id3demux support for mp4 and other usecases for id3demux

[Tim-Philipp Müller]

On Sun, 2012-11-04 at 22:38 -0800, deepthips wrote:

Hi,

> I want to integrate id3demux plugin to our stack. But I had some queries
> regarding this.
> 
>    1. Can id3demux support mp4 files as well.? I know it can support mp3.

id3demux will read and strip ID3 tags at the beginning or end of a file.
It doesn't care about the type of file.

>    2. Other than reading the TAG information, is there any other usecase for
> id3demux.?

Yes, it is required to strip off the ID3 data in an autoplugging
scenario, so that the typefinding mechanism can figure out the real file
type.

>    3. Can this parsing of TAG be done from any other demux like qtdemux or
> mpeg2/ts demux. Is id3demux mandatory for this.?

I have never seen an ID3-tagged mpeg2/ts file. I have only once seen an
ID3-tagged m4a file (I think it was some nokia application tht did
that..).

Quicktime files sometimes contain an ID3 tag embedded in the header. You
do not need id3demux to extract that, qtdemux will do that using the ID3
tag parsing helper functions from the libgsttag library in -base. The
id3demux element can't help with ID3 tags that are embedded in the
middle of the file.

Cheers
 -Tim