[FFmpeg-user] Can not resample 6 channels @ 48000 Hz to 6 channels @ 48000

Bernd Butscheidt bbutscheidt at yahoo.de
Sun Mar 27 22:24:47 CEST 2011

From: Mike Scheutzow <mjs973 at optonline.net>
To: FFmpeg user questions and RTFMs <ffmpeg-user at ffmpeg.org>
Sent: Sonntag, den 27. März 2011, 16:52:49 Uhr
subject: Re: [FFmpeg-user] Can not resample 6 channels @ 48000 Hz to 6 channels 
@ 48000

> Did you notice that the input to the resampler is "ch:2"? But it seems that 
>version of ffmpeg does not warn you that something bad is being done.

Yes, I was not clear about this and posed two question. Indeed neither of the 
two ffmpeg versions recognize the audio as mediainfo does it - which is 
5.1-ac3-audio. But at least the encoding starts with the older one.

>If your goal is to have 5.1 audio in the output file, then use '-acodec copy'. 
>Do not decode the audio, then try to re-encode it.

The goal behind my example is actually to reencode the audio - for reasons which 
go far beyond this topic. 

So question 1:
Why does ffmpeg not recognize the given audio correctly (assuming mediainfo does 
this job correctly)?

Question 2:
Why does the newer ffmpeg version not proceed with the reencode giving the error 
message in the subject?

Kind regards
Bernd B.

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