/*
  * 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);

 } 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);

 
 #endif /* AVCODEC_AC3DSP_H */