[FFmpeg-devel] [PATCH] code to parse mpeg4audio extradata
Wed Mar 19 17:49:51 CET 2008
Andreas ?man wrote:
> Baptiste Coudurier wrote:
>> Here is a patch that adds parsing of mpeg4audio extradata, and retrieve
>> needed infos for decoders (only mp3on4 atm, but will be needed for aac),
>> and will be used by mov demuxer ideally to correctly compute sample rate
>> and channels.
>> Also extract common mpeg4audio code from aac_parser.c.
> Sorry for the inadequate quoting, my thunderbird cannot inline the
> patch correctly... :/
You have to downgrade to 1.5 if you want patches inlined. Don't ask me
> + c->ext_sample_rate = get_bits(&gb, 24);
> + else
> + c->ext_sample_rate =
> + if ((c->object_type = get_bits(&gb, 5)) == 31)
> + c->object_type = 32 + get_bits(&gb, 6);
> + }
> GASpecificConfig() resides here, so either we need to add a callback,
> or the function must be split (at least for aac.c to use this)
Yes, it can be extended this way I think.
int ff_mpeg4audio_get_config(MPEG4AudioConfig *c, const uint8_t *buf,
int buf_size, int (*specific_config)(), void *v);
if (specific_config && specific_config(gb, v) < 0)
What do you think ?
> But without specific parser for all used audioObjectTypes i don't see
> how the code below here is supposed to work at all (since it will
> read the wrong bits)
Yes, probably, if we want to support all configurations and modes, it
will to be extended for sure, also maybe code could search syncword.
Baptiste COUDURIER GnuPG Key Id: 0x5C1ABAAA
SMARTJOG SAS http://www.smartjog.com
Key fingerprint 8D77134D20CC9220201FC5DB0AC9325C5C1ABAAA
Phone: +33 1 49966312
More information about the ffmpeg-devel