libavcodec/mlp.h

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/*
 * 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"

#define MAX_CHANNELS        16

#define MAX_MATRICES        15

#define MAX_SUBSTREAMS      2

#define MAX_SAMPLERATE      192000

#define MAX_BLOCKSIZE       (40 * (MAX_SAMPLERATE / 48000))

#define MAX_BLOCKSIZE_POW2  (64 * (MAX_SAMPLERATE / 48000))

#define NUM_FILTERS         2

#define MAX_FILTER_ORDER    8

#define END_OF_STREAM       0xd234d234

#define FIR 0
#define IIR 1

typedef struct {
    uint8_t     order; 
    uint8_t     shift; 

    int32_t     coeff[MAX_FILTER_ORDER];
    int32_t     state[MAX_FILTER_ORDER];
} FilterParams;

typedef struct {
    FilterParams filter_params[NUM_FILTERS];

    int16_t     huff_offset;      
    int32_t     sign_huff_offset; 
    uint8_t     codebook;         
    uint8_t     huff_lsbs;        
} ChannelParams;

extern const uint8_t ff_mlp_huffman_tables[3][18][2];

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);

uint8_t ff_mlp_restart_checksum(const uint8_t *buf, unsigned int bit_size);

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

void ff_mlp_init_crc(void);

static inline uint8_t xor_32_to_8(uint32_t value)
{
    value ^= value >> 16;
    value ^= value >>  8;
    return value;
}

#endif /* AVCODEC_MLP_H */

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