[FFmpeg-devel] id3v2 TSSE tag

[Justin Ruggles]

Michael Niedermayer wrote:

> On Sat, Oct 17, 2009 at 06:46:20PM -0400, Justin Ruggles wrote:
>> Hi,
>>
>> Currently, if the TSSE tag exists, the mp3 muxer writes it twice.  It
>> writes the original value as a TXXX/TSSE tag, then it writes a new TSSE
>> tag with the lavf version.  Is this the intended behavior?
> 
> i doubt thats intended ....
> hmm
> * the demuxer should return all tags
> * TSSE ?? what is TSSE? shouldnt that be renamed to something sane?
>   we likely dont want "TSSE" to be stored in mov when transcoding

According to the specs, TSSE is "Software/Hardware and settings used for
encoding".  iTunes mp4 uses "?too", mov uses "?enc", and nut uses
"Encoder".  I think using "encoder" as the generic value would be a good
choice.

> The question imho is should the muxer drop the encoder/muxer version
> if it finds one in the metadata or should ffmpeg.c filter it out ...
> iam not sure about which is better ATM

With our current metadata system, it seems more appropriate to do it at
the user level.  ffmpeg.c knows if stream copy is being used.  It could
leave the existing value alone if stream copy is being used and filter
it out otherwise.

I know we already write LIBAVFORMAT_IDENT as a new tag in several
muxers, but I'm not sure it's a good idea for them to be creating new
tags that are not in AVMetadata.  The encoder version and/or settings
can be added to AVMetadata at the user level if desired.

-Justin