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120 lines
4.8 KiB
120 lines
4.8 KiB
/* |
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* AC-3 DSP functions |
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* Copyright (c) 2011 Justin Ruggles |
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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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#ifndef AVCODEC_AC3DSP_H |
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#define AVCODEC_AC3DSP_H |
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#include <stdint.h> |
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/** |
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* Number of mantissa bits written for each bap value. |
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* bap values with fractional bits are set to 0 and are calculated separately. |
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*/ |
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extern const uint16_t ff_ac3_bap_bits[16]; |
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typedef struct AC3DSPContext { |
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/** |
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* Set each encoded exponent in a block to the minimum of itself and the |
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* exponents in the same frequency bin of up to 5 following blocks. |
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* @param exp pointer to the start of the current block of exponents. |
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* constraints: align 16 |
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* @param num_reuse_blocks number of blocks that will reuse exponents from the current block. |
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* constraints: range 0 to 5 |
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* @param nb_coefs number of frequency coefficients. |
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*/ |
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void (*ac3_exponent_min)(uint8_t *exp, int num_reuse_blocks, int nb_coefs); |
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/** |
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* Convert an array of float in range [-1.0,1.0] to int32_t with range |
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* [-(1<<24),(1<<24)] |
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* |
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* @param dst destination array of int32_t. |
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* constraints: 16-byte aligned |
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* @param src source array of float. |
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* constraints: 16-byte aligned |
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* @param len number of elements to convert. |
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* constraints: multiple of 32 greater than zero |
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*/ |
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void (*float_to_fixed24)(int32_t *dst, const float *src, unsigned int len); |
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/** |
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* Calculate bit allocation pointers. |
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* The SNR is the difference between the masking curve and the signal. AC-3 |
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* uses this value for each frequency bin to allocate bits. The snroffset |
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* parameter is a global adjustment to the SNR for all bins. |
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* |
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* @param[in] mask masking curve |
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* @param[in] psd signal power for each frequency bin |
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* @param[in] start starting bin location |
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* @param[in] end ending bin location |
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* @param[in] snr_offset SNR adjustment |
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* @param[in] floor noise floor |
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* @param[in] bap_tab look-up table for bit allocation pointers |
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* @param[out] bap bit allocation pointers |
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*/ |
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void (*bit_alloc_calc_bap)(int16_t *mask, int16_t *psd, int start, int end, |
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int snr_offset, int floor, |
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const uint8_t *bap_tab, uint8_t *bap); |
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/** |
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* Update bap counts using the supplied array of bap. |
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* |
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* @param[out] mant_cnt bap counts for 1 block |
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* @param[in] bap array of bap, pointing to start coef bin |
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* @param[in] len number of elements to process |
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*/ |
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void (*update_bap_counts)(uint16_t mant_cnt[16], uint8_t *bap, int len); |
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/** |
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* Calculate the number of bits needed to encode a set of mantissas. |
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* |
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* @param[in] mant_cnt bap counts for all blocks |
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* @return mantissa bit count |
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*/ |
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int (*compute_mantissa_size)(uint16_t mant_cnt[6][16]); |
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void (*extract_exponents)(uint8_t *exp, int32_t *coef, int nb_coefs); |
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void (*sum_square_butterfly_int32)(int64_t sum[4], const int32_t *coef0, |
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const int32_t *coef1, int len); |
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void (*sum_square_butterfly_float)(float sum[4], const float *coef0, |
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const float *coef1, int len); |
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int out_channels; |
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int in_channels; |
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void (*downmix)(float **samples, float **matrix, int len); |
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void (*downmix_fixed)(int32_t **samples, int16_t **matrix, int len); |
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} AC3DSPContext; |
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void ff_ac3dsp_init (AC3DSPContext *c, int bit_exact); |
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void ff_ac3dsp_init_arm(AC3DSPContext *c, int bit_exact); |
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void ff_ac3dsp_init_x86(AC3DSPContext *c, int bit_exact); |
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void ff_ac3dsp_init_mips(AC3DSPContext *c, int bit_exact); |
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void ff_ac3dsp_downmix(AC3DSPContext *c, float **samples, float **matrix, |
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int out_ch, int in_ch, int len); |
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void ff_ac3dsp_downmix_fixed(AC3DSPContext *c, int32_t **samples, int16_t **matrix, |
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int out_ch, int in_ch, int len); |
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void ff_ac3dsp_set_downmix_x86(AC3DSPContext *c); |
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#endif /* AVCODEC_AC3DSP_H */
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