static int read_header(ShortenContext *s) { int i, ret; int maxnlpc = 0; /* shorten signature */ if (get_bits_long(&s->gb, 32) != AV_RB32("ajkg")) { av_log(s->avctx, AV_LOG_ERROR, "missing shorten magic 'ajkg'\n"); return -1; } s->lpcqoffset = 0; s->blocksize = DEFAULT_BLOCK_SIZE; s->nmean = -1; s->version = get_bits(&s->gb, 8); s->internal_ftype = get_uint(s, TYPESIZE); s->channels = get_uint(s, CHANSIZE); if (s->channels > MAX_CHANNELS) { av_log(s->avctx, AV_LOG_ERROR, "too many channels: %d\n", s->channels); return -1; } s->avctx->channels = s->channels; /* get blocksize if version > 0 */ if (s->version > 0) { int skip_bytes, blocksize; blocksize = get_uint(s, av_log2(DEFAULT_BLOCK_SIZE)); if (!blocksize || blocksize > MAX_BLOCKSIZE) { av_log(s->avctx, AV_LOG_ERROR, "invalid or unsupported block size: %d\n", blocksize); return AVERROR(EINVAL); } s->blocksize = blocksize; maxnlpc = get_uint(s, LPCQSIZE); s->nmean = get_uint(s, 0); skip_bytes = get_uint(s, NSKIPSIZE); for (i=0; i<skip_bytes; i++) { skip_bits(&s->gb, 8); } } s->nwrap = FFMAX(NWRAP, maxnlpc); if ((ret = allocate_buffers(s)) < 0) return ret; if ((ret = init_offset(s)) < 0) return ret; if (s->version > 1) s->lpcqoffset = V2LPCQOFFSET; if (get_ur_golomb_shorten(&s->gb, FNSIZE) != FN_VERBATIM) { av_log(s->avctx, AV_LOG_ERROR, "missing verbatim section at beginning of stream\n"); return -1; } s->header_size = get_ur_golomb_shorten(&s->gb, VERBATIM_CKSIZE_SIZE); if (s->header_size >= OUT_BUFFER_SIZE || s->header_size < CANONICAL_HEADER_SIZE) { av_log(s->avctx, AV_LOG_ERROR, "header is wrong size: %d\n", s->header_size); return -1; } for (i=0; i<s->header_size; i++) s->header[i] = (char)get_ur_golomb_shorten(&s->gb, VERBATIM_BYTE_SIZE); if (decode_wave_header(s->avctx, s->header, s->header_size) < 0) return -1; s->cur_chan = 0; s->bitshift = 0; s->got_header = 1; return 0; }