[FFmpeg-devel] [PATCH] add dumpwave filter

[Tobias Rapp]

On 10.01.2018 18:18, Kyle Swanson wrote:
> Hi,
> 
> For this to be a part of libavfilter the output needs to be more generic
> than the just the Soundcloud format. If we want this to be generally useful
> it should probably just output an array of floats between 0.0 and 1.0. The
> consumer of this data (JS library, or whatever) can use this in whatever
> way it wants.

I agree. If the BWF Peak Envelope output which was suggested in the 
other thread does not match your demands and filter implementation is 
actually necessary I would prefer if the filter would attach the RMS 
value(s) as frame metadata instead of directly dumping to file. Frame 
metadata can then be re-used by other filters or dumped into file by 
using the existing "ametadata" filter.

This would be similar to:

ffmpeg -i input-file -f null -filter:a 
"asetnsamples=22050,astats=metadata=on,ametadata=print:file=stats-file.dat" 
/dev/null

BTW: The "astats" filter already provides some RMS values.

> If you send another patch, just reply to this thread because
> that makes it easier to follow (sending a patch as an attachment is OK).
> Here are some critiques:
> 
> [...]

Also when sending patches adding an increased version number helps 
sorting out which is the latest one (git format-patch -v2 ...).

Regards,
Tobias