ffmpeg 连接导致第二个输入文件的输出错误/乱码

Question

我正在尝试使用 ffmpeg concat demuxer 将两个视频连接在一起:一个 5 秒的介绍启动画面和一个 60 秒的主要/正文视频。我知道两个文件的编码必须相同才能正常工作。我认为它们是，但结果输出显示介绍很好，然后是完全乱码的正文。我错过了什么？

ffmpeg -f concat -i concat.txt -c copy output.mp4

concat.txt的内容:

file 'intro.mp4'
file 'body.mp4'

和 ffprobe 的输出对于两个输入文件:

介绍.mp4

ffprobe version 3.2.4 Copyright (c) 2007-2017 the FFmpeg developers
  built with Apple LLVM version 7.0.2 (clang-700.1.81)
  configuration: --prefix=/usr/local/Cellar/ffmpeg/3.2.4 --enable-shared --enable-pthreads --enable-gpl --enable-version3 --enable-hardcoded-tables --enable-avresample --cc=clang --host-cflags= --host-ldflags= --enable-libmp3lame --enable-libx264 --enable-libxvid --enable-opencl --disable-lzma --enable-vda
  libavutil      55. 34.101 / 55. 34.101
  libavcodec     57. 64.101 / 57. 64.101
  libavformat    57. 56.101 / 57. 56.101
  libavdevice    57.  1.100 / 57.  1.100
  libavfilter     6. 65.100 /  6. 65.100
  libavresample   3.  1.  0 /  3.  1.  0
  libswscale      4.  2.100 /  4.  2.100
  libswresample   2.  3.100 /  2.  3.100
  libpostproc    54.  1.100 / 54.  1.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'intro.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf57.56.101
  Duration: 00:00:05.04, start: 0.000000, bitrate: 73 kb/s
    Stream #0:0(eng): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 960x720 [SAR 1:1 DAR 4:3], 69 kb/s, 25 fps, 25 tbr, 12800 tbn, 50 tbc (default)
    Metadata:
      handler_name    : VideoHandler

正文.mp​​4

ffprobe version 3.2.4 Copyright (c) 2007-2017 the FFmpeg developers
  built with Apple LLVM version 7.0.2 (clang-700.1.81)
  configuration: --prefix=/usr/local/Cellar/ffmpeg/3.2.4 --enable-shared --enable-pthreads --enable-gpl --enable-version3 --enable-hardcoded-tables --enable-avresample --cc=clang --host-cflags= --host-ldflags= --enable-libmp3lame --enable-libx264 --enable-libxvid --enable-opencl --disable-lzma --enable-vda
  libavutil      55. 34.101 / 55. 34.101
  libavcodec     57. 64.101 / 57. 64.101
  libavformat    57. 56.101 / 57. 56.101
  libavdevice    57.  1.100 / 57.  1.100
  libavfilter     6. 65.100 /  6. 65.100
  libavresample   3.  1.  0 /  3.  1.  0
  libswscale      4.  2.100 /  4.  2.100
  libswresample   2.  3.100 /  2.  3.100
  libpostproc    54.  1.100 / 54.  1.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'body.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf57.56.101
  Duration: 00:00:36.84, start: 0.000000, bitrate: 5615 kb/s
    Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 960x720 [SAR 1:1 DAR 4:3], 5613 kb/s, 25 fps, 25 tbr, 12800 tbn, 50 tbc (default)
    Metadata:
      handler_name    : VideoHandler

ffmpeg 的输出:

ffmpeg version 3.2.4 Copyright (c) 2000-2017 the FFmpeg developers
  built with Apple LLVM version 7.0.2 (clang-700.1.81)
  configuration: --prefix=/usr/local/Cellar/ffmpeg/3.2.4 --enable-shared --enable-pthreads --enable-gpl --enable-version3 --enable-hardcoded-tables --enable-avresample --cc=clang --host-cflags= --host-ldflags= --enable-libmp3lame --enable-libx264 --enable-libxvid --enable-opencl --disable-lzma --enable-vda
  libavutil      55. 34.101 / 55. 34.101
  libavcodec     57. 64.101 / 57. 64.101
  libavformat    57. 56.101 / 57. 56.101
  libavdevice    57.  1.100 / 57.  1.100
  libavfilter     6. 65.100 /  6. 65.100
  libavresample   3.  1.  0 /  3.  1.  0
  libswscale      4.  2.100 /  4.  2.100
  libswresample   2.  3.100 /  2.  3.100
  libpostproc    54.  1.100 / 54.  1.100
[mov,mp4,m4a,3gp,3g2,mj2 @ 0x7fdda3018000] Auto-inserting h264_mp4toannexb bitstream filter
Input #0, concat, from 'concat.txt':
  Duration: N/A, start: 0.000000, bitrate: 69 kb/s
    Stream #0:0(eng): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 960x720 [SAR 1:1 DAR 4:3], 69 kb/s, 25 fps, 25 tbr, 12800 tbn, 50 tbc
    Metadata:
      handler_name    : VideoHandler
Output #0, mp4, to 'output.mp4':
  Metadata:
    encoder         : Lavf57.56.101
    Stream #0:0(eng): Video: h264 (High) ([33][0][0][0] / 0x0021), yuv420p, 960x720 [SAR 1:1 DAR 4:3], q=2-31, 69 kb/s, 25 fps, 25 tbr, 12800 tbn, 12800 tbc
    Metadata:
      handler_name    : VideoHandler
Stream mapping:
  Stream #0:0 -> #0:0 (copy)
Press [q] to stop, [?] for help
[mov,mp4,m4a,3gp,3g2,mj2 @ 0x7fdda3800000] Auto-inserting h264_mp4toannexb bitstream filter
frame= 1047 fps=973 q=-1.0 Lsize=   25299kB time=00:00:41.76 bitrate=4962.8kbits/s speed=38.8x    
video:25286kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.050621%

据我所知，除了比特率和语言之外，一切都是相同的。设置语言似乎没有什么区别。我已经尝试将介绍转码为更高的介绍比特率，但无法让它留在输出中。我可以对其中一个文件(最好是介绍)进行转码，但不知道还要尝试更改什么。想法？

Answer 1

感谢@Mulvya 的建议，我使用了mediainfo检查文件并注意到两者已使用不同的 crf 进行编码设置。使用相同的 crf 重新编码简介产生了一个有效的连接文件。