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• Problems loading G.729 decoder with FFmpeg API

  20 juillet 2015, par gapc

  I built a class with the use of the FFmpeg API to decode several audio files (mp3, ogg, G.729, etc) and load them into a data structure as raw audio data. Now for example when I run the following code :

  codec = avcodec_find_decoder(AV_CODEC_ID_G729);
  
  if (codec == NULL){
  
      printf("Codec not found");
  
      exit(1);
  
  }

  The program will indeed output the error message, but if I load mp3 or ogg codecs there’s no issue.

  So to double check I executed in the terminal ffmpeg -decoders to see if the decoder is supported (which I also checked online) and outputs :

  A....D g729                 G.729

  I need the decoder for G.729. Is there anything I’m missing or doing something wrong ? Is there a different way to load this decoder ? Any suggestions would be greatly appreciated.

  The FFmpeg version installed is 2.7.1 on a Debian system

  API use example : https://www.ffmpeg.org/doxygen/2.7/decoding_encoding_8c-example.html

• Ubuntu reduce video size with ffmepg and change format

  27 juillet 2015, par Arnas Pečelis

  I want to watermark, reduce weigth, resize and change format for selected videos.
  Also I need to keep quality as high as it possible.

  Now what I have :

  ffmpeg -i prepared/video.mp4 -i units/video_watermark.png -filter_complex overlay=10:10 -codec:a copy moved/video_test.mp4

  and I’m watermarking video, but the quality drops a lot. Also I have :

  ffmpeg -i prepared/video.mp4 -s 1280x720 -b 512k -vcodec mpeg1video -acodec copy

  but also I need to reduce weight also as lot as possible. The reconstructed videos will be shown as movies online. My question would be - is it possible to do it one line and change format to .mp4 ?

  PS. I have constructed command :

  ffmpeg -i downloaded/movie/movie.avi -c:v libx264 -acodec libfaac -b:a 64k -preset ultrafast -vf "movie=units/video_watermark.png [watermark]; [in][watermark] overlay=10:10 [out]" -movflags faststart prepared/movie.mp4

  but it returns me error :

  ffmpeg version 2.7.1 Copyright (c) 2000-2015 the FFmpeg developers
  
    built with gcc 4.8 (Ubuntu 4.8.4-2ubuntu1~14.04)
  
    configuration:
  
    libavutil      54. 27.100 / 54. 27.100
  
    libavcodec     56. 41.100 / 56. 41.100
  
    libavformat    56. 36.100 / 56. 36.100
  
    libavdevice    56.  4.100 / 56.  4.100
  
    libavfilter     5. 16.101 /  5. 16.101
  
    libswscale      3.  1.101 /  3.  1.101
  
    libswresample   1.  2.100 /  1.  2.100
  
  Unrecognized option 'preset'.
  
  Error splitting the argument list: Option not found

• Convert HLS (m3u8) to MP4 while preserving streaming gaps

  11 décembre 2019, par Tron

  I have a m3u8 file recorded from a live stream and want to convert it to a MP4 file. However, during the live stream, the broadcaster might go offline and online many times and I need to record the offline periods in the MP4. I’ve tried using ffmpeg to convert the m3u8 to MP4 using the following command

  ffmpeg -i in.m3u8 -c copy out.mp4

  However, the streaming gaps are disregarded in the output video. How can I preserve the streaming gaps using the timestamp info of the TS file and show empty content (black or white screen) during the gaps ?