/*
  * MLP codec common header file
  * Copyright (c) 2007-2008 Ian Caulfield
  *
  * 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_MLP_H
 #define AVCODEC_MLP_H

 
 #include <stdint.h>
 
 #include "avcodec.h"
 

 /** Last possible matrix channel for each codec */
 #define MAX_MATRIX_CHANNEL_MLP      5
 #define MAX_MATRIX_CHANNEL_TRUEHD   7

 /** Maximum number of channels in a valid stream.
  *  MLP   : 5.1 + 2 noise channels -> 8 channels
  *  TrueHD: 7.1                    -> 8 channels
  */
 #define MAX_CHANNELS                8

 
 /** Maximum number of matrices used in decoding; most streams have one matrix
  *  per output channel, but some rematrix a channel (usually 0) more than once.
  */

 #define MAX_MATRICES_MLP            6
 #define MAX_MATRICES_TRUEHD         8

 #define MAX_MATRICES                8

 /** Maximum number of substreams that can be decoded.
  *  MLP's limit is 2. TrueHD supports at least up to 3.

  */

 #define MAX_SUBSTREAMS      3

 /** which multiple of 48000 the maximum sample rate is */
 #define MAX_RATEFACTOR      4

 /** maximum sample frequency seen in files */

 #define MAX_SAMPLERATE      (MAX_RATEFACTOR * 48000)

 
 /** maximum number of audio samples within one access unit */

 #define MAX_BLOCKSIZE       (40 * MAX_RATEFACTOR)

 /** next power of two greater than MAX_BLOCKSIZE */

 #define MAX_BLOCKSIZE_POW2  (64 * MAX_RATEFACTOR)

 
 /** number of allowed filters */
 #define NUM_FILTERS         2
 

 /** The maximum number of taps in IIR and FIR filters. */
 #define MAX_FIR_ORDER       8
 #define MAX_IIR_ORDER       4

 /** Code that signals end of a stream. */
 #define END_OF_STREAM       0xd234d234
 

 #define FIR 0
 #define IIR 1
 
 /** filter data */

 typedef struct FilterParams {

     uint8_t     order; ///< number of taps in filter
     uint8_t     shift; ///< Right shift to apply to output of filter.
 

     int32_t     state[MAX_FIR_ORDER];

 } FilterParams;
 
 /** sample data coding information */

 typedef struct ChannelParams {

     FilterParams filter_params[NUM_FILTERS];

     int32_t     coeff[NUM_FILTERS][MAX_FIR_ORDER];

 
     int16_t     huff_offset;      ///< Offset to apply to residual values.
     int32_t     sign_huff_offset; ///< sign/rounding-corrected version of huff_offset
     uint8_t     codebook;         ///< Which VLC codebook to use to read residuals.
     uint8_t     huff_lsbs;        ///< Size of residual suffix not encoded using VLC.
 } ChannelParams;
 
 /** Tables defining the Huffman codes.
  *  There are three entropy coding methods used in MLP (four if you count
  *  "none" as a method). These use the same sequences for codes starting with

  *  00 or 01, but have different codes starting with 1.
  */

 extern const uint8_t ff_mlp_huffman_tables[3][18][2];
 
 /** MLP uses checksums that seem to be based on the standard CRC algorithm, but
  *  are not (in implementation terms, the table lookup and XOR are reversed).
  *  We can implement this behavior using a standard av_crc on all but the

  *  last element, then XOR that with the last element.
  */

 uint8_t  ff_mlp_checksum8 (const uint8_t *buf, unsigned int buf_size);
 uint16_t ff_mlp_checksum16(const uint8_t *buf, unsigned int buf_size);
 
 /** Calculate an 8-bit checksum over a restart header -- a non-multiple-of-8

  *  number of bits, starting two bits into the first byte of buf.
  */

 uint8_t ff_mlp_restart_checksum(const uint8_t *buf, unsigned int bit_size);
 
 /** XOR together all the bytes of a buffer.

  *  Does this belong in dspcontext?
  */

 uint8_t ff_mlp_calculate_parity(const uint8_t *buf, unsigned int buf_size);
 

 void ff_mlp_init_crc(void);

 /** XOR four bytes into one. */
 static inline uint8_t xor_32_to_8(uint32_t value)
 {
     value ^= value >> 16;
     value ^= value >>  8;
     return value;
 }
 

 typedef enum THDChannelModifier {
     THD_CH_MODIFIER_NOTINDICATED  = 0x0,
     THD_CH_MODIFIER_STEREO        = 0x0, // Stereo (not Dolby Surround)
     THD_CH_MODIFIER_LTRT          = 0x1, // Dolby Surround
     THD_CH_MODIFIER_LBINRBIN      = 0x2, // Dolby Headphone
     THD_CH_MODIFIER_MONO          = 0x3, // Mono or Dual Mono
     THD_CH_MODIFIER_NOTSURROUNDEX = 0x1, // Not Dolby Digital EX
     THD_CH_MODIFIER_SURROUNDEX    = 0x2, // Dolby Digital EX
 } THDChannelModifier;
 

 #endif /* AVCODEC_MLP_H */