ffmpegPortmonitor.cpp

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/*
 * SPDX-FileCopyrightText: 2006-2021 Istituto Italiano di Tecnologia (IIT)
 * SPDX-License-Identifier: BSD-3-Clause
 */
 
// Local imports
#include "ffmpegPortmonitor.h"
#include "constants.h"
// YARP imports
#include <yarp/os/LogComponent.h>
#include <yarp/os/Time.h>
#include <yarp/sig/all.h>
// Standard imports
#include <cstring>
#include <cmath>
#include <algorithm>
#include <iostream>
#include <sstream>
#include <mutex>
#include <iomanip>
 
// Ffmpeg imports
extern "C" {
    #include <libavcodec/avcodec.h>
    #include <libavutil/opt.h>
    #include <libavutil/imgutils.h>
    #include <libavformat/avformat.h>
    #include <libswscale/swscale.h>
}
 
using namespace yarp::os;
using namespace yarp::sig;
 
namespace {
 
// YARP logging component
YARP_LOG_COMPONENT(FFMPEGMONITOR,
                   "yarp.carrier.portmonitor.image_compression_ffmpeg",
                   yarp::os::Log::minimumPrintLevel(),
                   yarp::os::Log::LogTypeReserved,
                   yarp::os::Log::printCallback(),
                   nullptr)
}
 
void split(const std::string &s, char delim, std::vector<std::string> &elements) {
    std::istringstream iss(s);
    std::string item;
    while (std::getline(iss, item, delim)) {
        elements.push_back(item);
    }
}
 
// As per version 5.1.2 of ffmpeg, there seem to be race conditions between sws_scale and
// sws_freeContext even when called from different instances on different threads.
// We use a static mutex to prevent segmentation faults when connecting two port monitors
// to the same sender or receiver.
static std::mutex instances_mutex;
 
bool FfmpegMonitorObject::create(const yarp::os::Property& options)
{
    // Check if this is sender or not
    senderSide = (options.find("sender_side").asBool());
    printStatistics = false;
    previousFrameTime = yarp::os::Time::now();
    bandwidthRunningAverage = 0.0;
    lagRunningAverage = 0.0;
    statisticsCounter = -1;
    previousStatisticPrintTime = previousFrameTime;
 
    // Parse command line parameters and set them into global variable "paramsMap"
    std::string str = options.find("carrier").asString();
    int frameRate = 15;
    if (!getParamsFromCommandLine(str, codec, pixelFormat, frameRate)) {
        return false;
    }
 
    // Prepare codec context
    if (codecContext == NULL) {
        codecContext = avcodec_alloc_context3(codec);
    } else {
        yCError(FFMPEGMONITOR, "Codec context is already allocated");
        return false;
    }
    if (!codecContext) {
        yCError(FFMPEGMONITOR, "Could not allocate video codec context");
        return false;
    }
 
    if (!codec->pix_fmts)
    {
        yCWarning(FFMPEGMONITOR, "The specified codec (%s) has unknown available pixel formats. There might be visualization issues.", codec->name);
    }
    else
    {
        std::stringstream pixelFormatList;
        bool found = false;
        size_t i = 0;
        AVPixelFormat test = codec->pix_fmts[i];
 
        if (test == AV_PIX_FMT_NONE)
        {
            yCError(FFMPEGMONITOR, "The specified codec (%s) has no available pixel format.", codec->name);
            return false;
        }
 
        pixelFormatList << test;
        while (test != AV_PIX_FMT_NONE)
        {
            if (test == pixelFormat)
            {
                found = true;
                break;
            }
            ++i;
            test = codec->pix_fmts[i];
 
            if (test != AV_PIX_FMT_NONE)
            {
                pixelFormatList << ", " << test;
            }
        }
 
        if (!found)
        {
            AVPixelFormat suggestedFormat = avcodec_default_get_format(codecContext, codec->pix_fmts);
 
            if (pixelFormat == FFMPEGPORTMONITOR_DEFAULT_PIXEL_FORMAT)
            {
                yCError(FFMPEGMONITOR, "The specified codec (%s) is not compatible with the default pixel format AV_PIX_FMT_YUV420P (code %d). "
                                       "Try specifying the suggested pixel format of the codec with the option \"pixel_format.%d\". "
                                       "The available pixel formats are %s.",
                                        codec->name, FFMPEGPORTMONITOR_DEFAULT_PIXEL_FORMAT, suggestedFormat, pixelFormatList.str().c_str());
            }
            else
            {
                yCError(FFMPEGMONITOR, "The specified codec (%s) is not compatible with the specified pixel format (code %d). "
                                       "The available pixel formats are as follows %s (suggested = %d).",
                                        codec->name, pixelFormat, pixelFormatList.str().c_str(), suggestedFormat);
            }
            return false;
        }
    }
 
    firstTime = true;
 
    // Set time base parameter
    codecContext->time_base.num = 1;
    codecContext->time_base.den = frameRate;
    // Set command line params
    if (setCommandLineParams() == -1) {
        return false;
    }
 
    return true;
}
 
void FfmpegMonitorObject::destroy(void)
{
    paramsMap.clear();
 
    // Check if codec context is freeable, if yes free it.
    if (codecContext != NULL) {
#if LIBAVCODEC_VERSION_MAJOR < 61
        // See https://github.com/FFmpeg/FFmpeg/blob/n7.0/libavcodec/avcodec.h#L2381-L2384
        avcodec_close(codecContext);
#endif
        avcodec_free_context(&codecContext);
        codecContext = NULL;
    }
}
 
bool FfmpegMonitorObject::setparam(const yarp::os::Property& params)
{
    yCTrace(FFMPEGMONITOR, "setparam");
    return false;
}
 
bool FfmpegMonitorObject::getparam(yarp::os::Property& params)
{
    yCTrace(FFMPEGMONITOR, "getparam");
    return false;
}
 
bool FfmpegMonitorObject::accept(yarp::os::Things& thing)
{
    if (senderSide) {
        // If sender side
        yCTrace(FFMPEGMONITOR, "accept - sender");
        // Try to cast the Thing into an Image
        Image* img = thing.cast_as< Image >();
        // If cast fails, try to cast the Thing into a Bottle
        if(img == nullptr) {
            Bottle* bt = thing.cast_as<Bottle>();
            // If cast fails, return error
            if (bt == nullptr) {
                yCError(FFMPEGMONITOR, "Expected type Image or Bottle in sender side, but got wrong data type!");
                return false;
            }
        }
    }
    else {
        // If receiver side
        yCTrace(FFMPEGMONITOR, "accept - receiver");
        // Try to cast the Thing into a Bottle
        Bottle* bt = thing.cast_as<Bottle>();
        // If cast fails, return error
        if(bt == nullptr){
            yCError(FFMPEGMONITOR, "Expected type Bottle in receiver side, but got wrong data type!");
            return false;
        }
    }
    return true;
}
 
void FfmpegMonitorObject::updateStatistics(yarp::os::Bottle& inputBottle, double currentLag)
{
    double now = yarp::os::Time::now();
    const double printInterval = 5.0;
 
    if (statisticsCounter < 0)
    {
        previousFrameTime = now;
        previousStatisticPrintTime = now;
        statisticsCounter = 0;
    }
    else
    {
        size_t outputData{0};
        inputBottle.toBinary(&outputData);
        double dt = now - previousFrameTime;
        double bandwidth = outputData * 8 / dt /1000;
        int previousCounter = statisticsCounter;
        statisticsCounter++;
        bandwidthRunningAverage = (bandwidthRunningAverage * previousCounter + bandwidth) / statisticsCounter;
        lagRunningAverage = (lagRunningAverage * previousCounter + currentLag) / statisticsCounter;
 
    }
    if (now - previousStatisticPrintTime > printInterval)
    {
        previousStatisticPrintTime = now;
        statisticsCounter = 0;
        std::stringstream bandwidthString, lagString;
        bandwidthString << std::fixed << std::setprecision(2) << bandwidthRunningAverage;
        lagString << std::fixed << std::setprecision(3) << lagRunningAverage * 1000;
        yCInfo(FFMPEGMONITOR, "Statistics: current bandwidth %s kb/s, codec computational time %s ms",
               bandwidthString.str().c_str(), lagString.str().c_str());
    }
}
 
yarp::os::Things& FfmpegMonitorObject::update(yarp::os::Things& thing)
{
    double startTime = yarp::os::Time::now();
    if (senderSide) {
        bool success = true;
        yCTrace(FFMPEGMONITOR, "update - sender");
        // Cast Thing into an Image
        Image* img = thing.cast_as< Image >();
 
        if (img == nullptr) {
            Bottle* bot = thing.cast_as<Bottle>();
            if (!yarp::os::Portable::copyPortable(*bot, imageBottleBuffer))
            {
                yCError(FFMPEGMONITOR, "The input type is a Bottle, but it cannot be copied to an Image");
                success = false;
            }
            img = &imageBottleBuffer;
        }
 
        // Allocate memory for packet
        AVPacket *packet = av_packet_alloc();
        if (packet == NULL) {
            yCError(FFMPEGMONITOR, "Error in packet allocation");
            success = false;
        }
 
        // Call compress function
        if (success && compress(img, packet) != 0) {
            yCError(FFMPEGMONITOR, "Error in compression");
            success = false;
        }
 
        // Insert compressed image into a Bottle to be sent
        data.clear();
 
        int successCode = success ? 1 : 0;
        data.addInt32(successCode);
        data.addInt32(img->width());
        data.addInt32(img->height());
        data.addInt32(img->getPixelCode());
        data.addInt32(img->getPixelSize());
 
        if (success) {  // If compression was successful, insert also compressed data
            // Packet
            Value p(packet, sizeof(*packet));
            data.add(p);
            // Packet data
            Value d(packet->data, packet->size);
            data.add(d);
            // Buffer size
            data.addInt32(packet->buf->size);
            // Buffer data
            Value bd(packet->buf->data, packet->buf->size);
            data.add(bd);
 
            // Side data elements
            for (int i = 0; i < packet->side_data_elems; i++) {
                data.addInt32(packet->side_data[i].size);
                data.addInt32(packet->side_data[i].type);
                Value sd(packet->side_data[i].data, packet->side_data[i].size);
                data.add(sd);
            }
        }
 
        if (printStatistics)
        {
            updateStatistics(data, yarp::os::Time::now() - startTime);
        }
 
        th.setPortWriter(&data);
        // Free the memory allocated for the packet
        av_packet_unref(packet);
    }
    else {
 
        yCTrace(FFMPEGMONITOR, "update - receiver");
        // Cast the Thin as a Bottle
        Bottle* compressedBottle = thing.cast_as<Bottle>();
        // Fill the final image with zeros
        imageOut.zero();
        // Extract decompression data from the Bottle
        int width = compressedBottle->get(1).asInt32();
        int height = compressedBottle->get(2).asInt32();
        int pixelCode = compressedBottle->get(3).asInt32();
        int pixelSize = compressedBottle->get(4).asInt32();
        // Set information into final image
 
        if (pixelCode != VOCAB_PIXEL_INVALID)
        {
            imageOut.setPixelCode(pixelCode);
            imageOut.setPixelSize(pixelSize);
            imageOut.resize(width, height);
        }
        else
        {
            yCError(FFMPEGMONITOR, "Invalid input pixel code");
        }
 
        // Check if compression was successful
        if (compressedBottle->get(0).asInt32() == 1) {
            bool success = true;
            // Get compressed image from Bottle
            AVPacket* tmp = (AVPacket*) compressedBottle->get(5).asBlob();
            // Allocate memory for packet
            AVPacket* packet = av_packet_alloc();
            // Set all packet parameters
            packet->dts = tmp->dts;
            packet->duration = tmp->duration;
            packet->flags = tmp->flags;
            packet->pos = tmp->pos;
            packet->pts = tmp->pts;
            packet->side_data_elems = 0;
            packet->stream_index = tmp->stream_index;
            packet->size = tmp->size;
            // Image data
            packet->data = (uint8_t *) compressedBottle->get(6).asBlob();
            // Buffer data
            packet->buf = av_buffer_create((uint8_t *) compressedBottle->get(8).asBlob(),
                                            compressedBottle->get(7).asInt32(), av_buffer_default_free,
                                            nullptr, AV_BUFFER_FLAG_READONLY);
 
            // Packet side data
            for (int i = 0; i < tmp->side_data_elems; i++) {
 
                int ret = av_packet_add_side_data(packet,
                                                    (AVPacketSideDataType) compressedBottle->get(10).asInt32(),     // Type
                                                    (uint8_t *) compressedBottle->get(11).asBlob(),                 // Data
                                                    compressedBottle->get(9).asInt32());                            // Size
                if (ret < 0) {
                    success = false;
                    break;
                }
            }
 
            // Call to decompress function
            if (success && decompress(packet, width, height, pixelCode) != 0) {
                yCError(FFMPEGMONITOR, "Error in decompression");
            }
 
            if (printStatistics)
            {
                updateStatistics(*compressedBottle, yarp::os::Time::now() - startTime);
            }
 
            // Free memory allocated for side data and packet
            av_freep(&packet->side_data);
            av_freep(&packet);
 
        }
 
        th.setPortWriter(&imageOut);
 
    }
    return th;
}
 
int FfmpegMonitorObject::compress(Image* img, AVPacket *pkt) {
 
    yCTrace(FFMPEGMONITOR, "compress");
    AVFrame *startFrame;
    AVFrame *endFrame;
 
    // Get width and height
    int w = img->width();
    int h = img->height();
 
    // Allocate video frame for original frames
    startFrame = av_frame_alloc();
    if (startFrame == NULL) {
        yCError(FFMPEGMONITOR, "Cannot allocate starting frame!");
        return -1;
    }
 
    // Allocate a video frame for end frame
    endFrame = av_frame_alloc();
    if (endFrame == NULL) {
        yCError(FFMPEGMONITOR, "Cannot allocate end frame!");
        av_frame_free(&startFrame);
        return -1;
    }
 
    // Allocate space into start frame to contain data
    int success = av_image_alloc(startFrame->data, startFrame->linesize,
                    w, h,
                    (AVPixelFormat) FFMPEGPORTMONITOR_PIXELMAP[img->getPixelCode()], 16);
 
    if (success < 0) {
        yCError(FFMPEGMONITOR, "Cannot allocate starting frame buffer!");
        av_frame_free(&startFrame);
        av_frame_free(&endFrame);
        return -1;
    }
 
    // Set Image data into AVFrame
    startFrame->linesize[0] = img->getRowSize();
    // Free old pointer (because we will use the buffer contained into img)
    av_freep(&startFrame->data[0]);
    startFrame->data[0] = img->getRawImage();
    startFrame->height = h;
    startFrame->width = w;
    startFrame->format = (AVPixelFormat) FFMPEGPORTMONITOR_PIXELMAP[img->getPixelCode()];
 
    // Allocate memory for end frame data
    success = av_image_alloc(endFrame->data, endFrame->linesize,
                    w, h, pixelFormat, 16);
 
    if (success < 0) {
        yCError(FFMPEGMONITOR, "Cannot allocate end frame buffer!");
        av_frame_free(&startFrame);
        av_frame_free(&endFrame);
        return -1;
    }
 
    // Set end frame parameters
    endFrame->height = h;
    endFrame->width = w;
    endFrame->format = pixelFormat;
 
    {
        std::lock_guard<std::mutex> lock(instances_mutex);
 
        // Convert the image from start format into end format
        static struct SwsContext *img_convert_ctx;
 
        // Allocate context for conversion
        img_convert_ctx = sws_getContext(w, h,
                                         (AVPixelFormat) FFMPEGPORTMONITOR_PIXELMAP[img->getPixelCode()],
                w, h,
                pixelFormat,
                SWS_BICUBIC,
                NULL, NULL, NULL);
        if (img_convert_ctx == NULL) {
            yCError(FFMPEGMONITOR, "Cannot initialize pixel format conversion context!");
            av_freep(&endFrame->data[0]);
            av_frame_free(&startFrame);
            av_frame_free(&endFrame);
            return -1;
        }
 
        // Perform conversion
        int ret = sws_scale(img_convert_ctx, startFrame->data, startFrame->linesize, 0,
                            h, endFrame->data, endFrame->linesize);
 
        if (ret < 0) {
            yCError(FFMPEGMONITOR, "Could not convert pixel format!");
            sws_freeContext(img_convert_ctx);
            av_freep(&endFrame->data[0]);
            av_frame_free(&startFrame);
            av_frame_free(&endFrame);
            return -1;
        }
 
        if (firstTime) {
            // If this is the first compression
 
            // Set codec context parameters
            codecContext->width = w;
            codecContext->height = h;
            codecContext->pix_fmt = pixelFormat;
 
            // Open codec
            ret = avcodec_open2(codecContext, codec, NULL);
            if (ret < 0) {
                yCError(FFMPEGMONITOR, "Could not open codec");
                sws_freeContext(img_convert_ctx);
                av_freep(&endFrame->data[0]);
                av_frame_free(&startFrame);
                av_frame_free(&endFrame);
                return -1;
            }
            firstTime = false;
        }
 
        // Set presentation timestamp
#if LIBAVCODEC_VERSION_MAJOR >= 61
        // See https://github.com/FFmpeg/FFmpeg/commit/6b6f7db81932f94876ff4bcfd2da0582b8ab897e
        endFrame->pts = codecContext->frame_num;
#else
        endFrame->pts = codecContext->frame_number;
#endif
 
        // Send image frame to codec
        ret = avcodec_send_frame(codecContext, endFrame);
        if (ret < 0) {
            yCError(FFMPEGMONITOR, "Error sending a frame for encoding");
            sws_freeContext(img_convert_ctx);
            av_freep(&endFrame->data[0]);
            av_frame_free(&startFrame);
            av_frame_free(&endFrame);
            return -1;
        }
 
        // Receive compressed data into packet
        ret = avcodec_receive_packet(codecContext, pkt);
        sws_freeContext(img_convert_ctx);
        av_freep(&endFrame->data[0]);
        av_frame_free(&startFrame);
        av_frame_free(&endFrame);
 
 
        if (ret == AVERROR(EAGAIN)) {
            // Not enough data
            yCError(FFMPEGMONITOR, "Error EAGAIN");
            return -1;
        } else if (ret == AVERROR_EOF) {
            // End of file reached
            yCError(FFMPEGMONITOR, "Error EOF");
            return -1;
        } else if (ret < 0) {
            yCError(FFMPEGMONITOR, "Error during encoding");
            return -1;
        }
    }
 
    return 0;
}
 
int FfmpegMonitorObject::decompress(AVPacket* pkt, int w, int h, int pixelCode) {
 
    yCTrace(FFMPEGMONITOR, "decompress");
    AVFrame *startFrame;
    AVFrame *endFrame;
 
    if (firstTime) {
        // If this is the first decompression
 
        // Set codec context parameters
        codecContext->width = w;
        codecContext->height = h;
        codecContext->pix_fmt = pixelFormat;
 
        // Open codec
        int ret = avcodec_open2(codecContext, codec, NULL);
        if (ret < 0) {
            yCError(FFMPEGMONITOR, "Could not open codec");
            return -1;
        }
        firstTime = false;
    }
 
    // Allocate video frame
    startFrame = av_frame_alloc();
    if (startFrame == NULL) {
        yCError(FFMPEGMONITOR, "Could not allocate start frame!");
        return -1;
    }
 
    // Send compressed packet to codec
    int ret = avcodec_send_packet(codecContext, pkt);
    if (ret < 0) {
        yCError(FFMPEGMONITOR, "Error sending a frame for decoding");
        av_frame_free(&startFrame);
        return -1;
    }
 
    // Receive decompressed image into an AVFrame
    ret = avcodec_receive_frame(codecContext, startFrame);
    if (ret == AVERROR(EAGAIN)) {
        // No enough data
        yCError(FFMPEGMONITOR, "Error EAGAIN");
        av_frame_free(&startFrame);
        return -1;
    }
    else if (ret == AVERROR_EOF) {
        // End of file reached
        yCError(FFMPEGMONITOR, "Error EOF");
        av_frame_free(&startFrame);
        return -1;
    }
    else if (ret < 0) {
        yCError(FFMPEGMONITOR, "Error during decoding");
        av_frame_free(&startFrame);
        return -1;
    }
 
    // Allocate a video frame for end frame
    endFrame = av_frame_alloc();
    if (endFrame == NULL) {
        yCError(FFMPEGMONITOR, "Could not allocate start frame!");
        av_frame_free(&startFrame);
        return -1;
    }
 
    // Allocate memory into end frame to contain data
    int success = av_image_alloc(endFrame->data, endFrame->linesize,
                    w, h,
                    (AVPixelFormat) FFMPEGPORTMONITOR_PIXELMAP[pixelCode], 16);
 
    if (success < 0) {
        yCError(FFMPEGMONITOR, "Error allocating end frame buffer!");
        av_frame_free(&startFrame);
        av_frame_free(&endFrame);
        return -1;
    }
 
    // Set end frame parameters
    endFrame->height = h;
    endFrame->width = w;
    endFrame->format = (AVPixelFormat) FFMPEGPORTMONITOR_PIXELMAP[pixelCode];
 
    {
        std::lock_guard<std::mutex> lock(instances_mutex);
 
        // Convert the image into RGB format
        static struct SwsContext *img_convert_ctx;
 
        // Allocate conversion context
        img_convert_ctx = sws_getContext(w, h,
                                         pixelFormat,
                                         w, h,
                                         (AVPixelFormat) FFMPEGPORTMONITOR_PIXELMAP[pixelCode],
                                         SWS_BICUBIC,
                                         NULL, NULL, NULL);
        if (img_convert_ctx == NULL) {
            yCError(FFMPEGMONITOR, "Cannot initialize the pixel format conversion context!");
            av_freep(&endFrame->data[0]);
            av_frame_free(&endFrame);
            av_frame_free(&startFrame);
            return -1;
        }
 
        // Perform conversion
        ret = sws_scale(img_convert_ctx, startFrame->data, startFrame->linesize, 0,
                        h, endFrame->data, endFrame->linesize);
 
        if (ret < 0) {
            yCError(FFMPEGMONITOR, "Could not convert pixel format!");
            av_freep(&endFrame->data[0]);
            av_frame_free(&endFrame);
            av_frame_free(&startFrame);
            sws_freeContext(img_convert_ctx);
            return -1;
        }
 
        // Copy decompressed data from end frame to imageOut
        memcpy(imageOut.getRawImage(), endFrame->data[0], success);
 
        // Free allocated memory
        av_freep(&endFrame->data[0]);
        av_frame_free(&endFrame);
        av_frame_free(&startFrame);
        sws_freeContext(img_convert_ctx);
    }
 
    return 0;
 
}
 
bool FfmpegMonitorObject::getParamsFromCommandLine(std::string carrierString, const AVCodec*& codecOut, AVPixelFormat& pixelFormatOut, int& frameRate) {
 
    std::vector<std::string> parameters;
    // Split command line string using '+' delimiter
    split(carrierString, '+', parameters);
 
    bool standardCodec = false;
    bool customEnc     = false;
    bool customDec     = false;
 
    // Iterate over result strings
    for (std::string& param: parameters) {
 
        // Skip YARP initial parameters
        if (find(FFMPEGPORTMONITOR_IGNORE_PARAMS.begin(), FFMPEGPORTMONITOR_IGNORE_PARAMS.end(), param) != FFMPEGPORTMONITOR_IGNORE_PARAMS.end()) {
            continue;
        }
 
        // If there is no '.', the param is bad formatted, return error
        auto pointPosition = param.find('.');
        if (pointPosition == std::string::npos) {
            yCError(FFMPEGMONITOR, "Error while parsing parameter %s. Missing '.'!", param.c_str());
            return false;
        }
 
        // Otherwise, separate key and value
        std::string paramKey = param.substr(0, pointPosition);
        std::string paramValue = param.substr(pointPosition + 1, param.length());
 
        // Parsing codec
        if (paramKey == FFMPEGPORTMONITOR_CL_CODEC_KEY) {
 
            if (customEnc || customDec)
            {
                yCError(FFMPEGMONITOR, "Cannot set both %s and %s/%s together.",
                        FFMPEGPORTMONITOR_CL_CODEC_KEY.c_str(),
                        FFMPEGPORTMONITOR_CL_CUSTOM_ENC_KEY.c_str(),
                        FFMPEGPORTMONITOR_CL_CUSTOM_DEC_KEY.c_str());
                codecOut = nullptr;
                return false;
            }
 
            bool found = false;
            // Iterate over codecs command line possibilities
            for (size_t i = 0; i < FFMPEGPORTMONITOR_CL_CODECS.size(); i++) {
                // If found
                if (paramValue == FFMPEGPORTMONITOR_CL_CODECS[i]) {
                    // Set codec id basing on codec command line name
                    AVCodecID codecId = (AVCodecID) FFMPEGPORTMONITOR_CODE_CODECS[i];
                    // Find encoder/decoder
                    if (senderSide) {
                        codecOut = avcodec_find_encoder(codecId);
                    } else {
                        codecOut = avcodec_find_decoder(codecId);
                    }
 
                    if (!codecOut) {
                        yCError(FFMPEGMONITOR, "Can't find codec %s", paramValue.c_str());
                        codecOut = nullptr;
                        return false;
                    }
 
                    standardCodec = true;
                    found = true;
                    break;
                }
            }
 
            // If not found, unrecognized codec, return error
            if (!found) {
                yCError(FFMPEGMONITOR, "Unrecognized codec: %s", paramValue.c_str());
                return false;
            }
 
            continue; //avoid to add this parameter to paramsMap
        }
        else if (paramKey == FFMPEGPORTMONITOR_CL_CUSTOM_ENC_KEY)
        {
            if (!senderSide)
            {
                customEnc = true;
                continue; //The custom encoder need to be set on the sender side only. Later we check that the custom decoder has been set too.
            }
 
            if (standardCodec)
            {
                yCError(FFMPEGMONITOR, "Cannot set both %s and %s/%s together.",
                        FFMPEGPORTMONITOR_CL_CODEC_KEY.c_str(),
                        FFMPEGPORTMONITOR_CL_CUSTOM_ENC_KEY.c_str(),
                        FFMPEGPORTMONITOR_CL_CUSTOM_DEC_KEY.c_str());
                codecOut = nullptr;
                return false;
            }
 
 
            codecOut = avcodec_find_encoder_by_name(paramValue.c_str());
 
            if (!codecOut) {
                yCError(FFMPEGMONITOR, "Can't find encoder %s", paramValue.c_str());
                codecOut = nullptr;
                return false;
            }
 
            customEnc = true;
            continue;  //avoid to add this parameter to paramsMap
        }
        else if (paramKey == FFMPEGPORTMONITOR_CL_CUSTOM_DEC_KEY)
        {
            if (senderSide)
            {
                customDec = true;
                continue; //The custom decoder need to be set on the receiver side only. Later we check that the custom encoder has been set too.
            }
 
            if (standardCodec)
            {
                yCError(FFMPEGMONITOR, "Cannot set both %s and %s/%s together.",
                        FFMPEGPORTMONITOR_CL_CODEC_KEY.c_str(),
                        FFMPEGPORTMONITOR_CL_CUSTOM_ENC_KEY.c_str(),
                        FFMPEGPORTMONITOR_CL_CUSTOM_DEC_KEY.c_str());
                codecOut = nullptr;
                return false;
            }
 
            codecOut = avcodec_find_decoder_by_name(paramValue.c_str());
 
            if (!codecOut) {
                yCError(FFMPEGMONITOR, "Can't find decoder %s", paramValue.c_str());
                codecOut = nullptr;
                return false;
            }
 
            customDec = true;
            continue;  //avoid to add this parameter to paramsMap
        }
        else if (paramKey == FFMPEGPORTMONITOR_CL_PIXEL_FORMAT_KEY)
        {
            pixelFormatOut = static_cast<AVPixelFormat>(std::atoi(paramValue.c_str()));
            continue;  //avoid to add this parameter to paramsMap
        }
        else if (paramKey == FFMPEGPORTMONITOR_CL_FRAME_RATE_KEY)
        {
            frameRate = std::atoi(paramValue.c_str());
            continue;  //avoid to add this parameter to paramsMap
        }
        else if (paramKey == FFMPEGPORTMONITOR_CL_PRINT_STATISTICS_KEY)
        {
            printStatistics = std::atoi(paramValue.c_str());
            continue;  //avoid to add this parameter to paramsMap
        }
 
        // Save param into params map
        paramsMap.insert( std::pair<std::string, std::string>(paramKey, paramValue) );
    }
 
    if (!standardCodec && !customEnc && !customDec)
    {
        // Set default codec
        AVCodecID codecId = AV_CODEC_ID_MPEG2VIDEO;
        if (senderSide) {
            codecOut = avcodec_find_encoder(codecId);
        } else {
            codecOut = avcodec_find_decoder(codecId);
        }
 
        if (!codecOut) {
            yCError(FFMPEGMONITOR, "Can't find default codec (mpeg2video).");
            return false;
        }
    }
 
    if (customEnc && !customDec)
    {
        yCError(FFMPEGMONITOR, "A custom encoder has been specified, but not a custom decoder.");
        return false;
    }
 
    if (!customEnc && customDec)
    {
        yCError(FFMPEGMONITOR, "A custom decoder has been specified, but not a custom encoder.");
        return false;
    }
 
    return true;
 
}
 
int FfmpegMonitorObject::setCommandLineParams() {
 
    // Iterate over all saved parameters
    for (auto const& x : paramsMap) {
 
        // Get key and value
        std::string key = x.first;
        std::string value = x.second;
 
        // Try to set this pair (key, value) into codec context (global parameters).
        int globalError = av_opt_set(codecContext, key.c_str(), value.c_str(), 0);
        // Try to set this pair (key, value) into codec context -> priv data (parameters that are specific for a codec).
        int privError = av_opt_set(codecContext->priv_data, key.c_str(), value.c_str(), 0);
 
        // If the param exists, but the value is out of range
        if (globalError == AVERROR(ERANGE) || privError == AVERROR(ERANGE)) {
            yCError(FFMPEGMONITOR, "Parameter out of range: %s", key.c_str());
            return -1;
        }
        // If the param exists, but the value is invalid
        else if (globalError == AVERROR(EINVAL) || privError == AVERROR(EINVAL)) {
            yCError(FFMPEGMONITOR, "Invalid value for parameter: %s", key.c_str());
            return -1;
        }
        // If the param doesn't exists (we check only in sender side because some parameters doesn't exist in the decoders)
        else if (senderSide && globalError == AVERROR_OPTION_NOT_FOUND && privError == AVERROR_OPTION_NOT_FOUND) {
            yCError(FFMPEGMONITOR, "Parameter not found: %s", key.c_str());
            return -1;
        }
 
    }
    return 0;
}