129 lines
		
	
	
		
			4.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			129 lines
		
	
	
		
			4.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * audio encoder psychoacoustic model
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|  * Copyright (C) 2008 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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| #include "avcodec.h"
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| #include "psymodel.h"
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| #include "iirfilter.h"
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| 
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| extern const FFPsyModel ff_aac_psy_model;
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| 
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| av_cold int ff_psy_init(FFPsyContext *ctx, AVCodecContext *avctx,
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|                         int num_lens,
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|                         const uint8_t **bands, const int* num_bands)
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| {
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|     ctx->avctx = avctx;
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|     ctx->psy_bands = av_mallocz(sizeof(FFPsyBand) * PSY_MAX_BANDS * avctx->channels);
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|     ctx->bands     = av_malloc (sizeof(ctx->bands[0])     * num_lens);
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|     ctx->num_bands = av_malloc (sizeof(ctx->num_bands[0]) * num_lens);
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|     memcpy(ctx->bands,     bands,     sizeof(ctx->bands[0])     *  num_lens);
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|     memcpy(ctx->num_bands, num_bands, sizeof(ctx->num_bands[0]) *  num_lens);
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|     switch (ctx->avctx->codec_id) {
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|     case CODEC_ID_AAC:
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|         ctx->model = &ff_aac_psy_model;
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|         break;
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|     }
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|     if (ctx->model->init)
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|         return ctx->model->init(ctx);
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|     return 0;
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| }
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| 
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| FFPsyWindowInfo ff_psy_suggest_window(FFPsyContext *ctx,
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|                                       const int16_t *audio, const int16_t *la,
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|                                       int channel, int prev_type)
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| {
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|     return ctx->model->window(ctx, audio, la, channel, prev_type);
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| }
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| 
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| void ff_psy_set_band_info(FFPsyContext *ctx, int channel,
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|                           const float *coeffs, FFPsyWindowInfo *wi)
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| {
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|     ctx->model->analyze(ctx, channel, coeffs, wi);
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| }
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| 
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| av_cold void ff_psy_end(FFPsyContext *ctx)
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| {
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|     if (ctx->model->end)
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|         ctx->model->end(ctx);
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|     av_freep(&ctx->bands);
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|     av_freep(&ctx->num_bands);
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|     av_freep(&ctx->psy_bands);
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| }
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| 
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| typedef struct FFPsyPreprocessContext{
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|     AVCodecContext *avctx;
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|     float stereo_att;
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|     struct FFIIRFilterCoeffs *fcoeffs;
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|     struct FFIIRFilterState **fstate;
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| }FFPsyPreprocessContext;
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| 
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| #define FILT_ORDER 4
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| 
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| av_cold struct FFPsyPreprocessContext* ff_psy_preprocess_init(AVCodecContext *avctx)
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| {
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|     FFPsyPreprocessContext *ctx;
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|     int i;
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|     float cutoff_coeff = 0;
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|     ctx        = av_mallocz(sizeof(FFPsyPreprocessContext));
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|     ctx->avctx = avctx;
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| 
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|     if (avctx->cutoff > 0)
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|         cutoff_coeff = 2.0 * avctx->cutoff / avctx->sample_rate;
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| 
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|     if (cutoff_coeff)
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|     ctx->fcoeffs = ff_iir_filter_init_coeffs(FF_FILTER_TYPE_BUTTERWORTH, FF_FILTER_MODE_LOWPASS,
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|                                              FILT_ORDER, cutoff_coeff, 0.0, 0.0);
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|     if (ctx->fcoeffs) {
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|         ctx->fstate = av_mallocz(sizeof(ctx->fstate[0]) * avctx->channels);
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|         for (i = 0; i < avctx->channels; i++)
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|             ctx->fstate[i] = ff_iir_filter_init_state(FILT_ORDER);
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|     }
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|     return ctx;
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| }
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| 
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| void ff_psy_preprocess(struct FFPsyPreprocessContext *ctx,
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|                        const int16_t *audio, int16_t *dest,
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|                        int tag, int channels)
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| {
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|     int ch, i;
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|     if (ctx->fstate) {
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|         for (ch = 0; ch < channels; ch++)
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|             ff_iir_filter(ctx->fcoeffs, ctx->fstate[tag+ch], ctx->avctx->frame_size,
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|                           audio + ch, ctx->avctx->channels,
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|                           dest  + ch, ctx->avctx->channels);
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|     } else {
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|         for (ch = 0; ch < channels; ch++)
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|             for (i = 0; i < ctx->avctx->frame_size; i++)
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|                 dest[i*ctx->avctx->channels + ch] = audio[i*ctx->avctx->channels + ch];
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|     }
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| }
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| 
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| av_cold void ff_psy_preprocess_end(struct FFPsyPreprocessContext *ctx)
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| {
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|     int i;
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|     ff_iir_filter_free_coeffs(ctx->fcoeffs);
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|     if (ctx->fstate)
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|         for (i = 0; i < ctx->avctx->channels; i++)
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|             ff_iir_filter_free_state(ctx->fstate[i]);
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|     av_freep(&ctx->fstate);
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|     av_free(ctx);
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| }
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| 
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