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Diffstat (limited to 'ffmpeg1/libavcodec/ac3dsp.h')
| -rw-r--r-- | ffmpeg1/libavcodec/ac3dsp.h | 144 |
1 files changed, 144 insertions, 0 deletions
diff --git a/ffmpeg1/libavcodec/ac3dsp.h b/ffmpeg1/libavcodec/ac3dsp.h new file mode 100644 index 0000000..bafbc89 --- /dev/null +++ b/ffmpeg1/libavcodec/ac3dsp.h @@ -0,0 +1,144 @@ +/* + * AC-3 DSP utils + * 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 + */ + +#ifndef AVCODEC_AC3DSP_H +#define AVCODEC_AC3DSP_H + +#include <stdint.h> + +/** + * 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); + + /** + * Calculate the maximum MSB of the absolute value of each element in an + * array of int16_t. + * @param src input array + * constraints: align 16. values must be in range [-32767,32767] + * @param len number of values in the array + * constraints: multiple of 16 greater than 0 + * @return a value with the same MSB as max(abs(src[])) + */ + int (*ac3_max_msb_abs_int16)(const int16_t *src, int len); + + /** + * Left-shift each value in an array of int16_t by a specified amount. + * @param src input array + * constraints: align 16 + * @param len number of values in the array + * constraints: multiple of 32 greater than 0 + * @param shift left shift amount + * constraints: range [0,15] + */ + void (*ac3_lshift_int16)(int16_t *src, unsigned int len, unsigned int shift); + + /** + * Right-shift each value in an array of int32_t by a specified amount. + * @param src input array + * constraints: align 16 + * @param len number of values in the array + * constraints: multiple of 16 greater than 0 + * @param shift right shift amount + * constraints: range [0,31] + */ + void (*ac3_rshift_int32)(int32_t *src, unsigned int len, unsigned int shift); + + /** + * 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); + + void (*downmix)(float **samples, float (*matrix)[2], int out_ch, + int in_ch, int len); +} AC3DSPContext; + +void ff_ac3dsp_init (AC3DSPContext *c, int bit_exact); +void ff_ac3dsp_init_arm(AC3DSPContext *c, int bit_exact); +void ff_ac3dsp_init_x86(AC3DSPContext *c, int bit_exact); +void ff_ac3dsp_init_mips(AC3DSPContext *c, int bit_exact); + +#endif /* AVCODEC_AC3DSP_H */ |