FFMPEG mux 视频和音频(来自另一个视频) - 映射问题 [英] FFMPEG mux video and audio (from another video) - mapping issue

问题描述

我想将一个视频的音频放到另一个没有音频的视频中(在一个命令中):

I would like to place the audio from a video to another video without an audio (in one command):

ffmpeg.exe -i video1_noAudio.mov -i video2_wAudio.mov -vcodec copy -acodec copy video1_audioFromVideo2.mov

我猜-map"是正确的方法，但我对它感到困惑.

I guess "-map" is the correct way to do it but I got confused with it.

你能建议如何解决吗?

推荐答案

输入概览

input_0.mp4 具有所需的视频流，input_1.mp4 具有所需的音频流:

Overview of inputs

input_0.mp4 has the desired video stream and input_1.mp4 has the desired audio stream:

在 ffmpeg 中，流看起来像这样:

In ffmpeg the streams look like this:

$ ffmpeg -i input_0.mp4 -i input_1.mp4

Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'input_0.mp4':
  Duration: 00:01:48.50, start: 0.000000, bitrate: 4144 kb/s
    Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 1280x720, 4014 kb/s, SAR 115:87 DAR 1840:783, 23.98 fps, 23.98 tbr, 16k tbn, 47.95 tbc (default)
    Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 124 kb/s (default)

Input #1, mov,mp4,m4a,3gp,3g2,mj2, from 'input_1.mp4':
  Duration: 00:00:30.05, start: 0.000000, bitrate: 1754 kb/s
    Stream #1:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 720x480 [SAR 8:9 DAR 4:3], 1687 kb/s, 59.94 fps, 59.94 tbr, 60k tbn, 119.88 tbc (default)
    Stream #1:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 55 kb/s (default)

身份证号码

ffmpeg 指的是带有索引号的输入文件和流.格式为input_file_id:input_stream_id.由于 ffmpeg 从 0 开始计数，流 1:1 指的是来自 input_1.mp4 的音频.

ID numbers

ffmpeg refers to input files and streams with index numbers. The format is input_file_id:input_stream_id. Since ffmpeg starts counting from 0, stream 1:1 refers to the audio from input_1.mp4.

这可以通过流说明符来增强.例如，您可以告诉 ffmpeg 您想要来自第一个输入 (0:v:0) 的第一个视频流，以及来自第二个输入 (0:v:0) 的第一个音频流1:a:0).我更喜欢这种方法，因为它更有效.此外，它不太容易发生意外映射，因为 1:1 可以引用任何类型的流，而 2:v:3 只引用第四个视频流第三个输入文件.

This can be enhanced with stream specifiers. For example, you can tell ffmpeg that you want the first video stream from the first input (0:v:0), and the first audio stream from the second input (1:a:0). I prefer this method because it's more efficient. Also, it is less prone to accidental mapping because 1:1 can refer to any type of stream, while 2:v:3 only refers to the fourth video stream of the third input file.

-map 选项指示 ffmpeg 你想要什么流.从 input_0.mp4 复制视频和从 input_1.mp4 复制音频:

The -map option instructs ffmpeg what streams you want. To copy the video from input_0.mp4 and audio from input_1.mp4:

$ ffmpeg -i input_0.mp4 -i input_1.mp4 -c copy -map 0:0 -map 1:1 -shortest out.mp4

下一个例子将做同样的事情:

This next example will do the same thing:

$ ffmpeg -i input_0.mp4 -i input_1.mp4 -c copy -map 0:v:0 -map 1:a:0 -shortest out.mp4

• -map 0:v:0 可以翻译为:从第一个输入(0)，选择视频流类型(v)，第一个视频流 (0)

  • -map 0:v:0 can be translated as: from the first input (0), select video stream type (v), first video stream (0)

    -map 1:a:0 可以翻译为:从第二个输入(1)，选择音频流类型(a)，第一个音频流 (0)

    -map 1:a:0 can be translated as: from the second input (1), select audio stream type (a), first audio stream (0)

    • 使用 -c copy 流将被流复制，没有重新编码，所以不会有质量损失.如果要重新编码，请参阅FFmpeg Wiki:H.264 编码指南.

    • With -c copy the streams will be stream copied, not re-encoded, so there will be no quality loss. If you want to re-encode, see FFmpeg Wiki: H.264 Encoding Guide.

    -shortest 选项将使输出持续时间与最短输入流的持续时间相匹配.

    The -shortest option will cause the output duration to match the duration of the shortest input stream.

    请参阅-map 选项文档了解更多信息.

    See the -map option documentation for more info.

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