FFMPEG 重新编码 clip1 以匹配用于 concat demux 的 clip2

Question

我想使用 ffmpeg concat 连接两个视频剪辑。要使用 concat demuxer，两者都应该具有相同的编解码器设置。 clip2 要短得多，所以我想重新编码以匹配 clip1。最初，clip2 的 tbn 不匹配，我使用“-video_track_timescale 50000”对其进行了调整。切入clip2后的concat视频还是乱码(音频好像还可以)
这是 ffprobe 告诉 clip1 的内容:

ffprobe version N-80251-g0c7fa15 Copyright (c) 2007-2016 the FFmpeg developers
  built with gcc 4.8 (Ubuntu 4.8.4-2ubuntu1~14.04.3)
  configuration: --prefix=/home/tools/ffmpeg_build --pkg-config-flags=--static --extra-cflags=-I/home/tools/ffmpeg_build/include --extra-ldflags=-L/home/tools/ffmpeg_build/lib --bindir=/home/tools/bin --enable-gpl --enable-libass --enable-libfdk-aac --enable-libfreetype --enable-libmp3lame --enable-libopus --enable-libtheora --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libx265 --enable-nonfree
  libavutil      55. 24.100 / 55. 24.100
  libavcodec     57. 45.100 / 57. 45.100
  libavformat    57. 37.101 / 57. 37.101
  libavdevice    57.  0.101 / 57.  0.101
  libavfilter     6. 46.101 /  6. 46.101
  libswscale      4.  1.100 /  4.  1.100
  libswresample   2.  0.101 /  2.  0.101
  libpostproc    54.  0.100 / 54.  0.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'clip1.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 1
    compatible_brands: isomavc1
    creation_time   : 2020-11-09 01:16:52
  Duration: 01:23:09.33, start: 0.000000, bitrate: 2279 kb/s
    Stream #0:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p, 1280x720 [SAR 1:1 DAR 16:9], 2080 kb/s, 50 fps, 50 tbr, 50k tbn, 100 tbc (default)
    Metadata:
      creation_time   : 2020-11-09 01:16:52
      handler_name    : 11.07_21-45_ard_90_TVOON_DE.mpg.HD_video.h264@GPAC0.5.2-DEV-revVersion: 0.5.2-426-gc5ad4e4+dfsg5-1ubuntu0.1
    Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 196 kb/s (default)
    Metadata:
      creation_time   : 2020-11-09 01:17:45
      handler_name    : 11.07_21-45_ard_90_TVOON_DE.mpg.HD.aac@GPAC0.5.2-DEV-revVersion: 0.5.2-426-gc5ad4e4+dfsg5-1ubuntu0.1

来自剪辑2

ffprobe version N-80251-g0c7fa15 Copyright (c) 2007-2016 the FFmpeg developers
  built with gcc 4.8 (Ubuntu 4.8.4-2ubuntu1~14.04.3)
  configuration: --prefix=/home/tools/ffmpeg_build --pkg-config-flags=--static --extra-cflags=-I/home/tools/ffmpeg_build/include --extra-ldflags=-L/home/tools/ffmpeg_build/lib --bindir=/home/tools/bin --enable-gpl --enable-libass --enable-libfdk-aac --enable-libfreetype --enable-libmp3lame --enable-libopus --enable-libtheora --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libx265 --enable-nonfree
  libavutil      55. 24.100 / 55. 24.100
  libavcodec     57. 45.100 / 57. 45.100
  libavformat    57. 37.101 / 57. 37.101
  libavdevice    57.  0.101 / 57.  0.101
  libavfilter     6. 46.101 /  6. 46.101
  libswscale      4.  1.100 /  4.  1.100
  libswresample   2.  0.101 /  2.  0.101
  libpostproc    54.  0.100 / 54.  0.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'clip2.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf57.37.101
    comment         :  
  Duration: 00:18:42.02, start: 0.000000, bitrate: 1693 kb/s
    Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 1280x720 [SAR 1:1 DAR 16:9], 1553 kb/s, 50 fps, 50 tbr, 50k tbn, 100 tbc (default)
    Metadata:
      handler_name    : VideoHandler
    Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 130 kb/s (default)
    Metadata:
      handler_name    : SoundHandler

然后对于 concat :

/home/tools/bin/ffmpeg -f concat -i list.files  -y clip12.mp4

唯一的差距是与
剪辑1:2080 kb/s
剪辑2:1553 kb/s
这很重要吗？
如果是，如何重新编码 clip2 以匹配并导致 concat clip12 干净？
编辑(根据洛根的反馈):
使用最新的 ffprobe 探测输入剪辑。
剪辑1:

ffprobe version N-54874-ga1553b0cfb-static https://johnvansickle.com/ffmpeg/  Copyright (c) 2007-2020 the FFmpeg developers
  built with gcc 8 (Debian 8.3.0-6)
  configuration: --enable-gpl --enable-version3 --enable-static --disable-debug --disable-ffplay --disable-indev=sndio --disable-outdev=sndio --cc=gcc --enable-fontconfig --enable-frei0r --enable-gnutls --enable-gmp --enable-libgme --enable-gray --enable-libaom --enable-libfribidi --enable-libass --enable-libvmaf --enable-libfreetype --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-librubberband --enable-libsoxr --enable-libspeex --enable-libsrt --enable-libvorbis --enable-libopus --enable-libtheora --enable-libvidstab --enable-libvo-amrwbenc --enable-libvpx --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libdav1d --enable-libxvid --enable-libzvbi --enable-libzimg
  libavutil      56. 60.100 / 56. 60.100
  libavcodec     58.112.101 / 58.112.101
  libavformat    58. 64.100 / 58. 64.100
  libavdevice    58. 11.102 / 58. 11.102
  libavfilter     7. 88.102 /  7. 88.102
  libswscale      5.  8.100 /  5.  8.100
  libswresample   3.  8.100 /  3.  8.100
  libpostproc    55.  8.100 / 55.  8.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'clip1.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 1
    compatible_brands: isomavc1
    creation_time   : 2020-11-09T01:16:52.000000Z
  Duration: 01:23:09.33, start: 0.000000, bitrate: 2279 kb/s
    Stream #0:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p, 1280x720 [SAR 1:1 DAR 16:9], 2080 kb/s, 50 fps, 50 tbr, 50k tbn, 100 tbc (default)
    Metadata:
      creation_time   : 2020-11-09T01:16:52.000000Z
      handler_name    : 11.07_21-45_ard_90_TVOON_DE.mpg.HD_video.h264@GPAC0.5.2-DEV-revVersion: 0.5.2-426-gc5ad4e4+dfsg5-1ubuntu0.1
    Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 196 kb/s (default)
    Metadata:
      creation_time   : 2020-11-09T01:17:45.000000Z
      handler_name    : 11.07_21-45_ard_90_TVOON_DE.mpg.HD.aac@GPAC0.5.2-DEV-revVersion: 0.5.2-426-gc5ad4e4+dfsg5-1ubuntu0.1

更改 clip2 的命令和日志:

/usr/share/ffmpeg.4.3.1//ffmpeg-git-20201104-amd64-static/ffmpeg -i clip2.avi -ss 00:12:55  -t 00:05:48 -c:v libx264 -profile:v main -video_track_timescale 50k -c:a copy -y clip2.mp4 2> ffmpeg_clip2.log
ffmpeg version N-54874-ga1553b0cfb-static https://johnvansickle.com/ffmpeg/  Copyright (c) 2000-2020 the FFmpeg developers
  built with gcc 8 (Debian 8.3.0-6)
  configuration: --enable-gpl --enable-version3 --enable-static --disable-debug --disable-ffplay --disable-indev=sndio --disable-outdev=sndio --cc=gcc --enable-fontconfig --enable-frei0r --enable-gnutls --enable-gmp --enable-libgme --enable-gray --enable-libaom --enable-libfribidi --enable-libass --enable-libvmaf --enable-libfreetype --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-librubberband --enable-libsoxr --enable-libspeex --enable-libsrt --enable-libvorbis --enable-libopus --enable-libtheora --enable-libvidstab --enable-libvo-amrwbenc --enable-libvpx --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libdav1d --enable-libxvid --enable-libzvbi --enable-libzimg
  libavutil      56. 60.100 / 56. 60.100
  libavcodec     58.112.101 / 58.112.101
  libavformat    58. 64.100 / 58. 64.100
  libavdevice    58. 11.102 / 58. 11.102
  libavfilter     7. 88.102 /  7. 88.102
  libswscale      5.  8.100 /  5.  8.100
  libswresample   3.  8.100 /  3.  8.100
  libpostproc    55.  8.100 / 55.  8.100
Input #0, avi, from 'clip2.avi':
  Metadata:
    comment         :  
    encoder         : Lavf58.42.100
    encoded_by      : www.onlinetvrecorder.com
  Duration: 00:35:48.90, start: 0.000000, bitrate: 2243 kb/s
    Stream #0:0: Video: h264 (Main) (H264 / 0x34363248), yuv420p(progressive), 1280x720 [SAR 1:1 DAR 16:9], 2034 kb/s, 50 fps, 50 tbr, 50 tbn, 100 tbc
    Stream #0:1: Audio: mp3 (U[0][0][0] / 0x0055), 48000 Hz, stereo, fltp, 192 kb/s
Stream mapping:
  Stream #0:0 -> #0:0 (h264 (native) -> h264 (libx264))
  Stream #0:1 -> #0:1 (copy)
Press [q] to stop, [?] for help
frame=    0 fps=0.0 q=0.0 size=       0kB time=-577014:32:22.77 bitrate=  -0.0kbits/s speed=N/A  
...
frame=    0 fps=0.0 q=0.0 size=       0kB time=-577014:32:22.77 bitrate=  -0.0kbits/s speed=N/A
[libx264 @ 0x71fb740] using SAR=1/1
[libx264 @ 0x71fb740] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX FMA3
[libx264 @ 0x71fb740] profile Main, level 3.2, 4:2:0, 8-bit
[libx264 @ 0x71fb740] 264 - core 161 r3027 4121277 - H.264/MPEG-4 AVC codec - Copyleft 2003-2020 - 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=6 lookahead_threads=1 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=25 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 'clip2.mp4':
  Metadata:
    comment         :  
    encoded_by      : www.onlinetvrecorder.com
    encoder         : Lavf58.64.100
    Stream #0:0: Video: h264 (libx264) (avc1 / 0x31637661), yuv420p(progressive), 1280x720 [SAR 1:1 DAR 16:9], q=-1--1, 50 fps, 50k tbn, 50 tbc
    Metadata:
      encoder         : Lavc58.112.101 libx264
    Side data:
      cpb: bitrate max/min/avg: 0/0/0 buffer size: 0 vbv_delay: N/A
    Stream #0:1: Audio: mp3 (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 192 kb/s
frame=   15 fps=0.4 q=0.0 size=       0kB time=00:00:00.31 bitrate=   1.2kbits/s speed=0.00806x    
...
frame=17400 fps= 73 q=-1.0 Lsize=   62382kB time=00:05:47.97 bitrate=1468.6kbits/s speed=1.47x    
video:53846kB audio:8156kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.611439%
[libx264 @ 0x71fb740] frame I:157   Avg QP:18.21  size: 42082
[libx264 @ 0x71fb740] frame P:5607  Avg QP:22.21  size:  6677
[libx264 @ 0x71fb740] frame B:11636 Avg QP:23.93  size:   953
[libx264 @ 0x71fb740] consecutive B-frames:  8.3%  6.0%  5.0% 80.8%
[libx264 @ 0x71fb740] mb I  I16..4: 47.5%  0.0% 52.5%
[libx264 @ 0x71fb740] mb P  I16..4:  5.7%  0.0%  1.1%  P16..4: 35.4%  6.2%  3.0%  0.0%  0.0%    skip:48.4%
[libx264 @ 0x71fb740] mb B  I16..4:  0.2%  0.0%  0.0%  B16..8: 21.0%  0.4%  0.0%  direct: 0.5%  skip:77.9%  L0:45.1% L1:53.8% BI: 1.2%
[libx264 @ 0x71fb740] coded y,uvDC,uvAC intra: 24.6% 38.3% 6.0% inter: 2.8% 4.7% 0.0%
[libx264 @ 0x71fb740] i16 v,h,dc,p: 43% 24% 15% 18%
[libx264 @ 0x71fb740] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 26% 20% 19%  6%  7%  6%  6%  6%  4%
[libx264 @ 0x71fb740] i8c dc,h,v,p: 57% 20% 20%  4%
[libx264 @ 0x71fb740] Weighted P-Frames: Y:0.5% UV:0.4%
[libx264 @ 0x71fb740] ref P L0: 70.3% 12.1% 14.0%  3.6%  0.0%
[libx264 @ 0x71fb740] ref B L0: 92.9%  5.9%  1.2%
[libx264 @ 0x71fb740] ref B L1: 97.5%  2.5%
[libx264 @ 0x71fb740] kb/s:1267.54

我观察到我认为是音频 channel 的不匹配。
剪辑1:

/usr/share/ffmpeg.4.3.1//ffmpeg-git-20201104-amd64-static/ffprobe  clip1.mp4
    Stream #0:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p, 1280x720 [SAR 1:1 DAR 16:9], 2080 kb/s, 50 fps, 50 tbr, 50k tbn, 100 tbc (default)
    Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 196 kb/s (default)

剪辑2:

/usr/share/ffmpeg.4.3.1//ffmpeg-git-20201104-amd64-static/ffprobe  clip2.mp4 
    Stream #0:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p, 1280x720 [SAR 1:1 DAR 16:9], 1267 kb/s, 50 fps, 50 tbr, 50k tbn, 100 tbc (default)
    Stream #0:1(und): Audio: mp3 (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 192 kb/s (default)

可能需要匹配音频 channel 。我注意到concat的时间太长了。我期待 concat 只进行复制而不是重新渲染。

Answer 1

ffmpeg -i clip2.mp4 -c:v libx264 -profile:v main -c:a aac -video_track_timescale 50k clip2b.mp4

H.264 配置文件不同:h264 (Main)对比 h264 (High) .使用 -profile:v main选项。

音频格式不同:AAC 和 MP3。添加 -c:a aac .

将时间刻度 ( tbn ) 与 -video_track_timescale 匹配.