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• Streaming video (C# using FFmpeg AutoGen) sends multiple data requests

  14 juillet 2016, par williamtroup

  I’ve written a video generator that rights a video in h264 format (mp4). When I stream the video from my azure service, i’m seeing the following network traffic :

  

  The AVCodecContext layout I’m using is as follows :

  AVCodec* videoCodec = ffmpeg.avcodec_find_encoder(AVCodecID.AV_CODEC_ID_H264)
  
  AVCodecContext* videoCodecContext = ffmpeg.avcodec_alloc_context3(videoCodec);
  
  videoCodecContext->bit_rate = 400000;
  
  videoCodecContext->width = 1280;
  
  videoCodecContext->height = 720;
  
  videoCodecContext->gop_size = 12;
  
  videoCodecContext->max_b_frames = 1;
  
  videoCodecContext->pix_fmt = videoCodec->pix_fmts[0];
  
  videoCodecContext->codec_id = videoCodec->id;
  
  videoCodecContext->codec_type = videoCodec->type;
  
  videoCodecContext->time_base = new AVRational
  
  {
  
      num = 1,
  
      den = 30
  
  };
  
  
  
  ffmpeg.av_opt_set(videoCodecContext->priv_data, "preset", "ultrafast");

  I’m also tried setting the "movflags" option for avformat_write_header() via an AVDictionary, but then av_write_trailer() returns -2, cause the file to not finish writing.

  I cannot figure out how to solve this problem. Videos generating using Windows Movie Maker stream perfectly.

  I know this has something to do with mdat and mov positions.

  Also, this appears to only happening in Google Chrome.

• QTRLE is supported by ffmpeg ?

  22 avril 2016, par Sagar
  • I am trying to create video using QTRLE format with RGB24 or ARGB pixel format in ffmpeg library.But video is not played.
  • But is i use H264 format with yuv format then it’s working fine.

  • Is QTRLE is not supported by ffmpeg or i m doing any mistake ?

    static void video_encode_example(const char *filename, int codec_id)
    
    {
    
            AVCodec *codec;
    
            AVCodecContext *c = NULL;
    
            int i, ret, x, y, got_output;
    
            FILE *f;
    
            AVFrame *frame;
    
            AVPacket pkt;
    
            uint8_t endcode[] = { 0, 0, 1, 0xb7 };
    
    
    
            printf("Encode video file %s\n", filename);
    
    
    
            /* find the mpeg1 video encoder */
    
    
    
            codec = avcodec_find_encoder((AVCodecID) codec_id);
    
            //  codec = 28;
    
            if (!codec) {
    
                fprintf(stderr, "Codec not found : %d\n", codec_id);
    
                exit(1);
    
            }
    
    
    
            c = avcodec_alloc_context3(codec);
    
    
    
            if (!c) {
    
                fprintf(stderr, "Could not allocate video codec context\n");
    
                exit(1);
    
            }
    
    
    
            /* put sample parameters */
    
            c->bit_rate = 400000;
    
            /* resolution must be a multiple of two */
    
            c->width = 352;
    
            c->height = 288;
    
            /* frames per second */
    
            c->time_base = (AVRational ) { 1, 25 };
    
            /* emit one intra frame every ten frames
    
             * check frame pict_type before passing frame
    
             * to encoder, if frame->pict_type is AV_PICTURE_TYPE_I
    
             * then gop_size is ignored and the output of encoder
    
             * will always be I frame irrespective to gop_size
    
             */
    
            c->gop_size = 10;
    
            c->max_b_frames = 1;
    
            c->pix_fmt = AV_PIX_FMT_RGB24;
    
    
    
            if (codec_id == AV_CODEC_ID_H264)
    
                av_opt_set(c->priv_data, "preset", "slow", 0);
    
    
    
            /* open it */
    
            if (avcodec_open2(c, codec, NULL) < 0) {
    
                fprintf(stderr, "Could not open codec\n");
    
                exit(1);
    
            }
    
    
    
            f = fopen(filename, "wb");
    
            if (!f) {
    
                fprintf(stderr, "Could not open %s\n", filename);
    
                exit(1);
    
            }
    
    
    
            frame = av_frame_alloc();
    
            if (!frame) {
    
                fprintf(stderr, "Could not allocate video frame\n");
    
                exit(1);
    
            }
    
            frame->format = c->pix_fmt;
    
            frame->width = c->width;
    
            frame->height = c->height;
    
    
    
            /* 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 */
    
            ret = av_image_alloc(frame->data, frame->linesize, c->width, c->height,
    
                    c->pix_fmt, 32);
    
            if (ret < 0) {
    
                fprintf(stderr, "Could not allocate raw picture buffer\n");
    
                exit(1);
    
            }
    
            ////////////////////////////////////
    
            cv::Mat input = imread("image for creating video(image.png)");
    
            Mat output;
    
            resize(input, input, Size(c->width, c->height));
    
            cvtColor(input, input, CV_BGR2RGB);
    
    
    
            av_image_fill_arrays(frame->data, frame->linesize, input.data,
    
                    c->pix_fmt, c->width, c->height, 1);
    
    
    
            ////////////////////////////////////
    
    
    
            for (i = 0; i < 250; i++) {
    
                av_init_packet(&pkt);
    
                pkt.data = NULL;    // packet data will be allocated by the encoder
    
                pkt.size = 0;
    
    
    
                fflush(stdout);
    
    
    
                frame->pts = i;
    
    
    
                /* encode the image */
    
                ret = avcodec_encode_video2(c, &pkt, frame, &got_output);
    
                if (ret < 0) {
    
                    fprintf(stderr, "Error encoding frame\n");
    
                    exit(1);
    
                }
    
    
    
                if (got_output) {
    
                    printf("Write frame %3d (size=%5d)\n", i, pkt.size);
    
                    fwrite(pkt.data, 1, pkt.size, f);
    
                    av_packet_unref(&pkt);
    
                }
    
            }
    
    
    
            /* get the delayed frames */
    
            for (got_output = 1; got_output; i++) {
    
                fflush(stdout);
    
    
    
                ret = avcodec_encode_video2(c, &pkt, NULL, &got_output);
    
                if (ret < 0) {
    
                    fprintf(stderr, "Error encoding frame\n");
    
                    exit(1);
    
                }
    
    
    
                if (got_output) {
    
                    printf("Write frame %3d (size=%5d)\n", i, pkt.size);
    
                    fwrite(pkt.data, 1, pkt.size, f);
    
                    av_packet_unref(&pkt);
    
                }
    
            }
    
    
    
            /* add sequence end code to have a real mpeg file */
    
            fwrite(endcode, 1, sizeof(endcode), f);
    
            fclose(f);
    
    
    
            avcodec_close(c);
    
            av_free(c);
    
        //  av_freep(&frame->data[0]);
    
            av_frame_free(&frame);
    
            printf("\n");
    
    }
    
    
    
    int main() {
    
        av_register_all();
    
        video_encode_example("test.mov", AV_CODEC_ID_QTRLE);
    
    }

• Streaming video written using FFmpeg (C# using AutoGen) sends multiple data requests

  26 juin 2016, par williamtroup

  I’ve written a video generator that rights a video in h264 format (mp4). When I stream the video from my azure service, i’m seeing the following network traffic :

  

  The AVCodecContext layout I’m using is as follows :

  AVCodec* videoCodec = ffmpeg.avcodec_find_encoder(AVCodecID.AV_CODEC_ID_H264)
  
  AVCodecContext* videoCodecContext = ffmpeg.avcodec_alloc_context3(videoCodec);
  
  videoCodecContext->bit_rate = 400000;
  
  videoCodecContext->width = 1280;
  
  videoCodecContext->height = 720;
  
  videoCodecContext->gop_size = 12;
  
  videoCodecContext->max_b_frames = 1;
  
  videoCodecContext->pix_fmt = videoCodec->pix_fmts[0];
  
  videoCodecContext->codec_id = videoCodec->id;
  
  videoCodecContext->codec_type = videoCodec->type;
  
  videoCodecContext->time_base = new AVRational
  
  {
  
      num = 1,
  
      den = 30
  
  };
  
  
  
  ffmpeg.av_opt_set(videoCodecContext->priv_data, "preset", "ultrafast");

  I cannot figure out how to solve this problem. Videos generating using Windows Movie Maker stream perfectly.

  Also, this appears to only happening in Google Chrome.