[FFmpeg-devel] [PATCH] MLP/TrueHD decoder

[Michael Niedermayer]

Hi

On Thu, Nov 15, 2007 at 12:37:47PM +0000, Ian Caulfield wrote:
> On Nov 14, 2007 9:05 PM, Michael Niedermayer <michaelni at gmx.at> wrote:
> >
> > id only read enough in as needed for the size in the first pass
> 
> Here's a first pass at it.
> 
> > also we could add a special case for the case where the input containes
> > a whole packet or more so no memcpy is done but thats seperate
> > and we shouldnt waste time with it until the parser is in svn
> 
> I've left this for now.
[...]
> +static int mlp_parse(AVCodecParserContext *s,
> +                     AVCodecContext *avctx,
> +                     const uint8_t **poutbuf, int *poutbuf_size,
> +                     const uint8_t *buf, int buf_size)
> +{
> +    MLPParseContext *mp = s->priv_data;
> +    int sync_present;
> +    uint8_t parity_bits;
> +    int next;
> +    int i, p;
> +
> +    *poutbuf_size = 0;
> +    if (buf_size == 0)
> +        return 0;
> +
> +    if (!mp->in_sync) {
> +        // Not in sync - find a major sync header
> +
> +        for (i = 0; i < buf_size; i++) {
> +            mp->pc.state = (mp->pc.state << 8) | buf[i];
> +            if ((mp->pc.state & 0xfffffffe) == 0xf8726fba) {
> +                mp->in_sync = 1;
> +                mp->bytes_left = 0;
> +                break;
> +            }
> +        }
> +
> +        if (!mp->in_sync) {
> +            ff_combine_frame(&mp->pc, END_NOT_FOUND, &buf, &buf_size);
> +            return buf_size;
> +        }
> +
> +        ff_combine_frame(&mp->pc, i - 7, &buf, &buf_size);
> +
> +        return FFMAX(i - 7, 0);

i think this should be return i-7


[...]
> +        if ((((parity_bits >> 4) ^ parity_bits) & 0xF) != 0xF) {
> +            av_log(NULL, AV_LOG_INFO, "mlpparse: parity check failed\n");

please provide some non null context to av_log() otherwise its impossible
for an application with several decoders to make sense of the messages


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

It is not what we do, but why we do it that matters.
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