ffmpeg 将 MXF 视频的多个 (N) 单声道音频通道合并到 MP4 视频的多个 (M) 立体声通道
[英]ffmpeg merge multiple (N) mono audio channels of a MXF video to multiple (M) stereo channels of MP4 video
问题描述
I have an MXF file with 16 audio mono streams and I need to recode it in a mp4 file with 2<=n<=16 channels merging input streams, eg input channels 1 and 2 on output channel 1 and 9 and 10 on output channel 2. This job will be done with ffmpeg.
我有一个带有 16 个音频单声道流的 MXF 文件，我需要将它重新编码为一个 mp4 文件，其中 2<=n<=16 个通道合并输入流，例如输出通道 1 上的输入通道 1 和 2 以及输出通道上的 9 和 10 2.这项工作将使用ffmpeg完成。 I read the documentation and found the amerge and amix filters that would be nice, but they output one channel only.我阅读了文档，发现 amerge 和 amix 过滤器会很好，但它们只输出一个通道。 Is there any solution for this problem?这个问题有什么解决方案吗？
Thanks, Laura谢谢，劳拉
Find below the output of ffprobe on mxf file:在 mxf 文件上找到 ffprobe 的输出：
{ "streams":[ { "index":0, "codec_name":"mpeg2video", "codec_long_name":"MPEG-2 video", "profile":"4:2:2", "codec_type":"video", "codec_time_base":"1/25", "codec_tag_string":"[0][0][0][0]", "codec_tag":"0x0000", "width":1920, "height":1080, "coded_width":0, "coded_height":0, "has_b_frames":1, "sample_aspect_ratio":"1:1", "display_aspect_ratio":"16:9", "pix_fmt":"yuv422p", "level":2, "color_range":"tv", "color_space":"bt709", "color_transfer":"bt709", "color_primaries":"bt709", "chroma_location":"topleft", "field_order":"tt", "refs":1, "r_frame_rate":"25/1", "avg_frame_rate":"25/1", "time_base":"1/25", "start_pts":0, "start_time":"0.000000", "duration_ts":448, "duration":"17.920000", "bit_rate":"50000000", "disposition":{ "default":0, "dub":0, "original":0, "comment":0, "lyrics":0, "karaoke":0, "forced":0, "hearing_impaired":0, "visual_impaired":0, "clean_effects":0, "attached_pic":0, "timed_thumbnails":0 }, "tags":{ "file_package_umid":"0x060A2B340101010501010D2313000000968F75C6B5B34D6
1 个解决方案
解决方案1
2 已采纳 2020-02-13 22:33:10
The code is organised with line breaks.代码是用换行符组织的。 A \\ breaks a line in a Unix shell. \\在 Unix shell 中换行。
ffmpeg -i "in.mxf" \
-filter_complex "\
[a:0][a:1]amerge=inputs=2[ch1ch2];\
[a:8][a:9]amerge=inputs=2[ch9ch10]" \
-map 'v:0' \
-map '[ch1ch2]' \
-map '[ch9ch10]' \
-c:v copy \
-c:a aac -b:a 128k -ar 48000 -ac 2 \
"out.mp4"
- input输入
- filter_complex (use
"instead of'. If I use shell line breaks\\I get an error with single quotes')filter_complex （使用"而不是'。如果我使用 shell 换行符\\我会收到带有单引号的错误'） - use
amergefilter and select使用amerge过滤器并选择- 1st audio stream
a:0and第一个音频流a:0和 - 2nd audio stream
a:1,第二个音频流a:1， - merge them and合并它们和
- store it in output pad
ch1ch2(you can give it any name)将其存储在输出垫ch1ch2（您可以给它任何名称）
- 1st audio stream
- use another
amergefilter and select使用另一个amerge过滤器并选择- 9th audio stream
a:8and第 9 个音频流a:8和 - 10th audio stream
a:9,第 10 个音频流a:9， - merge them and合并它们和
- store it in output pad
ch9ch10将其存储在输出垫ch9ch10
- 9th audio stream
- map video stream (if you omit that, your output has no video)映射视频流（如果省略，则输出没有视频）
- map pad
ch1ch2to 1st audio stream将 pad ch1ch2映射到第一个音频流 - map pad
ch9ch10to 2nd audio stream将ch9ch10映射到第二个音频流 - copy video stream (if you omit that, your video will be reencoded)复制视频流（如果您省略它，您的视频将被重新编码）
- encode all audio streams with aac使用 aac 编码所有音频流
- output输出
Here the output has only the 2 mapped audio channels.这里的输出只有 2 个映射的音频通道。
If you want to keep some of the remaining channels you have to map them.如果您想保留一些剩余的频道，您必须映射它们。 You can even add -map 0 right after Line 7 to stack all streams underneath your merged ones.您甚至可以在第 7 行之后添加-map 0以将所有流堆叠在合并的流下方。 (But of course you would end up with 2+16 audio streams.) （当然，您最终会得到 2+16 个音频流。）
You can add more amerge filters.您可以添加更多的amerge过滤器。 Separate them with ;用;分隔它们You can also merge 3 audio streams with [a:0][a:1][a:2]amerge=inputs=3[ch1ch2ch3] .您还可以使用[a:0][a:1][a:2]amerge=inputs=3[ch1ch2ch3]合并 3 个音频流。 Name the audio channels with将音频通道命名为
-metadata:s:a:0 title="channel 1 and 2"
This is useful for testing because you can see the names in VLC.这对测试很有用，因为您可以在 VLC 中看到名称。
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