| /* |
| * RAW DTS demuxer |
| * Copyright (c) 2008 Benjamin Larsson |
| * |
| * This file is part of FFmpeg. |
| * |
| * 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. |
| * |
| * 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 FFmpeg; if not, write to the Free Software |
| * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| */ |
| |
| #include "libavcodec/bytestream.h" |
| #include "avformat.h" |
| #include "rawdec.h" |
| |
| #define DCA_MARKER_14B_BE 0x1FFFE800 |
| #define DCA_MARKER_14B_LE 0xFF1F00E8 |
| #define DCA_MARKER_RAW_BE 0x7FFE8001 |
| #define DCA_MARKER_RAW_LE 0xFE7F0180 |
| |
| static int dts_probe(AVProbeData *p) |
| { |
| const uint8_t *buf, *bufp; |
| uint32_t state = -1; |
| int markers[3] = {0}; |
| int sum, max; |
| int64_t diff = 0; |
| |
| buf = p->buf; |
| |
| for(; buf < (p->buf+p->buf_size)-2; buf+=2) { |
| bufp = buf; |
| state = (state << 16) | bytestream_get_be16(&bufp); |
| |
| /* regular bitstream */ |
| if (state == DCA_MARKER_RAW_BE || state == DCA_MARKER_RAW_LE) |
| markers[0]++; |
| |
| /* 14 bits big-endian bitstream */ |
| if (state == DCA_MARKER_14B_BE) |
| if ((bytestream_get_be16(&bufp) & 0xFFF0) == 0x07F0) |
| markers[1]++; |
| |
| /* 14 bits little-endian bitstream */ |
| if (state == DCA_MARKER_14B_LE) |
| if ((bytestream_get_be16(&bufp) & 0xF0FF) == 0xF007) |
| markers[2]++; |
| |
| if (buf - p->buf >= 4) |
| diff += FFABS(AV_RL16(buf) - AV_RL16(buf-4)); |
| } |
| sum = markers[0] + markers[1] + markers[2]; |
| max = markers[1] > markers[0]; |
| max = markers[2] > markers[max] ? 2 : max; |
| if (markers[max] > 3 && p->buf_size / markers[max] < 32*1024 && |
| markers[max] * 4 > sum * 3 && |
| diff / p->buf_size > 200) |
| return AVPROBE_SCORE_EXTENSION + 1; |
| |
| return 0; |
| } |
| |
| AVInputFormat ff_dts_demuxer = { |
| .name = "dts", |
| .long_name = NULL_IF_CONFIG_SMALL("raw DTS"), |
| .read_probe = dts_probe, |
| .read_header = ff_raw_audio_read_header, |
| .read_packet = ff_raw_read_partial_packet, |
| .flags = AVFMT_GENERIC_INDEX, |
| .extensions = "dts", |
| .raw_codec_id = AV_CODEC_ID_DTS, |
| }; |