Пример #1
0
static int mp_decode_frame(AVCodecContext *avctx,
                           void *data, int *got_frame,
                           AVPacket *avpkt)
{
    const uint8_t *buf = avpkt->data;
    int buf_size = avpkt->size;
    MotionPixelsContext *mp = avctx->priv_data;
    GetBitContext gb;
    int i, count1, count2, sz, ret;

    if ((ret = ff_reget_buffer(avctx, mp->frame)) < 0)
        return ret;

    /* le32 bitstream msb first */
    av_fast_padded_malloc(&mp->bswapbuf, &mp->bswapbuf_size, buf_size);
    if (!mp->bswapbuf)
        return AVERROR(ENOMEM);
    mp->dsp.bswap_buf((uint32_t *)mp->bswapbuf, (const uint32_t *)buf, buf_size / 4);
    if (buf_size & 3)
        memcpy(mp->bswapbuf + (buf_size & ~3), buf + (buf_size & ~3), buf_size & 3);
    init_get_bits(&gb, mp->bswapbuf, buf_size * 8);

    memset(mp->changes_map, 0, avctx->width * avctx->height);
    for (i = !(avctx->extradata[1] & 2); i < 2; ++i) {
        count1 = get_bits(&gb, 12);
        count2 = get_bits(&gb, 12);
        mp_read_changes_map(mp, &gb, count1, 8, i);
        mp_read_changes_map(mp, &gb, count2, 4, i);
    }

    mp->codes_count = get_bits(&gb, 4);
    if (mp->codes_count == 0)
        goto end;

    if (mp->changes_map[0] == 0) {
        *(uint16_t *)mp->frame->data[0] = get_bits(&gb, 15);
        mp->changes_map[0] = 1;
    }
    if (mp_read_codes_table(mp, &gb) < 0)
        goto end;

    sz = get_bits(&gb, 18);
    if (avctx->extradata[0] != 5)
        sz += get_bits(&gb, 18);
    if (sz == 0)
        goto end;

    if (mp->max_codes_bits <= 0)
        goto end;
    if (init_vlc(&mp->vlc, mp->max_codes_bits, mp->codes_count, &mp->codes[0].size, sizeof(HuffCode), 1, &mp->codes[0].code, sizeof(HuffCode), 4, 0))
        goto end;
    mp_decode_frame_helper(mp, &gb);
    ff_free_vlc(&mp->vlc);

end:
    if ((ret = av_frame_ref(data, mp->frame)) < 0)
        return ret;
    *got_frame       = 1;
    return buf_size;
}
static int mp_decode_frame(AVCodecContext *avctx,
                           void *data, int *data_size,
                           AVPacket *avpkt)
{
    const uint8_t *buf = avpkt->data;
    int buf_size = avpkt->size;
    MotionPixelsContext *mp = avctx->priv_data;
    GetBitContext gb;
    int i, count1, count2, sz;

    mp->frame.reference = 1;
    mp->frame.buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_PRESERVE | FF_BUFFER_HINTS_REUSABLE;
    if (avctx->reget_buffer(avctx, &mp->frame)) {
        av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
        return -1;
    }

    /* le32 bitstream msb first */
    av_fast_malloc(&mp->bswapbuf, &mp->bswapbuf_size, buf_size + FF_INPUT_BUFFER_PADDING_SIZE);
    if (!mp->bswapbuf)
        return AVERROR(ENOMEM);
    mp->dsp.bswap_buf((uint32_t *)mp->bswapbuf, (const uint32_t *)buf, buf_size / 4);
    if (buf_size & 3)
        memcpy(mp->bswapbuf + (buf_size & ~3), buf + (buf_size & ~3), buf_size & 3);
    init_get_bits(&gb, mp->bswapbuf, buf_size * 8);

    memset(mp->changes_map, 0, avctx->width * avctx->height);
    for (i = !(avctx->extradata[1] & 2); i < 2; ++i) {
        count1 = get_bits(&gb, 12);
        count2 = get_bits(&gb, 12);
        mp_read_changes_map(mp, &gb, count1, 8, i);
        mp_read_changes_map(mp, &gb, count2, 4, i);
    }

    mp->codes_count = get_bits(&gb, 4);
    if (mp->codes_count == 0)
        goto end;

    if (mp->changes_map[0] == 0) {
        *(uint16_t *)mp->frame.data[0] = get_bits(&gb, 15);
        mp->changes_map[0] = 1;
    }
    mp_read_codes_table(mp, &gb);

    sz = get_bits(&gb, 18);
    if (avctx->extradata[0] != 5)
        sz += get_bits(&gb, 18);
    if (sz == 0)
        goto end;

    init_vlc(&mp->vlc, mp->max_codes_bits, mp->codes_count, &mp->codes[0].size, sizeof(HuffCode), 1, &mp->codes[0].code, sizeof(HuffCode), 4, 0);
    mp_decode_frame_helper(mp, &gb);
    free_vlc(&mp->vlc);

end:
    *data_size = sizeof(AVFrame);
    *(AVFrame *)data = mp->frame;
    return buf_size;
}