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ffmpeg / libavcodec / qcelpdec.c @ cb377ec5

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/*
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 * QCELP decoder
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 * Copyright (c) 2007 Reynaldo H. Verdejo Pinochet
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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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/**
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 * @file qcelpdec.c
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 * QCELP decoder
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 * @author Reynaldo H. Verdejo Pinochet
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 */
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#include <stddef.h>
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#include "avcodec.h"
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#include "bitstream.h"
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#include "qcelp.h"
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#include "qcelpdata.h"
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#include "celp_math.h"
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#include "celp_filters.h"
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#undef NDEBUG
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#include <assert.h>
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/**
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 * Apply filter in pitch-subframe steps.
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 *
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 * @param memory buffer for the previous state of the filter
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 *        - must be able to contain 303 elements
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 *        - the 143 first elements are from the previous state
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 *        - the next 160 are for output
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 * @param v_in input filter vector
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 * @param gain per-subframe gain array, each element is between 0.0 and 2.0
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 * @param lag per-subframe lag array, each element is
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 *        - between 16 and 143 if its corresponding pfrac is 0,
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 *        - between 16 and 139 otherwise
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 * @param pfrac per-subframe boolean array, 1 if the lag is fractional, 0 otherwise
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 *
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 * @return filter output vector
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 */
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static const float *do_pitchfilter(float memory[303],
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                                   const float v_in[160],
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                                   const float gain[4],
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                                   const uint8_t *lag,
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                                   const uint8_t pfrac[4]) {
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    int         i, j;
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    float       *v_lag, *v_out;
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    const float *v_len;
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    v_out = memory + 143; // Output vector starts at memory[143].
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    for (i = 0; i < 4; i++)
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        if (gain[i]) {
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            v_lag = memory + 143 + 40 * i - lag[i];
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            for (v_len = v_in + 40; v_in < v_len; v_in++) {
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                if (pfrac[i]) { // If it is a fractional lag...
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                    for (j = 0, *v_out = 0.; j < 4; j++)
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                        *v_out += qcelp_hammsinc_table[j] * (v_lag[j-4] + v_lag[3-j]);
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                } else
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                    *v_out = *v_lag;
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                *v_out = *v_in + gain[i] * *v_out;
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                v_lag++;
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                v_out++;
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            }
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        } else {
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            memcpy(v_out, v_in, 40 * sizeof(float));
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            v_in  += 40;
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            v_out += 40;
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        }
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    memmove(memory, memory + 160, 143 * sizeof(float));
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    return memory + 143;
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}
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static void warn_insufficient_frame_quality(AVCodecContext *avctx,
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                                            const char *message) {
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    av_log(avctx, AV_LOG_WARNING, "Frame #%d, IFQ: %s\n", avctx->frame_number, message);
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}