Recherche avancée

Sur d’autres sites (7111)

• How to segment a video and then concatenate back into original one with ffmpeg

  23 décembre 2016, par steve

  I am surveying on distributed video transcoding with FFmpeg. I have found that there is a good script on https://github.com/nergdron/dve/blob/master/dve.

  The script mainly uses the segment and concatenate filters of FFmpeg. I want to do a simple test first. However, I can not split the video into segments and then concatenate back to original video (with the same codec). I have tried with the following command :

  a. Chunk the video

  ffmpeg -fflags +genpts -i Test.avi -map 0 -codec copy -f segment -segment_format avi -v error chunk-%03d.seg

  b. Building the chunking list :

  #!/bin/bash -e
  
  set -e
  
  echo "ffconcat version 1.0" > concat.txt
  
  for f in `ls chunk-*.seg | sort`; do
  
  echo "file $f" >> concat.txt
  
  done

  c. Concatenate the chunks

  ffmpeg  -y -v error -i concat.txt -f concat -map 0 -c copy -f avi output.avi

  Then when I run ffprobe I get the following message which says it is a non-interleaved AVI :

      ffprobe version N-82301-g1bbb18f Copyright (c) 2007-2016 the FFmpeg developers
  
    built with gcc 5.4.0 (GCC)
  
    configuration: --enable-gpl --enable-version3 --disable-w32threads --enable-dxva2 --enable-libmfx --enable-nvenc --enable-avisynth --enable-bzlib --enable-libebur128 --enable-fontconfig --enable-frei0r --enable-gnutls --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-libopenh264 --enable-libopenjpeg --enable-libopus --enable-librtmp --enable-libschroedinger --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxavs --enable-libxvid --enable-libzimg --enable-lzma --enable-decklink --enable-zlib
  
    libavutil      55. 35.100 / 55. 35.100
  
    libavcodec     57. 66.101 / 57. 66.101
  
    libavformat    57. 57.100 / 57. 57.100
  
    libavdevice    57.  2.100 / 57.  2.100
  
    libavfilter     6. 66.100 /  6. 66.100
  
    libswscale      4.  3.100 /  4.  3.100
  
    libswresample   2.  4.100 /  2.  4.100
  
    libpostproc    54.  2.100 / 54.  2.100
  
  [avi @ 00000000028e3700] non-interleaved AVI
  
  Input #0, avi, from 'output.avi':
  
    Metadata:
  
      encoder         : Lavf57.57.100
  
    Duration: 74:43:47.82, start: 0.000000, bitrate: 17 kb/s
  
      Stream #0:0: Video: mpeg4 (Advanced Simple Profile) (XVID / 0x44495658), yuv420p, 640x368 [SAR 1:1 DAR 40:23], 23.98 fps, 23.98 tbr, 23.98 tbn, 23.98 tbc
  
      Stream #0:1: Audio: mp3 (U[0][0][0] / 0x0055), 48000 Hz, stereo, s16p, 112 kb/s

  I have tried a few other things without success. Any help would be greatly appreciated. Thanks in advance !!

• Live video broadcasting in android using front and back facing cameras [on hold]

  1er décembre 2016, par Jun Kim

  This is my first time I am posting a question on Stack Overflow.

  I am currently developing an android application. My goal is to make an app that captures and records video and broadcasts it to other mobile devices as well as web browsers like facebook live.
  (Nowadays, famous apps like Youtube, Facebook, Twitch, Periscope has this function)

  Now, I am just researching what technologies and ways to develop this app.

  I have been researching and reading a lot of blogs and documentations for the past five weeks about FFMpeg, different types of streaming technologies, types of web servers etc. I decided to use MPEG-DASH for my app and nginx server (Nginx-rtmp-module).

  While searching further, I got stuck and confused about how I can possibly capture & record video using internal camera of Android mobile devices.

  I was thinking that I could use MediaRecorder to capture & record (I could hardly find an example using MediaRecorder to record video) and use FFMpeg
  to somehow encode with the certain video and audio codecs to make a container format and send it to nginx server to broadcast other devices.
  But then.... i am not sure if this is the right way to do it...

  My questions is... I would like to know the whole process (in detail if it possible) how I can possible record and broadcast to other devices.

  The whole process of recording video using internal camera that is in user’s mobile device and send the frame to the server to broadcast to other devices seems difficult to imagine for me... Can anyone elaborate ?

  Or any suggestion about how can I reach my goal ?
  Every help would be appreciated.

• crystalhd : Revert back to letting hardware handle packed b-frames

  16 octobre 2016, par Philip Langdale

  crystalhd : Revert back to letting hardware handle packed b-frames
  I’m not sure why, but the mpeg4_unpack_bframes bsf is not
  
  interacting well with seeking. Looking at the code, it should be
  
  ok, with possibly one warning shown, but I see it getting stuck
  
  for an extended period of time after a seek where a packed frame
  
  is cached to be shown later.
  So, I gave up on that and went back to making the old hardware
  
  based path work. Turns out that it wasn’t broken except that some
  
  samples have a 6 byte drop packet which I wasn’t accounting for.
  Now it works again and seeks are good.
  

  • [DH] libavcodec/crystalhd.c