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• Covert opengl framebuffer into ffmpeg encoded mp4 c++ [closed]

  14 mai 2022, par user19068953

  I want to make a program that takes an mp4 file as an input and draws something on top of it then gives the new video as an output. So far I have a program that takes a file name, have ffmpeg decode it and draw whatever i want with opengl (I have followed this tutorial that draws on top of the video separately : https://gist.github.com/hradec/a8b8ae0bf82891a5d853b06619839d9d) and have an opengl framebuffer. My question is how do put opengl's framebuffer on top of ffmpeg frames and generate a new video with it then give a new file as an output ? The framebuffer is allocated in fbo, so i want to encode it to ffmpeg, something like

  


   av_write_frame(state->fmt_ctx, &fbo) 


  


  is there a function like this that allows me to write frame data into a newly created video ?

  


  Here is my encoder :

  


      int VideoDecoder::write_frame()
{
    // Find a way to write OpenGL Frames here.
    av_packet_rescale_ts(&state->packet, VideoSt.Ctx->time_base, VideoSt.Stream->time_base);
    state->packet.stream_index = VideoSt.Stream->index;
    return av_interleaved_write_frame(state->fmt_ctx, &state->packet);
}


bool VideoDecoder::encode_video()
{

    // TODO: This is horrible fix this function.

    state->packet = { nullptr };
    av_init_packet(&state->packet);

    fflush(stdout);

    IMG_Buffer.SetNum(ColorBuffer.Num() * 4);
    uint8* DestPtr = nullptr;
    for (auto i = 0; i < ColorBuffer.Num(); i++)
    {
        DestPtr = &IMG_Buffer[i * 4];
        auto SrcPtr = ColorBuffer[i];
        *DestPtr++ = SrcPtr.R;
        *DestPtr++ = SrcPtr.G;
        *DestPtr++ = SrcPtr.B;
        *DestPtr++ = SrcPtr.A;
    }

    uint8* inData[1] = { IMG_Buffer.GetData() };


    sws_scale(SwsCtx, inData, InLineSize, 0, VideoSt.Ctx->height, VideoSt.Frame->data, VideoSt.Frame->linesize);

    VideoSt.Frame->pts = VideoSt.NextPts++;
    if (FFmpegEncode(VideoSt.Frame) < 0)
        return false;

    auto ret = WriteFrame();

    if (ret < 0)
    {
        auto errstr = FString(av_err2str(ret));
    }
    av_packet_unref(&state->packet);


    GotOutput = 0;
    auto ret = avcodec_send_frame(VideoSt.Ctx, frame);
    if (ret < 0 && ret != AVERROR_EOF) {
        auto errstr = FString(av_err2str(ret));
        return -1;
    }

    ret = avcodec_receive_packet(VideoSt.Ctx, &Pkt);
    if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF)
        return 0;

    if (ret < 0)
    {
        auto errstr = FString(av_make_error_string(ret).c_str());
        av_packet_unref(&Pkt);
        return -1;
    }

    GotOutput = 1;
    return 0;


    for (GotOutput = 1; GotOutput; count++)
    {
        fflush(stdout);

        FFmpegEncode(nullptr);

        if (GotOutput)
        {
            auto ret = WriteFrame(false);
            if (ret < 0)
            {
                auto errstr = FString(av_err2str(ret));
            }
            av_packet_unref(&Pkt);
        }
    }

    auto ret = av_write_trailer(FmtCtx);
    if (ret < 0)
    {
        auto errstr = FString(av_err2str(ret));
    }
}


  


  and here is my simple frame buffer :

  


  bool OpenGLRenderer::alloc_frame_buffer()
{
    unsigned int fbo;
    glGenFramebuffers(1, &fbo);

    if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE) return false;

    glBindFramebuffer(GL_FRAMEBUFFER, fbo);

    unsigned int texture;
    glGenTextures(1, &texture);
    glBindTexture(GL_TEXTURE_2D, texture);

    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, 800, 600, 0, GL_RGB, GL_UNSIGNED_BYTE, NULL);

    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);

    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, texture, 0);
}


  


• Pack H264 frames into MPEG2-TS

  13 décembre 2016, par Diz

  I have a live stream distributing raw H264 frames. The frames are encoded with x264. I am able to play the stream with ffplay, so it is working fine. Now I’d like to retransmit (or at least save locally in a MPEG2-TS file) this stream in a MPEG2-TS format using C/C++ code.

  What is the best way to achieve that ? I tried to investigate FFMPEG library and it looks like a complete hell for me. I also tried the code from this answer. I am able to write AVI file with that code, but if I replace "avi" with "mpeg" in the source code, the resulting video file cannot be played with a video player (VLC, mplayer) saying "MPEG : FATAL : EOF while searching for sequence header.".

  Question : What library or a sample code can you suggest me for this task ? Thanks in advance.

  Using LUbuntu 16.04.

• MBP Retina Isight and FFmpeg

  28 mars 2014, par Manuhoz

  I try to reach the video stream from my brand new MacBook Pro Retina (Mavericks) to use it as an input in ffmpeg (and stream it again via RTMP).

  I've tried different solutions in other stack overflow's topics but none seems to work :

  wacaw -L doesn't list any device

  Quicktime Broadcaster doesn't display any video (Audio only)

  but the Isight does work in Photo Booth.

  Any ideas ? Anyone working on the subject ?

  Thanks