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• Revision a37ee9d2e8 : Fix non-4:2:0 chroma MV calculation for SPLITMV The previous code was somewhat

  9 mai 2013, par John Koleszar

  Changed Paths :
   Modify /vp9/common/vp9_reconinter.c

  
  
  Fix non-4:2:0 chroma MV calculation for SPLITMV

  The previous code was somewhat vestigial for 16x16 MI units, but was
  incorrect when called with chroma blocks larger than 4x4 because the
  block index caused a reference to a non-existent BMI. This patch uses
  the same MV for all chroma subblocks in SPLITMV mode, which is
  suboptimal for non-4:2:0 subsamplings, but as SPLITMV may be removed
  in the near future, will use this as a stop gap.

  Change-Id : I3211cee5ccf1cfb426e5eef5353b0ce5bb92b4cd

• Remuxing DIVX to MP4 for iDevices

  16 octobre 2013, par Chris Robinson

  Please note, everything I refer to hereafter is using ffmpeg.

  I have a DIVX video which has an mpeg4 codec (MPEG4 Part 2) and an mp3 audio stream as given by ffmpeg -i file.avi. It's my understanding that I should simply be able to remux into an mp4 container for use with iTunes and iDevices by

  ffmpeg -i file.avi -vcodec copy -acodec copy output.mp4

  seeing as both codecs are complient with the Mpeg4 Part 14 specification. However I can't import these files into iTunes. I'm assuming this is because the FourCC of the original stream has been set to DIVX.

  Is there an easy way to change this without re-encoding the video stream ? I'm looking to remux rather than re-encode to keep losses to a minimum and because I have a massive library of DIVX files that I want to import into iTunes and ffmpeg is easily scriptable for addition of future files.

• Record sound with ffmpeg on ubuntu 12.04 [closed]

  27 juin 2012, par vzybilly

  I have been working for a few days on trying to get ffmpeg to record sound, a short list of what I've tried :

  #Crappy screen grab
  
  #ffmpeg -f x11grab -s "1366x768" -r "24" -i :0.0 -f mp4 ./out
  
  #awesome screen grab, grabbing sound but non out.
  
  #ffmpeg -f x11grab -s "1366x768" -r "24" -i :0.0 -f alsa -ac 2 -i pulse -vcodec libx264 -s "1366x768" -acodec libmp3lame -ab 128k -threads 0 -f mp4 ~/Desktop/vid
  
  #audio test, no audio in file.
  
  #ffmpeg -f alsa -ac 2 -i pulse -acodec libmp3lame -ab 128k -threads 0 -f mp3 ./test.mp3
  
  #awesome screen grab.
  
  #ffmpeg -f x11grab -s "1366x768" -r "24" -i :0.0 -threads 0 -sameq -an -f mp4 ~/Desktop/vid[/CODE]I'm running ubuntu 12.04 from beta(ish)

  it would be awesome if someone could help me get this to work all in one line or (the way i'm going) multiple instances of ffmpeg (screen grab, microphone, program)

  I have also tried the pavucontrol with doing the monitoring of when recording audio, but that does not help either.

  Thanks for all of your help, vzybilly 

  EDIT :
  This one crashed.

  $ ffmpeg -f alsa -ac 2 -i plughw:0,0 -f x11grab -r 100 -s 1366x768 -i :0.0 -acodec pcm_s16le -vcodec libx264 -preset ultrafast -threads 3 testVid.mkv
  
  ffmpeg version 0.8.3-4:0.8.3-0ubuntu0.12.04.1, Copyright (c) 2000-2012 the Libav developers
  
    built on Jun 12 2012 16:37:58 with gcc 4.6.3
  
  *** THIS PROGRAM IS DEPRECATED ***
  
  This program is only provided for compatibility and will be removed in a future release. Please use avconv instead.
  
  [alsa @ 0x8fce240] capture with some ALSA plugins, especially dsnoop, may hang.
  
  [alsa @ 0x8fce240] Estimating duration from bitrate, this may be inaccurate
  
  Input #0, alsa, from 'plughw:0,0':
  
    Duration: N/A, start: 433.999945, bitrate: N/A
  
      Stream #0.0: Audio: pcm_s16le, 48000 Hz, 2 channels, s16, 1536 kb/s
  
  [x11grab @ 0x8fde820] device: :0.0 -> display: :0.0 x: 0 y: 0 width: 1366 height: 768
  
  [x11grab @ 0x8fde820] shared memory extension  found
  
  [x11grab @ 0x8fde820] Estimating duration from bitrate, this may be inaccurate
  
  Input #1, x11grab, from ':0.0':
  
    Duration: N/A, start: 1340805516.368518, bitrate: N/A
  
      Stream #1.0: Video: rawvideo, bgra, 1366x768, -2147483 kb/s, 100 tbr, 1000k tbn, 100 tbc
  
  File 'testVid.mkv' already exists. Overwrite ? [y/N] y
  
  Incompatible pixel format 'bgra' for codec 'libx264', auto-selecting format 'yuv420p'
  
  [buffer @ 0x8fde700] w:1366 h:768 pixfmt:bgra
  
  [avsink @ 0x8fcdf20] auto-inserting filter 'auto-inserted scaler 0' between the filter 'src' and the filter 'out'
  
  [scale @ 0x8ff3ce0] w:1366 h:768 fmt:bgra -> w:1366 h:768 fmt:yuv420p flags:0x4
  
  [libx264 @ 0x8fdd920] lookaheadless mb-tree requires intra refresh or infinite keyint
  
  [libx264 @ 0x8fdd920] using cpu capabilities: MMX2 SSE2Fast SSSE3 FastShuffle SSE4.2
  
  [libx264 @ 0x8fdd920] profile Constrained Baseline, level 4.2
  
  [libx264 @ 0x8fdd920] 264 - core 120 r2151 a3f4407 - H.264/MPEG-4 AVC codec - Copyleft 2003-2011 - http://www.videolan.org/x264.html - options: cabac=0 ref=1 deblock=0:0:0 analyse=0:0 me=dia subme=0 psy=1 psy_rd=1.00:0.00 mixed_ref=0 me_range=16 chroma_me=1 trellis=0 8x8dct=0 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=0 threads=3 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=0 weightp=0 keyint=250 keyint_min=25 scenecut=0 intra_refresh=0 rc=crf mbtree=0 crf=23.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.25 aq=0
  
  Output #0, matroska, to 'archinstall4.mkv':
  
    Metadata:
  
      encoder         : Lavf53.21.0
  
      Stream #0.0: Video: libx264, yuv420p, 1366x768, q=-1--1, 1k tbn, 100 tbc
  
      Stream #0.1: Audio: pcm_s16le, 48000 Hz, 2 channels, s16, 1536 kb/s
  
  Stream mapping:
  
    Stream #1.0 -> #0.0
  
    Stream #0.0 -> #0.1
  
  Press ctrl-c to stop encoding
  
  [alsa @ 0x8fce240] ALSA buffer xrun.
  
  [matroska @ 0x8fcd980] Application provided invalid, non monotonically increasing dts to muxer in stream 1: 213 >= 213
  
  av_interleaved_write_frame(): Invalid argument

  Any thoughts ?

  EDIT & ANSWER :
  Got it all working with a script :

  #!/bin/bash
  
  #vzybilly
  
  #these are temp files
  
  aud="aud.mp3"
  
  vid="vid.mp4"
  
  #grab audio & pid
  
  ffmpeg -f alsa -ac 2 -i plughw:0,0 $aud &
  
  audPID=$!
  
  #grab screen & pid
  
  ffmpeg -f x11grab -s "1366x768" -r "24" -i :0.0 -threads 0 -sameq -an -f mp4 $vid &
  
  vidPID=$!
  
  #wait, till name given (that means stop)
  
  read -p "Stop by giving an Output video name?" out
  
  #stop audio and video with pids
  
  kill -n 2 $audPID
  
  kill -n 2 $vidPID
  
  echo "$out"
  
  #combine to the target output file
  
  ffmpeg -i $aud -i $vid -acodec copy -vcodec copy "$out"
  
  #purge the temp files
  
  rm $aud
  
  rm $vid