Les articles publiés sur le site

• Using custom hardware decoder with chromium browser ?

  2 juin 2016, par Sunny Shukla

  I am working on a custom hardware, where we are having a hardware decoder. This hardware decoder is working fine with linux applications and gstreamer. Now we are planning to extend hardware decoding support to chromium browser.

  To the best of my knowledge, chromium browser is using ffmpeg libraries for demuxing and decoding.

  So if I add our custom hardware decoder support to ffmpeg libraries, how would chromium browser will come to know to use our custom hardware decoder while playing videos ?

  Note :- We have only one hardware decoder on our custom hardware.

• Add audio file to audio stream at specific position in c++ FFmpeg

  2 juin 2016, par williamtroup

  I'm using the FFmpeg API in c++ to handle videos. I want to be able to add an audio file to an existing audio stream at a specific position, but cannot seem to find any reference in their documentation.

• ffmpeg udp live stream publish to rtmp

  2 juin 2016, par Pilskalns

  I need to make this chain: JVC HM650--UDP-->localhost-->ffmpeg(copy stream)-->nginx-rtmp

  On input I have UDP stream from camera (udp://@:35501) and I need it to publish to rtmp server (nginx with rtmp module). Apart everything works - I can play input on VLC, I can stream from FMLE to nginx etc. Except, this is my first time with ffmpeg and I can't get it work. So:

  This is best i have got:

  C:\ffmpeg\bin>ffmpeg -re -i udp://@:35501 -f flv "rtmp://192.168.1.17/live/live" -loglevel debug
  ffmpeg version N-69972-g6c91afe Copyright (c) 2000-2015 the FFmpeg developers
    built with gcc 4.9.2 (GCC)
    configuration: --enable-gpl --enable-version3 --disable-w32threads --enable-avisynth --enable-bzlib --enable-fontconfig --enable-frei0r --enable-gnu
  tls --enable-iconv --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libfreetype --enable-libgme --enable-libgsm --enable-
  libilbc --enable-libmodplug --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-l
  ibrtmp --enable-libschroedinger --enable-libsoxr --enable-libspeex --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvo-aacenc --
  enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxavs --ena
  ble-libxvid --enable-lzma --enable-decklink --enable-zlib
    libavutil      54. 19.100 / 54. 19.100
    libavcodec     56. 25.100 / 56. 25.100
    libavformat    56. 23.100 / 56. 23.100
    libavdevice    56.  4.100 / 56.  4.100
    libavfilter     5. 11.100 /  5. 11.100
    libswscale      3.  1.101 /  3.  1.101
    libswresample   1.  1.100 /  1.  1.100
    libpostproc    53.  3.100 / 53.  3.100
  Splitting the commandline.
  Reading option '-re' ... matched as option 're' (read input at native frame rate) with argument '1'.
  Reading option '-i' ... matched as input file with argument 'udp://@:35501'.
  Reading option '-f' ... matched as option 'f' (force format) with argument 'flv'.
  Reading option 'rtmp://192.168.1.17/live/live' ... matched as output file.
  Reading option '-loglevel' ... matched as option 'loglevel' (set logging level) with argument 'debug'.
  Finished splitting the commandline.
  Parsing a group of options: global .
  Applying option loglevel (set logging level) with argument debug.
  Successfully parsed a group of options.
  Parsing a group of options: input file udp://@:35501.
  Applying option re (read input at native frame rate) with argument 1.
  Successfully parsed a group of options.
  Opening an input file: udp://@:35501.
  [udp @ 0000000002c30760] end receive buffer size reported is 65536
  [AVIOContext @ 0000000002c513c0] Statistics: 0 bytes read, 0 seeks
  udp://@:35501: Immediate exit requested
  Received signal 2: terminating.
  
  C:\ffmpeg\bin>
  

  What is wrong with ffmpeg configuration?

  SOLUTION:

  The ffmpeg was listening on wrong version of UDP protocol:

  Even IPv6 is disabled on network cards, internally in system, using @ allowed ffmpeg listen at UDPv6.

  By using 127.0.0.1 tells ffmpeg to use clean UDP.

  Thanks, @thomas to make me think differently!

• ffmpeg publishing VP8 to Janus Gateway

  2 juin 2016, par GreenGiant

  I'm looking to use Janus Gateway to stream very low latency to a thousand viewers from a single source.

  I'm aiming for VP8 video streaming since H.264 support hasn't dropped in Chrome yet.

  My config is

  [gst-rpwc]
  type = rtp
  id = 1
  description = Test Stream
  audio = no
  video = yes
  videoport = 8004
  videopt = 100
  videortpmap = VP8/90000
  

  I'm testing initially on OSX with the built in webcam. This is the pipeline

  ffmpeg -f avfoundation  -video_size 640x480 -framerate 30 -i "0" -b:v 800k -c:v libvpx rtp://x.x.x.x:8004
  

  But I get the following error

  Input #0, avfoundation, from '0':
    Duration: N/A, start: 84921.465000, bitrate: N/A
      Stream #0:0: Video: rawvideo (UYVY / 0x59565955), uyvy422, 640x480, 30 fps, 30 tbr, 1000k tbn, 1000k tbc
  [NULL @ 0x7fb50a012000] Unable to find a suitable output format for 'rtp://178.62.29.190:8004'
  rtp://178.62.29.190:8004: Invalid argument
  

• C# extract frames from part of a video file

  2 juin 2016, par SiriusNik

  Using AForge ffmpeg wrapper you can extract frames from a video using the VideoFileReader class and save it as a bitmap.

  See this for the exemple: Extracting frames of a .avi file

  My problem with that is that you cannot specified where to start reading the frames. It always starts from the beginning of the video file.

  But what if i wanted to extract frames that are in the middle of a two hours long video file. Using that class you'd have to parse the whole first hour juste to get to those frames.

  Does anyone know a way to achieve that?