static int decode_2(SANMVideoContext *ctx)
{
    int cx, cy, ret;

    for (cy = 0; cy != ctx->aligned_height; cy += 8) {
        for (cx = 0; cx != ctx->aligned_width; cx += 8) {
            if (ret = codec2subblock(ctx, cx, cy, 8))
                return ret;
        }
    }

    return 0;
}