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• ffmpeg terminal : How can I re-encode a video file using all the parameters copied from another video ? [closed]

  5 décembre 2022, par Lever

  I have two videos A and B. How can I re-encode B using ALL the parameters of A ?
I would like to use both A and B as inputs, but all parameters are extracted from A, then B is re-encoded with the A-parameters including both video and audio. Is there a simple command to copy ALL the parameters of A ?

  


  Thanks !

  


  I know the typical parameters of a video includes the resolution, fps and so on. But it seems that I always miss something rather than get ALL the parameters to make A and B the same.

  


  The background is that I need to concatenate about 100 videos, but only a few of which has lower quality than others. I don't want to re-encode all of them. Therefore I'm trying to re-encode the lower ones to match the others, and then I can use the file-level concatenation command avoiding re-encode all of them.

  


• Having trouble compiling ffmpeg code in command terminal

  10 septembre 2019, par m00ncake

  I am having a bit of trouble compiling my c++ code in my terminal. I have ffmpeg installed as shown below.

  ffmpeg version n4.1 Copyright (c) 2000-2018 the FFmpeg developers
  
    built with gcc 7 (Ubuntu 7.4.0-1ubuntu1~18.04.1)
  
    configuration: --enable-gpl --enable-version3 --disable-static --enable-shared --enable-small --enable-avisynth --enable-chromaprint --enable-frei0r --enable-gmp --enable-gnutls --enable-ladspa --enable-libaom --enable-libass --enable-libcaca --enable-libcdio --enable-libcodec2 --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libjack --enable-libmodplug --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librsvg --enable-librubberband --enable-librtmp --enable-libshine --enable-libsmbclient --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtesseract --enable-libtheora --enable-libtwolame --enable-libv4l2 --enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxvid --enable-libxml2 --enable-libzmq --enable-libzvbi --enable-lv2 --enable-libmysofa --enable-openal --enable-opencl --enable-opengl --enable-libdrm
  
    libavutil      56. 22.100 / 56. 22.100
  
    libavcodec     58. 35.100 / 58. 35.100
  
    libavformat    58. 20.100 / 58. 20.100
  
    libavdevice    58.  5.100 / 58.  5.100
  
    libavfilter     7. 40.101 /  7. 40.101
  
    libswscale      5.  3.100 /  5.  3.100
  
    libswresample   3.  3.100 /  3.  3.100
  
    libpostproc    55.  3.100 / 55.  3.100
  
  Hyper fast Audio and Video encoder
  
  usage: ffmpeg [options] [[infile options] -i infile]... {[outfile options] outfile}...

  However, when I compile my c++ code, currently trying to get NTP timestamps from private data in ffmpeg but I need to include their headers ? I have looked into ffmpeg’s libavformat folder and it does have rtpdec.h but when I compile it in the command line, i get this error. (trying to include this header for RTSPState and RTSPStream as well as RTPDemuxContext)

  cf.cpp:11:10: fatal error: libavformat/rtsp.h: No such file or directory
  
   #include <libavformat></libavformat>rtpdec.h>
  
            ^~~~~~~~~~~~~~~~~~~~
  
  compilation terminated.

  This is my code :

  #include 
  
  #include 
  
  #include <iostream>
  
  #include <fstream>
  
  #include <sstream>
  
  
  
  extern "C" {
  
  #include <libavcodec></libavcodec>avcodec.h>
  
  #include <libavformat></libavformat>avformat.h>
  
  #include <libavformat></libavformat>avio.h>
  
  #include <libavformat></libavformat>rtpdec.h>
  
  #include <libswscale></libswscale>swscale.h>
  
  }
  
  
  
  int main(int argc, char** argv) {
  
  
  
      // Open the initial context variables that are needed
  
      SwsContext *img_convert_ctx;
  
      AVFormatContext* format_ctx = avformat_alloc_context();
  
      AVCodecContext* codec_ctx = NULL;
  
      int video_stream_index;
  
      uint32_t* last_rtcp_ts;
  
      double* base_time;
  
      double* time;
  
  
  
      // Register everything
  
      av_register_all();
  
      avformat_network_init();
  
  
  
      //open RTSP
  
      if (avformat_open_input(&amp;format_ctx, "rtsp://admin:password@192.168.1.67:554",
  
              NULL, NULL) != 0) {
  
          return EXIT_FAILURE;
  
      }
  
  
  
      if (avformat_find_stream_info(format_ctx, NULL) &lt; 0) {
  
          return EXIT_FAILURE;
  
      }
  
  
  
      //search video stream
  
      for (int i = 0; i &lt; format_ctx->nb_streams; i++) {
  
          if (format_ctx->streams[i]->codec->codec_type == AVMEDIA_TYPE_VIDEO)
  
              video_stream_index = i;
  
      }
  
  
  
      AVPacket packet;
  
      av_init_packet(&amp;packet);
  
  
  
      //open output file
  
      AVFormatContext* output_ctx = avformat_alloc_context();
  
  
  
      AVStream* stream = NULL;
  
      int cnt = 0;
  
  
  
      //start reading packets from stream and write them to file
  
      av_read_play(format_ctx);    //play RTSP
  
  
  
      // Get the codec
  
      AVCodec *codec = NULL;
  
      codec = avcodec_find_decoder(AV_CODEC_ID_H264);
  
      if (!codec) {
  
          exit(1);
  
      }
  
  
  
  // Add this to allocate the context by codec
  
  codec_ctx = avcodec_alloc_context3(codec);
  
  
  
  avcodec_get_context_defaults3(codec_ctx, codec);
  
  avcodec_copy_context(codec_ctx, format_ctx->streams[video_stream_index]->codec);
  
  std::ofstream output_file;
  
  
  
  if (avcodec_open2(codec_ctx, codec, NULL) &lt; 0)
  
      exit(1);
  
  
  
      img_convert_ctx = sws_getContext(codec_ctx->width, codec_ctx->height,
  
              codec_ctx->pix_fmt, codec_ctx->width, codec_ctx->height, AV_PIX_FMT_RGB24,
  
              SWS_BICUBIC, NULL, NULL, NULL);
  
  
  
      int size = avpicture_get_size(AV_PIX_FMT_YUV420P, codec_ctx->width,
  
              codec_ctx->height);
  
      uint8_t* picture_buffer = (uint8_t*) (av_malloc(size));
  
      AVFrame* picture = av_frame_alloc();
  
      AVFrame* picture_rgb = av_frame_alloc();
  
      int size2 = avpicture_get_size(AV_PIX_FMT_RGB24, codec_ctx->width,
  
              codec_ctx->height);
  
      uint8_t* picture_buffer_2 = (uint8_t*) (av_malloc(size2));
  
      avpicture_fill((AVPicture *) picture, picture_buffer, AV_PIX_FMT_YUV420P,
  
              codec_ctx->width, codec_ctx->height);
  
      avpicture_fill((AVPicture *) picture_rgb, picture_buffer_2, AV_PIX_FMT_RGB24,
  
              codec_ctx->width, codec_ctx->height);
  
  
  
      while (av_read_frame(format_ctx, &amp;packet) >= 0 &amp;&amp; cnt &lt; 1000) { //read ~ 1000 frames
  
  
  
          RTSPState* rt = format_ctx->priv_data;
  
          RTSPStream *rtsp_stream = rt->rtsp_streams[0];
  
          RTPDemuxContext* rtp_demux_context = rtsp_stream->transport_priv;
  
          uint32_t new_rtcp_ts = rtp_demux_context->last_rtcp_timestamp;
  
          uint64_t last_ntp_time = 0;
  
  
  
          if (new_rtcp_ts != *last_rtcp_ts) {
  
              *last_rtcp_ts = new_rtcp_ts;
  
              last_ntp_time = rtp_demux_context->last_rtcp_ntp_time;
  
              uint32_t seconds = ((last_ntp_time >> 32) &amp; 0xffffffff) - 2208988800;
  
              uint32_t fraction  = (last_ntp_time &amp; 0xffffffff);
  
              double useconds = ((double) fraction / 0xffffffff);
  
              *base_time = seconds + useconds;
  
              uint32_t d_ts = rtp_demux_context->timestamp - *last_rtcp_ts;
  
              *time = *base_time + d_ts / 90000.0;
  
              std::cout &lt;&lt; "Time is: " &lt;&lt; *time &lt;&lt; std::endl;
  
          }
  
  
  
          std::cout &lt;&lt; "1 Frame: " &lt;&lt; cnt &lt;&lt; std::endl;
  
          if (packet.stream_index == video_stream_index) {    //packet is video
  
              std::cout &lt;&lt; "2 Is Video" &lt;&lt; std::endl;
  
              if (stream == NULL) {    //create stream in file
  
                  std::cout &lt;&lt; "3 create stream" &lt;&lt; std::endl;
  
                  stream = avformat_new_stream(output_ctx,
  
                          format_ctx->streams[video_stream_index]->codec->codec);
  
                  avcodec_copy_context(stream->codec,
  
                          format_ctx->streams[video_stream_index]->codec);
  
                  stream->sample_aspect_ratio =
  
                          format_ctx->streams[video_stream_index]->codec->sample_aspect_ratio;
  
              }
  
              int check = 0;
  
              packet.stream_index = stream->id;
  
              std::cout &lt;&lt; "4 decoding" &lt;&lt; std::endl;
  
              int result = avcodec_decode_video2(codec_ctx, picture, &amp;check, &amp;packet);
  
              std::cout &lt;&lt; "Bytes decoded " &lt;&lt; result &lt;&lt; " check " &lt;&lt; check
  
                      &lt;&lt; std::endl;
  
              if (cnt > 100)    //cnt &lt; 0)
  
                      {
  
                  sws_scale(img_convert_ctx, picture->data, picture->linesize, 0,
  
                          codec_ctx->height, picture_rgb->data, picture_rgb->linesize);
  
                  std::stringstream file_name;
  
                  file_name &lt;&lt; "test" &lt;&lt; cnt &lt;&lt; ".ppm";
  
                  output_file.open(file_name.str().c_str());
  
                  output_file &lt;&lt; "P3 " &lt;&lt; codec_ctx->width &lt;&lt; " " &lt;&lt; codec_ctx->height
  
                          &lt;&lt; " 255\n";
  
                  for (int y = 0; y &lt; codec_ctx->height; y++) {
  
                      for (int x = 0; x &lt; codec_ctx->width * 3; x++)
  
                          output_file
  
                                  &lt;&lt; (int) (picture_rgb->data[0]
  
                                          + y * picture_rgb->linesize[0])[x] &lt;&lt; " ";
  
                  }
  
                  output_file.close();
  
              }
  
              cnt++;
  
          }
  
          av_free_packet(&amp;packet);
  
          av_init_packet(&amp;packet);
  
      }
  
      av_free(picture);
  
      av_free(picture_rgb);
  
      av_free(picture_buffer);
  
      av_free(picture_buffer_2);
  
  
  
      av_read_pause(format_ctx);
  
      avio_close(output_ctx->pb);
  
      avformat_free_context(output_ctx);
  
  
  
      return (EXIT_SUCCESS);
  
  }
  
  </sstream></fstream></iostream>

  The command i use to compile my code : g++ -w cf.cpp -o cf $(pkg-config --cflags --libs libavformat libswscale libavcodec)

  I am a bit new to coding in FFmpeg.

• Terminal : How to extract vobsub subtitles to bitmap images (jpg, png) ?

  5 août 2022, par DevonDahon

  How to extract image-based subtitles to bitmap images (jpg, png) ?

  


  I tried with ffmpeg, but it seems to work only with text-based subtitles.

  


  $ ffmpeg -i myvideo.mp4 -map "0:2" output.bre.srt
ffmpeg version 5.0.1 Copyright (c) 2000-2022 the FFmpeg developers
  built with Apple clang version 13.1.6 (clang-1316.0.21.2.5)
  configuration: --prefix=/usr/local/Cellar/ffmpeg/5.0.1_3 --enable-shared --enable-pthreads --enable-version3 --cc=clang --host-cflags= --host-ldflags= --enable-ffplay --enable-gnutls --enable-gpl --enable-libaom --enable-libbluray --enable-libdav1d --enable-libmp3lame --enable-libopus --enable-librav1e --enable-librist --enable-librubberband --enable-libsnappy --enable-libsrt --enable-libtesseract --enable-libtheora --enable-libvidstab --enable-libvmaf --enable-libvorbis --enable-libvpx --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libxvid --enable-lzma --enable-libfontconfig --enable-libfreetype --enable-frei0r --enable-libass --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libspeex --enable-libsoxr --enable-libzmq --enable-libzimg --disable-libjack --disable-indev=jack --enable-videotoolbox
  libavutil      57. 17.100 / 57. 17.100
  libavcodec     59. 18.100 / 59. 18.100
  libavformat    59. 16.100 / 59. 16.100
  libavdevice    59.  4.100 / 59.  4.100
  libavfilter     8. 24.100 /  8. 24.100
  libswscale      6.  4.100 /  6.  4.100
  libswresample   4.  3.100 /  4.  3.100
  libpostproc    56.  3.100 / 56.  3.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'myvideo.mp4':
  Metadata:
    major_brand     : mp42
    minor_version   : 512
    compatible_brands: mp42iso2avc1mp41
    creation_time   : 2022-08-03T21:58:07.000000Z
    encoder         : HandBrake 1.5.1 2022011000
  Duration: 00:11:05.40, start: 0.000000, bitrate: 1635 kb/s
  Stream #0:0[0x1](und): Video: h264 (High) (avc1 / 0x31637661), yuv420p(tv, smpte170m/bt470bg/bt470bg, progressive), 712x576 [SAR 16:15 DAR 178:135], 1454 kb/s, 25 fps, 25 tbr, 90k tbn (default)
    Metadata:
      creation_time   : 2022-08-03T21:58:07.000000Z
      handler_name    : VideoHandler
      vendor_id       : [0][0][0][0]
  Stream #0:1[0x2](bre): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 162 kb/s (default)
    Metadata:
      creation_time   : 2022-08-03T21:58:07.000000Z
      handler_name    : Stereo
      vendor_id       : [0][0][0][0]
  Stream #0:2[0x3](bre): Subtitle: dvd_subtitle (mp4s / 0x7334706D), 720x576, 6 kb/s (default)
    Metadata:
      creation_time   : 2022-08-03T21:58:07.000000Z
      handler_name    : Brezhoneg
  Stream #0:3[0x4](fra): Subtitle: dvd_subtitle (mp4s / 0x7334706D), 720x576, 6 kb/s
    Metadata:
      creation_time   : 2022-08-03T21:58:07.000000Z
      handler_name    : Français
Error initializing output stream 0:0 -- Subtitle encoding currently only possible from text to text or bitmap to bitmap
Stream mapping:
  Stream #0:2 -> #0:0 (dvd_subtitle (dvdsub) -> subrip (srt))
    Last message repeated 1 times