ffmpeg::avcodec_encode_video setting PTS h264

Question

I\'m trying to encode video as H264 using libavcodec

ffmpeg::avcodec_encode_video(codec,output,size,avframe);

returns an error that I don\'t hav

Answer 1

I had this problem too. I sloved the problem in this way:

Before you invoke

ffmpeg::avcodec_encode_video(codec,output,size,avframe);

you set the pts value of avframe an integer value which has an initial value 0 and increments by one every time, just like this:

avframe->pts = nextPTS();

The implementation of nextPTS() is:

int nextPTS()
{
    static int static_pts = 0;
    return static_pts ++;
}

After giving the pts of avframe a value, then encoded it. If encoding successfully. Add the following code:

    if (packet.pts != AV_NOPTS_VALUE)
        packet.pts = av_rescale_q(packet.pts, mOutputCodecCtxPtr->time_base, mOutputStreamPtr->time_base);
    if (packet.dts != AV_NOPTS_VALUE)
         packet.dts = av_rescale_q(packet.dts, mOutputCodecCtxPtr->time_base, mOutputStreamPtr->time_base);

It'll add correct dts value for the encoded AVFrame. Among the code, packe of type AVPacket, mOutputCodeCtxPtr of type AVCodecContext* and mOutputStreamPtr of type AVStream.

avcodec_encode_video returns 0 indicates the current frame is buffered, you have to flush all buffered frames after all frames have been encoded. The code flushs all buffered frame somewhat like:

int ret;
while((ret = ffmpeg::avcodec_encode_video(codec,output,size,NULL)) >0)
    ;// place your code here.