yading@11: /*
yading@11:  * RAW DTS demuxer
yading@11:  * Copyright (c) 2008 Benjamin Larsson
yading@11:  *
yading@11:  * This file is part of FFmpeg.
yading@11:  *
yading@11:  * FFmpeg is free software; you can redistribute it and/or
yading@11:  * modify it under the terms of the GNU Lesser General Public
yading@11:  * License as published by the Free Software Foundation; either
yading@11:  * version 2.1 of the License, or (at your option) any later version.
yading@11:  *
yading@11:  * FFmpeg is distributed in the hope that it will be useful,
yading@11:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@11:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@11:  * Lesser General Public License for more details.
yading@11:  *
yading@11:  * You should have received a copy of the GNU Lesser General Public
yading@11:  * License along with FFmpeg; if not, write to the Free Software
yading@11:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@11:  */
yading@11: 
yading@11: #include "libavcodec/bytestream.h"
yading@11: #include "avformat.h"
yading@11: #include "rawdec.h"
yading@11: 
yading@11: #define DCA_MARKER_14B_BE 0x1FFFE800
yading@11: #define DCA_MARKER_14B_LE 0xFF1F00E8
yading@11: #define DCA_MARKER_RAW_BE 0x7FFE8001
yading@11: #define DCA_MARKER_RAW_LE 0xFE7F0180
yading@11: 
yading@11: static int dts_probe(AVProbeData *p)
yading@11: {
yading@11:     const uint8_t *buf, *bufp;
yading@11:     uint32_t state = -1;
yading@11:     int markers[3] = {0};
yading@11:     int sum, max;
yading@11: 
yading@11:     buf = p->buf;
yading@11: 
yading@11:     for(; buf < (p->buf+p->buf_size)-2; buf+=2) {
yading@11:         bufp = buf;
yading@11:         state = (state << 16) | bytestream_get_be16(&bufp);
yading@11: 
yading@11:         /* regular bitstream */
yading@11:         if (state == DCA_MARKER_RAW_BE || state == DCA_MARKER_RAW_LE)
yading@11:             markers[0]++;
yading@11: 
yading@11:         /* 14 bits big-endian bitstream */
yading@11:         if (state == DCA_MARKER_14B_BE)
yading@11:             if ((bytestream_get_be16(&bufp) & 0xFFF0) == 0x07F0)
yading@11:                 markers[1]++;
yading@11: 
yading@11:         /* 14 bits little-endian bitstream */
yading@11:         if (state == DCA_MARKER_14B_LE)
yading@11:             if ((bytestream_get_be16(&bufp) & 0xF0FF) == 0xF007)
yading@11:                 markers[2]++;
yading@11:     }
yading@11:     sum = markers[0] + markers[1] + markers[2];
yading@11:     max = markers[1] > markers[0];
yading@11:     max = markers[2] > markers[max] ? 2 : max;
yading@11:     if (markers[max] > 3 && p->buf_size / markers[max] < 32*1024 &&
yading@11:         markers[max] * 4 > sum * 3)
yading@11:         return AVPROBE_SCORE_MAX/2+1;
yading@11: 
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: AVInputFormat ff_dts_demuxer = {
yading@11:     .name           = "dts",
yading@11:     .long_name      = NULL_IF_CONFIG_SMALL("raw DTS"),
yading@11:     .read_probe     = dts_probe,
yading@11:     .read_header    = ff_raw_audio_read_header,
yading@11:     .read_packet    = ff_raw_read_partial_packet,
yading@11:     .flags          = AVFMT_GENERIC_INDEX,
yading@11:     .extensions     = "dts",
yading@11:     .raw_codec_id   = AV_CODEC_ID_DTS,
yading@11: };