[opus] Antw: [EXT] Stop opusenc from generating any comments?

Ulrich Windl Ulrich.Windl at rz.uni-regensburg.de
Fri Jun 19 06:34:32 UTC 2020

>>> Terence Eden <terence.eden at gmail.com> schrieb am 19.04.2020 um 12:48 in
hV6XqSXVA at mail.gmail.com>:
> The opusenc tool automatically adds metadata - even if you don't specify
> any.
> For example, these tags are created by default on my files:
> ENCODER=opusenc from opus-tools 0.2
> ENCODER_OPTIONS=--bitrate 6 --comp 10 --framesize 60 --padding 0
> I've tried using `--discard-comments` but that has no effect.
> I've tried using `--comment ENCODER=` but that adds a duplicate tag.
> My limited knowledge of C suggests that the following lines in opusenc.c
> are where the magic happens:
> https://github.com/xiph/opus-tools/blob/master/src/opusenc.c#L480 
> https://github.com/xiph/opus-tools/blob/master/src/opusenc.c#L800 
> So, would it be possible to add a `--no-metada` option to completely
> suppress any metadata from being written?


Despite of the request that may make sense, I always found this kind of metadata useful, especially when it turned out that a specific encoder had a bug. So I could find any affected files and reencode.

Despite of comments I think there's also a random serial number added to the stream. If you consider that as NOUNCE (more or less) that would also be identifying information.

> I realise this is a niche requirement! I'm trying to create tiny audio
> files where every byte saved is important. I can use Mutagen to remove the
> metadata, but I'd like a way not to add it in the first place.

OK, your motivation is saving bytes...

> Thanks
> Terence

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