[FFmpeg-devel] [PATCH] Add a channels field to m4ac

[Baptiste Coudurier]

On 11/11/2009 10:48 AM, Alex Converse wrote:
> On Tue, Nov 10, 2009 at 7:15 PM, Baptiste Coudurier
> <baptiste.coudurier at gmail.com>  wrote:
>> On 11/10/2009 03:51 PM, Alex Converse wrote:
>>>
>>> As requested for the ALS decoder.
>>>
>>>
>>> m4ac.channels.diff
>>>
>>>
>>> diff --git a/libavcodec/mpeg4audio.c b/libavcodec/mpeg4audio.c
>>> index 6c0bc7d..8c96572 100644
>>> --- a/libavcodec/mpeg4audio.c
>>> +++ b/libavcodec/mpeg4audio.c
>>> @@ -57,6 +57,8 @@ int ff_mpeg4audio_get_config(MPEG4AudioConfig *c, const
>>> uint8_t *buf, int buf_si
>>>       c->object_type = get_object_type(&gb);
>>>       c->sample_rate = get_sample_rate(&gb,&c->sampling_index);
>>>       c->chan_config = get_bits(&gb, 4);
>>> +    if (c->chan_config<    FF_ARRAY_ELEMS(ff_mpeg4audio_channels))
>>> +        c->channels = ff_mpeg4audio_channels[c->chan_config];
>>>       c->sbr = -1;
>>>       if (c->object_type == AOT_SBR) {
>>>           c->ext_object_type = c->object_type;
>>> diff --git a/libavcodec/mpeg4audio.h b/libavcodec/mpeg4audio.h
>>> index 98cddad..a51a1a4 100644
>>> --- a/libavcodec/mpeg4audio.h
>>> +++ b/libavcodec/mpeg4audio.h
>>> @@ -36,6 +36,7 @@ typedef struct {
>>>       int ext_sampling_index;
>>>       int ext_sample_rate;
>>>       int ext_chan_config;
>>> +    int channels;
>>>   } MPEG4AudioConfig;
>>>
>>>   extern const int ff_mpeg4audio_sample_rates[16];
>>> diff --git a/libavformat/flvdec.c b/libavformat/flvdec.c
>>> index b3b3cc1..5b47f19 100644
>>> --- a/libavformat/flvdec.c
>>> +++ b/libavformat/flvdec.c
>>> @@ -412,7 +412,7 @@ static int flv_read_packet(AVFormatContext *s,
>>> AVPacket *pkt)
>>>                                            st->codec->extradata_size);
>>>                   if (cfg.chan_config>    7)
>>>                       return -1;
>>> -                st->codec->channels =
>>> ff_mpeg4audio_channels[cfg.chan_config];
>>> +                st->codec->channels = cfg.channels;
>>>                   st->codec->sample_rate = cfg.sample_rate;
>>>                   dprintf(s, "mp4a config channels %d sample rate %d\n",
>>>                           st->codec->channels, st->codec->sample_rate);
>>> diff --git a/libavformat/mov.c b/libavformat/mov.c
>>> index 3d67630..65d1aad 100644
>>> --- a/libavformat/mov.c
>>> +++ b/libavformat/mov.c
>>> @@ -436,7 +436,7 @@ int ff_mov_read_esds(AVFormatContext *fc,
>>> ByteIOContext *pb, MOVAtom atom)
>>>                                            st->codec->extradata_size);
>>>                   if (cfg.chan_config>    7)
>>>                       return -1;
>>> -                st->codec->channels =
>>> ff_mpeg4audio_channels[cfg.chan_config];
>>> +                st->codec->channels = cfg.channels;
>>>                   if (cfg.object_type == 29&&    cfg.sampling_index<    3) //
>>> old mp3on4
>>>                       st->codec->sample_rate =
>>> ff_mpa_freq_tab[cfg.sampling_index];
>>>                   else
>>>
>>
>> Ok with me.
>>
>> Btw I think the>  7 check can be dropped in demuxers.
>> It should be able to demux it even if wronly set, and since it is not used
>> anymore to address the array, it should be safe.
>
> Ok.
>
> Do I need to increment any version fields? This is going to keep new
> libavformat from playing nice with old libavcodec.

I'd say minor libavcodec.

I thought we decided that symbols used by libavformat should be part of 
the public API ?

-- 
Baptiste COUDURIER
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