[Libav-user] av_frame_is_writable

[Nicolas George]

Le tridi 23 ventôse, an CCXXIV, Tom Deseyn a écrit :
> When decoding an H264 file after setting refcounted_frames to 1, the
> decoded frames are not writable. Is this due to the input format?

In part, but this will happen with a lot of codecs.

In video encoding, most frames are coded as the difference from the previous
one. Or ones, or even next ones with B-frames.

That means the decoder needs frame N in order to decode frame N+1. If you
were to apply changes to frame N, they would change frame N+1 too, in an
unpredictable way.

Regards,

-- 
  Nicolas George
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