#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);
}


//bool libav::b_is_one_time_inited = false;

/////////////////////////
// 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 {
        int64_t response=seekToFrame(targetFrameIndex);
        if (response < 0)
            return false;
        if (response!=targetFrameIndex){
            cerr<<"libav::decoder asked for "<<targetFrameIndex<<", got "<<response<<endl; //does not seem to be aware of wrong frame
        }
    }
    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 0?
                            ts,              //target timestamp
                            ts,              //max timestamp
                            0);//flags AVSEEK_FLAG_ANY //doesn't seem to work great
    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;
    maybeInitFFMpegLib();
}

void libav::maybeInitFFMpegLib()
{
    if (b_is_one_time_inited)
        return;
    av_register_all();
    avcodec_register_all();
    avformat_network_init();
    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;
}




///////////////////////////
// encoder methods //
///////////////////////////


libav::encoder::encoder(const char * file_name, int width, int height, float _framerate,enum AVCodecID codec_id)
    : picture_yuv(NULL)
    , picture_rgb(NULL)
    , container(NULL)
{
    //multiply float seconds by this to get pts
    timebase=((float)AV_TIME_BASE_Q.den)/(AV_TIME_BASE_Q.num*_framerate*3.125f); //no idea where the 3.125 comes from

    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;

    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}; /////TODO FIX TO SUPPORT OTHER RATES
    // 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("");

//
//
// added audio init
    AVCodec * acodec = avcodec_find_encoder(AV_CODEC_ID_AAC);
    int ret = avcodec_open2(pCtx, acodec, NULL);
    if (ret < 0) {
        throw std::runtime_error("Could not open audio codec:");
        
    }

    if (pCtx->codec->capabilities & CODEC_CAP_VARIABLE_FRAME_SIZE)
            audio_input_frame_size = 10000;
    else
        audio_input_frame_size = pCtx->frame_size; //is coming out at 0?

    audiostep=((float)audio_input_frame_size)/(pCtx->sample_rate);


// are we supposed to use the same codeccontext?
//

    /* 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(float seconds,uint8_t *rgbdata)
{
    picture_rgb->data[0]=rgbdata;

    // 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;

    //no time stamps as is
    //http://dranger.com/ffmpeg/tutorial07.html

    picture_yuv->pts=(uint64_t)(seconds*timebase);

    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);
    }
}
void libav::encoder::write_frame(float seconds,uint16_t *audiodata){
    audio_frame = avcodec_alloc_frame();
    AVPacket pkt = { 0 }; // data and size must be 0;
    int got_packet, ret;
    av_init_packet(&pkt);
    audio_frame->nb_samples = audio_input_frame_size;
    uint8_t *sampleptr;
    int bufsize=audio_input_frame_size * av_get_bytes_per_sample(pCtx->sample_fmt) *pCtx->channels;
    if (audiodata) {
        sampleptr=(uint8_t*)audiodata;
    }
    else {
        sampleptr=new uint8_t[bufsize];
        memset(sampleptr,0,bufsize);
    }

     avcodec_fill_audio_frame(audio_frame, pCtx->channels, pCtx->sample_fmt,
                                 sampleptr,
                                 audio_input_frame_size *
                                 av_get_bytes_per_sample(pCtx->sample_fmt) *
                                 pCtx->channels, 0); //;

     audio_frame->pts=(uint64_t)(seconds*timebase);

     ret = avcodec_encode_audio2(pCtx, &pkt, audio_frame, &got_packet);
     if (!audiodata) {
        delete[] sampleptr;
    }
    if (ret < 0) {
        throw std::runtime_error("Audio encoding failed");
    }

    if (!got_packet)
            return;

    // ? pkt.stream_index = st->index; 

    ret = av_interleaved_write_frame(container, &pkt);
    avcodec_free_frame(&audio_frame);
}

/* 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;
}

bool libav::exporter::setup(int w,int h, int bitRate, int frameRate, std::string container){

    maybeInitFFMpegLib();

    this->w=w;
    this->h=h;
    this->bitRate=bitRate;
    this->frameRate=frameRate;
    this->container=container;

    return true;
}

bool libav::exporter::record(std::string filename){

    // allocate the output media context //
    avformat_alloc_output_context2(&oc, NULL, NULL, filename.c_str());
    if (!oc) {
        printf("Could not deduce output format from file extension: using MPEG.\n");
        avformat_alloc_output_context2(&oc, NULL, "mpeg", filename.c_str());
    }
    if (!oc) {
        return false;
    }
    fmt = oc->oformat;

    // Add the audio and video streams using the default format codecs
    // * and initialize the codecs. //
    video_st = NULL;
    audio_st = NULL;

    if (fmt->video_codec != AV_CODEC_ID_NONE) {
        video_st = add_stream(oc, &video_codec, fmt->video_codec);
    }
    if (fmt->audio_codec != AV_CODEC_ID_NONE) {
        audio_st = add_stream(oc, &audio_codec, fmt->audio_codec);
    }

    //set initial video params
    video_st->codec->width=w;
    video_st->codec->height=h;
    video_st->codec->time_base.num = 1;//codecCtx->ticks_per_frame;
    video_st->codec->time_base.den = frameRate;
    video_st->time_base = video_st->codec->time_base;
        //audioStream->time_base = codecCtx->time_base; //???has the capability of crashing

    video_st->codec->gop_size = 10; /* emit one intra frame every ten frames */
    video_st->codec->pix_fmt = PIX_FMT_YUV420P;

    // Now that all the parameters are set, we can open the audio and
    // * video codecs and allocate the necessary encode buffers. //
    if (video_st)
        open_video(oc, video_codec, video_st);
    if (audio_st) {
        audioframesize=open_audio(oc, audio_codec, audio_st);
        audiostep=((float)audioframesize)/(audio_st->codec->sample_rate);
        std::cerr << "opened audio codec with "<<audioframesize<<" frame size and "<<audiostep<<" seconds per frame"<<std::endl;
    }


    av_dump_format(oc, 0, filename.c_str(), 1);

    // open the output file, if needed //
    if (!(fmt->flags & AVFMT_NOFILE)) {
        int ret = avio_open(&oc->pb, filename.c_str(), AVIO_FLAG_WRITE);
        if (ret < 0) {
            std::cerr <<"Could not open " << filename.c_str() << std::endl;
            return false;
        }
    }

    // Write the stream header, if any. //
    int ret = avformat_write_header(oc, NULL);
    if (ret < 0) {
        //std::cerr <<"Error occurred when opening output file:" << av_err2str(ret) << std::endl;
        return false;
    }

    if (frame)
        frame->pts = 0;

    outputframe=0;

    return true;
}
bool libav::exporter::encodeFrame(unsigned char *pixels,uint16_t *samples){
    // Compute current audio and video time. //
    if (audio_st)
        audio_pts = (double)audio_st->pts.val * audio_st->time_base.num / audio_st->time_base.den;
    else
        audio_pts = 0.0;

    if (video_st)
        video_pts = (double)video_st->pts.val * video_st->time_base.num /
                    video_st->time_base.den;
    else
        video_pts = 0.0;

    // write interleaved audio and video frames //
    if (!video_st || (video_st && audio_st && audio_pts < video_pts)) {
        write_audio_frame(oc, audio_st, samples);
    } else {
        write_video_frame(oc, video_st, pixels);

        frame->pts += av_rescale_q(1, video_st->codec->time_base, video_st->time_base);
    }

    //std::cerr << "encoded frame " << outputframe << std::endl;
    outputframe++;

    return true;
}
bool libav::exporter::encodeFrame(unsigned char *pixels,AVPacket *audio){
    // Compute current audio and video time. //
    if (audio_st)
        audio_pts = (double)audio_st->pts.val * audio_st->time_base.num / audio_st->time_base.den;
    else
        audio_pts = 0.0;

    if (video_st)
        video_pts = (double)video_st->pts.val * video_st->time_base.num /
                    video_st->time_base.den;
    else
        video_pts = 0.0;

    // write interleaved audio and video frames //
    if (!video_st || (video_st && audio_st && audio_pts < video_pts)) {
        write_audio_frame(oc, audio_st, audio);
    } else {
        write_video_frame(oc, video_st, pixels);

        frame->pts += av_rescale_q(1, video_st->codec->time_base, video_st->time_base);
    }

    //std::cerr << "encoded frame " << outputframe << std::endl;
    outputframe++;

    return true;
}
bool libav::exporter::encodeFrame(unsigned char *pixels){
    video_pts = (double)video_st->pts.val * video_st->time_base.num / video_st->time_base.den;
    write_video_frame(oc, video_st, pixels);
    frame->pts += av_rescale_q(1, video_st->codec->time_base, video_st->time_base);
    outputframe++;
    return true;
}
bool libav::exporter::encodeFrame(uint16_t *samples){
    audio_pts = (double)audio_st->pts.val * audio_st->time_base.num / audio_st->time_base.den;
    write_audio_frame(oc, audio_st, samples);
    return true;
}
void libav::exporter::finishRecord(){

    av_write_trailer(oc);
    // Close each codec. //
    if (video_st)
        close_video(oc, video_st);
    if (audio_st)
        close_audio(oc, audio_st);

    if (!(fmt->flags & AVFMT_NOFILE))
        // Close the output file. //
        avio_close(oc->pb);

    // free the stream //
    avformat_free_context(oc);
}

AVStream* libav::exporter::add_stream(AVFormatContext *oc, AVCodec **codec,enum AVCodecID codec_id)
    {
        AVCodecContext *c;
        AVStream *st;

        // find the encoder //
        *codec = avcodec_find_encoder(codec_id);
        if (!(*codec)) {
            //fprintf(stderr, "Could not find encoder for '%s'\n",
            //        avcodec_get_name(codec_id));
            exit(1);
        }

        st = avformat_new_stream(oc, *codec);
        if (!st) {
            //fprintf(stderr, "Could not allocate stream\n");
            exit(1);
        }
        st->id = oc->nb_streams-1;
        c = st->codec;

        switch ((*codec)->type) {
        case AVMEDIA_TYPE_AUDIO:
            st->id = 1;
            c->sample_fmt  = AV_SAMPLE_FMT_S16;
            c->bit_rate    = 64000;
            c->sample_rate = 44100;
            c->channels    = 2;
            c->channel_layout=AV_CH_LAYOUT_STEREO;
            break;

        case AVMEDIA_TYPE_VIDEO:
            c->codec_id = codec_id;

            c->bit_rate = 400000;
            // Resolution must be a multiple of two. //
            c->width    = 352;
            c->height   = 288;
            // timebase: This is the fundamental unit of time (in seconds) in terms
            // * of which frame timestamps are represented. For fixed-fps content,
            // * timebase should be 1/framerate and timestamp increments should be
            // * identical to 1. //
            c->time_base.den = frameRate;
            c->time_base.num = 1;
            c->gop_size      = 12; // emit one intra frame every twelve frames at most //
            c->pix_fmt       = AV_PIX_FMT_YUV420P; //ADDED HARDCODED TJR 280513
            if (c->codec_id == AV_CODEC_ID_MPEG2VIDEO) {
                // just for testing, we also add B frames //
                c->max_b_frames = 2;
            }
            if (c->codec_id == AV_CODEC_ID_MPEG1VIDEO) {
                // Needed to avoid using macroblocks in which some coeffs overflow.
                // * This does not happen with normal video, it just happens here as
                // * the motion of the chroma plane does not match the luma plane. //
                c->mb_decision = 2;
            }
        break;

        default:
            break;
        }

        // Some formats want stream headers to be separate. //
        if (oc->oformat->flags & AVFMT_GLOBALHEADER)
            c->flags |= CODEC_FLAG_GLOBAL_HEADER;

        return st;
    }

void libav::exporter::open_video(AVFormatContext *oc, AVCodec *codec, AVStream *st)
    {
        int ret;
        AVCodecContext *c = st->codec;

        // open the codec //
        ret = avcodec_open2(c, codec, NULL);
        if (ret < 0) {
            //fprintf(stderr, "Could not open video codec: %s\n", av_err2str(ret));
            exit(1);
        }

        // allocate and init a re-usable frame //
        frame = avcodec_alloc_frame();
        if (!frame) {
            //fprintf(stderr, "Could not allocate video frame\n");
            exit(1);
        }

        // Allocate the encoded raw picture. //
        ret = avpicture_alloc(&dst_picture, c->pix_fmt, c->width, c->height);
        if (ret < 0) {
            //fprintf(stderr, "Could not allocate picture: %s\n", av_err2str(ret));
            exit(1);
        }

        // If the output format is not YUV420P, then a temporary YUV420P
        // * picture is needed too. It is then converted to the required
        // * output format. //
        if (c->pix_fmt != AV_PIX_FMT_YUV420P) {
            ret = avpicture_alloc(&src_picture, AV_PIX_FMT_RGB24, c->width, c->height);
            if (ret < 0) {
                //fprintf(stderr, "Could not allocate temporary picture: %s\n",
                //        av_err2str(ret));
                exit(1);
            }
        }

        // copy data and linesize picture pointers to frame //
        *((AVPicture *)frame) = dst_picture;

        outPixels = (uint8_t*)av_malloc(avpicture_get_size(PIX_FMT_YUV420P, st->codec->width,st->codec->height));
    }

    int libav::exporter::open_audio(AVFormatContext *oc, AVCodec *codec, AVStream *st)
    {
        AVCodecContext *c;
        int ret;

        c = st->codec;

        // open it //
        ret = avcodec_open2(c, codec, NULL);
        if (ret < 0) {
            //fprintf(stderr, "Could not open audio codec: %s\n", av_err2str(ret));
            exit(1);
        }

        // init signal generator //
        t     = 0;
        tincr = 2 * M_PI * 110.0 / c->sample_rate;
        // increment frequency by 110 Hz per second //
        tincr2 = 2 * M_PI * 110.0 / c->sample_rate / c->sample_rate;

        if (c->codec->capabilities & CODEC_CAP_VARIABLE_FRAME_SIZE)
            audio_input_frame_size = 10000;
        else
            audio_input_frame_size = c->frame_size;

        /*
        samples = av_malloc(audio_input_frame_size *
                            av_get_bytes_per_sample(c->sample_fmt) *
                            c->channels);
        if (!samples) {
            //fprintf(stderr, "Could not allocate audio samples buffer\n");
            exit(1);
        }
        */
        return audio_input_frame_size;
    }

    void libav::exporter::write_audio_frame(AVFormatContext *oc, AVStream *st,uint16_t *samples)
    {
        AVCodecContext *c;
        AVPacket pkt = { 0 }; // data and size must be 0;
        AVFrame *frame = avcodec_alloc_frame();
        int got_packet, ret;

        av_init_packet(&pkt);
        c = st->codec;

        //get_audio_frame(samples, audio_input_frame_size, c->channels);
        frame->nb_samples = audio_input_frame_size;
        uint8_t *sampleptr;
        int bufsize=audio_input_frame_size * av_get_bytes_per_sample(c->sample_fmt) *c->channels;
        if (samples) {
            sampleptr=(uint8_t*)samples;
        }
        else {
            sampleptr=new uint8_t[bufsize];
            memset(sampleptr,0,bufsize);
        }
        
        avcodec_fill_audio_frame(frame, c->channels, c->sample_fmt,
                                 sampleptr,
                                 audio_input_frame_size *
                                 av_get_bytes_per_sample(c->sample_fmt) *
                                 c->channels, 0); //;
        //frame->sample_rate=44100; //hard coded input rate- nope, this doesn't help
        //frame->format=AV_SAMPLE_FMT_S16P;
        //?? why is ffmpeg reporting fltp as the sample format??? doesn't seem to have an effect to change this though
        ret = avcodec_encode_audio2(c, &pkt, frame, &got_packet);
        if (!samples) {
            delete[] sampleptr;
        }
        if (ret < 0) {
            //fprintf(stderr, "Error encoding audio frame: %s\n", av_err2str(ret));
            exit(1);
        }

        if (!got_packet)
            return;

        pkt.stream_index = st->index;

        // Write the compressed frame to the media file. //
        ret = av_interleaved_write_frame(oc, &pkt);
        if (ret != 0) {
            //fprintf(stderr, "Error while writing audio frame: %s\n",
            //        av_err2str(ret));
            exit(1);
        }
        avcodec_free_frame(&frame);
    }

    void libav::exporter::write_audio_frame(AVFormatContext *oc, AVStream *st,AVPacket *pkt)
    {
        /*
        AVCodecContext *c;
        AVPacket pkt = { 0 }; // data and size must be 0;
        AVFrame *frame = avcodec_alloc_frame();
        int got_packet, ret;

        av_init_packet(&pkt);
        c = st->codec;

        //get_audio_frame(samples, audio_input_frame_size, c->channels);
        frame->nb_samples = audio_input_frame_size;
        uint8_t *sampleptr;
        int bufsize=audio_input_frame_size * av_get_bytes_per_sample(c->sample_fmt) *c->channels;
        if (samples) {
            sampleptr=(uint8_t*)samples;
        }
        else {
            sampleptr=new uint8_t[bufsize];
            memset(sampleptr,0,bufsize);
        }
        avcodec_fill_audio_frame(frame, c->channels, c->sample_fmt,
                                 sampleptr,
                                 audio_input_frame_size *
                                 av_get_bytes_per_sample(c->sample_fmt) *
                                 c->channels, 1);

        ret = avcodec_encode_audio2(c, &pkt, frame, &got_packet);
        if (!samples) {
            free(sampleptr);
        }
        if (ret < 0) {
            //fprintf(stderr, "Error encoding audio frame: %s\n", av_err2str(ret));
            exit(1);
        }

        if (!got_packet)
            return;
            */

        pkt->stream_index = st->index;

        // Write the compressed frame to the media file. //
        int ret = av_interleaved_write_frame(oc, pkt);
        if (ret != 0) {
            //fprintf(stderr, "Error while writing audio frame: %s\n",
            //        av_err2str(ret));
            exit(1);
        }
        //avcodec_free_frame(&frame);
        av_free_packet(pkt);
    }

    void libav::exporter::close_audio(AVFormatContext *oc, AVStream *st)
    {
        avcodec_close(st->codec);


    }

    void libav::exporter::write_video_frame(AVFormatContext *oc, AVStream *st, uint8_t *pixels)
    {
        int ret;
        static struct SwsContext *sws_ctx;
        AVCodecContext *c = st->codec;

/*
        if (frame_count >= STREAM_NB_FRAMES) {
            // No more frames to compress. The codec has a latency of a few
            // * frames if using B-frames, so we get the last frames by
            // * passing the same picture again. //
        } else {
            if (c->pix_fmt != AV_PIX_FMT_YUV420P) {
                // as we only generate a YUV420P picture, we must convert it
                // * to the codec pixel format if needed //
                if (!sws_ctx) {
                    sws_ctx = sws_getContext(c->width, c->height, AV_PIX_FMT_YUV420P,
                                             c->width, c->height, c->pix_fmt,
                                             sws_flags, NULL, NULL, NULL);
                    if (!sws_ctx) {
                        //fprintf(stderr,
                        //        "Could not initialize the conversion context\n");
                        exit(1);
                    }
                }
                fill_yuv_image(&src_picture, frame_count, c->width, c->height);
                sws_scale(sws_ctx,
                          (const uint8_t * const *)src_picture.data, src_picture.linesize,
                          0, c->height, dst_picture.data, dst_picture.linesize);
            } else {
                fill_yuv_image(&dst_picture, frame_count, c->width, c->height);
            }
        }
*/
        //always convert RGB to YUV
        //should be context allocated once per render instead of per frame??
        //
        //
        sws_ctx = sws_getContext(c->width, c->height, AV_PIX_FMT_RGB24,
                                             c->width, c->height, AV_PIX_FMT_YUV420P,
                                             sws_flags, NULL, NULL, NULL);

        avpicture_fill(&src_picture, pixels, PIX_FMT_RGB24, c->width,c->height);
        //avpicture_fill(&dst_picture, outPixels, PIX_FMT_YUV420P, c->width,c->height);

        sws_scale(sws_ctx, src_picture.data, src_picture.linesize, 0, c->height, dst_picture.data, dst_picture.linesize);
        //fill_yuv_image(&dst_picture, frame_count, c->width, c->height);
        if (oc->oformat->flags & AVFMT_RAWPICTURE) {
            // Raw video case - directly store the picture in the packet //
            AVPacket pkt;
            av_init_packet(&pkt);

            pkt.flags        |= AV_PKT_FLAG_KEY;
            pkt.stream_index  = st->index;
            pkt.data          = dst_picture.data[0];
            pkt.size          = sizeof(AVPicture);

            ret = av_interleaved_write_frame(oc, &pkt);
        } else {
            AVPacket pkt = { 0 };
            int got_packet;
            av_init_packet(&pkt);

            // encode the image //
            ret = avcodec_encode_video2(c, &pkt, frame, &got_packet);
            if (ret < 0) {
                //fprintf(stderr, "Error encoding video frame: %s\n", av_err2str(ret));
                exit(1);
            }
            // If size is zero, it means the image was buffered. //

            if (!ret && got_packet && pkt.size) {
                pkt.stream_index = st->index;

                // Write the compressed frame to the media file. //
                ret = av_interleaved_write_frame(oc, &pkt);
            } else {
                ret = 0;
            }
        }

        //
        //  added 22 may in memory leak run
        //
        sws_freeContext(sws_ctx); //should be done once per render instead of per frame??

        if (ret != 0) {
            //fprintf(stderr, "Error while writing video frame: %s\n", av_err2str(ret));
            exit(1);
        }
        frame_count++;

        //avcodec_free_frame(&frame);
    }

    void libav::exporter::close_video(AVFormatContext *oc, AVStream *st)
    {
        avcodec_close(st->codec);
        av_free(src_picture.data[0]);
        av_free(dst_picture.data[0]);
        av_free(frame);
        av_free(outPixels); //SIGSEV here???
    }