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media/libtheora/lib/decinfo.c@b8a032363ba2 (annotated)

media/libtheora/lib/decinfo.c

Thu, 22 Jan 2015 13:21:57 +0100

author
Michael Schloh von Bennewitz <michael@schloh.com>
date
Thu, 22 Jan 2015 13:21:57 +0100
branch
TOR_BUG_9701
changeset 15
b8a032363ba2
permissions
-rw-r--r--

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

michael@0 1 /********************************************************************
michael@0 2 * *
michael@0 3 * THIS FILE IS PART OF THE OggTheora SOFTWARE CODEC SOURCE CODE. *
michael@0 4 * USE, DISTRIBUTION AND REPRODUCTION OF THIS LIBRARY SOURCE IS *
michael@0 5 * GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *
michael@0 6 * IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING. *
michael@0 7 * *
michael@0 8 * THE Theora SOURCE CODE IS COPYRIGHT (C) 2002-2009 *
michael@0 9 * by the Xiph.Org Foundation and contributors http://www.xiph.org/ *
michael@0 10 * *
michael@0 11 ********************************************************************
michael@0 12
michael@0 13 function:
michael@0 14 last mod: $Id: decinfo.c 17276 2010-06-05 05:57:05Z tterribe $
michael@0 15
michael@0 16 ********************************************************************/
michael@0 17
michael@0 18 #include <stdlib.h>
michael@0 19 #include <string.h>
michael@0 20 #include <limits.h>
michael@0 21 #include "decint.h"
michael@0 22
michael@0 23
michael@0 24
michael@0 25 /*Unpacks a series of octets from a given byte array into the pack buffer.
michael@0 26 No checking is done to ensure the buffer contains enough data.
michael@0 27 _opb: The pack buffer to read the octets from.
michael@0 28 _buf: The byte array to store the unpacked bytes in.
michael@0 29 _len: The number of octets to unpack.*/
michael@0 30 static void oc_unpack_octets(oc_pack_buf *_opb,char *_buf,size_t _len){
michael@0 31 while(_len-->0){
michael@0 32 long val;
michael@0 33 val=oc_pack_read(_opb,8);
michael@0 34 *_buf++=(char)val;
michael@0 35 }
michael@0 36 }
michael@0 37
michael@0 38 /*Unpacks a 32-bit integer encoded by octets in little-endian form.*/
michael@0 39 static long oc_unpack_length(oc_pack_buf *_opb){
michael@0 40 long ret[4];
michael@0 41 int i;
michael@0 42 for(i=0;i<4;i++)ret[i]=oc_pack_read(_opb,8);
michael@0 43 return ret[0]|ret[1]<<8|ret[2]<<16|ret[3]<<24;
michael@0 44 }
michael@0 45
michael@0 46 static int oc_info_unpack(oc_pack_buf *_opb,th_info *_info){
michael@0 47 long val;
michael@0 48 /*Check the codec bitstream version.*/
michael@0 49 val=oc_pack_read(_opb,8);
michael@0 50 _info->version_major=(unsigned char)val;
michael@0 51 val=oc_pack_read(_opb,8);
michael@0 52 _info->version_minor=(unsigned char)val;
michael@0 53 val=oc_pack_read(_opb,8);
michael@0 54 _info->version_subminor=(unsigned char)val;
michael@0 55 /*verify we can parse this bitstream version.
michael@0 56 We accept earlier minors and all subminors, by spec*/
michael@0 57 if(_info->version_major>TH_VERSION_MAJOR||
michael@0 58 _info->version_major==TH_VERSION_MAJOR&&
michael@0 59 _info->version_minor>TH_VERSION_MINOR){
michael@0 60 return TH_EVERSION;
michael@0 61 }
michael@0 62 /*Read the encoded frame description.*/
michael@0 63 val=oc_pack_read(_opb,16);
michael@0 64 _info->frame_width=(ogg_uint32_t)val<<4;
michael@0 65 val=oc_pack_read(_opb,16);
michael@0 66 _info->frame_height=(ogg_uint32_t)val<<4;
michael@0 67 val=oc_pack_read(_opb,24);
michael@0 68 _info->pic_width=(ogg_uint32_t)val;
michael@0 69 val=oc_pack_read(_opb,24);
michael@0 70 _info->pic_height=(ogg_uint32_t)val;
michael@0 71 val=oc_pack_read(_opb,8);
michael@0 72 _info->pic_x=(ogg_uint32_t)val;
michael@0 73 val=oc_pack_read(_opb,8);
michael@0 74 _info->pic_y=(ogg_uint32_t)val;
michael@0 75 val=oc_pack_read(_opb,32);
michael@0 76 _info->fps_numerator=(ogg_uint32_t)val;
michael@0 77 val=oc_pack_read(_opb,32);
michael@0 78 _info->fps_denominator=(ogg_uint32_t)val;
michael@0 79 if(_info->frame_width==0||_info->frame_height==0||
michael@0 80 _info->pic_width+_info->pic_x>_info->frame_width||
michael@0 81 _info->pic_height+_info->pic_y>_info->frame_height||
michael@0 82 _info->fps_numerator==0||_info->fps_denominator==0){
michael@0 83 return TH_EBADHEADER;
michael@0 84 }
michael@0 85 /*Note: The sense of pic_y is inverted in what we pass back to the
michael@0 86 application compared to how it is stored in the bitstream.
michael@0 87 This is because the bitstream uses a right-handed coordinate system, while
michael@0 88 applications expect a left-handed one.*/
michael@0 89 _info->pic_y=_info->frame_height-_info->pic_height-_info->pic_y;
michael@0 90 val=oc_pack_read(_opb,24);
michael@0 91 _info->aspect_numerator=(ogg_uint32_t)val;
michael@0 92 val=oc_pack_read(_opb,24);
michael@0 93 _info->aspect_denominator=(ogg_uint32_t)val;
michael@0 94 val=oc_pack_read(_opb,8);
michael@0 95 _info->colorspace=(th_colorspace)val;
michael@0 96 val=oc_pack_read(_opb,24);
michael@0 97 _info->target_bitrate=(int)val;
michael@0 98 val=oc_pack_read(_opb,6);
michael@0 99 _info->quality=(int)val;
michael@0 100 val=oc_pack_read(_opb,5);
michael@0 101 _info->keyframe_granule_shift=(int)val;
michael@0 102 val=oc_pack_read(_opb,2);
michael@0 103 _info->pixel_fmt=(th_pixel_fmt)val;
michael@0 104 if(_info->pixel_fmt==TH_PF_RSVD)return TH_EBADHEADER;
michael@0 105 val=oc_pack_read(_opb,3);
michael@0 106 if(val!=0||oc_pack_bytes_left(_opb)<0)return TH_EBADHEADER;
michael@0 107 return 0;
michael@0 108 }
michael@0 109
michael@0 110 static int oc_comment_unpack(oc_pack_buf *_opb,th_comment *_tc){
michael@0 111 long len;
michael@0 112 int i;
michael@0 113 /*Read the vendor string.*/
michael@0 114 len=oc_unpack_length(_opb);
michael@0 115 if(len<0||len>oc_pack_bytes_left(_opb))return TH_EBADHEADER;
michael@0 116 _tc->vendor=_ogg_malloc((size_t)len+1);
michael@0 117 if(_tc->vendor==NULL)return TH_EFAULT;
michael@0 118 oc_unpack_octets(_opb,_tc->vendor,len);
michael@0 119 _tc->vendor[len]='\0';
michael@0 120 /*Read the user comments.*/
michael@0 121 _tc->comments=(int)oc_unpack_length(_opb);
michael@0 122 len=_tc->comments;
michael@0 123 if(len<0||len>(LONG_MAX>>2)||len<<2>oc_pack_bytes_left(_opb)){
michael@0 124 _tc->comments=0;
michael@0 125 return TH_EBADHEADER;
michael@0 126 }
michael@0 127 _tc->comment_lengths=(int *)_ogg_malloc(
michael@0 128 _tc->comments*sizeof(_tc->comment_lengths[0]));
michael@0 129 _tc->user_comments=(char **)_ogg_malloc(
michael@0 130 _tc->comments*sizeof(_tc->user_comments[0]));
michael@0 131 if(_tc->comment_lengths==NULL||_tc->user_comments==NULL){
michael@0 132 _tc->comments=0;
michael@0 133 return TH_EFAULT;
michael@0 134 }
michael@0 135 for(i=0;i<_tc->comments;i++){
michael@0 136 len=oc_unpack_length(_opb);
michael@0 137 if(len<0||len>oc_pack_bytes_left(_opb)){
michael@0 138 _tc->comments=i;
michael@0 139 return TH_EBADHEADER;
michael@0 140 }
michael@0 141 _tc->comment_lengths[i]=len;
michael@0 142 _tc->user_comments[i]=_ogg_malloc((size_t)len+1);
michael@0 143 if(_tc->user_comments[i]==NULL){
michael@0 144 _tc->comments=i;
michael@0 145 return TH_EFAULT;
michael@0 146 }
michael@0 147 oc_unpack_octets(_opb,_tc->user_comments[i],len);
michael@0 148 _tc->user_comments[i][len]='\0';
michael@0 149 }
michael@0 150 return oc_pack_bytes_left(_opb)<0?TH_EBADHEADER:0;
michael@0 151 }
michael@0 152
michael@0 153 static int oc_setup_unpack(oc_pack_buf *_opb,th_setup_info *_setup){
michael@0 154 int ret;
michael@0 155 /*Read the quantizer tables.*/
michael@0 156 ret=oc_quant_params_unpack(_opb,&_setup->qinfo);
michael@0 157 if(ret<0)return ret;
michael@0 158 /*Read the Huffman trees.*/
michael@0 159 return oc_huff_trees_unpack(_opb,_setup->huff_tables);
michael@0 160 }
michael@0 161
michael@0 162 static void oc_setup_clear(th_setup_info *_setup){
michael@0 163 oc_quant_params_clear(&_setup->qinfo);
michael@0 164 oc_huff_trees_clear(_setup->huff_tables);
michael@0 165 }
michael@0 166
michael@0 167 static int oc_dec_headerin(oc_pack_buf *_opb,th_info *_info,
michael@0 168 th_comment *_tc,th_setup_info **_setup,ogg_packet *_op){
michael@0 169 char buffer[6];
michael@0 170 long val;
michael@0 171 int packtype;
michael@0 172 int ret;
michael@0 173 val=oc_pack_read(_opb,8);
michael@0 174 packtype=(int)val;
michael@0 175 /*If we're at a data packet and we have received all three headers, we're
michael@0 176 done.*/
michael@0 177 if(!(packtype&0x80)&&_info->frame_width>0&&_tc->vendor!=NULL&&*_setup!=NULL){
michael@0 178 return 0;
michael@0 179 }
michael@0 180 /*Check the codec string.*/
michael@0 181 oc_unpack_octets(_opb,buffer,6);
michael@0 182 if(memcmp(buffer,"theora",6)!=0)return TH_ENOTFORMAT;
michael@0 183 switch(packtype){
michael@0 184 /*Codec info header.*/
michael@0 185 case 0x80:{
michael@0 186 /*This should be the first packet, and we should not already be
michael@0 187 initialized.*/
michael@0 188 if(!_op->b_o_s||_info->frame_width>0)return TH_EBADHEADER;
michael@0 189 ret=oc_info_unpack(_opb,_info);
michael@0 190 if(ret<0)th_info_clear(_info);
michael@0 191 else ret=3;
michael@0 192 }break;
michael@0 193 /*Comment header.*/
michael@0 194 case 0x81:{
michael@0 195 if(_tc==NULL)return TH_EFAULT;
michael@0 196 /*We shoud have already decoded the info header, and should not yet have
michael@0 197 decoded the comment header.*/
michael@0 198 if(_info->frame_width==0||_tc->vendor!=NULL)return TH_EBADHEADER;
michael@0 199 ret=oc_comment_unpack(_opb,_tc);
michael@0 200 if(ret<0)th_comment_clear(_tc);
michael@0 201 else ret=2;
michael@0 202 }break;
michael@0 203 /*Codec setup header.*/
michael@0 204 case 0x82:{
michael@0 205 oc_setup_info *setup;
michael@0 206 if(_tc==NULL||_setup==NULL)return TH_EFAULT;
michael@0 207 /*We should have already decoded the info header and the comment header,
michael@0 208 and should not yet have decoded the setup header.*/
michael@0 209 if(_info->frame_width==0||_tc->vendor==NULL||*_setup!=NULL){
michael@0 210 return TH_EBADHEADER;
michael@0 211 }
michael@0 212 setup=(oc_setup_info *)_ogg_calloc(1,sizeof(*setup));
michael@0 213 if(setup==NULL)return TH_EFAULT;
michael@0 214 ret=oc_setup_unpack(_opb,setup);
michael@0 215 if(ret<0){
michael@0 216 oc_setup_clear(setup);
michael@0 217 _ogg_free(setup);
michael@0 218 }
michael@0 219 else{
michael@0 220 *_setup=setup;
michael@0 221 ret=1;
michael@0 222 }
michael@0 223 }break;
michael@0 224 default:{
michael@0 225 /*We don't know what this header is.*/
michael@0 226 return TH_EBADHEADER;
michael@0 227 }break;
michael@0 228 }
michael@0 229 return ret;
michael@0 230 }
michael@0 231
michael@0 232
michael@0 233 /*Decodes one header packet.
michael@0 234 This should be called repeatedly with the packets at the beginning of the
michael@0 235 stream until it returns 0.*/
michael@0 236 int th_decode_headerin(th_info *_info,th_comment *_tc,
michael@0 237 th_setup_info **_setup,ogg_packet *_op){
michael@0 238 oc_pack_buf opb;
michael@0 239 if(_op==NULL)return TH_EBADHEADER;
michael@0 240 if(_info==NULL)return TH_EFAULT;
michael@0 241 oc_pack_readinit(&opb,_op->packet,_op->bytes);
michael@0 242 return oc_dec_headerin(&opb,_info,_tc,_setup,_op);
michael@0 243 }
michael@0 244
michael@0 245 void th_setup_free(th_setup_info *_setup){
michael@0 246 if(_setup!=NULL){
michael@0 247 oc_setup_clear(_setup);
michael@0 248 _ogg_free(_setup);
michael@0 249 }
michael@0 250 }

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