *)&addr, sizeof(addr)) == -1) {
-        throw std::runtime_error(std::string("Could not bind socket options in ") + __FUNCTION__ + "!");
-    }
-}
-
-void MultiStreamReceiver::createSampleWriters() {
-    struct stat sb;
-    if (stat(mTargetDir.c_str(), &sb) == 0 && S_ISDIR(sb.st_mode)) { // if directory exists then leave it as it is
-        //unlink(datasetName.c_str()); FIXME
-    } else if (mkdir(mTargetDir.c_str(), 0777) == -1) { // else: create directory for dataset
-        throw std::runtime_error("Could not create directory " + mTargetDir + "!");
-    }
-
-    if (chdir(mTargetDir.c_str()) == -1) {
-        throw std::runtime_error("Could not change to target directory!");
-    }
-
-    std::string nodeDirHint = "";
-
-    for (unsigned int & mClientNode : mClientNodes) {
-        std::string datasetName = std::string("node_") + inet_ntoa({ mClientNode });
-        mpSampleWriters.emplace_back(std::make_shared<SampleWriter<int16_t>>(datasetName, 2, STEREO_BUF_LEN / 2));
-        nodeDirHint += datasetName + "\n";
-    }
-
-    std::ofstream hintFile("node_dir_hint.txt", std::ios_base::out);
-    hintFile << nodeDirHint;
-    hintFile.close();
-
-    if (chdir("..") == -1) {
-        throw std::runtime_error("Could not change to target directory!");
-    }
-}
-
-
-void MultiStreamReceiver::start() {
-    if (mRunning) {
-        return;
-    }
-
-    // ----------------------------
-
-    createSampleWriters();
-    startNetworking();
-
-    // ----------------------------
-
-    mRunning = true;
-    mRecvThread = std::make_shared<std::thread>(fnRecv, this);
-}
-
-void MultiStreamReceiver::stop() {
-    if (!mRunning) {
-        return;
-    }
-
-    mRunning = false;
-    mRecvThread->join();
-    close(mSoc);
-    mpSampleWriters.clear();
-}
-
-// --------------------------------------
-
-#define RECV_BUFFER_SIZE (16000)
-
-void MultiStreamReceiver::fnRecv(MultiStreamReceiver *pMSR) {
-    // select-related structures
-    fd_set read_fds;
-    timeval tv;
-
-    // receive buffer
-    std::shared_ptr<uint32_t> pWordBuf = std::shared_ptr<uint32_t>(new uint32_t[(RECV_BUFFER_SIZE / 4) + 1]); // to have 4-byte alignment
-    auto * pRecvBuf = reinterpret_cast<uint8_t *>(pWordBuf.get());
-    auto * pAudioPayload = reinterpret_cast<AudioPayload *>(pWordBuf.get());
-
-    while (pMSR->mRunning) {
-        // fd-set
-        FD_ZERO(&read_fds);
-        FD_SET(pMSR->mSoc, &read_fds);
-
-        // timeout
-        tv.tv_sec = 0;
-        tv.tv_usec = 1E+06 / 4;
-
-        // wait for data
-        int fd_cnt = select(pMSR->mSoc + 1, &read_fds, nullptr, nullptr, &tv);
-
-        // if data is available on the socket
-        if ((fd_cnt > 0) && FD_ISSET(pMSR->mSoc, &read_fds)) {
-
-            ssize_t recv_size;
-            if ((recv_size = recv(pMSR->mSoc, pRecvBuf, RECV_BUFFER_SIZE, 0)) <= 0) {
-                throw std::runtime_error("Receive error!");
-            }
-
-            // get sample writer for the specific address
-            std::shared_ptr<SampleWriter<int16_t>> pSampleWriter = nullptr;
-            for (size_t i = 0; i < pMSR->mClientNodes.size(); i++) {
-                if (pMSR->mClientNodes[i] == pAudioPayload->addr) {
-                    pSampleWriter = pMSR->mpSampleWriters[i];
-                    break;
-                }
-            }
-
-            // if sample writer is found
-            if (pSampleWriter != nullptr) {
-                pSampleWriter->addSamples(pAudioPayload->pData, { pAudioPayload->timestamp_s, pAudioPayload->timestamp_ns });
-            }
-        }
-    }
-}
-
--- a/src/MultiStreamReceiver.h
+++ b/src/MultiStreamReceiver.h
@ -1,41 +0,0 @@
-//
-// Created by epagris on 2021. 11. 22..
-//
-
-#ifndef WFR_MULTISTREAMRECEIVER_H
-#define WFR_MULTISTREAMRECEIVER_H
-
-
-#include <netinet/in.h>
-#include <vector>
-#include <memory>
-#include <thread>
-#include "SampleWriter.h"
-
-class MultiStreamReceiver {
-public:
-    static constexpr unsigned short DEFAULT_PORT = 20220; // default port
-private:
-    std::vector<in_addr_t> mClientNodes; // client node addresses
-    int mSoc; // UDP-socket for receiving samples
-    std::shared_ptr<std::thread> mRecvThread; // thread for reception
-    static void fnRecv(MultiStreamReceiver * pMSR); // routine function running in separate thread
-    bool mRunning;
-    std::vector<std::shared_ptr<SampleWriter<int16_t>>> mpSampleWriters; // sample writers for streams
-    std::string mTargetDir; // target directory
-private:
-    void startNetworking(); // start networking
-    void createSampleWriters(); // construct sample writers
-public:
-    const unsigned short port; // port
-public:
-    explicit MultiStreamReceiver(const std::vector<in_addr_t>& nodes, const std::string& targetDir, unsigned short port = DEFAULT_PORT);
-    void start(); // start reception
-    void stop();
-
-    virtual ~MultiStreamReceiver();
-    // stop reception
-};
-
-
-#endif //WFR_MULTISTREAMRECEIVER_H
--- a/src/SampleReceiver.h
+++ b/src/SampleReceiver.h
@ -6,7 +6,7 @@
 #define WFR_SAMPLERECEIVER_H

 #include "MemoryPool.h"
-#include "Timestamp.h"
+#include "../libwfr/src/Timestamp.h"

 #include <vector>

--- a/src/SampleWriter.h
+++ b/src/SampleWriter.h
@ -1,195 +0,0 @@
-//
-// Created by epagris on 2021. 11. 01..
-//
-
-#ifndef WFR_SAMPLEWRITER_H
-#define WFR_SAMPLEWRITER_H
-
-#include <fstream>
-#include <string>
-#include <memory>
-#include <iostream>
-#include <sys/stat.h>
-#include <vector>
-#include <set>
-#include <queue>
-#include "Timestamp.h"
-
-#define DIRSEP '/'
-
-template<typename T> // T: sample datatype
-class SampleWriter {
-public:
-    static const std::string TS_FILENAME; // filename for timestamp file
-    static const std::string SAMPLE_FILENAME_PREFIX; // filename prefix for sample file
-    static const std::string FILE_EXT; // datafile extensions
-public:
-    // timestamp record
-    struct TimestampRecord {
-    public:
-        uint32_t ts_s, ts_ns; // timestamp
-    public:
-        TimestampRecord &operator=(const Timestamp &ts) {
-            ts_s = (uint32_t) ts.s;
-            ts_ns = (uint32_t) ts.ns;
-            return *this;
-        }
-    };
-
-private:
-    const size_t mChN; // number of channel PAIRS, immutable
-    const size_t mBlockSize; // buffer size, immutable
-private:
-    std::shared_ptr<TimestampRecord> mpTs; // timestamp records
-    std::vector<std::shared_ptr<T>> mpSamples; // sample buffer array
-
-    std::string mTsFileName; // timestamp filename
-    std::ofstream mTsFile; // timestamp file
-    std::vector<std::string> mSampleFileNames; // sample file names
-    std::vector<std::ofstream> mSampleFiles; // sample output files
-private:
-    Timestamp mTs[2]; // previous and current timestamp
-private:
-    unsigned long long mSamplesN; // number of samples written until now
-private:
-    // resize sample and record buffers
-    void prepareBuffers() {
-        // allocate timestamp data buffer
-        mpTs = std::shared_ptr<TimestampRecord>(new TimestampRecord[mBlockSize]);
-
-        // allocate sample data buffers
-        mpSamples.resize(mChN);
-        for (size_t i = 0; i < mChN; i++) {
-            mpSamples[i] = std::shared_ptr<T>(new T[mBlockSize]);
-        }
-    }
-
-    // prepare dataset environment
-    void prepareDatadir(const std::string &datasetName) {
-        struct stat sb;
-        if (stat(datasetName.c_str(), &sb) == 0 && S_ISDIR(sb.st_mode)) { // if directory exists then leave it as it is
-            //unlink(datasetName.c_str()); FIXME
-        } else if (mkdir(datasetName.c_str(), 0777) == -1) { // else: create directory for dataset
-            throw std::runtime_error("Could not create directory " + datasetName + "!");
-        }
-
-        std::string datadir_dirsep = datasetName + DIRSEP;
-
-        // generate file names
-        mTsFileName = TS_FILENAME + '.' + FILE_EXT; // timestamp
-
-        // samples
-        mSampleFileNames.resize(mChN);
-        for (size_t i = 0; i < mChN; i++) {
-            mSampleFileNames[i] = SAMPLE_FILENAME_PREFIX + std::to_string(i) + '.' + FILE_EXT;
-        }
-
-        // open timestamp file
-        mTsFile.open(datadir_dirsep + mTsFileName, std::ios_base::binary);
-        if (!mTsFile.is_open()) {
-            throw std::runtime_error("Could not open timestamp file " + mTsFileName + "!");
-        }
-
-        // open sample files
-        mSampleFiles.resize(mChN);
-        for (size_t i = 0; i < mChN; i++) {
-            mSampleFiles[i].open(datadir_dirsep + mSampleFileNames[i], std::ios_base::binary);
-            if (!mSampleFiles[i].is_open()) {
-                throw std::runtime_error("Could not open sample file " + mSampleFileNames[i] + "!");
-            }
-        }
-    }
-
-    // close files
-    void closeFiles() {
-        // close file storing timestamp files
-        mTsFile.close();
-
-        // close files stroring samples
-        for (size_t i = 0; i < mChN; i++) {
-            mSampleFiles[i].close();
-        }
-    }
-
-public:
-    explicit SampleWriter(const std::string &datasetName, size_t chN, size_t bufSize) : mChN(chN), mBlockSize(bufSize), mSamplesN(0) { // constr.
-        prepareBuffers();
-        prepareDatadir(datasetName);
-    }
-
-    ~SampleWriter() {
-        closeFiles();
-    }
-
-    // add n samples to file
-    void addSamples(const T *pSamples, const Timestamp &ts) {
-        // shift FIFO and store new timestamp
-        mTs[1] = mTs[0];
-        mTs[0] = ts;
-
-        // if previous timestamp is empty, then don't store samples since time interpolation can not be done
-        if (mTs[1].empty()) {
-            return;
-        }
-
-        // calculate time step size
-        Timestamp d = (mTs[0] - mTs[1]) / (double) mBlockSize;
-
-        // timestamp for time interpolation
-        Timestamp ts_interp = mTs[1];
-
-        // get channel pointers
-        T *ppCh[mChN];
-        for (size_t i = 0; i < mChN; i++) {
-            ppCh[i] = mpSamples[i].get();
-        }
-
-        // extract samples
-        for (size_t i = 0; i < mBlockSize; i++) {
-            // select record
-            T *pRawSamples = (short *) (pSamples + i * mChN);
-
-            // store sample for a channel
-            for (size_t ch = 0; ch < mChN; ch++) {
-                ppCh[ch][i] = pRawSamples[ch];
-            }
-
-            // step time
-            ts_interp += d;
-
-            // store timestamp
-            mpTs.get()[i] = ts_interp;
-        }
-
-        // write to file newly created records
-
-        // write timestamps
-        mTsFile.write((const char *) mpTs.get(), mBlockSize * sizeof(TimestampRecord));
-
-        // write samples
-        for (size_t ch = 0; ch < mChN; ch++) {
-            mSampleFiles[ch].write((const char *) ppCh[ch], mBlockSize * sizeof(T));
-        }
-
-        // increment counter
-        mSamplesN += mBlockSize;
-    }
-
-    // get number of samples written out
-    unsigned long long getSampleCnt() const {
-        return mSamplesN;
-    }
-
-};
-
-// static fields
-template<typename T>
-const std::string SampleWriter<T>::TS_FILENAME = "ts";
-
-template<typename T>
-const std::string SampleWriter<T>::SAMPLE_FILENAME_PREFIX = "ch_";
-
-template<typename T>
-const std::string SampleWriter<T>::FILE_EXT = "dat";
-
-#endif //WFR_SAMPLEWRITER_H
--- a/src/audio_types.h
+++ b/src/audio_types.h
@ -1,23 +0,0 @@
-//
-// Created by epagris on 2021. 11. 02..
-//
-
-#ifndef WFR_AUDIO_TYPES_H
-#define WFR_AUDIO_TYPES_H
-
-#include <cstdint>
-
-#define STEREO_BUF_LEN (2 * 192)
-#define PERIOD_LEN (STEREO_BUF_LEN / 2)
-#define SAMPLE_RATE (48000)
-
-typedef int16_t AudioSampleType;
-
-typedef struct {
-    uint32_t timestamp_s, timestamp_ns; // timestamp
-    uint32_t sample_cnt; // count of samples in packet
-    in_addr_t addr; // client node address
-    AudioSampleType pData[STEREO_BUF_LEN]; // buffer for stereo data
-} AudioPayload;
-
-#endif //WFR_AUDIO_TYPES_H
--- a/src/globals.h
+++ b/src/globals.h
@ -6,7 +6,7 @@
 #define WFR_GLOBALS_H

 #include <memory>
-#include "ServerBeacon.h"
+#include "../libwfr/src/ServerBeacon.h"

 struct Globals {
    std::shared_ptr<ServerBeacon> beacon; // beacon to detect client nodes
--- a/wfstream_analyzer.lua
+++ b/wfstream_analyzer.lua
@ -0,0 +1,68 @@
+-- @brief WaveFormStream analyzer for wireshark
+-- @author Epagris
+-- @date 2022.04.29.
+
+-- 1. Create parser objects
+local NAME = "WFS"  --Custom protocol name
+local MsgProto = Proto(NAME, "WaveFormStream over UDP")
+
+-- MsgProto Resolution fields for defining protocols
+local fields = MsgProto.fields
+fields.timestamp_s = ProtoField.uint32(NAME .. "TIMESTAMP_S", "timestamp_s", base.DEC)
+fields.timestamp_ns = ProtoField.uint32(NAME .. "TIMESTAMP_NS", "timestamp_ns", base.DEC)
+fields.sample_cnt = ProtoField.uint32(NAME .. "SAMPLE_CNT", "sample_cnt", base.DEC)
+fields.sample_size = ProtoField.uin16_t(NAME .. "SAMPLE_SIZE", "sample_size", base.DEC)
+fields.channel_count = ProtoField.uin16_t(NAME .. "CHANNEL_COUNT", "channel_count", base.DEC)
+fields.addr = ProtoField.ipv4(NAME .. "ADDR", "addr", base.DEC)
+
+local data_dis = Dissector.get("data")
+
+-- 2. Parser function dissect packet
+--[[
+    //Next, define the main function of the foo parser, which is called by wireshark
+    //The first parameter is the tvb type, which represents the data that needs to be parsed by this parser
+    //The second parameter is the Pinfo type, which is the information on the protocol parsing tree, including the display on the UI.
+    //The third parameter is the TreeItem type, which represents the upper parse tree.
+--]]
+
+function MsgProto.dissector (tvb, pinfo, tree)
+
+    --Create a subtree from the root tree to print parsed message data
+    local subtree = tree:add(MsgProto, tvb())
+    subtree:append_text(", msg_no: " .. tvb(0, 1):uint())
+    -- The protocol name displayed on the protocol line in the packet details
+    pinfo.cols.protocol = MsgProto.name
+
+    tvb_length = tvb:len()
+    -- dissect field one by one, and add to protocol tree
+    --Include a header in the message and continue to create tree parsing
+    local msg_head_tree = subtree:add(MsgProto, tvb(0,2), "MSG_HEADER") --"MSG_HEADER"The parameter replaces the protocol name display
+    msg_head_tree:add(fields.msg_no, tvb(0, 1))--Represents a byte starting from 0
+    msg_head_tree:add(fields.msg_version, tvb(1, 1))
+
+    subtree:add(fields.msg_len, tvb(2,1))
+
+    subtree:add(fields.length, tvb_length) --Display data slice length information without fetching data from slice memory
+    subtree:add(fields.data_length, tvb_length-8)
+
+    -- Bit Domain Continues to Create Tree Resolution
+    local msg_bitx_tree = subtree:add( fields.msg_bitx, tvb(3,1) )       -- bitfield
+    msg_bitx_tree:add(fields.msg_bit1,tvb(3,1))
+    msg_bitx_tree:add(fields.msg_bit2,tvb(3,1))
+    msg_bitx_tree:add(fields.msg_bit3,tvb(3,1))
+    msg_bitx_tree:add(fields.msg_bit4,tvb(3,1))
+
+    subtree:add_le(fields.local_id,tvb(4,4))
+    subtree:add_le(fields.remote_id,tvb(8,4))
+
+    data_dis:call(tvb(12):tvb(), pinfo, tree) --It is noteworthy to parse the data in the data stream after the message structure. call The parameter name must be tvb，？？？，I hope the big man will give me some advice.
+
+end
+
+-- 3 Register the parser to wireshark Analytical table register this dissector
+local udp_port_table = DissectorTable.get("tcp.port")
+
+--Adding parsed TCP Port, Identify Protocol Based on Port Number
+for i,port in ipairs{8001,8002} do
+    udp_port_table:add(port,MsgProto)
+end