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136 lines
3.9 KiB
136 lines
3.9 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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/** |
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* Get parity bit of bit 2..7 |
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*/ |
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static inline int g729_get_parity(uint8_t value) |
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{ |
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return (0x6996966996696996ULL >> (value >> 2)) & 1; |
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} |
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/* |
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This filter enhances harmonic components of the fixed-codebook vector to |
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improve the quality of the reconstructed speech. |
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/ fc_v[i], i < pitch_delay |
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fc_v[i] = < |
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\ fc_v[i] + gain_pitch * fc_v[i-pitch_delay], i >= pitch_delay |
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*/ |
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ff_acelp_weighted_vector_sum( |
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fc + pitch_delay_int[i], |
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fc + pitch_delay_int[i], |
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fc, |
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1 << 14, |
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av_clip(ctx->gain_pitch, SHARP_MIN, SHARP_MAX), |
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0, |
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14, |
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ctx->subframe_size - pitch_delay_int[i]); |
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ctx->gain_pitch = cb_gain_1st_8k[parm->gc_1st_index[i]][0] + |
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cb_gain_2nd_8k[parm->gc_2nd_index[i]][0]; |
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gain_corr_factor = cb_gain_1st_8k[parm->gc_1st_index[i]][1] + |
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cb_gain_2nd_8k[parm->gc_2nd_index[i]][1]; |
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/* Routine requires rounding to lowest. */ |
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ff_acelp_interpolate( |
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ctx->exc + i*ctx->subframe_size, |
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ctx->exc + i*ctx->subframe_size - pitch_delay_3x/3, |
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ff_acelp_interp_filter, |
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6, |
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(pitch_delay_3x%3)<<1, |
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10, |
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ctx->subframe_size); |
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ff_acelp_weighted_vector_sum( |
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ctx->exc + i * ctx->subframe_size, |
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ctx->exc + i * ctx->subframe_size, |
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fc, |
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(!voicing && ctx->frame_erasure) ? 0 : ctx->gain_pitch, |
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( voicing && ctx->frame_erasure) ? 0 : ctx->gain_code, |
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1<<13, |
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14, |
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ctx->subframe_size); |
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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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