[FFmpeg-devel] [PATCH] use new metadata API in mov (de)muxer

[Aurelien Jacobs]

Baptiste Coudurier wrote:

> Hi,
> 
> On 2/14/2009 5:13 PM, Aurelien Jacobs wrote:
> > Aurelien Jacobs wrote:
> > 
> >> Baptiste Coudurier wrote:
> >> 
> >>> Hi Aurelien,
> >>> 
> >>> Aurelien Jacobs wrote:
> >>>> Hi,
> >>>> 
> >>>> Attached patch converts the mov muxer and demuxer to the new
> >>>> metadata API. It properly (de)mux lang when available. Note
> >>>> that current muxer code set lang to english when lang is
> >>>> unknown. I left this behavior unchanged, especially because I
> >>>> don't know what numeric language code to use for unknown
> >>>> language.
> >>>> 
> >>>> [...]
> >>>> 
> >>>> -    case MKTAG(0xa9,'n','a','m'): -        str = c->fc->title;
> >>>> size = sizeof(c->fc->title); break; +    case
> >>>> MKTAG(0xa9,'n','a','m'): key = "title";     break; +    case
> >>>> MKTAG(0xa9,'a','u','t'): case MKTAG(0xa9,'A','R','T'): -
> >>>> case MKTAG(0xa9,'w','r','t'): -        str = c->fc->author;
> >>>> size = sizeof(c->fc->author); break; -    case
> >>>> MKTAG(0xa9,'c','p','y'): -        str = c->fc->copyright; size
> >>>> = sizeof(c->fc->copyright); break; +    case
> >>>> MKTAG(0xa9,'w','r','t'): key = "author";    break; +    case
> >>>> MKTAG(0xa9,'c','p','y'): key = "copyright"; break; case
> >>>> MKTAG(0xa9,'c','m','t'): -    case MKTAG(0xa9,'i','n','f'): -
> >>>> str = c->fc->comment; size = sizeof(c->fc->comment); break; -
> >>>> case MKTAG(0xa9,'a','l','b'): -        str = c->fc->album; size
> >>>> = sizeof(c->fc->album); break; +    case
> >>>> MKTAG(0xa9,'i','n','f'): key = "comment";   break; +    case
> >>>> MKTAG(0xa9,'a','l','b'): key = "album";     break; +    case
> >>>> MKTAG(0xa9,'d','a','y'): key = "year";      break; +    case
> >>>> MKTAG(0xa9,'g','e','n'): key = "genre";     break; +    case
> >>>> MKTAG(0xa9,'t','o','o'): +    case MKTAG(0xa9,'e','n','c'): key
> >>>> = "muxer";     break;
> >>> I saw that in vorbis demuxer you exported metadata "as is", but
> >>> here you apply some generic metadata.
> >>> 
> >>> 1) Shouldn't we also export "as is" everything in "udta" atom
> >>> coded in a somewhat standard way (itunes, 3gp, mov) ? This is
> >>> what I would call "generic" and user could retrieve it if
> >>> wanted.
> >> That would indeed be more generic, but from my understanding, the 
> >> metadata key is supposed to be a user understandable string. A end 
> >> user application should display the straight key string. mov atom
> >> identifier don't really qualify as user readable string... BTW:
> >> does mov have a small limited set of well know supported metadata
> >> atom, or is anyone allowed to set any random metadata at will ?
> > 
> > Well. I still think my patch is the right way to do it. For formats
> > which don't have free text keys, the demuxer should export the small
> > set of allowed tags each with a comprehensible text key.
> 
> Well, I'm still not happy with the language mechanism, but oh well...
> 
> > So finally, here is the demuxer part of the patch, split, but 
> > otherwise unchanged. First patch switch to the new API. Second patch
> > adds support for a few more tags.
> 
> I also think that before adding more tags we should clean the code by
> using an array.

OK. Applied the demuxer patch. I will send a patch to use an array for
keys/atom.

Aurel