| /* | |
| * AC-3 DSP functions | |
| * Copyright (c) 2011 Justin Ruggles | |
| * | |
| * This file is part of FFmpeg. | |
| * | |
| * FFmpeg is free software; you can redistribute it and/or | |
| * modify it under the terms of the GNU Lesser General Public | |
| * License as published by the Free Software Foundation; either | |
| * version 2.1 of the License, or (at your option) any later version. | |
| * | |
| * FFmpeg is distributed in the hope that it will be useful, | |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
| * Lesser General Public License for more details. | |
| * | |
| * You should have received a copy of the GNU Lesser General Public | |
| * License along with FFmpeg; if not, write to the Free Software | |
| * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
| */ | |
| /** | |
| * Number of mantissa bits written for each bap value. | |
| * bap values with fractional bits are set to 0 and are calculated separately. | |
| */ | |
| extern const uint16_t ff_ac3_bap_bits[16]; | |
| typedef struct AC3DSPContext { | |
| /** | |
| * Set each encoded exponent in a block to the minimum of itself and the | |
| * exponents in the same frequency bin of up to 5 following blocks. | |
| * @param exp pointer to the start of the current block of exponents. | |
| * constraints: align 16 | |
| * @param num_reuse_blocks number of blocks that will reuse exponents from the current block. | |
| * constraints: range 0 to 5 | |
| * @param nb_coefs number of frequency coefficients. | |
| */ | |
| void (*ac3_exponent_min)(uint8_t *exp, int num_reuse_blocks, int nb_coefs); | |
| /** | |
| * Convert an array of float in range [-1.0,1.0] to int32_t with range | |
| * [-(1<<24),(1<<24)] | |
| * | |
| * @param dst destination array of int32_t. | |
| * constraints: 16-byte aligned | |
| * @param src source array of float. | |
| * constraints: 16-byte aligned | |
| * @param len number of elements to convert. | |
| * constraints: multiple of 32 greater than zero | |
| */ | |
| void (*float_to_fixed24)(int32_t *dst, const float *src, unsigned int len); | |
| /** | |
| * Calculate bit allocation pointers. | |
| * The SNR is the difference between the masking curve and the signal. AC-3 | |
| * uses this value for each frequency bin to allocate bits. The snroffset | |
| * parameter is a global adjustment to the SNR for all bins. | |
| * | |
| * @param[in] mask masking curve | |
| * @param[in] psd signal power for each frequency bin | |
| * @param[in] start starting bin location | |
| * @param[in] end ending bin location | |
| * @param[in] snr_offset SNR adjustment | |
| * @param[in] floor noise floor | |
| * @param[in] bap_tab look-up table for bit allocation pointers | |
| * @param[out] bap bit allocation pointers | |
| */ | |
| void (*bit_alloc_calc_bap)(int16_t *mask, int16_t *psd, int start, int end, | |
| int snr_offset, int floor, | |
| const uint8_t *bap_tab, uint8_t *bap); | |
| /** | |
| * Update bap counts using the supplied array of bap. | |
| * | |
| * @param[out] mant_cnt bap counts for 1 block | |
| * @param[in] bap array of bap, pointing to start coef bin | |
| * @param[in] len number of elements to process | |
| */ | |
| void (*update_bap_counts)(uint16_t mant_cnt[16], uint8_t *bap, int len); | |
| /** | |
| * Calculate the number of bits needed to encode a set of mantissas. | |
| * | |
| * @param[in] mant_cnt bap counts for all blocks | |
| * @return mantissa bit count | |
| */ | |
| int (*compute_mantissa_size)(uint16_t mant_cnt[6][16]); | |
| void (*extract_exponents)(uint8_t *exp, int32_t *coef, int nb_coefs); | |
| void (*sum_square_butterfly_int32)(int64_t sum[4], const int32_t *coef0, | |
| const int32_t *coef1, int len); | |
| void (*sum_square_butterfly_float)(float sum[4], const float *coef0, | |
| const float *coef1, int len); | |
| int out_channels; | |
| int in_channels; | |
| void (*downmix)(float **samples, float **matrix, int len); | |
| void (*downmix_fixed)(int32_t **samples, int16_t **matrix, int len); | |
| } AC3DSPContext; | |
| void ff_ac3dsp_init (AC3DSPContext *c); | |
| void ff_ac3dsp_init_arm(AC3DSPContext *c); | |
| void ff_ac3dsp_init_x86(AC3DSPContext *c); | |
| void ff_ac3dsp_init_mips(AC3DSPContext *c); | |
| void ff_ac3dsp_downmix(AC3DSPContext *c, float **samples, float **matrix, | |
| int out_ch, int in_ch, int len); | |
| void ff_ac3dsp_downmix_fixed(AC3DSPContext *c, int32_t **samples, int16_t **matrix, | |
| int out_ch, int in_ch, int len); | |
| void ff_ac3dsp_set_downmix_x86(AC3DSPContext *c); | |