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2b501b553f
DTS primarly needs to be separated from PCM, and PCM can contain cliping and overshoots at the very start which can mimic DTS headers. If this isnt sufficient then more of the DTS stream has to be decoded and analyzed Fixes ticket3784 Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
87 lines
2.7 KiB
C
87 lines
2.7 KiB
C
/*
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* RAW DTS demuxer
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* Copyright (c) 2008 Benjamin Larsson
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*
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* This file is part of FFmpeg.
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*
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* FFmpeg is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* FFmpeg is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with FFmpeg; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#include "libavcodec/bytestream.h"
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#include "avformat.h"
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#include "rawdec.h"
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#define DCA_MARKER_14B_BE 0x1FFFE800
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#define DCA_MARKER_14B_LE 0xFF1F00E8
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#define DCA_MARKER_RAW_BE 0x7FFE8001
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#define DCA_MARKER_RAW_LE 0xFE7F0180
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static int dts_probe(AVProbeData *p)
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{
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const uint8_t *buf, *bufp;
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uint32_t state = -1;
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int markers[4] = {0};
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int sum, max, i;
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int64_t diff = 0;
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buf = p->buf + FFMIN(4096, p->buf_size);
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for(; buf < (p->buf+p->buf_size)-2; buf+=2) {
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bufp = buf;
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state = (state << 16) | bytestream_get_be16(&bufp);
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/* regular bitstream */
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if (state == DCA_MARKER_RAW_BE)
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markers[0]++;
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if (state == DCA_MARKER_RAW_LE)
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markers[1]++;
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/* 14 bits big-endian bitstream */
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if (state == DCA_MARKER_14B_BE)
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if ((bytestream_get_be16(&bufp) & 0xFFF0) == 0x07F0)
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markers[2]++;
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/* 14 bits little-endian bitstream */
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if (state == DCA_MARKER_14B_LE)
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if ((bytestream_get_be16(&bufp) & 0xF0FF) == 0xF007)
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markers[3]++;
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if (buf - p->buf >= 4)
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diff += FFABS(((int16_t)AV_RL16(buf)) - (int16_t)AV_RL16(buf-4));
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}
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sum = markers[0] + markers[1] + markers[2] + markers[3];
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max = 0;
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for (i=1; i<4; i++)
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if (markers[max] < markers[i])
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max = i;
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if (markers[max] > 3 && p->buf_size / markers[max] < 32*1024 &&
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markers[max] * 4 > sum * 3 &&
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diff / p->buf_size > 200)
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return AVPROBE_SCORE_EXTENSION + 1;
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return 0;
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}
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AVInputFormat ff_dts_demuxer = {
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.name = "dts",
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.long_name = NULL_IF_CONFIG_SMALL("raw DTS"),
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.read_probe = dts_probe,
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.read_header = ff_raw_audio_read_header,
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.read_packet = ff_raw_read_partial_packet,
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.flags = AVFMT_GENERIC_INDEX,
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.extensions = "dts",
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.raw_codec_id = AV_CODEC_ID_DTS,
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};
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