Audio 使用ffmpeg连接音频文件

我正在尝试使用ffmpeg连接ac3和aac

jpn_op.m4a的ffprobe：

Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'jpn_op.m4a':
Metadata:
major_brand     : M4A 
minor_version   : 512
compatible_brands: M4A isomiso2
encoder         : Lavf58.76.100
Duration: 00:01:17.28, start: 0.000000, bitrate: 224 kb/s
Stream #0:0(jpn): Audio: ac3 (ac-3 / 0x332D6361), 48000 Hz, stereo, fltp, 224 kb/s (default)
Metadata:
  handler_name    : SoundHandler
  vendor_id       : [0][0][0][0]
Side data:
  audio service type: main

工程编号m4a的FFU探头

Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'eng_nop.m4a':
Metadata:
major_brand     : M4A 
minor_version   : 512
compatible_brands: M4A isomiso2
encoder         : Lavf58.76.100
Duration: 00:22:09.26, start: 0.023000, bitrate: 41 kb/s
Stream #0:0(und): Audio: aac (HE-AAC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 39 kb/s (default)
Metadata:
  handler_name    : SoundHandler
  vendor_id       : [0][0][0][0]

我试过这个：

ffmpeg -f concat -i concat_files.txt -c copy final.m4a -y

concat_files.txt包含：

file 'jpn_op.m4a'
file 'eng_nop.m4a'

ffprobe的final.m4a

Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'final.m4a':
Metadata:
major_brand     : M4A 
minor_version   : 512
compatible_brands: M4A isomiso2
encoder         : Lavf58.76.100
Duration: 00:23:26.50, start: 0.000000, bitrate: 51 kb/s
Stream #0:0(jpn): Audio: ac3 (ac-3 / 0x332D6361), 48000 Hz, stereo, fltp, 224 kb/s (default)
Metadata:
  handler_name    : SoundHandler
  vendor_id       : [0][0][0][0]
Side data:
  audio service type: main

---

但是，final.m4a格式和属性必须相同，concat demuxer才能工作。重新编码其中一个文件以匹配另一个文件，然后连接

Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'final.m4a':
Metadata:
major_brand     : M4A 
minor_version   : 512
compatible_brands: M4A isomiso2
encoder         : Lavf58.76.100
Duration: 00:23:26.50, start: 0.000000, bitrate: 51 kb/s
Stream #0:0(jpn): Audio: ac3 (ac-3 / 0x332D6361), 48000 Hz, stereo, fltp, 224 kb/s (default)
Metadata:
  handler_name    : SoundHandler
  vendor_id       : [0][0][0][0]
Side data:
  audio service type: main

或者使用以下选项：