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• avfilter/fade : add color option.

  8 novembre 2013, par Clément Bœsch

  avfilter/fade : add color option.
  Fixes Ticket #1822.
  

  • [DH] doc/filters.texi
  • [DH] libavfilter/vf_fade.c

• Split a movie into 1000+ shots using PyAV in a single pass ?

  3 mai 2019, par Andrew Klaassen

  I need to split a 44 minute MP4 into 1000 shots (i.e. separate MP4s) with ffmpeg. I want to do it quickly (i.e. in a single pass rather than 1000 passes), I need perfect frame accuracy, and I need to do it in Windows.

  The Windows command-line length limit is stopping me from doing this, and I’m wondering if someone could show me an example of how to do this using a library like PyAV or Avpy. (Libraries like ffmpeg-python and ffmpy won’t help, since they simply construct an ffmpeg command line and run it, leading to the same Windows command-line length issue that I already have.)

  After much testing and gnashing of teeth, I’ve learned that the only way to get perfect frame accuracy from ffmpeg, 100% of the time, is to use the "select" filter. ("-ss" in the newest versions of ffmpeg is frame accurate 99% of the time ; unfortunately, that’s not good enough for this application.)

  There are two ways to use "select" for this. There’s the slow way, which I’m doing now, and which requires having ffmpeg open the file 1000 times :

  for (start, end, name) in shots:
  
      audio_start = start / frame_rate
  
      audio_end = end + 1 / frame_rate
  
      cmd = [
  
          path_to_ffmpeg,
  
          '-y',
  
          '-i', input_movie,
  
          '-vf', r'select=between(n\,%s\,%s),setpts=PTS-STARTPTS' % (start, end),
  
          '-af', 'atrim=%s:%s,asetpts=PTS-STARTPTS' % (audio_start, audio_end),
  
          '-c:v', 'libx264',
  
          '-c:a', 'aac',
  
          '-write_tmcd', '0',
  
          '-g', '1',
  
          '-r', str(frame_rate),
  
          name + '.mp4',
  
          '-af', 'atrim=%s:%s' % (audio_start, audio_end),
  
          name + '.wav',
  
      ]
  
      subprocess.call(cmd)

  And there’s the fast way, which causes the Windows command line to explode when there are too many shots. The long command line leads to a failure to run :

  cmd = [
  
      path_to_ffmpeg,
  
      '-y',
  
      '-i',
  
      input_movie,
  
  ]
  
  for (start, end, name) in shots:
  
      audio_start = start / frame_rate
  
      audio_end = end + 1 / frame_rate
  
      cmd.extend([
  
          '-vf', r'select=between(n\,%s\,%s),setpts=PTS-STARTPTS' % (start, end),
  
          '-af', 'atrim=%s:%s,asetpts=PTS-STARTPTS' % (audio_start, audio_end),
  
          '-c:v', 'libx264',
  
          '-c:a', 'aac',
  
          '-write_tmcd', '0',
  
          '-g', '1',
  
          '-r', str(frame_rate),
  
          name + '.mp4',
  
          '-af', 'atrim=%s:%s' % (audio_start, audio_end),
  
          name + '.wav',
  
      ]
  
  subprocess.call(cmd)

  I’ve looked through the documentation of PyAV and Avpy, but I haven’t been able to figure out whether the second form of my function is something I could do there, or how I’d go about doing it. If it is possible, would someone be able to write a function equivalent to my second function, using either library ?

• Getting a lot of Tail Silence when combining an image and audio into mp4 movie

  1er avril 2023, par Meryan

  As it can be seen from this snapshot the audio HELLO.mp3 combined with bitmap HELLO.jpg produced a movie HELLO_aac.mp4 that has a huge amount of tail silence

  


  

  


  The command line I was helped to put together is the following

  


  ======================== 
IN_FILES=-i ".\HELLO.JPG" -i ".\HELLO.MP3"    
OUT_FILE=".\HELLO_aac.MP4"   
EXE="S:\_BINS\FFmpeg 4.2.1 20200112\bin\ffmpeg.exe"  
OPTIONS= -loop 1   -i ".\HELLO.JPG" -i ".\HELLO.MP3"    -vf "scale=-1:1080,pad=1920:1080:(1920-iw)/2:(1080-ih)/2,setsar=1"  -c:v libx264 -profile:v main -pix_fmt yuv420p -r 24 -video_track_timescale 24000    -c:a aac    -shortest -y ".\HELLO_aac.MP4"     
======================== 



  


  Here is the captured output from FFmpeg

  


  ffmpeg version git-2020-01-10-3d894db Copyright (c) 2000-2020 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. 65.103 / 58. 65.103
  libavformat    58. 35.101 / 58. 35.101
  libavdevice    58.  9.103 / 58.  9.103
  libavfilter     7. 70.101 /  7. 70.101
  libswscale      5.  6.100 /  5.  6.100
  libswresample   3.  6.100 /  3.  6.100
  libpostproc    55.  6.100 / 55.  6.100
Input #0, image2, from '.\HELLO.JPG':
  Duration: 00:00:00.04, start: 0.000000, bitrate: 23923 kb/s
    Stream #0:0: Video: mjpeg (Baseline), yuvj420p(pc, bt470bg/unknown/unknown), 1600x1200 [SAR 120:120 DAR 4:3], 25 fps, 25 tbr, 25 tbn, 25 tbc
[mp3 @ 000002019015d4c0] Estimating duration from bitrate, this may be inaccurate
Input #1, mp3, from '.\HELLO.MP3':
  Metadata:
    genre           : Blues
    id3v2_priv.XMP  : <?xpacket begin="\xef\xbb\xbf" id="W5M0MpCehiHzreSzNTczkc9d"?>\x0a\x0a \x0a  s
    Stream #1:0: Audio: mp3, 24000 Hz, mono, fltp, 32 kb/s
Stream mapping:
  Stream #0:0 -> #0:0 (mjpeg (native) -> h264 (libx264))
  Stream #1:0 -> #0:1 (mp3 (mp3float) -> aac (native))
Press [q] to stop, [?] for help
[swscaler @ 0000020190b10380] deprecated pixel format used, make sure you did set range correctly
[swscaler @ 0000020190b10380] Warning: data is not aligned! This can lead to a speed loss
[libx264 @ 0000020190759300] using SAR=1/1
[libx264 @ 0000020190759300] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX FMA3 BMI2 AVX2
[libx264 @ 0000020190759300] profile Main, level 4.0, 4:2:0, 8-bit
[libx264 @ 0000020190759300] 264 - core 158 - H.264/MPEG-4 AVC codec - Copyleft 2003-2019 - http://www.videolan.org/x264.html - options: cabac=1 ref=3 deblock=1:0:0 analyse=0x1:0x111 me=hex subme=7 psy=1 psy_rd=1.00:0.00 mixed_ref=1 me_range=16 chroma_me=1 trellis=1 8x8dct=0 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=-2 threads=34 lookahead_threads=5 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=3 b_pyramid=2 b_adapt=1 b_bias=0 direct=1 weightb=1 open_gop=0 weightp=2 keyint=250 keyint_min=24 scenecut=40 intra_refresh=0 rc_lookahead=40 rc=crf mbtree=1 crf=23.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00
Output #0, mp4, to '.\HELLO_aac.MP4':
  Metadata:
    encoder         : Lavf58.35.101
    Stream #0:0: Video: h264 (libx264) (avc1 / 0x31637661), yuv420p(progressive), 1920x1080 [SAR 1:1 DAR 16:9], q=-1--1, 24 fps, 24k tbn, 24 tbc
    Metadata:
      encoder         : Lavc58.65.103 libx264
    Side data:
      cpb: bitrate max/min/avg: 0/0/0 buffer size: 0 vbv_delay: N/A
    Stream #0:1: Audio: aac (LC) (mp4a / 0x6134706D), 24000 Hz, mono, fltp, 69 kb/s
    Metadata:
      encoder         : Lavc58.65.103 aac
frame=   69 fps=0.0 q=0.0 size=       0kB time=00:00:00.00 bitrate=N/A dup=0 drop=1 speed=   0x    
frame=   97 fps=0.0 q=-1.0 Lsize=     128kB time=00:00:03.91 bitrate= 267.1kbits/s dup=0 drop=2 speed=5.04x    
video:119kB audio:6kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 2.208101%
[libx264 @ 0000020190759300] frame I:1     Avg QP:12.88  size:103994
[libx264 @ 0000020190759300] frame P:24    Avg QP:14.05  size:   224
[libx264 @ 0000020190759300] frame B:72    Avg QP:12.67  size:   160
[libx264 @ 0000020190759300] consecutive B-frames:  1.0%  0.0%  0.0% 99.0%
[libx264 @ 0000020190759300] mb I  I16..4: 61.7%  0.0% 38.3%
[libx264 @ 0000020190759300] mb P  I16..4:  0.1%  0.0%  0.0%  P16..4:  0.5%  0.1%  0.0%  0.0%  0.0%    skip:99.3%
[libx264 @ 0000020190759300] mb B  I16..4:  0.0%  0.0%  0.0%  B16..8:  1.6%  0.0%  0.0%  direct: 0.0%  skip:98.4%  L0:81.1% L1:18.9% BI: 0.0%
[libx264 @ 0000020190759300] coded y,uvDC,uvAC intra: 34.5% 17.3% 15.6% inter: 0.0% 0.1% 0.0%
[libx264 @ 0000020190759300] i16 v,h,dc,p: 70% 19%  7%  3%
[libx264 @ 0000020190759300] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 40% 22% 12%  4%  5%  5%  3%  5%  4%
[libx264 @ 0000020190759300] i8c dc,h,v,p: 80%  8% 10%  2%
[libx264 @ 0000020190759300] Weighted P-Frames: Y:0.0% UV:0.0%
[libx264 @ 0000020190759300] ref P L0: 97.6%  0.3%  1.5%  0.6%
[libx264 @ 0000020190759300] ref B L0:  1.8% 98.2%
[libx264 @ 0000020190759300] ref B L1: 99.9%  0.1%
[libx264 @ 0000020190759300] kb/s:239.28
[aac @ 000002019075bf40] Qavg: 8004.814
======================== 


  


  I have also tried the following command line

  


  "S:\_BINS\ffmpeg-2023-03-20\bin\ffmpeg.exe" -loop 1 -i "HELLO.JPG" -i "HELLO.MP3" -c:v libx264 -tune stillimage -c:a aac -b:a 192k -pix_fmt yuv420p -y -shortest "HELLO_aac.mp4"    


  


  With similar long dead tail silence ???