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• FFmpeg : Encoder did not produce proper pts, making some up

  22 novembre 2022, par Chroluma

  I'm trying to convert a yuv image to jpg format via FFmpeg. But I occured [image2 @ 0x38750] Encoder did not produce proper pts, making some up. while the program was encoding. I looked up some references that someone said avcodec_send_frame can only be used when the frames is more than one. Can I use this way to achieve image conversion ? Here is my code :

  


  int ff_yuv422P_to_jpeg(int imgWidth, int imgHeight, uint8_t* yuvData, int yuvLength)
{
    /* ===== define ===== */
    const char* OutputFileName = "img.jpg";
    int retval = 0;

    /* ===== context ===== */
    struct AVFormatContext* pFormatCtx = avformat_alloc_context();
    avformat_alloc_output_context2(&pFormatCtx, NULL, NULL, OutputFileName);
    struct AVOutputFormat* fmt = pFormatCtx->oformat;

    struct AVStream* video_st = avformat_new_stream(pFormatCtx, 0);
    if (!video_st)
    {
        retval = 1;
        perror("ff_yuv422_to_jpeg(): avformat_new_stream");
        goto out_close_ctx;
    }

    /* ===== codec ===== */
    struct AVCodecContext* pCodecCtx = avcodec_alloc_context3(NULL);
    if (avcodec_parameters_to_context(pCodecCtx, video_st->codecpar) < 0)
    {
        retval = 2;
        perror("ff_yuv422_to_jpeg(): avcodec_parameters_to_context");
        goto out_close_ctx;
    }

    pCodecCtx->codec_id = fmt->video_codec;
    pCodecCtx->codec_type = AVMEDIA_TYPE_VIDEO;
    pCodecCtx->pix_fmt = AV_PIX_FMT_YUVJ422P;
    pCodecCtx->width = imgWidth;
    pCodecCtx->height = imgHeight;
    pCodecCtx->time_base.num = 1;
    pCodecCtx->time_base.den = 25;

    //dump info
    av_dump_format(pFormatCtx, 0, OutputFileName, 1);

    struct AVCodec *pCodec = avcodec_find_encoder(pCodecCtx->codec_id);
    if (!pCodec)
    {
        retval = 3;
        perror("ff_yuv422_to_jpeg(): avcodec_find_encoder");
        goto out_close_st;
    }

    if (avcodec_open2(pCodecCtx, pCodec, NULL) < 0)
    {
        retval = 4;
        perror("ff_yuv422_to_jpeg(): avcodec_open2");
        goto out_close_st;
    }

    /* ===== frame ===== */
    struct AVFrame* pictureFrame = av_frame_alloc();
    pictureFrame->width = pCodecCtx->width;
    pictureFrame->height = pCodecCtx->height;
    pictureFrame->format = AV_PIX_FMT_YUVJ422P;

    int picSize = av_image_get_buffer_size(AV_PIX_FMT_YUVJ422P, pCodecCtx->width, pCodecCtx->height, 1);
    uint8_t* pictureBuffer = (uint8_t*)av_malloc(picSize);
    av_image_fill_arrays(pictureFrame->data, pictureFrame->linesize, pictureBuffer, AV_PIX_FMT_YUVJ422P, pCodecCtx->width, pCodecCtx->height, 1);

    /* ===== write header ===== */
    int notUseRetVal = avformat_write_header(pFormatCtx, NULL);
    
    struct AVPacket* pkt = av_packet_alloc();
    av_new_packet(pkt, imgHeight * imgWidth * 3);
    pictureFrame->data[0] = pictureBuffer + 0 * (yuvLength / 4);
    pictureFrame->data[1] = pictureBuffer + 2 * (yuvLength / 4);
    pictureFrame->data[2] = pictureBuffer + 3 * (yuvLength / 4);

    /* ===== encode ===== */
    int ret = avcodec_send_frame(pCodecCtx, pictureFrame);
    while (ret >= 0)
    {
        pkt->stream_index = video_st->index;
        ret = avcodec_receive_packet(pCodecCtx, pkt);
        if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF)
        {
            retval = 5;
            perror("ff_yuv422_to_jpeg(): avcodec_receive_packet");
            goto out_close_picture;
        }
        else if (ret < 0)
        {
            retval = 6;
            perror("ff_yuv422_to_jpeg(): avcodec_receive_packet ret < 0");
            goto out_close_picture;
        }
        av_write_frame(pFormatCtx, pkt);
    }
    av_packet_unref(pkt);

    /* ===== write trailer ===== */
    av_write_trailer(pFormatCtx);

#if Print_Debug_Info
    printf("yuv2jpg Encode Success.\n");
#endif

out_close_picture:
    if (pictureFrame) av_free(pictureFrame);
    if (pictureBuffer) av_free(pictureBuffer);

out_close_st:
    // old school
    // if (video_st) avcodec_close(video_st->codec);

out_close_ctx:
    if (pFormatCtx) avformat_free_context(pFormatCtx);

out_return:
    return retval;
}


  


  and my log :

  


  Output #0, image2, to 'img.jpg':
    Stream #0:0: Unknown: none
[image2 @ 0x38750] Encoder did not produce proper pts, making some up.
ff_yuv422_to_jpeg(): avcodec_receive_packet: Success


  


  I looked up the avcodec_receive_packet()'s reference, and my code return error code AVERROR(EAGAIN).

  


• Using ffmpeg to interpolate images without making video

  28 août 2020, par interwebjill

  The following ffmpeg command works well to interpolate my set of images :

  


  ffmpeg -r <fps> -i <input /> -filter:v minterpolate=fps=:scd=none:mi_mode=blend -pix_fmt yuvj420p <output>&#xA;</output></fps>

  


  however, instead of outputting a video, I would like to instead output a directory of image files which include the original images plus the interpolated images. Is this possible with ffmpeg and if so, what are the commands ?

  


  I could not find a solution in the ffmpeg documentation or on the wiki.

  


• Powershell : Start-Job a script, cannot connect to youtube

  16 mai 2016, par Kostas Georgokitsos

  I am a bit new to PS, so please bear with me. I have written a script that starts an ffmpeg proccess, and in an endless loop waits for the process, and restarts it as ffmpeg is a bit shaky. ffmpeg is taking an rtsp stream from a camera and forwards it to youtube.

  # initialization
  
  $buffer_size = "30720k" # 60 sec * 512kbps
  
  $ffm = "C:\Users\kostas\Downloads\_software\ffmpeg-20160308-git-5061579-win32-static\bin\ffmpeg.exe"
  
  $params = "-f lavfi -i aevalsrc=0  -thread_queue_size 512 -i rtsp://$($usr):$($pw)@$($cam_ip):554/mpeg-4/ch1/main//av_stream/ -f flv -vcodec copy -acodec aac -bufsize $($buffer_size) rtmp://a.rtmp.youtube.com/live2/$($youtube_key)"
  
  $params_bak = $params.Replace('/live2/','/live2/?backup=1/')
  
  # start stream(s)
  
  while (1 -eq 1) {
  
    $err_log = "C:\Users\kostas\Documents\logs\Stream_Error-$(Get-Date -Format dd-MM-yyyy_HH-mm-ss).log"
  
    $out_log = "C:\Users\kostas\Documents\logs\Stream-$(Get-Date -Format dd-MM-yyyy_HH-mm-ss).log"
  
    $strm_app = Start-Process $ffm $params -PassThru -WindowStyle Minimized -RedirectStandardError $err_log -RedirectStandardOutput $out_log
  
    Wait-Process $strm_app.Id
  
  } 

  When I call the script from the powershell prompt directly like .\youtube_cam_1.ps1 all is well, but the powershell prompt locks, obviously.

  When I start like Start-Job -FilePath C:\Users\kostas\Documents\youtube_cam_1.ps1 the job starts allright and I also see the ffmpeg process starting and running, but the youtube channel stays offline. Now to the funny bit : doing Stop-Job does not kill the ffmpeg process, and suddenly ffmpeg can connect to youtube.

  I want to start and run several camera streams (i.e. ffmpeg instances) in the end and need the looping script to somehow go into the background. Is Start-Job the wrong way to do it ?

  What is happening ?