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• Revision 45aa6f15b0 : Remove redundant bsize mapping in motion search Both single frame and compound

  5 décembre 2013, par Jingning Han

  Changed Paths :
   Modify /vp9/encoder/vp9_rdopt.c

  
  
  Remove redundant bsize mapping in motion search

  Both single frame and compound inter motion search run with luma
  component only. Hence removing the block size mapping therein.

  Change-Id : I217488e702432ae9fa0e95bf6f516ebb36b5c79b

• FFMPEG error : Error while parsing expression 'PTS-STARTPTS+/TB' while trying to merge two videos with different starting time [closed]

  13 octobre 2020, par Sankalpa Sarkar

  I was trying to merge two videos in .webm format side-by-side, with the exception that the second video might start a bit later than the first video, in which case there will be a blank buffer on the right side till it starts. To do that, I deployed the following code :

  


     DIFF=$(($start_ts-$BASEts))
   DIFFms=`echo "scale=0;$DIFF/1000" | bc`
   DIFFs=`echo "scale=4;$DIFF/1000000" | bc`
   ffmpeg -i a.webm -i b.webm -filter_complex \
    "[0]pad=2*iw:1*ih[l];[1]setpts=PTS-STARTPTS+$DIFFs/TB[1v]; [l][1v]overlay=x=W/2[v]; \
    [1]adelay=$DIFFms|$DIFFms[1a]; \
    [0][1a]amix=inputs=2[a]" \
    -map "[v]" -map "[a]" -vcodec libvpx -cpu-used -5 -deadline realtime finalOutput.webm


  


  However, I keep getting this error :

  


  [Parsed_setpts_1 @ 0x5598b680cdc0] [Eval @ 0x7ffcb6ae1550] Undefined constant or missing '(' in '/TB'
[Parsed_setpts_1 @ 0x5598b680cdc0] Error while parsing expression 'PTS-STARTPTS+/TB'
[AVFilterGraph @ 0x5598b67872a0] Error initializing filter 'setpts' with args 'PTS-STARTPTS+/TB'
Error initializing complex filters.
Invalid argument


  


  It is not recognizing the DIFFs variable at all and is hence unable to process the code. I tried replacing the entire setpts in a different variable as well and using it in setpts while merging. That process did not work either

  


• Two pass encoding for VP8 using FFmpeg libraries

  20 mars 2014, par taansari

  I am trying to simulate two-pass encoding using FFmpeg libraries. Code I have so far is working fine for h264 codec, now I want it to work also for VP8. Normal encoding (i.e. single pass) works fine, both for mp4, and webm ; but the changes in code for two pass works only for mp4s. I have tried to tally code from ffmpeg.c file, and add it up in my encoding routines.

  Looking closer at different locations, developer logs, etc., I have come down to following possibilities :

  • 'stats_out' buffer is never allocated (though documentation says it is allocated automatically for encoding)
  • avcodec_encode_video2(c, &pkt, frame, &got_output) never sets 'got_output' for first pass

  Necessary bits of code :

  https://gist.github.com/anonymous/3e01cfdeb64fd577cc48

  In above code, for CODEC_FLAG_PASS1, stats file is created, but stats_out is always NULL, and avcodec_encode_video2() never sets got_output, so code under it is never executed.

  Apparently I have missed out something, but cannot understand what, exactly. Can anyone guide me towards my mistake ?

  Thanks !