yading@10: /* yading@10: * AC-3 DSP utils yading@10: * Copyright (c) 2011 Justin Ruggles yading@10: * yading@10: * This file is part of FFmpeg. yading@10: * yading@10: * FFmpeg is free software; you can redistribute it and/or yading@10: * modify it under the terms of the GNU Lesser General Public yading@10: * License as published by the Free Software Foundation; either yading@10: * version 2.1 of the License, or (at your option) any later version. yading@10: * yading@10: * FFmpeg is distributed in the hope that it will be useful, yading@10: * but WITHOUT ANY WARRANTY; without even the implied warranty of yading@10: * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU yading@10: * Lesser General Public License for more details. yading@10: * yading@10: * You should have received a copy of the GNU Lesser General Public yading@10: * License along with FFmpeg; if not, write to the Free Software yading@10: * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA yading@10: */ yading@10: yading@10: #ifndef AVCODEC_AC3DSP_H yading@10: #define AVCODEC_AC3DSP_H yading@10: yading@10: #include yading@10: yading@10: /** yading@10: * Number of mantissa bits written for each bap value. yading@10: * bap values with fractional bits are set to 0 and are calculated separately. yading@10: */ yading@10: extern const uint16_t ff_ac3_bap_bits[16]; yading@10: yading@10: typedef struct AC3DSPContext { yading@10: /** yading@10: * Set each encoded exponent in a block to the minimum of itself and the yading@10: * exponents in the same frequency bin of up to 5 following blocks. yading@10: * @param exp pointer to the start of the current block of exponents. yading@10: * constraints: align 16 yading@10: * @param num_reuse_blocks number of blocks that will reuse exponents from the current block. yading@10: * constraints: range 0 to 5 yading@10: * @param nb_coefs number of frequency coefficients. yading@10: */ yading@10: void (*ac3_exponent_min)(uint8_t *exp, int num_reuse_blocks, int nb_coefs); yading@10: yading@10: /** yading@10: * Calculate the maximum MSB of the absolute value of each element in an yading@10: * array of int16_t. yading@10: * @param src input array yading@10: * constraints: align 16. values must be in range [-32767,32767] yading@10: * @param len number of values in the array yading@10: * constraints: multiple of 16 greater than 0 yading@10: * @return a value with the same MSB as max(abs(src[])) yading@10: */ yading@10: int (*ac3_max_msb_abs_int16)(const int16_t *src, int len); yading@10: yading@10: /** yading@10: * Left-shift each value in an array of int16_t by a specified amount. yading@10: * @param src input array yading@10: * constraints: align 16 yading@10: * @param len number of values in the array yading@10: * constraints: multiple of 32 greater than 0 yading@10: * @param shift left shift amount yading@10: * constraints: range [0,15] yading@10: */ yading@10: void (*ac3_lshift_int16)(int16_t *src, unsigned int len, unsigned int shift); yading@10: yading@10: /** yading@10: * Right-shift each value in an array of int32_t by a specified amount. yading@10: * @param src input array yading@10: * constraints: align 16 yading@10: * @param len number of values in the array yading@10: * constraints: multiple of 16 greater than 0 yading@10: * @param shift right shift amount yading@10: * constraints: range [0,31] yading@10: */ yading@10: void (*ac3_rshift_int32)(int32_t *src, unsigned int len, unsigned int shift); yading@10: yading@10: /** yading@10: * Convert an array of float in range [-1.0,1.0] to int32_t with range yading@10: * [-(1<<24),(1<<24)] yading@10: * yading@10: * @param dst destination array of int32_t. yading@10: * constraints: 16-byte aligned yading@10: * @param src source array of float. yading@10: * constraints: 16-byte aligned yading@10: * @param len number of elements to convert. yading@10: * constraints: multiple of 32 greater than zero yading@10: */ yading@10: void (*float_to_fixed24)(int32_t *dst, const float *src, unsigned int len); yading@10: yading@10: /** yading@10: * Calculate bit allocation pointers. yading@10: * The SNR is the difference between the masking curve and the signal. AC-3 yading@10: * uses this value for each frequency bin to allocate bits. The snroffset yading@10: * parameter is a global adjustment to the SNR for all bins. yading@10: * yading@10: * @param[in] mask masking curve yading@10: * @param[in] psd signal power for each frequency bin yading@10: * @param[in] start starting bin location yading@10: * @param[in] end ending bin location yading@10: * @param[in] snr_offset SNR adjustment yading@10: * @param[in] floor noise floor yading@10: * @param[in] bap_tab look-up table for bit allocation pointers yading@10: * @param[out] bap bit allocation pointers yading@10: */ yading@10: void (*bit_alloc_calc_bap)(int16_t *mask, int16_t *psd, int start, int end, yading@10: int snr_offset, int floor, yading@10: const uint8_t *bap_tab, uint8_t *bap); yading@10: yading@10: /** yading@10: * Update bap counts using the supplied array of bap. yading@10: * yading@10: * @param[out] mant_cnt bap counts for 1 block yading@10: * @param[in] bap array of bap, pointing to start coef bin yading@10: * @param[in] len number of elements to process yading@10: */ yading@10: void (*update_bap_counts)(uint16_t mant_cnt[16], uint8_t *bap, int len); yading@10: yading@10: /** yading@10: * Calculate the number of bits needed to encode a set of mantissas. yading@10: * yading@10: * @param[in] mant_cnt bap counts for all blocks yading@10: * @return mantissa bit count yading@10: */ yading@10: int (*compute_mantissa_size)(uint16_t mant_cnt[6][16]); yading@10: yading@10: void (*extract_exponents)(uint8_t *exp, int32_t *coef, int nb_coefs); yading@10: yading@10: void (*sum_square_butterfly_int32)(int64_t sum[4], const int32_t *coef0, yading@10: const int32_t *coef1, int len); yading@10: yading@10: void (*sum_square_butterfly_float)(float sum[4], const float *coef0, yading@10: const float *coef1, int len); yading@10: yading@10: void (*downmix)(float **samples, float (*matrix)[2], int out_ch, yading@10: int in_ch, int len); yading@10: } AC3DSPContext; yading@10: yading@10: void ff_ac3dsp_init (AC3DSPContext *c, int bit_exact); yading@10: void ff_ac3dsp_init_arm(AC3DSPContext *c, int bit_exact); yading@10: void ff_ac3dsp_init_x86(AC3DSPContext *c, int bit_exact); yading@10: void ff_ac3dsp_init_mips(AC3DSPContext *c, int bit_exact); yading@10: yading@10: #endif /* AVCODEC_AC3DSP_H */