[FFmpeg-devel] [PATCH] G.722 decoder

[Michael Niedermayer]

On Wed, Sep 08, 2010 at 06:06:42PM +0300, Martin Storsj? wrote:
[...]
> +static int g722_decode_frame(AVCodecContext *avctx, void *data,
> +                             int *data_size, AVPacket *avpkt)
> +{
> +    G722Context *c = avctx->priv_data;
> +    int16_t *out_buf = data;
> +    int j, out_len = 0;
> +    const int skip = 8 - avctx->bits_per_coded_sample;
> +    const int16_t *quantizer_table = low_inv_quants[skip];
> +    GetBitContext gb;
> +
> +    init_get_bits(&gb, avpkt->data, avpkt->size * 8);
> +
> +    for (j = 0; j < avpkt->size; j++) {
> +        int ilow, ihigh, rlow;
> +        int dhigh, rhigh;
> +        int xout1, xout2;
> +
> +        ihigh = get_bits(&gb, 2);
> +        ilow = get_bits(&gb, 6 - skip);
> +        skip_bits(&gb, skip);
> +
> +        rlow = av_clip((c->band[0].scale_factor * quantizer_table[ilow] >> 10)
> +                      + c->band[0].s_predictor, -16384, 16383);
> +        update_low_predictor(&c->band[0], ilow >> (2 - skip));
> +
> +        dhigh = c->band[1].scale_factor * high_inv_quant[ihigh] >> 10;
> +        rhigh = av_clip(dhigh + c->band[1].s_predictor, -16384, 16383);
> +        update_high_predictor(&c->band[1], dhigh, ihigh);
> +
> +        c->prev_samples[c->prev_samples_pos++] = rlow + rhigh;
> +        c->prev_samples[c->prev_samples_pos++] = rlow - rhigh;
> +        apply_qmf(c->prev_samples + c->prev_samples_pos - 24,
> +                  &xout1, &xout2);
> +        out_buf[out_len++] = av_clip_int16(xout1 >> 12);
> +        out_buf[out_len++] = av_clip_int16(xout2 >> 12);
> +        if (c->prev_samples_pos >= PREV_SAMPLES_BUF_SIZE) {
> +            memmove(c->prev_samples,
> +                    c->prev_samples + c->prev_samples_pos - 22,
> +                    22 * sizeof(c->prev_samples[0]));
> +            c->prev_samples_pos = 22;
> +        }

lowres could be checked for this
except that iam fine with the patch

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

Many things microsoft did are stupid, but not doing something just because
microsoft did it is even more stupid. If everything ms did were stupid they
would be bankrupt already.
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