diff options
Diffstat (limited to 'libavformat/dtsdec.c')
| -rw-r--r-- | libavformat/dtsdec.c | 130 |
1 files changed, 109 insertions, 21 deletions
diff --git a/libavformat/dtsdec.c b/libavformat/dtsdec.c index 90e9d38582..8c985b8877 100644 --- a/libavformat/dtsdec.c +++ b/libavformat/dtsdec.c @@ -2,25 +2,29 @@ * RAW DTS demuxer * Copyright (c) 2008 Benjamin Larsson * - * This file is part of Libav. + * This file is part of FFmpeg. * - * Libav is free software; you can redistribute it and/or + * FFmpeg is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * - * Libav is distributed in the hope that it will be useful, + * FFmpeg is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public - * License along with Libav; if not, write to the Free Software + * License along with FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ +#include "libavutil/crc.h" + #include "libavcodec/bytestream.h" +#include "libavcodec/dca.h" #include "libavcodec/dca_syncwords.h" +#include "libavcodec/get_bits.h" #include "avformat.h" #include "rawdec.h" @@ -29,34 +33,118 @@ static int dts_probe(AVProbeData *p) { const uint8_t *buf, *bufp; uint32_t state = -1; - int markers[3] = {0}; - int sum, max; + int markers[4*16] = {0}; + int exss_markers = 0, exss_nextpos = 0; + int sum, max, pos, i; + int64_t diff = 0; + uint8_t hdr[12 + AV_INPUT_BUFFER_PADDING_SIZE] = { 0 }; - buf = p->buf; + for (pos = FFMIN(4096, p->buf_size); pos < p->buf_size - 2; pos += 2) { + int marker, sample_blocks, sample_rate, sr_code, framesize; + int lfe, wide_hdr, hdr_size; + GetBitContext gb; - for(; buf < (p->buf+p->buf_size)-2; buf+=2) { - bufp = buf; + bufp = buf = p->buf + pos; state = (state << 16) | bytestream_get_be16(&bufp); + if (pos >= 4) + diff += FFABS(((int16_t)AV_RL16(buf)) - (int16_t)AV_RL16(buf-4)); + + /* extension substream (EXSS) */ + if (state == DCA_SYNCWORD_SUBSTREAM) { + if (pos < exss_nextpos) + continue; + + init_get_bits(&gb, buf - 2, 96); + skip_bits_long(&gb, 42); + + wide_hdr = get_bits1(&gb); + hdr_size = get_bits(&gb, 8 + 4 * wide_hdr) + 1; + framesize = get_bits(&gb, 16 + 4 * wide_hdr) + 1; + if (hdr_size & 3 || framesize & 3) + continue; + if (hdr_size < 16 || framesize < hdr_size) + continue; + if (pos - 2 + hdr_size > p->buf_size) + continue; + if (av_crc(av_crc_get_table(AV_CRC_16_CCITT), 0xffff, buf + 3, hdr_size - 5)) + continue; + + if (pos == exss_nextpos) + exss_markers++; + else + exss_markers = FFMAX(1, exss_markers - 1); + exss_nextpos = pos + framesize; + continue; + } + /* regular bitstream */ - if (state == DCA_SYNCWORD_CORE_BE || state == DCA_SYNCWORD_CORE_LE) - markers[0]++; + if (state == DCA_SYNCWORD_CORE_BE && + (bytestream_get_be16(&bufp) & 0xFC00) == 0xFC00) + marker = 0; + else if (state == DCA_SYNCWORD_CORE_LE && + (bytestream_get_be16(&bufp) & 0x00FC) == 0x00FC) + marker = 1; /* 14 bits big-endian bitstream */ - if (state == DCA_SYNCWORD_CORE_14B_BE) - if ((bytestream_get_be16(&bufp) & 0xFFF0) == 0x07F0) - markers[1]++; + else if (state == DCA_SYNCWORD_CORE_14B_BE && + (bytestream_get_be16(&bufp) & 0xFFF0) == 0x07F0) + marker = 2; /* 14 bits little-endian bitstream */ - if (state == DCA_SYNCWORD_CORE_14B_LE) - if ((bytestream_get_be16(&bufp) & 0xF0FF) == 0xF007) - markers[2]++; + else if (state == DCA_SYNCWORD_CORE_14B_LE && + (bytestream_get_be16(&bufp) & 0xF0FF) == 0xF007) + marker = 3; + else + continue; + + if (avpriv_dca_convert_bitstream(buf-2, 12, hdr, 12) < 0) + continue; + + init_get_bits(&gb, hdr, 96); + skip_bits_long(&gb, 39); + + sample_blocks = get_bits(&gb, 7) + 1; + if (sample_blocks < 8) + continue; + + framesize = get_bits(&gb, 14) + 1; + if (framesize < 95) + continue; + + skip_bits(&gb, 6); + sr_code = get_bits(&gb, 4); + sample_rate = avpriv_dca_sample_rates[sr_code]; + if (sample_rate == 0) + continue; + + get_bits(&gb, 5); + if (get_bits(&gb, 1)) + continue; + + skip_bits_long(&gb, 9); + lfe = get_bits(&gb, 2); + if (lfe > 2) + continue; + + marker += 4* sr_code; + + markers[marker] ++; } - sum = markers[0] + markers[1] + markers[2]; - max = markers[1] > markers[0]; - max = markers[2] > markers[max] ? 2 : max; + + if (exss_markers > 3) + return AVPROBE_SCORE_EXTENSION + 1; + + sum = max = 0; + for (i=0; i<FF_ARRAY_ELEMS(markers); i++) { + sum += markers[i]; + if (markers[max] < markers[i]) + max = i; + } + if (markers[max] > 3 && p->buf_size / markers[max] < 32*1024 && - markers[max] * 4 > sum * 3) + markers[max] * 4 > sum * 3 && + diff / p->buf_size > 200) return AVPROBE_SCORE_EXTENSION + 1; return 0; |