libavcodec/mlp.h

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00001 /*
00002  * MLP codec common header file
00003  * Copyright (c) 2007-2008 Ian Caulfield
00004  *
00005  * This file is part of FFmpeg.
00006  *
00007  * FFmpeg is free software; you can redistribute it and/or
00008  * modify it under the terms of the GNU Lesser General Public
00009  * License as published by the Free Software Foundation; either
00010  * version 2.1 of the License, or (at your option) any later version.
00011  *
00012  * FFmpeg is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
00015  * Lesser General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU Lesser General Public
00018  * License along with FFmpeg; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
00022 #ifndef AVCODEC_MLP_H
00023 #define AVCODEC_MLP_H
00024 
00025 #include <stdint.h>
00026 
00027 #include "avcodec.h"
00028 
00030 #define MAX_CHANNELS 16
00031 
00035 #define MAX_MATRICES 15
00036 
00040 #define MAX_SUBSTREAMS 2
00041 
00043 #define MAX_SAMPLERATE 192000
00044 
00046 #define MAX_BLOCKSIZE (40 * (MAX_SAMPLERATE / 48000))
00047 
00048 #define MAX_BLOCKSIZE_POW2 (64 * (MAX_SAMPLERATE / 48000))
00049 
00051 #define NUM_FILTERS 2
00052 
00057 #define MAX_FILTER_ORDER 8
00058 
00060 #define END_OF_STREAM 0xd234d234
00061 
00062 #define FIR 0
00063 #define IIR 1
00064 
00066 typedef struct {
00067 uint8_t order; 
00068 uint8_t shift; 
00069 
00070 int32_t coeff[MAX_FILTER_ORDER];
00071 int32_t state[MAX_FILTER_ORDER];
00072 } FilterParams;
00073 
00075 typedef struct {
00076 FilterParams filter_params[NUM_FILTERS];
00077 
00078 int16_t huff_offset; 
00079 int32_t sign_huff_offset; 
00080 uint8_t codebook; 
00081 uint8_t huff_lsbs; 
00082 } ChannelParams;
00083 
00089 extern const uint8_t ff_mlp_huffman_tables[3][18][2];
00090 
00096 uint8_t ff_mlp_checksum8 (const uint8_t *buf, unsigned int buf_size);
00097 uint16_t ff_mlp_checksum16(const uint8_t *buf, unsigned int buf_size);
00098 
00102 uint8_t ff_mlp_restart_checksum(const uint8_t *buf, unsigned int bit_size);
00103 
00107 uint8_t ff_mlp_calculate_parity(const uint8_t *buf, unsigned int buf_size);
00108 
00109 void ff_mlp_init_crc(void);
00110 
00112 static inline uint8_t xor_32_to_8(uint32_t value)
00113 {
00114 value ^= value >> 16;
00115 value ^= value >> 8;
00116 return value;
00117 }
00118 
00119 #endif /* AVCODEC_MLP_H */

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