1 | /* |
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2 | * DreamDVD V0.9 - DVD-Player for Dreambox |
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3 | * Copyright (C) 2007 by Seddi |
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4 | * |
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5 | * This DVD Player is based upon the great work from the libdvdnav project, |
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6 | * a52dec library, ffmpeg and the knowledge from all the people who made |
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7 | * watching DVD within linux possible. |
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8 | * |
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9 | * DreamDVD is free software; you can redistribute it and/or modify |
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10 | * it under the terms of the GNU General Public License as published by |
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11 | * the Free Software Foundation; either version 2 of the License, or |
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12 | * (at your option) any later version. |
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13 | * |
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14 | * DreamDVD is distributed in the hope that it will be useful, |
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15 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
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16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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17 | * GNU General Public License for more details. |
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18 | * |
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19 | * You should have received a copy of the GNU General Public License |
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20 | * along with this program; if not, write to the Free Software |
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21 | * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA |
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22 | * |
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23 | * part of libdreamdvd |
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24 | */ |
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25 | |
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26 | #include <stdio.h> |
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27 | #include <stdlib.h> |
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28 | #include <string.h> |
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29 | |
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30 | #include <errno.h> |
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31 | #include <getopt.h> |
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32 | #include <math.h> |
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33 | #include <inttypes.h> |
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34 | #include <dlfcn.h> |
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35 | |
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36 | |
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37 | #include "a52dec.h" |
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38 | |
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39 | |
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40 | // try to dynamically load and wrap liba52.so.0 |
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41 | |
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42 | int ddvd_load_liba52() |
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43 | { |
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44 | a52_handle = dlopen("liba52.so.0",RTLD_LAZY); |
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45 | |
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46 | if (a52_handle) |
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47 | { |
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48 | a52_init = (a52_state_t* (*)(uint32_t)) dlsym(a52_handle, "a52_init"); |
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49 | a52_samples = (sample_t* (*)(a52_state_t*)) dlsym(a52_handle, "a52_samples"); |
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50 | a52_syncinfo = (int (*)(uint8_t*, int*, int*, int*)) dlsym(a52_handle, "a52_syncinfo"); |
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51 | a52_frame = (int (*)(a52_state_t* ,uint8_t* ,int* ,level_t* ,sample_t)) dlsym(a52_handle, "a52_frame"); |
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52 | a52_block = (int (*)(a52_state_t*)) dlsym(a52_handle, "a52_block"); |
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53 | a52_free = (void (*)(a52_state_t*)) dlsym(a52_handle, "a52_free"); |
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54 | |
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55 | printf("libdreamdvd: soft ac3 decoding is available, liba52.so.0 loaded !\n"); |
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56 | return 1; |
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57 | } |
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58 | else |
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59 | { |
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60 | printf("libdreamdvd: soft ac3 decoding is not available, liba52.so.0 not found !\n"); |
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61 | return 0; |
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62 | } |
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63 | } |
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64 | |
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65 | // close dynamically loaded liba52.so.0 |
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66 | |
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67 | void ddvd_close_liba52() |
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68 | { |
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69 | dlclose(a52_handle); |
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70 | } |
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71 | |
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72 | // convert 32bit samples to 16bit |
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73 | |
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74 | static inline int16_t a52_convert (int32_t i) |
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75 | { |
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76 | i >>= 15; |
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77 | return (i > 32767) ? 32767 : ((i < -32768) ? -32768 : i); |
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78 | } |
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79 | |
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80 | // liba52 gives us 256 samples left - 256 samples right |
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81 | // we need 1 left - 1 right so lets sort them |
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82 | |
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83 | static void a52_convert2s16_2 (sample_t * _f, int16_t * s16) |
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84 | { |
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85 | int i; |
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86 | int32_t * f = (int32_t *) _f; |
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87 | |
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88 | for (i = 0; i < 256; i++) { |
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89 | s16[2*i] = a52_convert (f[i]); |
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90 | s16[2*i+1] = a52_convert (f[i+256]); |
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91 | } |
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92 | } |
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93 | |
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94 | // a52 decode function (needs liba52) |
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95 | |
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96 | int ddvd_ac3_decode(const uint8_t *input, unsigned int len, int16_t *output) |
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97 | { |
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98 | static int sample_rate; |
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99 | static int flags; |
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100 | int bit_rate; |
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101 | int out_len=0; |
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102 | const uint8_t *end; |
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103 | end=input+len; |
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104 | |
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105 | static uint8_t buf[3840]; |
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106 | static uint8_t * bufptr = buf; |
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107 | static uint8_t * bufpos = buf + 7; |
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108 | |
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109 | while (1) { |
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110 | len = end - input; |
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111 | if (!len) |
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112 | break; |
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113 | if (len > bufpos - bufptr) |
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114 | len = bufpos - bufptr; |
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115 | |
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116 | memcpy (bufptr, input, len); |
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117 | bufptr += len; |
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118 | input += len; |
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119 | |
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120 | if (bufptr == bufpos) { |
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121 | if (bufpos == buf + 7) { |
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122 | int length; |
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123 | |
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124 | length = a52_syncinfo (buf, &flags, &sample_rate, &bit_rate); |
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125 | if (!length) { |
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126 | for (bufptr = buf; bufptr < buf + 6; bufptr++) |
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127 | bufptr[0] = bufptr[1]; |
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128 | continue; |
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129 | } |
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130 | bufpos = buf + length; |
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131 | } else { |
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132 | level_t level; |
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133 | sample_t bias; |
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134 | int i; |
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135 | |
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136 | flags=A52_DOLBY|A52_ADJUST_LEVEL; |
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137 | |
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138 | bias=0; |
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139 | level=(1 << 26); |
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140 | |
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141 | if (a52_frame (state, buf, &flags, &level, bias)) |
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142 | goto error; |
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143 | |
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144 | for (i = 0; i < 6; i++) { |
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145 | if (a52_block (state)) |
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146 | goto error; |
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147 | a52_convert2s16_2(a52_samples(state),output); |
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148 | output+=512; |
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149 | out_len+=1024; |
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150 | } |
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151 | bufptr = buf; |
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152 | bufpos = buf + 7; |
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153 | continue; |
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154 | error: |
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155 | bufptr = buf; |
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156 | bufpos = buf + 7; |
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157 | } |
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158 | } |
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159 | } |
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160 | return out_len; |
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161 | } |
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