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IMC decoder
Originally committed as revision 6839 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Kostya Shishkov
@@ -0,0 +1,816 @@
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/*
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* IMC compatible decoder
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* Copyright (c) 2002-2004 Maxim Poliakovski
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* Copyright (c) 2006 Benjamin Larsson
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* Copyright (c) 2006 Konstantin Shishkov
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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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/**
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* @file imc.c IMC - Intel Music Coder
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* A mdct based codec using a 256 points large transform
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* divied into 32 bands with some mix of scale factors.
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* Only mono is supported.
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*
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*/
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#include <math.h>
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#include <stddef.h>
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#include <stdio.h>
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#define ALT_BITSTREAM_READER
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#include "avcodec.h"
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#include "bitstream.h"
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#include "dsputil.h"
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#include "imcdata.h"
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#define IMC_FRAME_ID 0x21
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#define BANDS 32
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#define COEFFS 256
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typedef struct {
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float old_floor[BANDS];
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float flcoeffs1[BANDS];
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float flcoeffs2[BANDS];
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float flcoeffs3[BANDS];
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float flcoeffs4[BANDS];
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float flcoeffs5[BANDS];
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float flcoeffs6[BANDS];
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float CWdecoded[COEFFS];
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/** MDCT tables */
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//@{
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float mdct_sine_window[COEFFS];
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float post_cos[COEFFS];
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float post_sin[COEFFS];
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float pre_coef1[COEFFS];
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float pre_coef2[COEFFS];
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float last_fft_im[COEFFS];
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//@}
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int bandWidthT[BANDS]; ///< codewords per band
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int bitsBandT[BANDS]; ///< how many bits per codeword in band
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int CWlengthT[COEFFS]; ///< how many bits in each codeword
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int levlCoeffBuf[BANDS];
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int bandFlagsBuf[BANDS]; ///< flags for each band
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int sumLenArr[BANDS]; ///< bits for all coeffs in band
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int skipFlagRaw[BANDS]; ///< skip flags are stored in raw form or not
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int skipFlagBits[BANDS]; ///< bits used to code skip flags
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int skipFlagCount[BANDS]; ///< skipped coeffients per band
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int skipFlags[COEFFS]; ///< skip coefficient decoding or not
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int codewords[COEFFS]; ///< raw codewords read from bitstream
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float sqrt_tab[30];
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GetBitContext gb;
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VLC huffman_vlc[4][4];
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float flcf1, flcf2;
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int decoder_reset;
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float one_div_log2;
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DSPContext dsp;
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FFTContext fft;
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DECLARE_ALIGNED_16(FFTComplex, samples[COEFFS/2]);
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DECLARE_ALIGNED_16(float, out_samples[COEFFS]);
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} IMCContext;
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static int imc_decode_init(AVCodecContext * avctx)
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{
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int i, j;
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IMCContext *q = avctx->priv_data;
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double r1, r2;
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q->decoder_reset = 1;
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for(i = 0; i < BANDS; i++)
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q->old_floor[i] = 1.0;
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/* Build mdct window, a simple sine window normalized with sqrt(2) */
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for(i = 0; i < COEFFS; i++)
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q->mdct_sine_window[i] = sin((i + 0.5) / 512.0 * M_PI) * sqrt(2.0);
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for(i = 0; i < COEFFS/2; i++){
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q->post_cos[i] = cos(i / 256.0 * M_PI);
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q->post_sin[i] = sin(i / 256.0 * M_PI);
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r1 = sin((i * 4.0 + 1.0) / 1024.0 * M_PI);
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r2 = cos((i * 4.0 + 1.0) / 1024.0 * M_PI);
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if (i & 0x1)
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{
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q->pre_coef1[i] = (r1 + r2) * sqrt(2.0);
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q->pre_coef2[i] = -(r1 - r2) * sqrt(2.0);
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}
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else
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{
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q->pre_coef1[i] = -(r1 + r2) * sqrt(2.0);
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q->pre_coef2[i] = (r1 - r2) * sqrt(2.0);
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}
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q->last_fft_im[i] = 0;
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}
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q->flcf1 = log2(10) * 0.05703125;
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q->flcf2 = log2(10) * 0.25;
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/* Generate a square root table */
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for(i = 0; i < 30; i++) {
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q->sqrt_tab[i] = sqrt(i);
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}
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/* initialize the VLC tables */
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for(i = 0; i < 4 ; i++) {
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for(j = 0; j < 4; j++) {
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init_vlc (&q->huffman_vlc[i][j], 9, imc_huffman_sizes[i],
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imc_huffman_lens[i][j], 1, 1,
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imc_huffman_bits[i][j], 2, 2, 0);
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}
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}
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q->one_div_log2 = 1/log(2);
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ff_fft_init(&q->fft, 7, 1);
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dsputil_init(&q->dsp, avctx);
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return 0;
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}
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static void imc_calculate_coeffs(IMCContext* q, float* flcoeffs1, float* flcoeffs2, int* bandWidthT,
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float* flcoeffs3, float* flcoeffs5)
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{
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float workT1[BANDS];
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float workT2[BANDS];
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float workT3[BANDS];
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float snr_limit = 1.e-30;
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float accum = 0.0;
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int i, cnt2;
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for(i = 0; i < BANDS; i++) {
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flcoeffs5[i] = workT2[i] = 0.0;
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if (bandWidthT[i]){
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workT1[i] = flcoeffs1[i] * flcoeffs1[i];
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flcoeffs3[i] = 2.0 * flcoeffs2[i];
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} else {
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workT1[i] = 0.0;
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flcoeffs3[i] = -30000.0;
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}
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workT3[i] = bandWidthT[i] * workT1[i] * 0.01;
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if (workT3[i] <= snr_limit)
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workT3[i] = 0.0;
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}
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for(i = 0; i < BANDS; i++) {
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for(cnt2 = i; cnt2 < cyclTab[i]; cnt2++)
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flcoeffs5[cnt2] = flcoeffs5[cnt2] + workT3[i];
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workT2[cnt2-1] = workT2[cnt2-1] + workT3[i];
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}
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for(i = 1; i < BANDS; i++) {
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accum = (workT2[i-1] + accum) * imc_weights1[i-1];
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flcoeffs5[i] += accum;
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}
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for(i = 0; i < BANDS; i++)
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workT2[i] = 0.0;
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for(i = 0; i < BANDS; i++) {
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for(cnt2 = i-1; cnt2 > cyclTab2[i]; cnt2--)
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flcoeffs5[cnt2] += workT3[i];
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workT2[cnt2+1] += workT3[i];
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}
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accum = 0.0;
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for(i = BANDS-2; i >= 0; i--) {
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accum = (workT2[i+1] + accum) * imc_weights2[i];
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flcoeffs5[i] += accum;
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//there is missing code here, but it seems to never be triggered
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}
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}
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static void imc_read_level_coeffs(IMCContext* q, int stream_format_code, int* levlCoeffs)
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{
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int i;
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VLC *hufftab[4];
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int start = 0;
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const uint8_t *cb_sel;
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int s;
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s = stream_format_code >> 1;
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hufftab[0] = &q->huffman_vlc[s][0];
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hufftab[1] = &q->huffman_vlc[s][1];
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hufftab[2] = &q->huffman_vlc[s][2];
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hufftab[3] = &q->huffman_vlc[s][3];
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cb_sel = imc_cb_select[s];
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if(stream_format_code & 4)
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start = 1;
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if(start)
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levlCoeffs[0] = get_bits(&q->gb, 7);
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for(i = start; i < BANDS; i++){
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levlCoeffs[i] = get_vlc2(&q->gb, hufftab[cb_sel[i]]->table, hufftab[cb_sel[i]]->bits, 2);
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if(levlCoeffs[i] == 17)
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levlCoeffs[i] += get_bits(&q->gb, 4);
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}
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}
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static void imc_decode_level_coefficients(IMCContext* q, int* levlCoeffBuf, float* flcoeffs1,
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float* flcoeffs2)
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{
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int i, level;
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float tmp, tmp2;
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//maybe some frequency division thingy
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flcoeffs1[0] = 20000.0 / pow (2, levlCoeffBuf[0] * q->flcf1);
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flcoeffs2[0] = log2(flcoeffs1[0]);
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tmp = flcoeffs1[0];
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tmp2 = flcoeffs2[0];
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for(i = 1; i < BANDS; i++) {
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level = levlCoeffBuf[i];
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if (level == 16) {
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flcoeffs1[i] = 1.0;
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flcoeffs2[i] = 0.0;
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} else {
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if (level < 17)
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level -=7;
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else if (level <= 24)
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level -=32;
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else
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level -=16;
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tmp *= imc_exp_tab[15 + level];
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tmp2 += q->flcf2 * level;
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flcoeffs1[i] = tmp;
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flcoeffs2[i] = tmp2;
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}
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}
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}
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static void imc_decode_level_coefficients2(IMCContext* q, int* levlCoeffBuf, float* old_floor, float* flcoeffs1,
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float* flcoeffs2) {
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int i;
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//FIXME maybe flag_buf = noise coding and flcoeffs1 = new scale factors
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// and flcoeffs2 old scale factors
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// might be incomplete due to a missing table that is in the binary code
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for(i = 0; i < BANDS; i++) {
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flcoeffs1[i] = 0;
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if(levlCoeffBuf[i] < 16) {
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flcoeffs1[i] = imc_exp_tab2[levlCoeffBuf[i]] * old_floor[i];
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flcoeffs2[i] = (levlCoeffBuf[i]-7) * q->flcf2 + flcoeffs2[i];
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} else {
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flcoeffs1[i] = old_floor[i];
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}
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}
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}
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/**
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* Perform bit allocation depending on bits available
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*/
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static int bit_allocation (IMCContext* q, int stream_format_code, int freebits, int flag) {
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int i, j;
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const float limit = -1.e20;
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float highest = 0.0;
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int indx;
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int t1 = 0;
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int t2 = 1;
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float summa = 0.0;
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int iacc = 0;
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int summer = 0;
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int rres, cwlen;
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float lowest = 1.e10;
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int low_indx = 0;
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float workT[32];
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int flg;
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int found_indx = 0;
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for(i = 0; i < BANDS; i++)
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highest = FFMAX(highest, q->flcoeffs1[i]);
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for(i = 0; i < BANDS-1; i++) {
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q->flcoeffs4[i] = q->flcoeffs3[i] - log2(q->flcoeffs5[i]);
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}
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q->flcoeffs4[BANDS - 1] = limit;
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highest = highest * 0.25;
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for(i = 0; i < BANDS; i++) {
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indx = -1;
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if ((band_tab[i+1] - band_tab[i]) == q->bandWidthT[i])
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indx = 0;
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if ((band_tab[i+1] - band_tab[i]) > q->bandWidthT[i])
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indx = 1;
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if (((band_tab[i+1] - band_tab[i])/2) >= q->bandWidthT[i])
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indx = 2;
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if (indx == -1)
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return -1;
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q->flcoeffs4[i] = q->flcoeffs4[i] + xTab[(indx*2 + (q->flcoeffs1[i] < highest)) * 2 + flag];
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}
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if (stream_format_code & 0x2) {
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q->flcoeffs4[0] = limit;
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q->flcoeffs4[1] = limit;
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q->flcoeffs4[2] = limit;
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q->flcoeffs4[3] = limit;
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}
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for(i = (stream_format_code & 0x2)?4:0; i < BANDS-1; i++) {
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iacc += q->bandWidthT[i];
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summa += q->bandWidthT[i] * q->flcoeffs4[i];
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}
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q->bandWidthT[BANDS-1] = 0;
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summa = (summa * 0.5 - freebits) / iacc;
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for(i = 0; i < BANDS/2; i++) {
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rres = summer - freebits;
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if((rres >= -8) && (rres <= 8)) break;
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summer = 0;
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iacc = 0;
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for(j = (stream_format_code & 0x2)?4:0; j < BANDS; j++) {
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cwlen = clip((int)((q->flcoeffs4[j] * 0.5) - summa + 0.5), 0, 6);
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q->bitsBandT[j] = cwlen;
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summer += q->bandWidthT[j] * cwlen;
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if (cwlen > 0)
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iacc += q->bandWidthT[j];
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}
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flg = t2;
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t2 = 1;
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if (freebits < summer)
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t2 = -1;
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if (i == 0)
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flg = t2;
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if(flg != t2)
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t1++;
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summa = (float)(summer - freebits) / ((t1 + 1) * iacc) + summa;
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}
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for(i = (stream_format_code & 0x2)?4:0; i < BANDS; i++) {
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for(j = band_tab[i]; j < band_tab[i+1]; j++)
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q->CWlengthT[j] = q->bitsBandT[i];
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}
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if (freebits > summer) {
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for(i = 0; i < BANDS; i++) {
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workT[i] = (q->bitsBandT[i] == 6) ? -1.e20 : (q->bitsBandT[i] * -2 + q->flcoeffs4[i] - 0.415);
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}
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highest = 0.0;
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do{
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if (highest <= -1.e20)
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break;
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found_indx = 0;
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highest = -1.e20;
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for(i = 0; i < BANDS; i++) {
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if (workT[i] > highest) {
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highest = workT[i];
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found_indx = i;
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}
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}
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if (highest > -1.e20) {
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workT[found_indx] -= 2.0;
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if (++(q->bitsBandT[found_indx]) == 6)
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workT[found_indx] = -1.e20;
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for(j = band_tab[found_indx]; j < band_tab[found_indx+1] && (freebits > summer); j++){
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q->CWlengthT[j]++;
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summer++;
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}
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}
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}while (freebits > summer);
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}
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if (freebits < summer) {
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for(i = 0; i < BANDS; i++) {
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workT[i] = q->bitsBandT[i] ? (q->bitsBandT[i] * -2 + q->flcoeffs4[i] + 1.585) : 1.e20;
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}
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if (stream_format_code & 0x2) {
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workT[0] = 1.e20;
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workT[1] = 1.e20;
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workT[2] = 1.e20;
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workT[3] = 1.e20;
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}
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while (freebits < summer){
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lowest = 1.e10;
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low_indx = 0;
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for(i = 0; i < BANDS; i++) {
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if (workT[i] < lowest) {
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lowest = workT[i];
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low_indx = i;
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}
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}
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//if(lowest >= 1.e10) break;
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workT[low_indx] = lowest + 2.0;
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if (!(--q->bitsBandT[low_indx]))
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workT[low_indx] = 1.e20;
|
||||
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||||
for(j = band_tab[low_indx]; j < band_tab[low_indx+1] && (freebits < summer); j++){
|
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if(q->CWlengthT[j] > 0){
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||||
q->CWlengthT[j]--;
|
||||
summer--;
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
return 0;
|
||||
}
|
||||
|
||||
static void imc_get_skip_coeff(IMCContext* q) {
|
||||
int i, j;
|
||||
|
||||
memset(q->skipFlagBits, 0, sizeof(q->skipFlagBits));
|
||||
memset(q->skipFlagCount, 0, sizeof(q->skipFlagCount));
|
||||
for(i = 0; i < BANDS; i++) {
|
||||
if (!q->bandFlagsBuf[i] || !q->bandWidthT[i])
|
||||
continue;
|
||||
|
||||
if (!q->skipFlagRaw[i]) {
|
||||
q->skipFlagBits[i] = band_tab[i+1] - band_tab[i];
|
||||
|
||||
for(j = band_tab[i]; j < band_tab[i+1]; j++) {
|
||||
if ((q->skipFlags[j] = get_bits(&q->gb,1)))
|
||||
q->skipFlagCount[i]++;
|
||||
}
|
||||
} else {
|
||||
for(j = band_tab[i]; j < (band_tab[i+1]-1); j += 2) {
|
||||
if(!get_bits1(&q->gb)){//0
|
||||
q->skipFlagBits[i]++;
|
||||
q->skipFlags[j]=1;
|
||||
q->skipFlags[j+1]=1;
|
||||
q->skipFlagCount[i] += 2;
|
||||
}else{
|
||||
if(get_bits1(&q->gb)){//11
|
||||
q->skipFlagBits[i] +=2;
|
||||
q->skipFlags[j]=0;
|
||||
q->skipFlags[j+1]=1;
|
||||
q->skipFlagCount[i]++;
|
||||
}else{
|
||||
q->skipFlagBits[i] +=3;
|
||||
q->skipFlags[j+1]=0;
|
||||
if(!get_bits1(&q->gb)){//100
|
||||
q->skipFlags[j]=1;
|
||||
q->skipFlagCount[i]++;
|
||||
}else{//101
|
||||
q->skipFlags[j]=0;
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
if (j < band_tab[i+1]) {
|
||||
q->skipFlagBits[i]++;
|
||||
if ((q->skipFlags[j] = get_bits(&q->gb,1)))
|
||||
q->skipFlagCount[i]++;
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
/**
|
||||
* Increase highest' band coefficient sizes as some bits won't be used
|
||||
*/
|
||||
static void imc_adjust_bit_allocation (IMCContext* q, int summer) {
|
||||
float workT[32];
|
||||
int corrected = 0;
|
||||
int i, j;
|
||||
float highest = 0;
|
||||
int found_indx=0;
|
||||
|
||||
for(i = 0; i < BANDS; i++) {
|
||||
workT[i] = (q->bitsBandT[i] == 6) ? -1.e20 : (q->bitsBandT[i] * -2 + q->flcoeffs4[i] - 0.415);
|
||||
}
|
||||
|
||||
while (corrected < summer) {
|
||||
if(highest <= -1.e20)
|
||||
break;
|
||||
|
||||
highest = -1.e20;
|
||||
|
||||
for(i = 0; i < BANDS; i++) {
|
||||
if (workT[i] > highest) {
|
||||
highest = workT[i];
|
||||
found_indx = i;
|
||||
}
|
||||
}
|
||||
|
||||
if (highest > -1.e20) {
|
||||
workT[found_indx] -= 2.0;
|
||||
if (++(q->bitsBandT[found_indx]) == 6)
|
||||
workT[found_indx] = -1.e20;
|
||||
|
||||
for(j = band_tab[found_indx]; j < band_tab[found_indx+1] && (corrected < summer); j++) {
|
||||
if (!q->skipFlags[j] && (q->CWlengthT[j] < 6)) {
|
||||
q->CWlengthT[j]++;
|
||||
corrected++;
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
void imc_imdct256(IMCContext *q) {
|
||||
int i;
|
||||
float re, im;
|
||||
|
||||
/* prerotation */
|
||||
for(i=0; i < COEFFS/2; i++){
|
||||
q->samples[i].re = -(q->pre_coef1[i] * q->CWdecoded[COEFFS-1-i*2]) -
|
||||
(q->pre_coef2[i] * q->CWdecoded[i*2]);
|
||||
q->samples[i].im = (q->pre_coef2[i] * q->CWdecoded[COEFFS-1-i*2]) -
|
||||
(q->pre_coef1[i] * q->CWdecoded[i*2]);
|
||||
}
|
||||
|
||||
/* FFT */
|
||||
ff_fft_permute(&q->fft, q->samples);
|
||||
ff_fft_calc (&q->fft, q->samples);
|
||||
|
||||
/* postrotation, window and reorder */
|
||||
for(i = 0; i < COEFFS/2; i++){
|
||||
re = (q->samples[i].re * q->post_cos[i]) + (-q->samples[i].im * q->post_sin[i]);
|
||||
im = (-q->samples[i].im * q->post_cos[i]) - (q->samples[i].re * q->post_sin[i]);
|
||||
q->out_samples[i*2] = (q->mdct_sine_window[COEFFS-1-i*2] * q->last_fft_im[i]) + (q->mdct_sine_window[i*2] * re);
|
||||
q->out_samples[COEFFS-1-i*2] = (q->mdct_sine_window[i*2] * q->last_fft_im[i]) - (q->mdct_sine_window[COEFFS-1-i*2] * re);
|
||||
q->last_fft_im[i] = im;
|
||||
}
|
||||
}
|
||||
|
||||
static int inverse_quant_coeff (IMCContext* q, int stream_format_code) {
|
||||
int i, j;
|
||||
int middle_value, cw_len, max_size;
|
||||
const float* quantizer;
|
||||
|
||||
for(i = 0; i < BANDS; i++) {
|
||||
for(j = band_tab[i]; j < band_tab[i+1]; j++) {
|
||||
q->CWdecoded[j] = 0;
|
||||
cw_len = q->CWlengthT[j];
|
||||
|
||||
if (cw_len <= 0 || q->skipFlags[j])
|
||||
continue;
|
||||
|
||||
max_size = 1 << cw_len;
|
||||
middle_value = max_size >> 1;
|
||||
|
||||
if (q->codewords[j] >= max_size || q->codewords[j] < 0)
|
||||
return -1;
|
||||
|
||||
if (cw_len >= 4){
|
||||
quantizer = imc_quantizer2[(stream_format_code & 2) >> 1];
|
||||
if (q->codewords[j] >= middle_value)
|
||||
q->CWdecoded[j] = quantizer[q->codewords[j] - 8] * q->flcoeffs6[i];
|
||||
else
|
||||
q->CWdecoded[j] = -quantizer[max_size - q->codewords[j] - 8 - 1] * q->flcoeffs6[i];
|
||||
}else{
|
||||
quantizer = imc_quantizer1[((stream_format_code & 2) >> 1) | (q->bandFlagsBuf[i] << 1)];
|
||||
if (q->codewords[j] >= middle_value)
|
||||
q->CWdecoded[j] = quantizer[q->codewords[j] - 1] * q->flcoeffs6[i];
|
||||
else
|
||||
q->CWdecoded[j] = -quantizer[max_size - 2 - q->codewords[j]] * q->flcoeffs6[i];
|
||||
}
|
||||
}
|
||||
}
|
||||
return 0;
|
||||
}
|
||||
|
||||
|
||||
static int imc_get_coeffs (IMCContext* q) {
|
||||
int i, j, cw_len, cw;
|
||||
|
||||
for(i = 0; i < BANDS; i++) {
|
||||
if(!q->sumLenArr[i]) continue;
|
||||
if (q->bandFlagsBuf[i] || q->bandWidthT[i]) {
|
||||
for(j = band_tab[i]; j < band_tab[i+1]; j++) {
|
||||
cw_len = q->CWlengthT[j];
|
||||
cw = 0;
|
||||
|
||||
if (get_bits_count(&q->gb) + cw_len > 512){
|
||||
//av_log(NULL,0,"Band %i coeff %i cw_len %i\n",i,j,cw_len);
|
||||
return -1;
|
||||
}
|
||||
|
||||
if(cw_len && (!q->bandFlagsBuf[i] || !q->skipFlags[j]))
|
||||
cw = get_bits(&q->gb, cw_len);
|
||||
|
||||
q->codewords[j] = cw;
|
||||
}
|
||||
}
|
||||
}
|
||||
return 0;
|
||||
}
|
||||
|
||||
static int imc_decode_frame(AVCodecContext * avctx,
|
||||
void *data, int *data_size,
|
||||
uint8_t * buf, int buf_size)
|
||||
{
|
||||
|
||||
IMCContext *q = avctx->priv_data;
|
||||
|
||||
int stream_format_code;
|
||||
int imc_hdr, i, j;
|
||||
int flag;
|
||||
int bits, summer;
|
||||
int counter, bitscount;
|
||||
uint16_t *buf16 = (uint16_t *) buf;
|
||||
|
||||
/* FIXME: input should not be modified */
|
||||
for(i = 0; i < FFMIN(buf_size, avctx->block_align) / 2; i++)
|
||||
buf16[i] = bswap_16(buf16[i]);
|
||||
|
||||
init_get_bits(&q->gb, buf, 512);
|
||||
|
||||
/* Check the frame header */
|
||||
imc_hdr = get_bits(&q->gb, 9);
|
||||
if (imc_hdr != IMC_FRAME_ID) {
|
||||
av_log(avctx, AV_LOG_ERROR, "imc frame header check failed!\n");
|
||||
av_log(avctx, AV_LOG_ERROR, "got %x instead of 0x21.\n", imc_hdr);
|
||||
return -1;
|
||||
}
|
||||
stream_format_code = get_bits(&q->gb, 3);
|
||||
|
||||
if(stream_format_code & 1){
|
||||
av_log(avctx, AV_LOG_ERROR, "Stream code format %X is not supported\n", stream_format_code);
|
||||
return -1;
|
||||
}
|
||||
|
||||
// av_log(avctx, AV_LOG_DEBUG, "stream_format_code = %d\n", stream_format_code);
|
||||
|
||||
if (stream_format_code & 0x04)
|
||||
q->decoder_reset = 1;
|
||||
|
||||
if(q->decoder_reset) {
|
||||
memset(q->out_samples, 0, sizeof(q->out_samples));
|
||||
for(i = 0; i < BANDS; i++)q->old_floor[i] = 1.0;
|
||||
for(i = 0; i < COEFFS; i++)q->CWdecoded[i] = 0;
|
||||
q->decoder_reset = 0;
|
||||
}
|
||||
|
||||
flag = get_bits1(&q->gb);
|
||||
imc_read_level_coeffs(q, stream_format_code, q->levlCoeffBuf);
|
||||
|
||||
if (stream_format_code & 0x4)
|
||||
imc_decode_level_coefficients(q, q->levlCoeffBuf, q->flcoeffs1, q->flcoeffs2);
|
||||
else
|
||||
imc_decode_level_coefficients2(q, q->levlCoeffBuf, q->old_floor, q->flcoeffs1, q->flcoeffs2);
|
||||
|
||||
memcpy(q->old_floor, q->flcoeffs1, 32 * sizeof(float));
|
||||
|
||||
counter = 0;
|
||||
for (i=0 ; i<BANDS ; i++) {
|
||||
if (q->levlCoeffBuf[i] == 16) {
|
||||
q->bandWidthT[i] = 0;
|
||||
counter++;
|
||||
} else
|
||||
q->bandWidthT[i] = band_tab[i+1] - band_tab[i];
|
||||
}
|
||||
memset(q->bandFlagsBuf, 0, BANDS * sizeof(int));
|
||||
for(i = 0; i < BANDS-1; i++) {
|
||||
if (q->bandWidthT[i])
|
||||
q->bandFlagsBuf[i] = get_bits1(&q->gb);
|
||||
}
|
||||
|
||||
imc_calculate_coeffs(q, q->flcoeffs1, q->flcoeffs2, q->bandWidthT, q->flcoeffs3, q->flcoeffs5);
|
||||
|
||||
bitscount = 0;
|
||||
/* first 4 bands will be assigned 5 bits per coefficient */
|
||||
if (stream_format_code & 0x2) {
|
||||
bitscount += 15;
|
||||
|
||||
q->bitsBandT[0] = 5;
|
||||
q->CWlengthT[0] = 5;
|
||||
q->CWlengthT[1] = 5;
|
||||
q->CWlengthT[2] = 5;
|
||||
for(i = 1; i < 4; i++){
|
||||
bits = (q->levlCoeffBuf[i] == 16) ? 0 : 5;
|
||||
q->bitsBandT[i] = bits;
|
||||
for(j = band_tab[i]; j < band_tab[i+1]; j++) {
|
||||
q->CWlengthT[j] = bits;
|
||||
bitscount += bits;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
if(bit_allocation (q, stream_format_code, 512 - bitscount - get_bits_count(&q->gb), flag) < 0) {
|
||||
av_log(avctx, AV_LOG_ERROR, "Bit allocations failed\n");
|
||||
q->decoder_reset = 1;
|
||||
return -1;
|
||||
}
|
||||
|
||||
for(i = 0; i < BANDS; i++) {
|
||||
q->sumLenArr[i] = 0;
|
||||
q->skipFlagRaw[i] = 0;
|
||||
for(j = band_tab[i]; j < band_tab[i+1]; j++)
|
||||
q->sumLenArr[i] += q->CWlengthT[j];
|
||||
if (q->bandFlagsBuf[i])
|
||||
if( (((band_tab[i+1] - band_tab[i]) * 1.5) > q->sumLenArr[i]) && (q->sumLenArr[i] > 0))
|
||||
q->skipFlagRaw[i] = 1;
|
||||
}
|
||||
|
||||
imc_get_skip_coeff(q);
|
||||
|
||||
for(i = 0; i < BANDS; i++) {
|
||||
q->flcoeffs6[i] = q->flcoeffs1[i];
|
||||
/* band has flag set and at least one coded coefficient */
|
||||
if (q->bandFlagsBuf[i] && (band_tab[i+1] - band_tab[i]) != q->skipFlagCount[i]){
|
||||
q->flcoeffs6[i] *= q->sqrt_tab[band_tab[i+1] - band_tab[i]] /
|
||||
q->sqrt_tab[(band_tab[i+1] - band_tab[i] - q->skipFlagCount[i])];
|
||||
}
|
||||
}
|
||||
|
||||
/* calculate bits left, bits needed and adjust bit allocation */
|
||||
bits = summer = 0;
|
||||
|
||||
for(i = 0; i < BANDS; i++) {
|
||||
if (q->bandFlagsBuf[i]) {
|
||||
for(j = band_tab[i]; j < band_tab[i+1]; j++) {
|
||||
if(q->skipFlags[j]) {
|
||||
summer += q->CWlengthT[j];
|
||||
q->CWlengthT[j] = 0;
|
||||
}
|
||||
}
|
||||
bits += q->skipFlagBits[i];
|
||||
summer -= q->skipFlagBits[i];
|
||||
}
|
||||
}
|
||||
imc_adjust_bit_allocation(q, summer);
|
||||
|
||||
for(i = 0; i < BANDS; i++) {
|
||||
q->sumLenArr[i] = 0;
|
||||
|
||||
for(j = band_tab[i]; j < band_tab[i+1]; j++)
|
||||
if (!q->skipFlags[j])
|
||||
q->sumLenArr[i] += q->CWlengthT[j];
|
||||
}
|
||||
|
||||
memset(q->codewords, 0, sizeof(q->codewords));
|
||||
|
||||
if(imc_get_coeffs(q) < 0) {
|
||||
av_log(avctx, AV_LOG_ERROR, "Read coefficients failed\n");
|
||||
q->decoder_reset = 1;
|
||||
return 0;
|
||||
}
|
||||
|
||||
if(inverse_quant_coeff(q, stream_format_code) < 0) {
|
||||
av_log(avctx, AV_LOG_ERROR, "Inverse quantization of coefficients failed\n");
|
||||
q->decoder_reset = 1;
|
||||
return 0;
|
||||
}
|
||||
|
||||
memset(q->skipFlags, 0, sizeof(q->skipFlags));
|
||||
|
||||
imc_imdct256(q);
|
||||
|
||||
q->dsp.float_to_int16(data, q->out_samples, COEFFS);
|
||||
|
||||
*data_size = COEFFS * sizeof(int16_t);
|
||||
|
||||
return avctx->block_align;
|
||||
}
|
||||
|
||||
|
||||
static int imc_decode_close(AVCodecContext * avctx)
|
||||
{
|
||||
IMCContext *q = avctx->priv_data;
|
||||
|
||||
ff_fft_end(&q->fft);
|
||||
return 0;
|
||||
}
|
||||
|
||||
|
||||
AVCodec imc_decoder = {
|
||||
.name = "imc",
|
||||
.type = CODEC_TYPE_AUDIO,
|
||||
.id = CODEC_ID_IMC,
|
||||
.priv_data_size = sizeof(IMCContext),
|
||||
.init = imc_decode_init,
|
||||
.close = imc_decode_close,
|
||||
.decode = imc_decode_frame,
|
||||
};
|
||||
Reference in New Issue
Block a user