Opened 4 years ago

Last modified 2 years ago

#3173 open enhancement

afade-fadeout on pipe:0 stream

Reported by: Fusl Owned by:
Priority: wish Component: avfilter
Version: git-master Keywords: afade
Cc: Blocked By:
Blocking: Reproduced by developer: no
Analyzed by developer: no

Description

Hello,

is it possible to implement a way to apply fadeout-effects to a pipe:0-stream? I think this is possible when buffering the input audio for the time of fadeout-seconds specified and when pipe:0 has been closed, apple the effect on the buffer. Is this correct and can this be implemented in FFmpeg?

Thanks!

Change History (5)

comment:1 Changed 4 years ago by cehoyos

  • Component changed from FFmpeg to avfilter
  • Keywords afade added
  • Status changed from new to open
  • Version changed from unspecified to git-master

Related to ticket #2631.
Note that most developers believe that this is not a good idea.

comment:2 Changed 4 years ago by Fusl

Why is that? Please explain, because i don't think that this is not a good idea.

/Edit: Ok, i overlooked the link to ticket #2631 but still can't see why this isn't a good idea so far...

Last edited 4 years ago by Fusl (previous) (diff)

comment:3 Changed 4 years ago by richardpl

buffering needs memory, better approach would be to know when audio ends.

comment:4 Changed 4 years ago by Fusl

Yeah, i know that it needs more memory. I think, exactly the raw format size of how long the audio buffer is.

A wav file (pcm_s16le, Audio: pcm_s16le ([1][0][0][0] / 0x0001), 44100 Hz, stereo, s16, 1411 kb/s) with a length of time=00:00:04.98 has exactly

fusl@thinkbook  ffmpegtest   ls -alF test.wav
-rw-r--r-- 1 fusl users 875788 Nov 29 14:57 test.wav

And i don't think that 875KiB would use much more memory inside ffmpeg.

Also i think that a notice in the documentation and the manual page, that it COULD use much memory when input type is a stream, is enough, isn't it?

comment:5 Changed 2 years ago by richardpl

I guess you could use asetnsamples to set number of samples per frame to some high number so fading is done in one go.

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