[vlc-devel] [PATCH 2/5] libmp4: Add function MP4_BoxGetSmooBox()

[Frederic YHUEL]

On Tue, May 22, 2012 at 5:52 PM, Robert Forsman
<bob.forsman at ericsson.com> wrote:
> On Tue, 22 May 2012 11:11:09 -0400
> Frédéric Yhuel <fyhuel at viotech.net> wrote:
>
>> +MP4_Box_t *MP4_BoxGetSmooBox( stream_t *s )
>> +{
>> +    /* p_chunk is a virtual root container for the smoo box */
>> +    MP4_Box_t *p_chunk;
>> +    MP4_Box_t *p_smoo;
>> +
>
> After a couple of years of adding to my file analysis tool I found
> myself looking at code and saying "where the hell did this come from?"
> Especially on some of the more obscure stuff like various closed
> caption formats.
>
> I've never heard of a 'smoo' box, so it might help coders who come
> along behind you to have a comment at the top of the function like
>
> // ISO 14496-12 section 7.2.2.2
>

Hello Robert,

You are right.

There is an explanation in the previous patch message and in the
Smooth Streaming module code, but it should probably be duplicated in
the libmp4 code.

SmooBox is a very simple MP4 box, used only for the stream_filter to
send information to the demux. As this box is not aimed to travel
across networks, simplicity of the design is better than compactness


Best regards
Frédéric