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85 lines
2.1 KiB
85 lines
2.1 KiB
/* |
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* G.729 decoder |
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* Copyright (c) 2008 Vladimir Voroshilov |
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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 <stdlib.h> |
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#include <inttypes.h> |
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#include <limits.h> |
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#include <stdio.h> |
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#include <string.h> |
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#include <math.h> |
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#include <assert.h> |
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#include "avcodec.h" |
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#include "libavutil/avutil.h" |
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#include "bitstream.h" |
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/** |
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* minimum quantized LSF value (3.2.4) |
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* 0.005 in Q13 |
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*/ |
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#define LSFQ_MIN 40 |
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/** |
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* maximum quantized LSF value (3.2.4) |
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* 3.135 in Q13 |
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*/ |
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#define LSFQ_MAX 25681 |
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/** |
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* minimum LSF distance (3.2.4) |
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* 0.0391 in Q13 |
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*/ |
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#define LSFQ_DIFF_MIN 321 |
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/** |
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* minimum gain pitch value (3.8, Equation 47) |
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* 0.2 in (1.14) |
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*/ |
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#define SHARP_MIN 3277 |
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/** |
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* maximum gain pitch value (3.8, Equation 47) |
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* (EE) This does not comply with the specification. |
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* Specification says about 0.8, which should be |
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* 13107 in (1.14), but reference C code uses |
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* 13017 (equals to 0.7945) instead of it. |
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*/ |
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#define SHARP_MAX 13017 |
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/** |
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* \brief pseudo random number generator |
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*/ |
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static inline uint16_t g729_random(uint16_t value) |
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{ |
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return 31821 * value + 13849; |
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} |
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AVCodec g729_decoder = |
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{ |
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"g729", |
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CODEC_TYPE_AUDIO, |
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CODEC_ID_G729, |
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sizeof(G729_Context), |
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ff_g729_decoder_init, |
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NULL, |
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NULL, |
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ff_g729_decode_frame, |
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.long_name = NULL_IF_CONFIG_SMALL("G.729"), |
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};
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