ffmpeg - 将 5.1 PRORES 转换为 Prores 立体声

Question

我正在尝试从具有以下音轨布局的 Prores 中提取只有 2.0 的 Prores 视频(L R 在同一轨道上)。如何使用 FFmpeg 库来做到这一点？
我无法从以下 ffmpeg 库规范 https://trac.ffmpeg.org/wiki/AudioChannelManipulation#a2monostereo 中找出要使用的命令
所需的输出 PRORES 包含以下轨道布局
轨道 0 - 视频 (src Stream #0:0)
轨道 1 - L R (src Stream #0:1)
以下是源视频/音频轨道布局

Stream #0:0(eng): Video: prores (HQ) (apch / 0x68637061), yuv422p10le(tv, bt709, progressive), 1920x1080, 171944 kb/s, SAR 1:1 DAR 16:9, 23.98 fps, 23.98 tbr, 23976 tbn, 23976 tbc (default)
Metadata:
  creation_time   : 2019-05-21T01:26:51.000000Z
  handler_name    : Apple Video Media Handler
  encoder         : Apple ProRes 422 HQ
Stream #0:1(eng): Audio: pcm_s24le (in24 / 0x34326E69), 48000 Hz, 1 channels (FL), s32 (24 bit), 1152 kb/s (default)
Metadata:
  creation_time   : 2019-05-21T01:26:51.000000Z
  handler_name    : Apple Sound Media Handler
Stream #0:2(eng): Audio: pcm_s24le (in24 / 0x34326E69), 48000 Hz, 1 channels (FR), s32 (24 bit), 1152 kb/s (default)
Metadata:
  creation_time   : 2019-05-21T01:26:51.000000Z
  handler_name    : Apple Sound Media Handler
Stream #0:3(eng): Audio: pcm_s24le (in24 / 0x34326E69), 48000 Hz, mono, s32 (24 bit), 1152 kb/s (default)
Metadata:
  creation_time   : 2019-05-21T01:26:51.000000Z
  handler_name    : Apple Sound Media Handler
Stream #0:4(eng): Audio: pcm_s24le (in24 / 0x34326E69), 48000 Hz, 1 channels (LFE), s32 (24 bit), 1152 kb/s (default)
Metadata:
  creation_time   : 2019-05-21T01:26:51.000000Z
  handler_name    : Apple Sound Media Handler
Stream #0:5(eng): Audio: pcm_s24le (in24 / 0x34326E69), 48000 Hz, 1 channels (BL), s32 (24 bit), 1152 kb/s (default)
Metadata:
  creation_time   : 2019-05-21T01:26:51.000000Z
  handler_name    : Apple Sound Media Handler
Stream #0:6(eng): Audio: pcm_s24le (in24 / 0x34326E69), 48000 Hz, 1 channels (BR), s32 (24 bit), 1152 kb/s (default)
Metadata:
  creation_time   : 2019-05-21T01:26:51.000000Z
  handler_name    : Apple Sound Media Handler
Stream #0:7(eng): Audio: pcm_s24le (in24 / 0x34326E69), 48000 Hz, downmix, s32 (24 bit), 2304 kb/s (default)
Metadata:
  creation_time   : 2019-05-21T01:26:51.000000Z
  handler_name    : Apple Sound Media Handler
Stream #0:8(eng): Data: none (tmcd / 0x64636D74) (default)
Metadata:
  creation_time   : 2020-03-17T19:58:52.000000Z
  handler_name    : Time Code Media Handler
  reel_name       :
  timecode        : 00:00:00:00

Answer 1

如果您希望将前两个音轨提取为单个立体声轨道，请使用

ffmpeg -i in.mov -filter_complex "[0:a:0][0:a:1]join=inputs=2:channel_layout=stereo" -c:v copy out.mov

如果您想复制现有的缩混音轨 (#0:7)，请使用

ffmpeg -i in.mov -map 0:v -map 0:7 -c copy out.mov