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ffmpeg / libavcodec / g729dec.c @ 730c1e4a

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/*
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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 "get_bits.h"
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#include "g729.h"
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#include "lsp.h"
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#include "celp_math.h"
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#include "acelp_filters.h"
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#include "acelp_pitch_delay.h"
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#include "acelp_vectors.h"
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#include "g729data.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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typedef struct {
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    int sample_rate;
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    uint8_t packed_frame_size;  ///< input frame size(in bytes)
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    uint8_t unpacked_frame_size;///< output frame size (in bytes)
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    uint8_t fc_indexes_bits;    ///< size (in bits) of fixed-codebook index entry
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    /// mr_energy = mean_energy + 10 * log10(2^26  * subframe_size) in (7.13)
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    int mr_energy;
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} G729FormatDescription;
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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_prng(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 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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    if (avctx->channels != 1) {
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        av_log(avctx, AV_LOG_ERROR, "Only mono sound is supported (requested channels: %d).\n", avctx->channels);
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        return AVERROR_NOFMT;
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    }
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        ff_acelp_weighted_vector_sum(fc + pitch_delay_int[i],
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                                     fc + pitch_delay_int[i],
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                                     fc, 1 << 14,
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                                     av_clip(ctx->gain_pitch, SHARP_MIN, SHARP_MAX),
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                                     0, 14,
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                                     SUBFRAME_SIZE - pitch_delay_int[i]);
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        if (ctx->frame_erasure) {
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            ctx->gain_pitch = (29491 * ctx->gain_pitch) >> 15; // 0.90 (0.15)
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            ctx->gain_code  = ( 2007 * ctx->gain_code ) >> 11; // 0.98 (0.11)
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            gain_corr_factor = 0;
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        } else {
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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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        ff_acelp_weighted_vector_sum(ctx->exc + i * SUBFRAME_SIZE,
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                                     ctx->exc + i * SUBFRAME_SIZE, 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, 14, SUBFRAME_SIZE);
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    if (buf_size < packed_frame_size) {
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        av_log(avctx, AV_LOG_ERROR, "Error processing packet: packet size too small\n");
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        return AVERROR(EIO);
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    }
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    if (*data_size < unpacked_frame_size) {
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        av_log(avctx, AV_LOG_ERROR, "Error processing packet: output buffer too small\n");
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        return AVERROR(EIO);
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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(G729Context),
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    decoder_init,
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    NULL,
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    NULL,
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    decode_frame,
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    .long_name = NULL_IF_CONFIG_SMALL("G.729"),
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};