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• What is ffmpeg trying to do when fps is shown gradually decreasing for a given frame ?

  30 mars 2015, par eternalthinker

  I’ve been trying to create an animated overlay over an FLV video, and trying to get the output in MP4 format. I initially used ffmpeg version 1.26. But, as the filters seem to support better options with the latest format, I compiled ffmpeg version 2.61 from source.

  Now the encoding seems to work fine, but the command stays at one point for too long, where it is seen that the fps drops to smaller values, and the ’drop’ value changes accordingly. I used the fps filter to supply fps=25 option, and now the encoding is stuck at the same point, only the drop value remains 0, while fps is shown dropping to smaller values, taking a long time as before.

  

  In the screenshot above, all values remain same, while fps keep dropping to smaller values. After 10fps, it drops by 0.1 and continues past 1, to 0.9 etc. I didn’t wait until it went down further, as the whole thing was taking too much time.

  What can I do to avoid this, and tell ffmpeg to move on with one framerate ? That is, to finish encoding after the 21.45 seconds shown here, and not try to tweak fps or whatever it is trying to do here.

  The full command I am using is this :

  ffmpeg -y -i BaseVideo.flv  -loop 1 -i 1overlay.png  -loop 1 -filter_complex '[1:v] fade=out:20:20:alpha=1:start_time=4:d=3:c=white [V2]; [0:v][V2] overlay, fps=25' -c:v libx264 -strict -2 result.mp4

• Protocol for streaming : From a client to the server

  30 décembre 2015, par the-owner

  Context : I work in C++ with msvc2013 win32, QT-IDE, ffmpeg.

  I am looking for a protocol in order to stream video from the server to client and mostly from client to the server (two-way). On the server side, there is a tcp protocol already implemented (with QTcp).

  Question :
  For the server to client, obviously there is the RTP protocole (which is a derived UDP protocol), but for streaming into the inverse way, is there a protocol for streaming (images/video) where the client (as a client) could send a (live)stream to the server ? And is it possible (and easy) to implement this protocol under FFMPEG or QT ? (with a avformat_alloc_output_context2() for example)

  Otherwise, if FFMPEG or QT are not enough for doing this task : Is there a library that can do that under Visual-C++ Win32 ?

• FFMPEG JAVA ffmpeg doesn't work in .jar application

  3 février 2020, par xkenzzo

  FFMPEG works only in developer mode. When I compile my jar program it returns the following error
  the log of the program launched with eclipse in this case everything works

    ffmpeg version git-2019-12-29-e20c6d9 Copyright (c) 2000-2019 the FFmpeg developers
  
    built with gcc 9.2.1 (GCC) 20191125
  
    configuration: --enable-gpl --enable-version3 --enable-sdl2 --enable-fontconfig --enable-gnutls --enable-iconv --enable-libass --enable-libdav1d --enable-libbluray --enable-libfreetype --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libtheora --enable-libtwolame --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libzimg --enable-lzma --enable-zlib --enable-gmp --enable-libvidstab --enable-libvorbis --enable-libvo-amrwbenc --enable-libmysofa --enable-libspeex --enable-libxvid --enable-libaom --enable-libmfx --enable-ffnvcodec --enable-cuvid --enable-d3d11va --enable-nvenc --enable-nvdec --enable-dxva2 --enable-avisynth --enable-libopenmpt --enable-amf
  
    libavutil      56. 38.100 / 56. 38.100
  
    libavcodec     58. 65.100 / 58. 65.100
  
    libavformat    58. 35.101 / 58. 35.101
  
    libavdevice    58.  9.101 / 58.  9.101
  
    libavfilter     7. 70.100 /  7. 70.100
  
    libswscale      5.  6.100 /  5.  6.100
  
    libswresample   3.  6.100 /  3.  6.100
  
    libpostproc    55.  6.100 / 55.  6.100
  
  Input #0, h264, from '.h264':
  
    Duration: N/A, bitrate: N/A
  
      Stream #0:0: Video: h264 (Main), yuv420p(progressive), 3840x2160 [SAR 1:1 DAR 16:9], 60 fps, 60 tbr, 1200k tbn, 120 tbc
  
  Output #0, mp4, to '.mp4':
  
    Metadata:
  
      encoder         : Lavf58.35.101
  
      Stream #0:0: Video: h264 (Main) (avc1 / 0x31637661), yuv420p(progressive), 3840x2160 [SAR 1:1 DAR 16:9], q=2-31, 60 fps, 60 tbr, 15360 tbn, 120 tbc
  
  Stream mapping:
  
    Stream #0:0 -> #0:0 (copy)
  
  Press [q] to stop, [?] for help
  
  [mp4 @ 000001cedad59440] 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
  
  frame= 9273 fps=0.0 q=-1.0 Lsize=  121326kB time=00:01:17.26 bitrate=12863.3kbits/s speed= 207x    
  
  video:121287kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.032451%

  This is where it gets complicated. You can observe the messages that FFMPEG returns to me when I launch my program compile in jar :

  > [h264 @ 0000017c43e5b700] error while decoding MB 58 6, bytestream -14
  
  > [h264 @ 0000017c43e5b700] concealing 30951 DC, 30951 AC, 30951 MV
  
  > errors in I frame [h264 @ 0000017c43e49d80] Stream #0: not enough
  
  > frames to estimate rate; consider increasing probesize [h264 @
  
  > 0000017c43e49d80] decoding for stream 0 failed

  This is the java code which thanks to the ProcessBuilder will launch FFMPEG :

  String urlVideoMp4 = movie.getPath().replace(".h264", ".mp4");
  
  
  
  File videoFinal = new File(urlVideoMp4);
  
  //checking if new video exists : if not, creating it with FFMPEG
  
  
  
  LOG.info("moviePath : " + movie);
  
  ProcessBuilder processBuilder = new ProcessBuilder(FFMPEG, "-framerate", "60", "-r", "120", "-i", movie.getPath(),"-c:v", "copy", urlVideoMp4);
  
  LOG.debug(processBuilder.command());
  
  
  
  processBuilder.inheritIO().start().waitFor();
  
  
  
  return videoFinal;