dependencies installer

1 files changed, 755 insertions, 0 deletions

diff --git a/libavwrapper/libavwrapper.cpp b/libavwrapper/libavwrapper.cpp
new file mode 100755
index 0000000..5e1a50d
--- /dev/null
+++ b/libavwrapper/libavwrapper.cpp
@@ -0,0 +1,755 @@
+    #include "libavwrapper.h"
+
+
+extern "C"
+{
+#include <libswscale/swscale.h>
+}
+
+/*
+#include <QNetworkReply>
+#include <QNetworkRequest>
+#include <QEventLoop>
+#include <QFileInfo>
+#include <QMutexLocker>
+#include <QDebug>
+*/
+
+#include <stdexcept>
+#include <iostream>
+#include <cassert>
+
+using namespace std;
+
+// Translated to C++ by Christopher Bruns May 2012
+// from ffmeg_adapt.c in whisk package by Nathan Clack, Mark Bolstadt, Michael Meeuwisse
+
+//QMutex decoder::mutex;
+
+// Avoid link error on some macs
+#ifdef __APPLE__
+extern "C" {
+#include <stdlib.h>
+#include <errno.h>
+// #include "compiler/compiler.h"
+
+/*
+ * Darwin doesn't have posix_memalign(), provide a private
+ * weak alternative
+ */
+    /*
+int __weak posix_memalign(void **ptr, size_t align, size_t size)
+{
+       if (*ptr)
+               return 0;
+
+       return ENOMEM;
+}
+*/
+}
+#endif
+
+// Custom read function so FFMPEG does not need to read from a local file by name.
+// But rather from a stream derived from a URL or whatever.
+extern "C" {
+
+int readFunction(void* opaque, uint8_t* buf, int buf_size)
+{
+    //QIODevice* stream = (QIODevice*)opaque;
+    ifstream* stream = (ifstream*)opaque;
+    //int numBytes = 
+    stream->read((char*)buf, (streamsize)buf_size);
+    return stream->gcount();  //?? is this right
+    //numBytes; //TODO work out
+}
+
+// http://cdry.wordpress.com/2009/09/09/using-custom-io-callbacks-with-ffmpeg/
+int64_t seekFunction(void* opaque, int64_t offset, int whence)
+{
+    //QIODevice* stream = (QIODevice*)opaque;
+    ifstream* stream = (ifstream*)opaque;
+    if (stream == NULL)
+        return -1;
+    else if (whence == AVSEEK_SIZE)
+        return -1; // "size of my handle in bytes"
+    //else if (stream->isSequential())
+    //    return -1; // cannot seek a sequential stream //presume this would be certain kind of network stream
+    else if (whence == SEEK_CUR) { // relative to start of file
+        if (! stream->seekg(offset,ios_base::cur)) //stream->pos() + offset) )
+            return -1;
+    }
+    else if (whence == SEEK_END) { // relative to end of file
+        assert(offset < 0);
+        if (! stream->seekg(offset,ios_base::end)) //stream->size() + offset) )
+            return -1;
+    }
+    else if (whence == SEEK_SET) { // relative to start of file
+        if (! stream->seekg(offset) )
+            return -1;
+    }
+    else {
+        assert(false);
+    }
+    return stream->tellg();
+}
+
+}
+
+
+/////////////////////////////
+// AVPacketWrapper methods //
+/////////////////////////////
+
+
+class AVPacketWrapper
+{
+public:
+    AVPacketWrapper();
+    virtual ~AVPacketWrapper();
+    void free();
+
+    AVPacket packet;
+};
+
+
+AVPacketWrapper::AVPacketWrapper()
+{
+    packet.destruct = NULL;
+}
+
+/* virtual */
+AVPacketWrapper::~AVPacketWrapper()
+{
+    free();
+}
+
+void AVPacketWrapper::free()
+{
+    av_free_packet(&packet);
+}
+
+
+/////////////////////////
+// decoder methods //
+/////////////////////////
+
+libav::decoder::decoder(PixelFormat pixelFormat)
+    : isOpen(false)
+{
+    initialize();
+    format = pixelFormat;
+}
+
+/*
+decoder::decoder(QUrl url, PixelFormat pixelFormat)
+    : isOpen(false)
+{
+    //QMutexLocker lock(&decoder::mutex);
+    initialize();
+    format = pixelFormat;
+    isOpen = open(url, pixelFormat);
+}
+*/
+
+/* virtual */
+libav::decoder::~decoder()
+{
+    //QMutexLocker lock(&decoder::mutex);
+    if (NULL != Sctx) {
+        sws_freeContext(Sctx);
+        Sctx = NULL;
+    }
+    if (NULL != pRaw) {
+        av_free(pRaw);
+        pRaw = NULL;
+    }
+    if (NULL != pFrameRGB) {
+        av_free(pFrameRGB);
+        pFrameRGB = NULL;
+    }
+    if (NULL != pCtx) {
+        avcodec_close(pCtx);
+        pCtx = NULL;
+    }
+    if (NULL != container) {
+        avformat_close_input(&container);
+        container = NULL;
+    }
+    if (NULL != buffer) {
+        av_free(buffer);
+        buffer = NULL;
+    }
+    if (NULL != blank) {
+        av_free(blank);
+        blank = NULL;
+    }
+    /*
+    if (NULL != avioContext) {
+        av_free(avioContext);
+        avioContext = NULL;
+    }
+    */
+    //QNetworkreply
+    //if (reply != NULL) {
+     //   reply->deleteLater();
+     //   reply = NULL;
+    //} 
+    // Don't need to free pCodec?
+}
+/*
+bool decoder::open(QUrl url, enum PixelFormat formatParam)
+{
+    if (url.isEmpty())
+        return false;
+
+    // Is the movie source a local file?
+    if (url.host() == "localhost")
+        url.setHost("");
+    QString fileName = url.toLocalFile();
+    if ( (! fileName.isEmpty())
+        && (QFileInfo(fileName).exists()) )
+    {
+        // return open(fileName, formatParam); // for testing only
+
+        // Yes, the source is a local file
+        fileStream.setFileName(fileName);
+        // qDebug() << fileName;
+        if (! fileStream.open(QIODevice::ReadOnly))
+            return false;
+        return open(fileStream, fileName, formatParam);
+    }
+
+    // ...No, the source is not a local file
+    if (url.host() == "")
+        url.setHost("localhost");
+    fileName = url.path();
+
+    // http://stackoverflow.com/questions/9604633/reading-a-file-located-in-memory-with-libavformat
+    // Load from URL
+    QEventLoop loop; // for synchronous url fetch http://stackoverflow.com/questions/5486090/qnetworkreply-wait-for-finished
+    QObject::connect(&networkManager, SIGNAL(finished(QNetworkReply*)),
+            &loop, SLOT(quit()));
+    QNetworkRequest request = QNetworkRequest(url);
+    // qDebug() << "networkManager" << __FILE__ << __LINE__;
+    reply = networkManager.get(request);
+    loop.exec();
+    if (reply->error() != QNetworkReply::NoError) {
+        // qDebug() << reply->error();
+        reply->deleteLater();
+        reply = NULL;
+        return false;
+    }
+    QIODevice * stream = reply;
+    // Mpeg needs seekable device, so create in-memory buffer if necessary
+    if (stream->isSequential()) {
+        byteArray = stream->readAll();
+        fileBuffer.setBuffer(&byteArray);
+        fileBuffer.open(QIODevice::ReadOnly);
+        if (! fileBuffer.seek(0))
+            return false;
+        stream = &fileBuffer;
+        assert(! stream->isSequential());
+    }
+    bool result = open(*stream, fileName, formatParam);
+    return result;
+}
+
+bool decoder::open(QIODevice& fileStream, QString& fileName, enum PixelFormat formatParam)
+{
+    // http://stackoverflow.com/questions/9604633/reading-a-file-located-in-memory-with-libavformat
+    // I think AVIOContext is the trick used to redivert the input stream
+    ioBuffer = (unsigned char *)av_malloc(ioBufferSize + FF_INPUT_BUFFER_PADDING_SIZE); // can get av_free()ed by libav
+    avioContext = avio_alloc_context(ioBuffer, ioBufferSize, 0, (void*)(&fileStream), &readFunction, NULL, &seekFunction);
+    container = avformat_alloc_context();
+    container->pb = avioContext;
+
+    // Open file, check usability
+    std::string fileNameStd = fileName.toStdString();
+    if (!avtry( avformat_open_input(&container, fileNameStd.c_str(), NULL, NULL), fileNameStd ))
+        return false;
+    return openUsingInitializedContainer(formatParam);
+}
+*/
+// file name based method for historical continuity
+bool libav::decoder::open(char* fileName, enum PixelFormat formatParam){
+
+     if (!avtry( avformat_open_input(&container, fileName, NULL, NULL), string(fileName) ))
+        return false;
+    return openUsingInitializedContainer(formatParam);
+}
+bool libav::decoder::open(string& fileName, enum PixelFormat formatParam)
+{
+    // Open file, check usability
+
+    if (!avtry( avformat_open_input(&container, fileName.c_str(), NULL, NULL), fileName ))
+        return false;
+    return openUsingInitializedContainer(formatParam);
+}
+
+
+bool libav::decoder::openUsingInitializedContainer(enum PixelFormat formatParam)
+{
+    format = formatParam;
+    sc = getNumberOfChannels();
+
+    if (!avtry( avformat_find_stream_info(container, NULL), "Cannot find stream information." ))
+        return false;
+    if (!avtry( videoStream=av_find_best_stream(container, AVMEDIA_TYPE_VIDEO, -1, -1, &pCodec, 0), "Cannot find a video stream." ))
+        return false;
+    pCtx=container->streams[videoStream]->codec;
+    width  = pCtx->width;
+    height = pCtx->height;
+    if (!avtry( avcodec_open2(pCtx, pCodec, NULL), "Cannot open video decoder." ))
+        return false;
+
+    /* Frame rate fix for some codecs */
+    if( pCtx->time_base.num > 1000 && pCtx->time_base.den == 1 )
+        pCtx->time_base.den = 1000;
+
+    /* Compute the total number of frames in the file */
+    /* duration is in microsecs */
+    numFrames = (int)(( container->duration / (double)AV_TIME_BASE ) * pCtx->time_base.den + 0.5);
+
+    /* Get framebuffers */
+    if (! (pRaw = avcodec_alloc_frame()) )
+        throw std::runtime_error("");
+    if (! (pFrameRGB = avcodec_alloc_frame()) )
+        throw std::runtime_error("");
+
+    /* Create data buffer */
+    if (format == PIX_FMT_NONE) {
+        numBytes = 0;
+        buffer = NULL;
+        blank = NULL;
+        pFrameRGB = NULL;
+        Sctx = NULL;
+    }
+    else {
+        numBytes = avpicture_get_size( format, pCtx->width, pCtx->height ); // RGB24 format
+        if (! (buffer   = (uint8_t*)av_malloc(numBytes + FF_INPUT_BUFFER_PADDING_SIZE)) ) // RGB24 format
+            throw std::runtime_error("");
+        if (! (blank    = (uint8_t*)av_mallocz(avpicture_get_size(pCtx->pix_fmt,width,height))) ) // native codec format
+            throw std::runtime_error("");
+
+        /* Init buffers */
+        avpicture_fill( (AVPicture * ) pFrameRGB, buffer, format,
+                        pCtx->width, pCtx->height );
+
+        /* Init scale & convert */
+        if (! (Sctx=sws_getContext(
+                pCtx->width,
+                pCtx->height,
+                pCtx->pix_fmt,
+                width,
+                height,
+                format,
+                SWS_POINT, // fastest?
+                NULL,NULL,NULL)) )
+            throw std::runtime_error("");
+    }
+
+    /* Give some info on stderr about the file & stream */
+    //dump_format(container, 0, fname, 0);
+
+    previousFrameIndex = -1;
+    return true;
+}
+
+bool libav::decoder::fetchFrame(int targetFrameIndex)
+{
+    if ((targetFrameIndex < 0) || (targetFrameIndex > numFrames))
+        return false;
+    if (targetFrameIndex == (previousFrameIndex + 1)) {
+        if (! readNextFrame(targetFrameIndex))
+            return false;
+    }
+    else
+        if (seekToFrame(targetFrameIndex) < 0)
+            return false;
+    previousFrameIndex = targetFrameIndex;
+    return true;
+}
+
+// \returns current frame on success, otherwise -1
+int libav::decoder::seekToFrame(int targetFrameIndex)
+{
+    int64_t duration = container->streams[videoStream]->duration;
+    int64_t ts = av_rescale(duration,targetFrameIndex,numFrames);
+    int64_t tol = av_rescale(duration,1,2*numFrames);
+    if ( (targetFrameIndex < 0) || (targetFrameIndex >= numFrames) ) {
+        return -1;
+    }
+    int result = avformat_seek_file( container, //format context
+                            videoStream,//stream id
+                            0,               //min timestamp
+                            ts,              //target timestamp
+                            ts,              //max timestamp
+                            0); //AVSEEK_FLAG_ANY),//flags
+    if (result < 0)
+        return -1;
+
+    avcodec_flush_buffers(pCtx);
+    if (! readNextFrame(targetFrameIndex))
+        return -1;
+
+    return targetFrameIndex;
+}
+
+bool libav::decoder::readNextFrame(int targetFrameIndex)
+{
+    AVPacket packet = {0};
+    av_init_packet(&packet);
+    bool result = readNextFrameWithPacket(targetFrameIndex, packet, pRaw);
+    av_free_packet(&packet);
+    return result;
+}
+
+// WARNING this method can raise an exception
+bool libav::decoder::readNextFrameWithPacket(int targetFrameIndex, AVPacket& packet, AVFrame* pYuv)
+{
+    int finished = 0;
+    do {
+        finished = 0;
+        av_free_packet(&packet);
+        int result;
+        if (!avtry(av_read_frame( container, &packet ), "Failed to read frame"))
+            return false; // !!NOTE: see docs on packet.convergence_duration for proper seeking
+        if( packet.stream_index != videoStream ) /* Is it what we're trying to parse? */
+            continue;
+        if (!avtry(avcodec_decode_video2( pCtx, pYuv, &finished, &packet ), "Failed to decode video"))
+            return false;
+        // handle odd cases and debug
+        if((pCtx->codec_id==CODEC_ID_RAWVIDEO) && !finished)
+        {
+            avpicture_fill( (AVPicture * ) pYuv, blank, pCtx->pix_fmt,width, height ); // set to blank frame
+            finished = 1;
+        }
+#if 0 // very useful for debugging
+        cout << "Packet - pts:" << (int)packet.pts;
+        cout << " dts:" << (int)packet.dts;
+        cout << " - flag: " << packet.flags;
+        cout << " - finished: " << finished;
+        cout << " - Frame pts:" << (int)pYuv->pts;
+        cout << " " << (int)pYuv->best_effort_timestamp;
+        cout << endl;
+        /* printf("Packet - pts:%5d dts:%5d (%5d) - flag: %1d - finished: %3d - Frame pts:%5d %5d\n",
+               (int)packet.pts,(int)packet.dts,
+               packet.flags,finished,
+               (int)pYuv->pts,(int)pYuv->best_effort_timestamp); */
+#endif
+        if(!finished) {
+            if (packet.pts == AV_NOPTS_VALUE)
+                throw std::runtime_error("");
+            if (packet.size == 0) // packet.size==0 usually means EOF
+                break;
+        }
+    } while ( (!finished) || (pYuv->best_effort_timestamp < targetFrameIndex));
+
+    av_free_packet(&packet);
+
+    if (format != PIX_FMT_NONE) {
+        sws_scale(Sctx,              // sws context
+                  pYuv->data,        // src slice
+                  pYuv->linesize,    // src stride
+                  0,                      // src slice origin y
+                  pCtx->height,      // src slice height
+                  pFrameRGB->data,        // dst
+                  pFrameRGB->linesize );  // dst stride
+    }
+
+    previousFrameIndex = targetFrameIndex;
+    return true;
+}
+
+uint8_t libav::decoder::getPixelIntensity(int x, int y, Channel c) const
+{
+    return *(pFrameRGB->data[0] + y * pFrameRGB->linesize[0] + x * sc + c);
+}
+
+int libav::decoder::getNumberOfFrames() const { return numFrames; }
+
+int libav::decoder::getWidth() const { return width; }
+
+int libav::decoder::getHeight() const { return height; }
+
+int libav::decoder::getNumberOfChannels() const
+{
+    switch(format)
+    {
+    case PIX_FMT_BGRA:
+        return 4;
+        break;
+    case PIX_FMT_RGB24:
+        return 3;
+        break;
+    case PIX_FMT_GRAY8:
+        return 1;
+        break;
+    default:
+        return 0;
+        break;
+    }
+    return 0;
+}
+
+void libav::decoder::initialize()
+{
+    Sctx = NULL;
+    pRaw = NULL;
+    pFrameRGB = NULL;
+    pCtx = NULL;
+    container = NULL;
+    buffer = NULL;
+    blank = NULL;
+    pCodec = NULL;
+    format = PIX_FMT_NONE;
+    //network stuff
+    //reply = NULL;
+    //ioBuffer = NULL;
+    //avioContext = NULL;
+    decoder::maybeInitFFMpegLib();
+}
+
+void libav::decoder::maybeInitFFMpegLib()
+{
+    if (decoder::b_is_one_time_inited)
+        return;
+    av_register_all();
+    avcodec_register_all();
+    avformat_network_init();
+    decoder::b_is_one_time_inited = true;
+}
+
+bool libav::decoder::avtry(int result, const std::string& msg) {
+    if ((result < 0) && (result != AVERROR_EOF)) {
+        char buf[1024];
+        av_strerror(result, buf, sizeof(buf));
+        std::string message = std::string("libav::Error: ") + msg + buf;
+        //qDebug() << QString(message.c_str());
+        cerr<<message<<endl;
+        return false;
+    }
+    return true;
+}
+
+bool libav::decoder::b_is_one_time_inited = false;
+
+
+
+///////////////////////////
+// encoder methods //
+///////////////////////////
+
+
+libav::encoder::encoder(const char * file_name, int width, int height, enum AVCodecID codec_id)
+    : picture_yuv(NULL)
+    , picture_rgb(NULL)
+    , container(NULL)
+{
+    if (0 != (width % 2))
+        cerr << "WARNING: Video width is not a multiple of 2" << endl;
+    if (0 != (height % 2))
+        cerr << "WARNING: Video height is not a multiple of 2" << endl;
+
+    decoder::maybeInitFFMpegLib();
+
+    container = avformat_alloc_context();
+    if (NULL == container)
+        throw std::runtime_error("Unable to allocate format context");
+
+    AVOutputFormat * fmt = av_guess_format(NULL, file_name, NULL);
+    if (!fmt)
+        fmt = av_guess_format("mpeg", NULL, NULL);
+    if (!fmt)
+        throw std::runtime_error("Unable to deduce video format");
+    container->oformat = fmt;
+
+    fmt->video_codec = codec_id;
+    // fmt->video_codec = CODEC_ID_H264; // fails to write
+
+    AVStream * video_st = avformat_new_stream(container, NULL);
+
+    pCtx = video_st->codec;
+    pCtx->codec_id = fmt->video_codec;
+    pCtx->codec_type = AVMEDIA_TYPE_VIDEO;
+    // resolution must be a multiple of two
+    pCtx->width = width;
+    pCtx->height = height;
+
+    // bit_rate determines image quality
+    pCtx->bit_rate = width * height * 4; // ?
+    // pCtx->qmax = 50; // no effect?
+
+    // "high quality" parameters from http://www.cs.ait.ac.th/~on/mplayer/pl/menc-feat-enc-libavcodec.html
+    // vcodec=mpeg4:mbd=2:mv0:trell:v4mv:cbp:last_pred=3:predia=2:dia=2:vmax_b_frames=2:vb_strategy=1:precmp=2:cmp=2:subcmp=2:preme=2:vme=5:naq:qns=2
+    if (false) // does not help
+    // if (pCtx->codec_id == CODEC_ID_MPEG4)
+    {
+        pCtx->mb_decision = 2;
+        pCtx->last_predictor_count = 3;
+        pCtx->pre_dia_size = 2;
+        pCtx->dia_size = 2;
+        pCtx->max_b_frames = 2;
+        pCtx->b_frame_strategy = 2;
+        pCtx->trellis = 2;
+        pCtx->compression_level = 2;
+        pCtx->global_quality = 300;
+        pCtx->pre_me = 2;
+        pCtx->mv0_threshold = 1;
+        // pCtx->quantizer_noise_shaping = 2; // deprecated
+        // TODO
+    }
+
+    pCtx->time_base = (AVRational){1, 25};
+    // pCtx->time_base = (AVRational){1, 10};
+    pCtx->gop_size = 12; // emit one intra frame every twelve frames
+    // pCtx->max_b_frames = 0;
+    pCtx->pix_fmt = PIX_FMT_YUV420P;
+    if (fmt->flags & AVFMT_GLOBALHEADER)
+        pCtx->flags |= CODEC_FLAG_GLOBAL_HEADER;
+
+    if (pCtx->codec_id == CODEC_ID_H264)
+    {
+        // http://stackoverflow.com/questions/3553003/encoding-h-264-with-libavcodec-x264
+        pCtx->coder_type = 1;  // coder = 1
+        pCtx->flags|=CODEC_FLAG_LOOP_FILTER;   // flags=+loop
+        pCtx->me_cmp|= 1;  // cmp=+chroma, where CHROMA = 1
+        // pCtx->partitions|=X264_PART_I8X8+X264_PART_I4X4+X264_PART_P8X8+X264_PART_B8X8; // partitions=+parti8x8+parti4x4+partp8x8+partb8x8
+        pCtx->me_method=ME_HEX;    // me_method=hex
+        pCtx->me_subpel_quality = 7;   // subq=7
+        pCtx->me_range = 16;   // me_range=16
+        pCtx->gop_size = 250;  // g=250
+        pCtx->keyint_min = 25; // keyint_min=25
+        pCtx->scenechange_threshold = 40;  // sc_threshold=40
+        pCtx->i_quant_factor = 0.71; // i_qfactor=0.71
+        pCtx->b_frame_strategy = 1;  // b_strategy=1
+        pCtx->qcompress = 0.6; // qcomp=0.6
+        pCtx->qmin = 10;   // qmin=10
+        pCtx->qmax = 51;   // qmax=51
+        pCtx->max_qdiff = 4;   // qdiff=4
+        pCtx->max_b_frames = 3;    // bf=3
+        pCtx->refs = 3;    // refs=3
+        // pCtx->directpred = 1;  // directpred=1
+        pCtx->trellis = 1; // trellis=1
+        // pCtx->flags2|=CODEC_FLAG2_BPYRAMID+CODEC_FLAG2_MIXED_REFS+CODEC_FLAG2_WPRED+CODEC_FLAG2_8X8DCT+CODEC_FLAG2_FASTPSKIP;  // flags2=+bpyramid+mixed_refs+wpred+dct8x8+fastpskip
+        // pCtx->weighted_p_pred = 2; // wpredp=2
+        // libx264-main.ffpreset preset
+        // pCtx->flags2|=CODEC_FLAG2_8X8DCT;
+        // pCtx->flags2^=CODEC_FLAG2_8X8DCT;    // flags2=-dct8x8
+    }
+
+    AVCodec * codec = avcodec_find_encoder(pCtx->codec_id);
+    if (NULL == codec)
+        throw std::runtime_error("Unable to find Mpeg4 codec");
+    if (codec->pix_fmts)
+        pCtx->pix_fmt = codec->pix_fmts[0];
+    {
+        //QMutexLocker lock(&decoder::mutex);
+        if (avcodec_open2(pCtx, codec, NULL) < 0)
+            throw std::runtime_error("Error opening codec");
+    }
+
+    /* Get framebuffers */
+    if (! (picture_yuv = avcodec_alloc_frame()) ) // final frame format
+        throw std::runtime_error("");
+    if (! (picture_rgb = avcodec_alloc_frame()) ) // rgb version I can understand easily
+        throw std::runtime_error("");
+    /* the image can be allocated by any means and av_image_alloc() is
+         * just the most convenient way if av_malloc() is to be used */
+    if ( av_image_alloc(picture_yuv->data, picture_yuv->linesize,
+                       pCtx->width, pCtx->height, pCtx->pix_fmt, 1) < 0 )
+        throw std::runtime_error("Error allocating YUV frame buffer");
+    if ( av_image_alloc(picture_rgb->data, picture_rgb->linesize,
+                   pCtx->width, pCtx->height, PIX_FMT_RGB24, 1) < 0 )
+        throw std::runtime_error("Error allocating RGB frame buffer");
+
+    /* Init scale & convert */
+    if (! (Sctx=sws_getContext(
+            width,
+            height,
+            PIX_FMT_RGB24,
+            pCtx->width,
+            pCtx->height,
+            pCtx->pix_fmt,
+            SWS_BICUBIC,NULL,NULL,NULL)) )
+        throw std::runtime_error("");
+
+    /* open the output file */
+    if (!(fmt->flags & AVFMT_NOFILE))
+    {
+        //QMutexLocker lock(&decoder::mutex);
+        if (avio_open(&container->pb, file_name, AVIO_FLAG_WRITE) < 0)
+             throw std::runtime_error("Error opening output video file");
+    }
+    avformat_write_header(container, NULL);
+}
+
+void libav::encoder::setPixelIntensity(int x, int y, int c, uint8_t value)
+{
+    uint8_t * ptr = picture_rgb->data[0] + y * picture_rgb->linesize[0] + x * 3 + c;
+    *ptr = value;
+}
+
+void libav::encoder::write_frame()
+{
+    // convert from RGB24 to YUV
+    sws_scale(Sctx,              // sws context
+              picture_rgb->data,        // src slice
+              picture_rgb->linesize,    // src stride
+              0,                      // src slice origin y
+              pCtx->height,      // src slice height
+              picture_yuv->data,        // dst
+              picture_yuv->linesize );  // dst stride
+
+    /* encode the image */
+    // use non-deprecated avcodec_encode_video2(...)
+    AVPacket packet;
+    av_init_packet(&packet);
+    packet.data = NULL;
+    packet.size = 0;
+
+    int got_packet;
+    int ret = avcodec_encode_video2(pCtx,
+                                    &packet,
+                                    picture_yuv,
+                                    &got_packet);
+    if (ret < 0)
+        throw std::runtime_error("Video encoding failed");
+    if (got_packet)
+    {
+        // std::cout << "encoding frame" << std::endl;
+        int result = av_write_frame(container, &packet);
+        av_destruct_packet(&packet);
+    }
+}
+
+/* virtual */
+libav::encoder::~encoder()
+{
+    int result = av_write_frame(container, NULL); // flush
+    result = av_write_trailer(container);
+    {
+        //QMutexLocker lock(&decoder::mutex);
+        avio_close(container->pb);
+    }
+    for (int i = 0; i < container->nb_streams; ++i)
+        av_freep(container->streams[i]);
+    av_free(container);
+    container = NULL;
+
+    {
+        //QMutexLocker lock(&decoder::mutex);
+        avcodec_close(pCtx);
+    }
+    av_free(pCtx);
+    pCtx = NULL;
+    av_free(picture_yuv->data[0]);
+    av_free(picture_yuv);
+    picture_yuv = NULL;
+    av_free(picture_rgb->data[0]);
+    av_free(picture_rgb);
+    picture_rgb = NULL;
+}
+
+
+