[NUT-devel] Codec id - random notes

Luca Barbato lu_zero at gentoo.org
Thu Jun 22 11:41:59 CEST 2006

Michael Niedermayer wrote:
[avi way or highway]

Not sure, I'd rather have a bitfield as hint in the info packet and just
 let advanced player and decoders know about it.

I won't use avi just because the twocc for audio.

Proponents of alternative systems consider them because they don't like
the idea of cluttering the tag list with producer specific and
nonstandard tags while you may archive the same result adding an
optional field to explain what you should do.

if $specific_encoder got to the point of being standard but retains the
tag it used when wasn't standard at all what would happen to the decoder
if you just store the information "format mp4v, encoded by xvid,
workarounds A,B,C" as XVID?

if you store it as tag = mp4v X-encoder= "xvid-$ver_pretty_sane"
- players not caring could try to play it at their best and in this case
have no problems.
- players with a complete decoder will see the lack of hints and decode
it properly
- players particularly smart could also use the encoder string and pick
the matching decoder if present.

if you just store the tag as XVID
- players will still try to play it as if the workarounds are necessary
and maybe trigger workarounds that aren't meant to be used.
- players not knowing about XVID will still either play the guess game
or give up.

On the other hand:
- using different tags you deliver the information in a more compact
(but more ambiguous) form
- having hints and other metadata as described looks overengineering
quite a bit and will require some work to support it properly (if we
care just about lavc it isn't that hard, but...).

Did I sum up Michael position and the previous ones correctly?

lu - yes, I don't have strong opinions about it, I just want to have NUT
out as soon as possible.



Luca Barbato

Gentoo/linux Gentoo/PPC

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