forked from osmocom/wireshark
111 lines
4.1 KiB
C
111 lines
4.1 KiB
C
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/* mpeg-audio.h
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*
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* MPEG Audio header dissection
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* Written by Shaun Jackman <sjackman@gmail.com>
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* Copyright 2007 Shaun Jackman
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*
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* $Id$
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*
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* Wiretap Library
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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*
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* This program 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
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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*/
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#ifndef MPA_H
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#define MPA_H 1
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struct mpa {
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unsigned emphasis :2;
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unsigned original :1;
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unsigned copyright :1;
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unsigned modeext :2;
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unsigned mode :2;
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unsigned private :1;
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unsigned padding :1;
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unsigned frequency :2;
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unsigned bitrate :4;
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unsigned protection :1;
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unsigned layer :2;
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unsigned version :2;
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unsigned sync :11;
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};
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#define MPA_UNMARSHAL_SYNC(n) ((n) >> 21 & 0x7ff)
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#define MPA_UNMARSHAL_VERSION(n) ((n) >> 19 & 0x3)
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#define MPA_UNMARSHAL_LAYER(n) ((n) >> 17 & 0x3)
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#define MPA_UNMARSHAL_PROTECTION(n) ((n) >> 16 & 0x1)
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#define MPA_UNMARSHAL_BITRATE(n) ((n) >> 12 & 0xf)
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#define MPA_UNMARSHAL_FREQUENCY(n) ((n) >> 10 & 0x3)
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#define MPA_UNMARSHAL_PADDING(n) ((n) >> 9 & 0x1)
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#define MPA_UNMARSHAL_PRIVATE(n) ((n) >> 8 & 0x1)
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#define MPA_UNMARSHAL_MODE(n) ((n) >> 6 & 0x3)
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#define MPA_UNMARSHAL_MODEEXT(n) ((n) >> 4 & 0x3)
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#define MPA_UNMARSHAL_COPYRIGHT(n) ((n) >> 3 & 0x1)
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#define MPA_UNMARSHAL_ORIGINAL(n) ((n) >> 2 & 0x1)
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#define MPA_UNMARSHAL_EMPHASIS(n) ((n) >> 0 & 0x3)
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#define MPA_UNMARSHAL(mpa, n) do { \
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(mpa)->sync = MPA_UNMARSHAL_SYNC(n); \
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(mpa)->version = MPA_UNMARSHAL_VERSION(n); \
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(mpa)->layer = MPA_UNMARSHAL_LAYER(n); \
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(mpa)->protection = MPA_UNMARSHAL_PROTECTION(n); \
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(mpa)->bitrate = MPA_UNMARSHAL_BITRATE(n); \
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(mpa)->frequency = MPA_UNMARSHAL_FREQUENCY(n); \
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(mpa)->padding = MPA_UNMARSHAL_PADDING(n); \
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(mpa)->private = MPA_UNMARSHAL_PRIVATE(n); \
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(mpa)->mode = MPA_UNMARSHAL_MODE(n); \
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(mpa)->modeext = MPA_UNMARSHAL_MODEEXT(n); \
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(mpa)->copyright = MPA_UNMARSHAL_COPYRIGHT(n); \
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(mpa)->original = MPA_UNMARSHAL_ORIGINAL(n); \
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(mpa)->emphasis = MPA_UNMARSHAL_EMPHASIS(n); \
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} while (0)
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extern const int mpa_versions[4];
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extern const int mpa_layers[4];
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extern const unsigned mpa_samples[3][3];
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extern const unsigned mpa_bitrates[3][3][16]; /* kb/s */
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extern const unsigned mpa_frequencies[3][4]; /* Hz */
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extern const unsigned mpa_padding[3];
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#define MPA_VERSION(mpa) (mpa_versions[(mpa)->version])
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#define MPA_LAYER(mpa) (mpa_layers[(mpa)->layer])
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#define MPAV(mpa) MPA_VERSION(mpa)
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#define MPAL(mpa) MPA_LAYER(mpa)
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#define MPA_SAMPLES(mpa) (mpa_samples[MPAV(mpa)][MPAL(mpa)])
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#define MPA_BITRATE(mpa) (1000 * \
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(mpa_bitrates[MPAV(mpa)][MPAL(mpa)][(mpa)->bitrate]))
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#define MPA_FREQUENCY(mpa) \
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(mpa_frequencies[MPAV(mpa)][(mpa)->frequency])
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#define MPA_PADDING(mpa)((mpa)->padding ? mpa_padding[MPAL(mpa)] : 0)
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#define MPA_DATA_BYTES(mpa) (MPA_BITRATE(mpa) * MPA_SAMPLES(mpa) \
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/ MPA_FREQUENCY(mpa) / 8)
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#define MPA_BYTES(mpa) (MPA_DATA_BYTES(mpa) + MPA_PADDING(mpa))
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#define MPA_DURATION_NS(mpa) \
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(1000000000 / MPA_FREQUENCY(mpa) * MPA_SAMPLES(mpa))
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enum { MPA_SYNC = 0x7ff };
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#define MPA_SYNC_VALID(mpa) ((mpa)->sync == MPA_SYNC)
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#define MPA_VERSION_VALID(mpa) (MPA_VERSION(mpa) >= 0)
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#define MPA_LAYER_VALID(mpa) (MPA_LAYER(mpa) >= 0)
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#define MPA_BITRATE_VALID(mpa) (MPA_BITRATE(mpa) > 0)
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#define MPA_FREQUENCY_VALID(mpa) (MPA_FREQUENCY(mpa) > 0)
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#define MPA_VALID(mpa) (MPA_SYNC_VALID(mpa) \
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&& MPA_VERSION_VALID(mpa) && MPA_LAYER_VALID(mpa) \
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&& MPA_BITRATE_VALID(mpa) && MPA_FREQUENCY_VALID(mpa))
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#endif
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