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• ffmpeg muxing time getting an error

  5 février 2017, par Asif Shariar

  i am getting error when i muxing a file ,i try to mux a file i use muxing example , but i always geting an error in ret does not meet ffmpeg ptr value ,

  is use this code

  OutputStream video_st = { 0 }, audio_st = { 0 };
  
  const char *filename;
  
  AVOutputFormat *fmt;
  
  AVFormatContext *oc;
  
  AVCodec *audio_codec = nullptr, *video_codec = nullptr;
  
  int ret;
  
  int have_video = 0, have_audio = 0;
  
  int encode_video = 0, encode_audio = 0;
  
  AVDictionary *opt = NULL;
  
  int i;
  
  
  
  /* Initialize libavcodec, and register all codecs and formats. */
  
  av_register_all();
  
  
  
  
  
  
  
  filename = "C:/Users/Admin/Desktop/Videotest/_test.mp4";
  
  
  
  /* allocate the output media context */
  
  avformat_alloc_output_context2(&oc, NULL, NULL, filename);
  
  if (!oc) {
  
      printf("Could not deduce output format from file extension: using MPEG.\n");
  
      avformat_alloc_output_context2(&oc, NULL, "mpeg", filename);
  
  }
  
  if (!oc) {
  
      exit;
  
  }
  
  
  
  
  
  fmt = oc->oformat;
  
  
  
  /* Add the audio and video streams using the default format codecs
  
  * and initialize the codecs. */
  
  if (fmt->video_codec != AV_CODEC_ID_NONE) {
  
      add_stream(&video_st, oc, &video_codec, fmt->video_codec);
  
      have_video = 1;
  
      encode_video = 1;
  
  }
  
  if (fmt->audio_codec != AV_CODEC_ID_NONE) {
  
      add_stream(&audio_st, oc, &audio_codec, fmt->audio_codec);
  
      have_audio = 1;
  
      encode_audio = 1;
  
  }
  
  
  
  /* Now that all the parameters are set, we can open the audio and
  
  * video codecs and allocate the necessary encode buffers. */
  
  if (have_video)
  
      open_video(oc, video_codec, &video_st, opt);
  
  
  
  if (have_audio)
  
      open_audio(oc, audio_codec, &audio_st, opt);
  
  
  
  av_dump_format(oc, 0, filename, 1);
  
  
  
  /* open the output file, if needed */
  
  if (!(fmt->flags & AVFMT_NOFILE)) {
  
      ret = avio_open(&oc->pb, filename, AVIO_FLAG_WRITE);
  
      if (ret < 0) {
  
          exit;
  
      }
  
  }
  
  
  
  /* Write the stream header, if any. */
  
  ret = avformat_write_header(oc, &opt);
  
  if (ret < 0) {
  
      exit;
  
  }
  
  
  
  while (encode_video || encode_audio) {
  
      /* select the stream to encode */
  
      if (encode_video &&
  
          (!encode_audio || av_compare_ts(video_st.next_pts, video_st.enc->time_base,
  
              audio_st.next_pts, audio_st.enc->time_base) <= 0)) {
  
          encode_video = !write_video_frame(oc, &video_st);
  
      }
  
      else {
  
          encode_audio = !write_audio_frame(oc, &audio_st);
  
      }
  
  }
  
  
  
  /* Write the trailer, if any. The trailer must be written before you
  
  * close the CodecContexts open when you wrote the header; otherwise
  
  * av_write_trailer() may try to use memory that was freed on
  
  * av_codec_close(). */
  
  av_write_trailer(oc);
  
  
  
  /* Close each codec. */
  
  if (have_video)
  
      close_stream(oc, &video_st);
  
  if (have_audio)
  
      close_stream(oc, &audio_st);
  
  
  
  if (!(fmt->flags & AVFMT_NOFILE))
  
      /* Close the output file. */
  
      avio_closep(&oc->pb);
  
  
  
  /* free the stream */
  
  avformat_free_context(oc);

  error logs

  av_log(s, AV_LOG_ERROR, "muxer does not support non seekable output\n");

  error getting here

  /* Write the stream header, if any. */
  
  ret = avformat_write_header(oc, &opt);

  how can i fix this error

• FFMPEG : av_interleaved_write_frame() : Connection reset by peer

  9 mars 2017, par mrcatmann

  I try to broadcast a video from one of my servers to a RTMP server based on NGINX-RTMP. But sometimes there are reconnects because of bad network on RTMP server, and then ffmpeg gives me errors like

  av_interleaved_write_frame(): Connection reset by peer
  
  [flv @ 0x30351a0] Failed to update header with correct duration.
  
  [flv @ 0x30351a0] Failed to update header with correct filesize.
  
  Error writing trailer of (address): Connection reset by peer"

  Tried to use "reconnect" command, but it didn’t help me. The full FFMPEG command is :

  ffmpeg -reconnect 1 -reconnect_at_eof 1 -reconnect_streamed 1 -reconnect_delay_max 4274 -re -i "(file)" -s 640x360 -aspect 16:9  -c copy -f flv "(stream address)" 

  Is there a way to bypass this ? I can’t play the same video from the beginning in this situation, it needs to be continued from the same point.

• ffmpeg video stream output multiply when I modify viedo in OpenCV

  30 mars 2017, par trojek

  I try to implement a proof of concept program which : (1)get video from webcam, (2)do some operations on it, (3)stream modified video on a web page.

  I do it as follows :

  1) In open CV : open webcam stream and output frames as a rawvideo, capture.py looks :

    import cv2
  
    import sys
  
  
  
    cap = cv2.VideoCapture(0)
  
    while(cap.isOpened()):
  
      ret, frame = cap.read()
  
      if(ret):
  
        sys.stdout.write(frame.tostring())
  
      else:
  
        break

  2) Run ffmpeg server by execute : python2 capture.py | ffmpeg -framerate 30 -f rawvideo -pixel_format bgr24 -video_size 640x480 -i - -f mpegts -codec:v mpeg1video -s 640x480 -b:v 2500k -bf 0 http://localhost:8081/supersecret

  3) Run Websocket relay and http-server according to the instruction on page : https://github.com/phoboslab/jsmpeg, in order to stream video in a browser.

  I get the stream in browser, but when I apply any change(e.g. frame = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)) on the frame inside capture.py file I get 9 small stream instead of one.

  The same situation occurs when I change video resolution while starting ffmpeg server. When I stream directly from /dev/video0 insted of pipe I get the proper stream.

  How can I do some operations on the video and get the single image stream ?