Function decode_frame

libavcodec/wcmv.c:42–210

} WCMVContext;

static int decode_frame(AVCodecContext *avctx, AVFrame *frame,
                        int *got_frame, AVPacket *avpkt)
{
    WCMVContext *s = avctx->priv_data;
    z_stream *const zstream = &s->zstream.zstream;
    int skip, blocks, zret, ret, intra = 0, flags = 0, bpp = s->bpp;
    GetByteContext gb;
    uint8_t *dst;

    ret = inflateReset(zstream);
    if (ret != Z_OK) {
        av_log(avctx, AV_LOG_ERROR, "Inflate reset error: %d\n", ret);
        return AVERROR_EXTERNAL;
    }

    bytestream2_init(&gb, avpkt->data, avpkt->size);
    blocks = bytestream2_get_le16(&gb);
    if (!blocks)
        flags |= FF_REGET_BUFFER_FLAG_READONLY;

    if ((ret = ff_reget_buffer(avctx, s->prev_frame, flags)) < 0)
        return ret;

    if (blocks > 5) {
        GetByteContext bgb;
        int x = 0, size;

        if (blocks * 8 >= 0xFFFF)
            size = bytestream2_get_le24(&gb);
        else if (blocks * 8 >= 0xFF)
            size = bytestream2_get_le16(&gb);
        else
            size = bytestream2_get_byte(&gb);

        skip = bytestream2_tell(&gb);
        if (size > avpkt->size - skip)
            return AVERROR_INVALIDDATA;

        zstream->next_in   = avpkt->data + skip;
        zstream->avail_in  = size;
        zstream->next_out  = s->block_data;
        zstream->avail_out = sizeof(s->block_data);

        zret = inflate(zstream, Z_FINISH);
        if (zret != Z_STREAM_END) {
            av_log(avctx, AV_LOG_ERROR,
                   "Inflate failed with return code: %d.\n", zret);
            return AVERROR_INVALIDDATA;
        }

        ret = inflateReset(zstream);
        if (ret != Z_OK) {
            av_log(avctx, AV_LOG_ERROR, "Inflate reset error: %d\n", ret);
            return AVERROR_EXTERNAL;
        }

        bytestream2_skip(&gb, size);
        bytestream2_init(&bgb, s->block_data, blocks * 8);