mirror of
https://github.com/librempeg/librempeg
synced 2024-11-22 09:02:20 +00:00
83 lines
2.6 KiB
C
83 lines
2.6 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[3] = {0};
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int sum, max;
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int64_t diff = 0;
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buf = p->buf;
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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 || state == DCA_MARKER_RAW_LE)
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markers[0]++;
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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[1]++;
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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[2]++;
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if (buf - p->buf >= 4)
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diff += FFABS(AV_RL16(buf) - AV_RL16(buf-4));
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}
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sum = markers[0] + markers[1] + markers[2];
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max = markers[1] > markers[0];
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max = markers[2] > markers[max] ? 2 : max;
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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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