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• problems reading output from ffmpeg

  4 août 2016, par JLucas

  I am trying to read raw BGR24 image data from ffmpeg into a C++ application. The C++ application will then process the image further using openCV.
  jpg -> ffmpeg -> application -> openCV

  I started by storing the output from ffmpeg into a file and reading that file from within the application. OpenCV apparently accepts this as it happily displays the image.
  However, it fails when piping the output from ffmpeg directly into stdin of the application.

  I changed the program to just save the input to a file and I compared the two files. The first 1856 bytes are the same, but after that the file saved from stdin differs and after that the entire file is just hex D1 (or decimal 209).

  bytes read from stdin

  bytes read from file

  I presume that I am making a mistake while reading stdin instead of ffmpeg having a different output. But I find it very strange that the first part is the same.
  This is the code I use to read stdin

  char* img = (char*) malloc(FRM_SIZE_BYTES);
  
  cout << "array address: " << &img;
  
  cout << "array of size: " << FRM_SIZE_BYTES << endl;
  
  
  
  int read = int read = read_stdin(img, FRM_SIZE_BYTES);
  
  cout << "read " << read << " bytes" << endl;
  
  
  
  int read_stdin(char* buffer, int count) 
  
  {
  
      int read = 0;
  
      char in;
  
      for (int i = 0; i < count; i++) {
  
          cin >>  in;
  
          buffer[i] = in;
  
          read++;
  
      }
  
      return read;
  
  }

  this is how I try to read the file

  ifstream image;
  
  image.open("img.raw", ios_base::binary | ios_base::in);
  
  std::streampos start, end;  
  
  char* imgFile = (char*)malloc(FRM_SIZE_BYTES);
  
  image.read(imgFile, FRM_SIZE_BYTES);
  
  image.close();

  Any help would be appreciated

• ffmpeg save video H.265 from rtsp but i can't open it

  14 juin 2021, par Сергей Брандуков

  By mistake on the IP camera in the settings there was a value of the H.265 codec (should be h.264)

  


      # ffmpeg -i rtsp://admin:admin@192.168.100.22:554/main -y -c:v copy /home/ubuntu/Video/8/tst_256.mp4
ffmpeg version 4.2.4-1ubuntu0.1 Copyright (c) 2000-2020 the FFmpeg developers
  built with gcc 9 (Ubuntu 9.3.0-10ubuntu2)
  configuration: --prefix=/usr --extra-version=1ubuntu0.1 --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --arch=amd64 --enable-gpl --disable-stripping --enable-avresample --disable-filter=resample --enable-avisynth --enable-gnutls --enable-ladspa --enable-libaom --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libcodec2 --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libjack --enable-libmp3lame --enable-libmysofa --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librsvg --enable-librubberband --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxml2 --enable-libxvid --enable-libzmq --enable-libzvbi --enable-lv2 --enable-omx --enable-openal --enable-opencl --enable-opengl --enable-sdl2 --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-nvenc --enable-chromaprint --enable-frei0r --enable-libx264 --enable-shared
  libavutil      56. 31.100 / 56. 31.100
  libavcodec     58. 54.100 / 58. 54.100
  libavformat    58. 29.100 / 58. 29.100
  libavdevice    58.  8.100 / 58.  8.100
  libavfilter     7. 57.100 /  7. 57.100
  libavresample   4.  0.  0 /  4.  0.  0
  libswscale      5.  5.100 /  5.  5.100
  libswresample   3.  5.100 /  3.  5.100
  libpostproc    55.  5.100 / 55.  5.100
[hevc @ 0x55e8744be3c0] Invalid NAL unit 0, skipping.
[hevc @ 0x55e8744be3c0] VPS 0 does not exist
[hevc @ 0x55e8744be3c0] Invalid NAL unit 0, skipping.
[hevc @ 0x55e8744be3c0] VPS 0 does not exist
[rtsp @ 0x55e8744ba6c0] max delay reached. need to consume packet
[rtsp @ 0x55e8744ba6c0] RTP: missed 84 packets
Input #0, rtsp, from 'rtsp://admin:admin@192.168.100.22:554/main':
  Metadata:
    title           : RTSP/RTP stream from IPNC
    comment         : main
  Duration: N/A, start: 0.000000, bitrate: N/A
    Stream #0:0: Video: hevc (Main), yuvj420p(pc, bt709), 2048x1536, 50 tbr, 90k tbn, 90k tbc
    Stream #0:1: Data: none
    Stream #0:2: Data: none
Output #0, mp4, to '/home/ubuntu/Video/8/tst_256.mp4':
  Metadata:
    title           : RTSP/RTP stream from IPNC
    comment         : main
    encoder         : Lavf58.29.100
    Stream #0:0: Video: hevc (Main) (hev1 / 0x31766568), yuvj420p(pc, bt709), 2048x1536, q=2-31, 50 tbr, 90k tbn, 90k tbc
Stream mapping:
  Stream #0:0 -> #0:0 (copy)
Press [q] to stop, [?] for help
[mp4 @ 0x55e874532440] Timestamps are unset in a packet for stream 0. This is deprecated and will stop working in the future. Fix your code to set the timestamps properly
[mp4 @ 0x55e874532440] Non-monotonous DTS in output stream 0:0; previous: 0, current: 0; changing to 1. This may result in incorrect timestamps in the output file.
[mp4 @ 0x55e874532440] Non-monotonous DTS in output stream 0:0; previous: 1, current: 0; changing to 2. This may result in incorrect timestamps in the output file.
[mp4 @ 0x55e874532440] Non-monotonous DTS in output stream 0:0; previous: 216000, current: 110136; changing to 216001. This may result in incorrect timestamps in the output file.
[mp4 @ 0x55e874532440] Non-monotonous DTS in output stream 0:0; previous: 216001, current: 124536; changing to 216002. This may result in incorrect timestamps in the output file.
[mp4 @ 0x55e874532440] Non-monotonous DTS in output stream 0:0; previous: 216002, current: 146226; changing to 216003. This may result in incorrect timestamps in the output file.
[mp4 @ 0x55e874532440] Non-monotonous DTS in output stream 0:0; previous: 216003, current: 160536; changing to 216004. This may result in incorrect timestamps in the output file.
[mp4 @ 0x55e874532440] Non-monotonous DTS in output stream 0:0; previous: 216004, current: 175026; changing to 216005. This may result in incorrect timestamps in the output file.
[mp4 @ 0x55e874532440] Non-monotonous DTS in output stream 0:0; previous: 216005, current: 200136; changing to 216006. This may result in incorrect timestamps in the output file.
[mp4 @ 0x55e874532440] Non-monotonous DTS in output stream 0:0; previous: 216006, current: 214536; changing to 216007. This may result in incorrect timestamps in the output file.
[mp4 @ 0x55e874532440] Non-monotonous DTS in output stream 0:0; previous: 855816, current: 851365; changing to 855817. This may result in incorrect timestamps in the output file.
frame=  100 fps=6.6 q=-1.0 Lsize=   10247kB time=00:00:18.03 bitrate=4653.6kbits/s speed=1.19x    
video:10245kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.021781%
Exiting normally, received signal 2.


  


  there is a file, the size is not empty, the video player shows a black screen, I also can not make out the video into frames

  


  # ffmpeg -i tst_256.mp4 -q:v 1 -r 1  1/%05d.jpg
ffmpeg version 4.2.4-1ubuntu0.1 Copyright (c) 2000-2020 the FFmpeg developers
  built with gcc 9 (Ubuntu 9.3.0-10ubuntu2)
  configuration: --prefix=/usr --extra-version=1ubuntu0.1 --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --arch=amd64 --enable-gpl --disable-stripping --enable-avresample --disable-filter=resample --enable-avisynth --enable-gnutls --enable-ladspa --enable-libaom --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libcodec2 --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libjack --enable-libmp3lame --enable-libmysofa --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librsvg --enable-librubberband --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxml2 --enable-libxvid --enable-libzmq --enable-libzvbi --enable-lv2 --enable-omx --enable-openal --enable-opencl --enable-opengl --enable-sdl2 --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-nvenc --enable-chromaprint --enable-frei0r --enable-libx264 --enable-shared
  libavutil      56. 31.100 / 56. 31.100
  libavcodec     58. 54.100 / 58. 54.100
  libavformat    58. 29.100 / 58. 29.100
  libavdevice    58.  8.100 / 58.  8.100
  libavfilter     7. 57.100 /  7. 57.100
  libavresample   4.  0.  0 /  4.  0.  0
  libswscale      5.  5.100 /  5.  5.100
  libswresample   3.  5.100 /  3.  5.100
  libpostproc    55.  5.100 / 55.  5.100
[AVBSFContext @ 0x555c46ce3540] No start code is found.
tst_256.mp4: could not find codec parameters
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'tst_256.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2mp41
    title           : RTSP/RTP stream from IPNC
    encoder         : Lavf58.29.100
    comment         : main
  Duration: 00:00:18.04, bitrate: N/A
    Stream #0:0(und): Video: hevc (hev1 / 0x31766568), none, 2048x1536, 4652 kb/s, 5.54 fps, 90k tbn (default)
    Metadata:
      handler_name    : VideoHandler
Stream mapping:
  Stream #0:0 -> #0:0 (hevc (native) -> mjpeg (native))
Press [q] to stop, [?] for help
[hevc @ 0x555c46cf6dc0] No start code is found.
[hevc @ 0x555c46cf6dc0] Error splitting the input into NAL units.
[hevc @ 0x555c46d07300] No start code is found.
[hevc @ 0x555c46d07300] Error splitting the input into NAL units.
[hevc @ 0x555c46d17d00] No start code is found.
[hevc @ 0x555c46d17d00] Error splitting the input into NAL units.
[hevc @ 0x555c46d286c0] No start code is found.
[hevc @ 0x555c46d286c0] Error splitting the input into NAL units.
[hevc @ 0x555c46d39000] No start code is found.
[hevc @ 0x555c46d39000] Error splitting the input into NAL units.
[hevc @ 0x555c46d499c0] No start code is found.
[hevc @ 0x555c46d499c0] Error splitting the input into NAL units.
[hevc @ 0x555c46d5a400] No start code is found.
[hevc @ 0x555c46d5a400] Error splitting the input into NAL units.
[hevc @ 0x555c46d6ae40] No start code is found.
...
hevc @ 0x555c46cf6dc0] No start code is found.
[hevc @ 0x555c46cf6dc0] Error splitting the input into NAL units.
Error while decoding stream #0:0: Invalid data found when processing input
    Last message repeated 7 times
Cannot determine format of input stream 0:0 after EOF
Error marking filters as finished


  


  Is it possible to somehow extract frames from this video or the video stream was not saved ?

  


• match an image to a specific frame within a video with ffmpeg

  2 juin 2021, par az0

  I have some images that were taken from a video via screen capture. I would like to know when in the video these images appear (timestamps). Is there a way to programmatically match an image with a specific frame in a video using ffmpeg or some other tool ?

  



  I am very open to different technologies as I'm eager to automate this. It would be extremely time consuming to do this manually.