static int fraps2_decode_plane(FrapsContext *s, uint8_t *dst, int stride, int w, int h, const uint8_t *src, int size, int Uoff, const int step) { int i, j; GetBitContext gb; VLC vlc; Node nodes[512]; for(i = 0; i < 256; i++) nodes[i].count = bytestream_get_le32(&src); size -= 1024; if (ff_huff_build_tree(s->avctx, &vlc, 256, nodes, huff_cmp, FF_HUFFMAN_FLAG_ZERO_COUNT) < 0) return -1; /* we have built Huffman table and are ready to decode plane */ /* convert bits so they may be used by standard bitreader */ s->dsp.bswap_buf((uint32_t *)s->tmpbuf, (const uint32_t *)src, size >> 2); init_get_bits(&gb, s->tmpbuf, size * 8); for(j = 0; j < h; j++){ for(i = 0; i < w*step; i += step){ dst[i] = get_vlc2(&gb, vlc.table, 9, 3); /* lines are stored as deltas between previous lines * and we need to add 0x80 to the first lines of chroma planes */ if(j) dst[i] += dst[i - stride]; else if(Uoff) dst[i] += 0x80; } dst += stride; if(get_bits_left(&gb) < 0){ free_vlc(&vlc); return -1; } } free_vlc(&vlc); return 0; }