FFmpeg 错误地连接两个 m4a 文件

Question

问题是，当我使用 concat demuxer 连接两个 m4a 文件时，ffmpeg 生成的文件持续时间不正确。您可以看到输出文件的持续时间与两个输入文件组合的持续时间有很大不同。请帮我找出其中的问题。我的最终目标是将无声音频附加到音频文件的末尾。为此，我使用 ffmpeg 生成无声音频文件，然后尝试将其与其他音频文件连接。

我用来生成音频文件的命令：

ffmpeg -nostdin -loglevel error -y -threads 0 -filter_complex aevalsrc=0 -t 4 /home/ec2-user/videocreation/temp/silence.m4a

我用于连接的命令：

ffmpeg -f concat -safe 0 -i temp.txt -c copy output.m4a

我在 temp.txt 中列出了两个文件路径：

[ec2-user@ip-10-0-1-126 server]$ cat temp.txt 
file /home/ec2-user/videoData/DnXptC4ld8/FADING_OUT_VOLUP_Blrt_Decrypt_1ed5c4d569d8a1f23428b65217f65eaf_audio.m4a
file /home/ec2-user/videocreation/temp/silence.m4a

第一个文件 ffprobe:

[ec2-user@ip-10-0-1-126 server]$ ffprobe /home/ec2-user/videoData/DnXptC4ld8/FADING_OUT_VOLUP_Blrt_Decrypt_1ed5c4d569d8a1f23428b65217f65eaf_audio.m4a 
ffprobe version N-80097-g89e9393 Copyright (c) 2007-2016 the FFmpeg developers
  built with gcc 4.8.5 (GCC) 20150623 (Red Hat 4.8.5-4)
  configuration: --prefix=/home/ec2-user/ffmpeg_build --extra-cflags=-I/home/ec2-user/ffmpeg_build/include --extra-ldflags=-L/home/ec2-user/ffmpeg_build/lib --bindir=/home/ec2-user/bin --pkg-config-flags=--static --enable-gpl --enable-nonfree --enable-libfdk-aac --enable-libfreetype --enable-libmp3lame --enable-libopus --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libx265
  libavutil      55. 24.100 / 55. 24.100
  libavcodec     57. 43.100 / 57. 43.100
  libavformat    57. 37.100 / 57. 37.100
  libavdevice    57.  0.101 / 57.  0.101
  libavfilter     6. 46.100 /  6. 46.100
  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 '/home/ec2-user/videoData/DnXptC4ld8/FADING_OUT_VOLUP_Blrt_Decrypt_1ed5c4d569d8a1f23428b65217f65eaf_audio.m4a':
  Metadata:
    major_brand     : M4A 
    minor_version   : 512
    compatible_brands: isomiso2
    encoder         : Lavf57.44.100
  Duration: 00:00:01.77, start: 0.000000, bitrate: 4 kb/s
    Stream #0:0(und): Audio: aac (LC) (mp4a / 0x6134706D), 11025 Hz, mono, fltp, 0 kb/s (default)
    Metadata:
      handler_name    : SoundHandler

第二个文件 ffprobe:

[ec2-user@ip-10-0-1-126 server]$ ffprobe /home/ec2-user/videocreation/temp/silence.m4a
ffprobe version N-80097-g89e9393 Copyright (c) 2007-2016 the FFmpeg developers
  built with gcc 4.8.5 (GCC) 20150623 (Red Hat 4.8.5-4)
  configuration: --prefix=/home/ec2-user/ffmpeg_build --extra-cflags=-I/home/ec2-user/ffmpeg_build/include --extra-ldflags=-L/home/ec2-user/ffmpeg_build/lib --bindir=/home/ec2-user/bin --pkg-config-flags=--static --enable-gpl --enable-nonfree --enable-libfdk-aac --enable-libfreetype --enable-libmp3lame --enable-libopus --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libx265
  libavutil      55. 24.100 / 55. 24.100
  libavcodec     57. 43.100 / 57. 43.100
  libavformat    57. 37.100 / 57. 37.100
  libavdevice    57.  0.101 / 57.  0.101
  libavfilter     6. 46.100 /  6. 46.100
  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 '/home/ec2-user/videocreation/temp/silence.m4a':
  Metadata:
    major_brand     : M4A 
    minor_version   : 512
    compatible_brands: isomiso2
    encoder         : Lavf57.44.100
  Duration: 00:00:04.02, start: 0.000000, bitrate: 4 kb/s
    Stream #0:0(und): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, mono, fltp, 1 kb/s (default)
    Metadata:
      handler_name    : SoundHandler

输出文件 ffprobe:

[ec2-user@ip-10-0-1-126 server]$ ffprobe output.m4a 
ffprobe version N-80097-g89e9393 Copyright (c) 2007-2016 the FFmpeg developers
  built with gcc 4.8.5 (GCC) 20150623 (Red Hat 4.8.5-4)
  configuration: --prefix=/home/ec2-user/ffmpeg_build --extra-cflags=-I/home/ec2-user/ffmpeg_build/include --extra-ldflags=-L/home/ec2-user/ffmpeg_build/lib --bindir=/home/ec2-user/bin --pkg-config-flags=--static --enable-gpl --enable-nonfree --enable-libfdk-aac --enable-libfreetype --enable-libmp3lame --enable-libopus --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libx265
  libavutil      55. 24.100 / 55. 24.100
  libavcodec     57. 43.100 / 57. 43.100
  libavformat    57. 37.100 / 57. 37.100
  libavdevice    57.  0.101 / 57.  0.101
  libavfilter     6. 46.100 /  6. 46.100
  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 'output.m4a':
  Metadata:
    major_brand     : M4A 
    minor_version   : 512
    compatible_brands: isomiso2
    encoder         : Lavf57.37.100
  Duration: 00:00:23.22, start: 0.000000, bitrate: 0 kb/s
    Stream #0:0(und): Audio: aac (LC) (mp4a / 0x6134706D), 11025 Hz, mono, fltp, 0 kb/s (default)
    Metadata:
      handler_name    : SoundHandler

Answer 1

文件需要具有相同的属性。您的静音文件具有不同的采样率。使用

ffmpeg -f lavfi -i anullsrc -ar 11025 -ac 1 -t 4 silence.m4a

FFmpeg 错误地连接两个 m4a 文件

FFmpeg concatenates two m4a files incorrectly

audio

ffmpeg

ffprobe