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	ba87f0801d
	
	
	
		
			
			Passing an explicit filename to this command is only necessary if the documentation in the @file block refers to a file different from the one the block resides in. Originally committed as revision 22921 to svn://svn.ffmpeg.org/ffmpeg/trunk
		
			
				
	
	
		
			103 lines
		
	
	
		
			3.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			103 lines
		
	
	
		
			3.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * Musepack decoder core
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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
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|  * Musepack decoder core
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|  * MPEG Audio Layer 1/2 -like codec with frames of 1152 samples
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|  * divided into 32 subbands.
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|  */
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| 
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| #include "avcodec.h"
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| #include "get_bits.h"
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| #include "dsputil.h"
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| #include "mpegaudio.h"
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| 
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| #include "mpc.h"
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| #include "mpcdata.h"
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| 
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| void ff_mpc_init(void)
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| {
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|     ff_mpa_synth_init(ff_mpa_synth_window);
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| }
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| 
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| /**
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|  * Process decoded Musepack data and produce PCM
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|  */
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| static void mpc_synth(MPCContext *c, int16_t *out)
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| {
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|     int dither_state = 0;
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|     int i, ch;
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|     OUT_INT samples[MPA_MAX_CHANNELS * MPA_FRAME_SIZE], *samples_ptr;
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| 
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|     for(ch = 0;  ch < 2; ch++){
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|         samples_ptr = samples + ch;
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|         for(i = 0; i < SAMPLES_PER_BAND; i++) {
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|             ff_mpa_synth_filter(c->synth_buf[ch], &(c->synth_buf_offset[ch]),
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|                                 ff_mpa_synth_window, &dither_state,
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|                                 samples_ptr, 2,
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|                                 c->sb_samples[ch][i]);
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|             samples_ptr += 64;
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|         }
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|     }
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|     for(i = 0; i < MPC_FRAME_SIZE*2; i++)
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|         *out++=samples[i];
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| }
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| 
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| void ff_mpc_dequantize_and_synth(MPCContext * c, int maxband, void *data)
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| {
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|     int i, j, ch;
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|     Band *bands = c->bands;
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|     int off;
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|     float mul;
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| 
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|     /* dequantize */
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|     memset(c->sb_samples, 0, sizeof(c->sb_samples));
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|     off = 0;
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|     for(i = 0; i <= maxband; i++, off += SAMPLES_PER_BAND){
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|         for(ch = 0; ch < 2; ch++){
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|             if(bands[i].res[ch]){
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|                 j = 0;
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|                 mul = mpc_CC[bands[i].res[ch]] * mpc_SCF[bands[i].scf_idx[ch][0]];
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|                 for(; j < 12; j++)
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|                     c->sb_samples[ch][j][i] = mul * c->Q[ch][j + off];
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|                 mul = mpc_CC[bands[i].res[ch]] * mpc_SCF[bands[i].scf_idx[ch][1]];
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|                 for(; j < 24; j++)
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|                     c->sb_samples[ch][j][i] = mul * c->Q[ch][j + off];
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|                 mul = mpc_CC[bands[i].res[ch]] * mpc_SCF[bands[i].scf_idx[ch][2]];
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|                 for(; j < 36; j++)
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|                     c->sb_samples[ch][j][i] = mul * c->Q[ch][j + off];
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|             }
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|         }
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|         if(bands[i].msf){
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|             int t1, t2;
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|             for(j = 0; j < SAMPLES_PER_BAND; j++){
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|                 t1 = c->sb_samples[0][j][i];
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|                 t2 = c->sb_samples[1][j][i];
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|                 c->sb_samples[0][j][i] = t1 + t2;
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|                 c->sb_samples[1][j][i] = t1 - t2;
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|             }
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|         }
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|     }
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| 
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|     mpc_synth(c, data);
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| }
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