static int vp3_decode_frame(AVCodecContext *avctx,
                            void *data, int *data_size,
                            AVPacket *avpkt)
{
    const uint8_t *buf = avpkt->data;
    int buf_size = avpkt->size;
    Vp3DecodeContext *s = avctx->priv_data;
    GetBitContext gb;
    static int counter = 0;
    int i;

    init_get_bits(&gb, buf, buf_size * 8);

    if (s->theora && get_bits1(&gb))
    {
        av_log(avctx, AV_LOG_ERROR, "Header packet passed to frame decoder, skipping\n");
        return -1;
    }

    s->keyframe = !get_bits1(&gb);
    if (!s->theora)
        skip_bits(&gb, 1);
    for (i = 0; i < 3; i++)
        s->last_qps[i] = s->qps[i];

    s->nqps=0;
    do{
        s->qps[s->nqps++]= get_bits(&gb, 6);
    } while(s->theora >= 0x030200 && s->nqps<3 && get_bits1(&gb));
    for (i = s->nqps; i < 3; i++)
        s->qps[i] = -1;

    if (s->avctx->debug & FF_DEBUG_PICT_INFO)
        av_log(s->avctx, AV_LOG_INFO, " VP3 %sframe #%d: Q index = %d\n",
            s->keyframe?"key":"", counter, s->qps[0]);
    counter++;

    if (s->qps[0] != s->last_qps[0])
        init_loop_filter(s);

    for (i = 0; i < s->nqps; i++)
        // reinit all dequantizers if the first one changed, because
        // the DC of the first quantizer must be used for all matrices
        if (s->qps[i] != s->last_qps[i] || s->qps[0] != s->last_qps[0])
            init_dequantizer(s, i);

    if (avctx->skip_frame >= AVDISCARD_NONKEY && !s->keyframe)
        return buf_size;

    if (s->keyframe) {
        if (!s->theora)
        {
            skip_bits(&gb, 4); /* width code */
            skip_bits(&gb, 4); /* height code */
            if (s->version)
            {
                s->version = get_bits(&gb, 5);
                if (counter == 1)
                    av_log(s->avctx, AV_LOG_DEBUG, "VP version: %d\n", s->version);
            }
        }
        if (s->version || s->theora)
        {
                if (get_bits1(&gb))
                    av_log(s->avctx, AV_LOG_ERROR, "Warning, unsupported keyframe coding type?!\n");
            skip_bits(&gb, 2); /* reserved? */
        }

        if (s->last_frame.data[0] == s->golden_frame.data[0]) {
            if (s->golden_frame.data[0])
                avctx->release_buffer(avctx, &s->golden_frame);
            s->last_frame= s->golden_frame; /* ensure that we catch any access to this released frame */
        } else {
            if (s->golden_frame.data[0])
                avctx->release_buffer(avctx, &s->golden_frame);
            if (s->last_frame.data[0])
                avctx->release_buffer(avctx, &s->last_frame);
        }

        s->golden_frame.reference = 3;
        if(avctx->get_buffer(avctx, &s->golden_frame) < 0) {
            av_log(s->avctx, AV_LOG_ERROR, "vp3: get_buffer() failed\n");
            return -1;
        }

        /* golden frame is also the current frame */
        s->current_frame= s->golden_frame;

        /* time to figure out pixel addresses? */
        if (!s->pixel_addresses_initialized)
        {
            vp3_calculate_pixel_addresses(s);
            s->pixel_addresses_initialized = 1;
        }
    } else {
        /* allocate a new current frame */
        s->current_frame.reference = 3;
        if (!s->pixel_addresses_initialized) {
            av_log(s->avctx, AV_LOG_ERROR, "vp3: first frame not a keyframe\n");
            return -1;
        }
        if(avctx->get_buffer(avctx, &s->current_frame) < 0) {
            av_log(s->avctx, AV_LOG_ERROR, "vp3: get_buffer() failed\n");
            return -1;
        }
    }

    s->current_frame.qscale_table= s->qscale_table; //FIXME allocate individual tables per AVFrame
    s->current_frame.qstride= 0;

    init_frame(s, &gb);

    if (unpack_superblocks(s, &gb)){
        av_log(s->avctx, AV_LOG_ERROR, "error in unpack_superblocks\n");
        return -1;
    }
    if (unpack_modes(s, &gb)){
        av_log(s->avctx, AV_LOG_ERROR, "error in unpack_modes\n");
        return -1;
    }
    if (unpack_vectors(s, &gb)){
        av_log(s->avctx, AV_LOG_ERROR, "error in unpack_vectors\n");
        return -1;
    }
    if (unpack_block_qpis(s, &gb)){
        av_log(s->avctx, AV_LOG_ERROR, "error in unpack_block_qpis\n");
        return -1;
    }
    if (unpack_dct_coeffs(s, &gb)){
        av_log(s->avctx, AV_LOG_ERROR, "error in unpack_dct_coeffs\n");
        return -1;
    }

    for (i = 0; i < s->macroblock_height; i++)
        render_slice(s, i);

    // filter the last row
    for (i = 0; i < 3; i++) {
        int row = (s->height >> (3+!!i)) - 1;
        apply_loop_filter(s, i, row, row+1);
    }

    *data_size=sizeof(AVFrame);
    *(AVFrame*)data= s->current_frame;

    /* release the last frame, if it is allocated and if it is not the
     * golden frame */
    if ((s->last_frame.data[0]) &&
        (s->last_frame.data[0] != s->golden_frame.data[0]))
        avctx->release_buffer(avctx, &s->last_frame);

    /* shuffle frames (last = current) */
    s->last_frame= s->current_frame;
    s->current_frame.data[0]= NULL; /* ensure that we catch any access to this released frame */

    return buf_size;
}