多次修剪（音频）ffmpeg期间的缓冲区错误

Question

我正在尝试修剪和连接音频文件的多个部分。经过多次搜索，这似乎有效。

ffmpeg -i dd.3gpp -filter_complex "[0]atrim=start=00:00:00.060:end=00:00:46.580[a];[0]atrim=start=00:0:50.250:end=00:01:50.670[b];[a][b]concat=n=2:v=0:a=1" output.mp3

然而，没过多久我就意识到它只有在修剪部分之间的间隔很短的情况下才有效。将第二个修剪部分的时间戳更改为此，

ffmpeg -i dd.3gpp -filter_complex "[0]atrim=start=00:00:00.060:end=00:00:46.580[a];[0]atrim=start=00:03:23.250:end=00:06:50.670[b];[a][b]concat=n=2:v=0:a=1" output.mp3

它不断向我抛出这个错误。

[out_0_0 @ 000001df0a98d6c0] 100 个缓冲区在 out_0_0 中排队，可能出现问题。[out_0_0 @ 000001df0a98d6c0] 1000 个缓冲区在 out_0_0 中排队，可能出现问题。

报告

ffmpeg version git-2019-12-12-f58bda6 Copyright (c) 2000-2019 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. 36.101 / 56. 36.101
  libavcodec     58. 65.100 / 58. 65.100
  libavformat    58. 35.101 / 58. 35.101
  libavdevice    58.  9.101 / 58.  9.101
  libavfilter     7. 68.100 /  7. 68.100
  libswscale      5.  6.100 /  5.  6.100
  libswresample   3.  6.100 /  3.  6.100
  libpostproc    55.  6.100 / 55.  6.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'dd.3gpp':
  Metadata:
    major_brand     : 3gp4
    minor_version   : 0
    compatible_brands: isom3gp4
    creation_time   : 2019-12-14T18:42:01.000000Z
    com.android.version: 7.0
  Duration: 00:08:46.06, start: 0.000000, bitrate: 129 kb/s
    Stream #0:0(eng): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 128 kb/s (default)
    Metadata:
      creation_time   : 2019-12-14T18:42:01.000000Z
      handler_name    : SoundHandle
Stream mapping:
  Stream #0:0 (aac) -> atrim
  Stream #0:0 (aac) -> atrim
  concat -> Stream #0:0 (libmp3lame)
Press [q] to stop, [?] for help
Output #0, mp3, to 'output.mp3':
  Metadata:
    major_brand     : 3gp4
    minor_version   : 0
    compatible_brands: isom3gp4
    com.android.version: 7.0
    TSSE            : Lavf58.35.101
    Stream #0:0: Audio: mp3 (libmp3lame), 48000 Hz, stereo, fltp (default)
    Metadata:
      encoder         : Lavc58.65.100 libmp3lame
size=     170kB time=00:00:10.84 bitrate= 128.5kbits/s speed=21.7x    
size=     256kB time=00:00:19.77 bitrate= 106.0kbits/s speed=19.7x    
size=     256kB time=00:00:28.17 bitrate=  74.4kbits/s speed=18.7x    
size=     512kB time=00:00:39.69 bitrate= 105.7kbits/s speed=19.8x    
[out_0_0 @ 000001df0a98d6c0] 100 buffers queued in out_0_0, something may be wrong.
[out_0_0 @ 000001df0a98d6c0] 1000 buffers queued in out_0_0, something may be wrong.
size=    1280kB time=00:01:33.09 bitrate= 112.6kbits/s speed=22.9x    
size=    1521kB time=00:01:37.27 bitrate= 128.1kbits/s speed=22.9x    
video:0kB audio:1520kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.023446%

是不是有什么地方做错了？欢迎所有建议。

Answer 1

所以在研究了这两个代码一段时间之后，

ffmpeg -i dd.3gpp -filter_complex "[0]atrim=start=00:00:00.060:end=00:00:46.580[a];[0]atrim=start=00:0:50.250:end=00:01:50.670[b];[a][b]concat=n=2:v=0:a=1" output.mp3

ffmpeg -i dd.3gpp -filter_complex "[0]atrim=start=00:00:00.060:end=00:00:46.580[a];[0]atrim=start=00:03:23.250:end=00:06:50.670[b];[a][b]concat=n=2:v=0:a=1" output.mp3

看来缓冲区错误与两次修剪之间的时间间隔是否短无关。

相反，时间戳的格式似乎是问题所在。我将时间戳更改为S+[.m...], 而不是[HH:]MM:SS[.m...]

ffmpeg -i dd.3gpp -filter_complex "[0]atrim=start=0.060:end=46.580[a];[0]atrim=start=203.250:end=410.670[b];[a][b]concat=n=2:v=0:a=1" output.mp3

并且错误不再出现。00:00:ss.m..第一个代码工作正常，因为我认为所有时间戳都落在秒列 ( ) 内。我必须说，我对为什么格式在这种情况下起作用一无所知。也许这里的专业人士可以解释得更好。