CODEWITHSUNDEEP
ffmpeg
Android Developer
Android Developer

Reputation: 9663

ffmpeg map filter option

What does below ffmpeg option do?

 -map [v] -map [a]

and

 -map 0

I have read this but still not able to understand exactly what it does and when to use them?

Upvotes: 3

Views: 4559

Answers (1)

llogan
llogan

Reputation: 134103

The -map option can refer to arbitrary stream labels or specific input streams.

  • -map [v] -map [a] – Select the streams arbitrarily labeled v and a. For example, these could be the outputs of filtering:

    ffmpeg -i input -filter_complex "[0:v]scale=iw/2:-1[v];[0:a]afade=d=5[a]" -map "[v]" -map "[a]" output

  • -map 0 – Select all streams from input 0. ffmpeg begins counting from 0, so this is the first input; using -map 4 would refer to the fifth input. Because the default stream selection behavior only chooses one stream per stream type, using -map 0 is useful if you want to select all streams from input 0. Example:

    ffmpeg -i input0 -i input1 -map 0 -map 1 output

Also see:

Upvotes: 6

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