[FFmpeg-devel] [PATCH] IRCAM Sound Format demuxer

[Michael Niedermayer]

On Tue, Apr 20, 2010 at 01:03:33PM -0500, Daniel Verkamp wrote:
[...]
> +static const uint32_t be_tags[] = {
> +    0x64A30200, // Sun (native)
> +    0x64A30400, // NeXT
> +    0x0001A364, // VAX
> +    0x0003A364, // MIPS (SGI)
> +};
> +
> +static const uint32_t le_tags[] = {
> +    0x64A30100, // VAX (native)
> +    0x64A30300, // MIPS (DECstation)
> +    0x0002A364, // Sun
> +};
> +
> +static int identify(uint32_t tag)
> +{
> +    int i;
> +
> +    for (i = 0; i < FF_ARRAY_ELEMS(be_tags); i++)
> +        if (be_tags[i] == tag)
> +            return 1;
> +
> +    for (i = 0; i < FF_ARRAY_ELEMS(le_tags); i++)
> +        if (le_tags[i] == tag)
> +            return 0;

isnt a
if(t=a ||t=b || ...
simpler?


> +
> +    return -1;
> +}
> +
> +static enum CodecID get_codec(uint32_t tag, int be)
> +{
> +    const AVCodecTag *tags = be ? be_codec_tags : le_codec_tags;
> +    enum CodecID codec_id = ff_codec_get_id(tags, tag);
> +    if (codec_id == CODEC_ID_NONE)
> +        codec_id = ff_codec_get_id(generic_codec_tags, tag);
> +    return codec_id;
> +}
> +
> +static int probe(AVProbeData *p)
> +{
> +    unsigned char *buf = p->buf;
> +    int be, channels, sample_rate;
> +    uint32_t tag;
> +
> +    if (p->buf_size <= 16)
> +        return 0;
> +
> +    be = identify(AV_RB32(buf));
> +    if (be < 0)
> +        return 0;
> +
> +    if (be) {
> +        sample_rate = av_int2flt(AV_RB32(buf + 4));
> +        channels    = AV_RB32(buf + 8);
> +        tag         = AV_RB32(buf + 12);
> +    } else {
> +        sample_rate = av_int2flt(AV_RL32(buf + 4));
> +        channels    = AV_RL32(buf + 8);
> +        tag         = AV_RL32(buf + 12);
> +    }
> +
> +    if (sample_rate <= 0 || channels <= 0 || channels > 256)
> +        return 0;
> +
> +    tag = be ? AV_RB32(buf + 12) : AV_RL32(buf + 12);

a read_r32(uint8_t *, int endianness)
seems usefull here (iam not sure if we have something like this already)


> +    if (get_codec(tag, be) == CODEC_ID_NONE)
> +        return 0;

this isnt nice
someone might want to demux even unknown codecs


[..]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

He who knows, does not speak. He who speaks, does not know. -- Lao Tsu
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