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4349 | Serge | 1 | /* |
2 | * VC-1 and WMV3 parser |
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3 | * Copyright (c) 2006-2007 Konstantin Shishkov |
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4 | * Partly based on vc9.c (c) 2005 Anonymous, Alex Beregszaszi, Michael Niedermayer |
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5 | * |
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6 | * This file is part of FFmpeg. |
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7 | * |
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8 | * FFmpeg is free software; you can redistribute it and/or |
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9 | * modify it under the terms of the GNU Lesser General Public |
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10 | * License as published by the Free Software Foundation; either |
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11 | * version 2.1 of the License, or (at your option) any later version. |
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12 | * |
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13 | * FFmpeg is distributed in the hope that it will be useful, |
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14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
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15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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16 | * Lesser General Public License for more details. |
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17 | * |
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18 | * You should have received a copy of the GNU Lesser General Public |
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19 | * License along with FFmpeg; if not, write to the Free Software |
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20 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
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21 | */ |
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22 | |||
23 | /** |
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24 | * @file |
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25 | * VC-1 and WMV3 parser |
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26 | */ |
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27 | |||
28 | #include "libavutil/attributes.h" |
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29 | #include "parser.h" |
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30 | #include "vc1.h" |
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31 | #include "get_bits.h" |
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32 | |||
33 | typedef struct { |
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34 | ParseContext pc; |
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35 | VC1Context v; |
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36 | } VC1ParseContext; |
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37 | |||
38 | static void vc1_extract_headers(AVCodecParserContext *s, AVCodecContext *avctx, |
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39 | const uint8_t *buf, int buf_size) |
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40 | { |
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41 | VC1ParseContext *vpc = s->priv_data; |
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42 | GetBitContext gb; |
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43 | const uint8_t *start, *end, *next; |
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44 | uint8_t *buf2 = av_mallocz(buf_size + FF_INPUT_BUFFER_PADDING_SIZE); |
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45 | |||
46 | vpc->v.s.avctx = avctx; |
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47 | vpc->v.parse_only = 1; |
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48 | vpc->v.first_pic_header_flag = 1; |
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49 | next = buf; |
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50 | s->repeat_pict = 0; |
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51 | |||
52 | for(start = buf, end = buf + buf_size; next < end; start = next){ |
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53 | int buf2_size, size; |
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54 | int ret; |
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55 | |||
56 | next = find_next_marker(start + 4, end); |
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57 | size = next - start - 4; |
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58 | buf2_size = vc1_unescape_buffer(start + 4, size, buf2); |
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59 | init_get_bits(&gb, buf2, buf2_size * 8); |
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60 | if(size <= 0) continue; |
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61 | switch(AV_RB32(start)){ |
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62 | case VC1_CODE_SEQHDR: |
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63 | ff_vc1_decode_sequence_header(avctx, &vpc->v, &gb); |
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64 | break; |
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65 | case VC1_CODE_ENTRYPOINT: |
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66 | ff_vc1_decode_entry_point(avctx, &vpc->v, &gb); |
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67 | break; |
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68 | case VC1_CODE_FRAME: |
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69 | if(vpc->v.profile < PROFILE_ADVANCED) |
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70 | ret = ff_vc1_parse_frame_header (&vpc->v, &gb); |
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71 | else |
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72 | ret = ff_vc1_parse_frame_header_adv(&vpc->v, &gb); |
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73 | |||
74 | if (ret < 0) |
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75 | break; |
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76 | |||
77 | /* keep AV_PICTURE_TYPE_BI internal to VC1 */ |
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78 | if (vpc->v.s.pict_type == AV_PICTURE_TYPE_BI) |
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79 | s->pict_type = AV_PICTURE_TYPE_B; |
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80 | else |
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81 | s->pict_type = vpc->v.s.pict_type; |
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82 | |||
83 | if (avctx->ticks_per_frame > 1){ |
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84 | // process pulldown flags |
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85 | s->repeat_pict = 1; |
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86 | // Pulldown flags are only valid when 'broadcast' has been set. |
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87 | // So ticks_per_frame will be 2 |
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88 | if (vpc->v.rff){ |
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89 | // repeat field |
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90 | s->repeat_pict = 2; |
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91 | }else if (vpc->v.rptfrm){ |
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92 | // repeat frames |
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93 | s->repeat_pict = vpc->v.rptfrm * 2 + 1; |
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94 | } |
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95 | } |
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96 | |||
97 | if (vpc->v.broadcast && vpc->v.interlace && !vpc->v.psf) |
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98 | s->field_order = vpc->v.tff ? AV_FIELD_TT : AV_FIELD_BB; |
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99 | else |
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100 | s->field_order = AV_FIELD_PROGRESSIVE; |
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101 | |||
102 | break; |
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103 | } |
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104 | } |
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105 | |||
106 | av_free(buf2); |
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107 | } |
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108 | |||
109 | /** |
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110 | * Find the end of the current frame in the bitstream. |
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111 | * @return the position of the first byte of the next frame, or -1 |
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112 | */ |
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113 | static int vc1_find_frame_end(ParseContext *pc, const uint8_t *buf, |
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114 | int buf_size) { |
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115 | int pic_found, i; |
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116 | uint32_t state; |
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117 | |||
118 | pic_found= pc->frame_start_found; |
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119 | state= pc->state; |
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120 | |||
121 | i=0; |
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122 | if(!pic_found){ |
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123 | for(i=0; i |
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124 | state= (state<<8) | buf[i]; |
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125 | if(state == VC1_CODE_FRAME || state == VC1_CODE_FIELD){ |
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126 | i++; |
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127 | pic_found=1; |
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128 | break; |
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129 | } |
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130 | } |
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131 | } |
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132 | |||
133 | if(pic_found){ |
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134 | /* EOF considered as end of frame */ |
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135 | if (buf_size == 0) |
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136 | return 0; |
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137 | for(; i |
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138 | state= (state<<8) | buf[i]; |
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139 | if(IS_MARKER(state) && state != VC1_CODE_FIELD && state != VC1_CODE_SLICE){ |
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140 | pc->frame_start_found=0; |
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141 | pc->state=-1; |
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142 | return i-3; |
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143 | } |
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144 | } |
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145 | } |
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146 | pc->frame_start_found= pic_found; |
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147 | pc->state= state; |
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148 | return END_NOT_FOUND; |
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149 | } |
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150 | |||
151 | static int vc1_parse(AVCodecParserContext *s, |
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152 | AVCodecContext *avctx, |
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153 | const uint8_t **poutbuf, int *poutbuf_size, |
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154 | const uint8_t *buf, int buf_size) |
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155 | { |
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156 | VC1ParseContext *vpc = s->priv_data; |
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157 | int next; |
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158 | |||
159 | if(s->flags & PARSER_FLAG_COMPLETE_FRAMES){ |
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160 | next= buf_size; |
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161 | }else{ |
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162 | next= vc1_find_frame_end(&vpc->pc, buf, buf_size); |
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163 | |||
164 | if (ff_combine_frame(&vpc->pc, next, &buf, &buf_size) < 0) { |
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165 | *poutbuf = NULL; |
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166 | *poutbuf_size = 0; |
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167 | return buf_size; |
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168 | } |
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169 | } |
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170 | |||
171 | vc1_extract_headers(s, avctx, buf, buf_size); |
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172 | |||
173 | *poutbuf = buf; |
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174 | *poutbuf_size = buf_size; |
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175 | return next; |
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176 | } |
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177 | |||
178 | static int vc1_split(AVCodecContext *avctx, |
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179 | const uint8_t *buf, int buf_size) |
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180 | { |
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181 | int i; |
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182 | uint32_t state= -1; |
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183 | int charged=0; |
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184 | |||
185 | for(i=0; i |
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186 | state= (state<<8) | buf[i]; |
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187 | if(IS_MARKER(state)){ |
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188 | if(state == VC1_CODE_SEQHDR || state == VC1_CODE_ENTRYPOINT){ |
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189 | charged=1; |
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190 | }else if(charged){ |
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191 | return i-3; |
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192 | } |
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193 | } |
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194 | } |
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195 | return 0; |
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196 | } |
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197 | |||
198 | static av_cold int vc1_parse_init(AVCodecParserContext *s) |
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199 | { |
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200 | VC1ParseContext *vpc = s->priv_data; |
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201 | vpc->v.s.slice_context_count = 1; |
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202 | return ff_vc1_init_common(&vpc->v); |
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203 | } |
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204 | |||
205 | AVCodecParser ff_vc1_parser = { |
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206 | .codec_ids = { AV_CODEC_ID_VC1 }, |
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207 | .priv_data_size = sizeof(VC1ParseContext), |
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208 | .parser_init = vc1_parse_init, |
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209 | .parser_parse = vc1_parse, |
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210 | .parser_close = ff_parse_close, |
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211 | .split = vc1_split, |
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212 | };8)><8)>>8)><8)>8)><8)>>>=>> |