1/* 2 * RAW DTS demuxer 3 * Copyright (c) 2008 Benjamin Larsson 4 * 5 * This file is part of FFmpeg. 6 * 7 * FFmpeg is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU Lesser General Public 9 * License as published by the Free Software Foundation; either 10 * version 2.1 of the License, or (at your option) any later version. 11 * 12 * FFmpeg is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 15 * Lesser General Public License for more details. 16 * 17 * You should have received a copy of the GNU Lesser General Public 18 * License along with FFmpeg; if not, write to the Free Software 19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 20 */ 21 22#include "libavcodec/bytestream.h" 23#include "avformat.h" 24#include "rawdec.h" 25 26#define DCA_MARKER_14B_BE 0x1FFFE800 27#define DCA_MARKER_14B_LE 0xFF1F00E8 28#define DCA_MARKER_RAW_BE 0x7FFE8001 29#define DCA_MARKER_RAW_LE 0xFE7F0180 30 31static int dts_probe(AVProbeData *p) 32{ 33 const uint8_t *buf, *bufp; 34 uint32_t state = -1; 35 int markers[3] = {0}; 36 int sum, max; 37 int64_t diff = 0; 38 39 buf = p->buf; 40 41 for(; buf < (p->buf+p->buf_size)-2; buf+=2) { 42 bufp = buf; 43 state = (state << 16) | bytestream_get_be16(&bufp); 44 45 /* regular bitstream */ 46 if (state == DCA_MARKER_RAW_BE || state == DCA_MARKER_RAW_LE) 47 markers[0]++; 48 49 /* 14 bits big-endian bitstream */ 50 if (state == DCA_MARKER_14B_BE) 51 if ((bytestream_get_be16(&bufp) & 0xFFF0) == 0x07F0) 52 markers[1]++; 53 54 /* 14 bits little-endian bitstream */ 55 if (state == DCA_MARKER_14B_LE) 56 if ((bytestream_get_be16(&bufp) & 0xF0FF) == 0xF007) 57 markers[2]++; 58 59 if (buf - p->buf >= 4) 60 diff += FFABS(AV_RL16(buf) - AV_RL16(buf-4)); 61 } 62 sum = markers[0] + markers[1] + markers[2]; 63 max = markers[1] > markers[0]; 64 max = markers[2] > markers[max] ? 2 : max; 65 if (markers[max] > 3 && p->buf_size / markers[max] < 32*1024 && 66 markers[max] * 4 > sum * 3 && 67 diff / p->buf_size > 200) 68 return AVPROBE_SCORE_EXTENSION + 1; 69 70 return 0; 71} 72 73AVInputFormat ff_dts_demuxer = { 74 .name = "dts", 75 .long_name = NULL_IF_CONFIG_SMALL("raw DTS"), 76 .read_probe = dts_probe, 77 .read_header = ff_raw_audio_read_header, 78 .read_packet = ff_raw_read_partial_packet, 79 .flags = AVFMT_GENERIC_INDEX, 80 .extensions = "dts", 81 .raw_codec_id = AV_CODEC_ID_DTS, 82}; 83