[FFmpeg-devel] [PATCH] Add four metadata tags to 3gp files

Horacio Sanson hsanson
Tue Sep 9 02:51:11 CEST 2008

On Tue, Sep 9, 2008 at 4:16 AM, Baptiste Coudurier
<baptiste.coudurier at smartjog.com> wrote:
> Hi,
> Horacio Sanson wrote:
>> Japanese mobile phones (Au, Softbank and Docomo) display these four tags when
>> accessing 3gp and 3g2 files properties. Our content providers mandate we put
>> these on all media we distribute, specially copyright.
> Humm I understand.
>> I would like to ask how to support other languages in the text strings?? I
>> really need this to support Japanese characters so any tips on how to do this
>> are welcome...
> You could set AVStream->language and use it.

Correct me if wrong but this AVStream->language would be per track in
the case of MP4 based files. These tags I need are general to the
whole presentation so I think this would not be useful for my

>> ------------------------------------------------------------------------
>> Index: libavformat/movenc.c
>> ===================================================================
>> --- libavformat/movenc.c      (?????"????????? 15260)
>> +++ libavformat/movenc.c      (???????????"???)
>> @@ -1315,13 +1315,17 @@
>>          put_be32(pb, 0); /* size */
>>          put_tag(pb, "udta");
>> -        if (mov->mode & MODE_3GP) {
>> +        if (mov->mode & MODE_3GP || mov->mode & MODE_3G2) {
> This is a different issue, and must be submited as a different patch,
> can you confirm these metadata tags are allowed in 3g2 and quote the
> specs ? Thanks.

Never seen the spec for 3g2 file format, I assumed it is not too
different from the 3GPP file format (TS 26.244) if it is not please
information about the 3g2 spec name is appreciated.

>>              mov_write_3gp_udta_tag(pb, s, "titl", s->title);
>>              mov_write_3gp_udta_tag(pb, s, "auth", s->author);
>>              mov_write_3gp_udta_tag(pb, s, "gnre", s->genre);
>>              mov_write_3gp_udta_tag(pb, s, "dscp", s->comment);
>>              mov_write_3gp_udta_tag(pb, s, "albm", s->album);
>>              mov_write_3gp_udta_tag(pb, s, "yrrc", "nil");
>> +            mov_write_string_tag(pb, "\251nam", s->title, 0);
>> +            mov_write_string_tag(pb, "\251aut", s->author, 0);
>> +            mov_write_string_tag(pb, "\251des", s->comment, 0);
>> +            mov_write_string_tag(pb, "\251cpy", s->copyright, 0);
> Are these standardized in 3gp ? I don't think so, 3gp uses differents
> tags IIRC like coded. Doesn't your content providers support 3gp tags ?
> I might be inclined to allow this if not...

Believe me I wish I could quote the standard and tell you these tags
are there but I can't. Blame Quicktime pro that is the defacto
authoring tool used by all content creators here in Japan. Quicktime's
 property editor allows to add these four tags to MOV, 3gpp and 3g2
files that are displayed on all mobile phones in Japan (i.e. a lot of
devices) so pretty much is a standard here.

On the other hand these tags are exactly the same tags used in
MODE_MOV, I simply add them to 3gp and 3g2 files. Maybe it would be
better to not differentiate between these three modes at all and add
all those tags to the files (3gp, 3p2, mov, mp4) so the tags can be
seen in as many devices/programs as possible.... just an idea.

> In the mean time, muxer now writes copyright tag.
> --
> Baptiste COUDURIER                              GnuPG Key Id: 0x5C1ABAAA
> Smartjog USA Inc.                                http://www.smartjog.com
> Key fingerprint                 8D77134D20CC9220201FC5DB0AC9325C5C1ABAAA
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