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

[Alex Converse]

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.