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-rw-r--r--media/libtheora/lib/decinfo.c274
1 files changed, 274 insertions, 0 deletions
diff --git a/media/libtheora/lib/decinfo.c b/media/libtheora/lib/decinfo.c
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+++ b/media/libtheora/lib/decinfo.c
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+/********************************************************************
+ * *
+ * THIS FILE IS PART OF THE OggTheora SOFTWARE CODEC SOURCE CODE. *
+ * USE, DISTRIBUTION AND REPRODUCTION OF THIS LIBRARY SOURCE IS *
+ * GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *
+ * IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING. *
+ * *
+ * THE Theora SOURCE CODE IS COPYRIGHT (C) 2002-2009 *
+ * by the Xiph.Org Foundation and contributors http://www.xiph.org/ *
+ * *
+ ********************************************************************
+
+ function:
+ last mod: $Id$
+
+ ********************************************************************/
+
+#include <stdlib.h>
+#include <string.h>
+#include <limits.h>
+#include "decint.h"
+
+/*Only used for fuzzing.*/
+#if defined(HAVE_MEMORY_CONSTRAINT)
+static const int MAX_FUZZING_WIDTH = 16384;
+static const int MAX_FUZZING_HEIGHT = 16384;
+#endif
+
+
+/*Unpacks a series of octets from a given byte array into the pack buffer.
+ No checking is done to ensure the buffer contains enough data.
+ _opb: The pack buffer to read the octets from.
+ _buf: The byte array to store the unpacked bytes in.
+ _len: The number of octets to unpack.*/
+static void oc_unpack_octets(oc_pack_buf *_opb,char *_buf,size_t _len){
+ while(_len-->0){
+ long val;
+ val=oc_pack_read(_opb,8);
+ *_buf++=(char)val;
+ }
+}
+
+/*Unpacks a 32-bit integer encoded by octets in little-endian form.*/
+static long oc_unpack_length(oc_pack_buf *_opb){
+ long ret[4];
+ int i;
+ for(i=0;i<4;i++)ret[i]=oc_pack_read(_opb,8);
+ return ret[0]|ret[1]<<8|ret[2]<<16|ret[3]<<24;
+}
+
+static int oc_info_unpack(oc_pack_buf *_opb,th_info *_info){
+ long val;
+ /*Check the codec bitstream version.*/
+ val=oc_pack_read(_opb,8);
+ _info->version_major=(unsigned char)val;
+ val=oc_pack_read(_opb,8);
+ _info->version_minor=(unsigned char)val;
+ val=oc_pack_read(_opb,8);
+ _info->version_subminor=(unsigned char)val;
+ /*verify we can parse this bitstream version.
+ We accept earlier minors and all subminors, by spec*/
+ if(_info->version_major>TH_VERSION_MAJOR||
+ (_info->version_major==TH_VERSION_MAJOR&&
+ _info->version_minor>TH_VERSION_MINOR)){
+ return TH_EVERSION;
+ }
+ /*Read the encoded frame description.*/
+ val=oc_pack_read(_opb,16);
+ _info->frame_width=(ogg_uint32_t)val<<4;
+ val=oc_pack_read(_opb,16);
+ _info->frame_height=(ogg_uint32_t)val<<4;
+ val=oc_pack_read(_opb,24);
+ _info->pic_width=(ogg_uint32_t)val;
+ val=oc_pack_read(_opb,24);
+ _info->pic_height=(ogg_uint32_t)val;
+ val=oc_pack_read(_opb,8);
+ _info->pic_x=(ogg_uint32_t)val;
+ val=oc_pack_read(_opb,8);
+ _info->pic_y=(ogg_uint32_t)val;
+ val=oc_pack_read(_opb,32);
+ _info->fps_numerator=(ogg_uint32_t)val;
+ val=oc_pack_read(_opb,32);
+ _info->fps_denominator=(ogg_uint32_t)val;
+ if(_info->frame_width==0||_info->frame_height==0||
+ _info->pic_width+_info->pic_x>_info->frame_width||
+ _info->pic_height+_info->pic_y>_info->frame_height||
+ _info->fps_numerator==0||_info->fps_denominator==0){
+ return TH_EBADHEADER;
+ }
+#if defined(HAVE_MEMORY_CONSTRAINT)
+ if(_info->frame_width>=MAX_FUZZING_WIDTH&&_info->frame_height>=MAX_FUZZING_HEIGHT){
+ return TH_EBADHEADER;
+ }
+#endif
+ /*Note: The sense of pic_y is inverted in what we pass back to the
+ application compared to how it is stored in the bitstream.
+ This is because the bitstream uses a right-handed coordinate system, while
+ applications expect a left-handed one.*/
+ _info->pic_y=_info->frame_height-_info->pic_height-_info->pic_y;
+ val=oc_pack_read(_opb,24);
+ _info->aspect_numerator=(ogg_uint32_t)val;
+ val=oc_pack_read(_opb,24);
+ _info->aspect_denominator=(ogg_uint32_t)val;
+ val=oc_pack_read(_opb,8);
+ _info->colorspace=(th_colorspace)val;
+ val=oc_pack_read(_opb,24);
+ _info->target_bitrate=(int)val;
+ val=oc_pack_read(_opb,6);
+ _info->quality=(int)val;
+ val=oc_pack_read(_opb,5);
+ _info->keyframe_granule_shift=(int)val;
+ val=oc_pack_read(_opb,2);
+ _info->pixel_fmt=(th_pixel_fmt)val;
+ if(_info->pixel_fmt==TH_PF_RSVD)return TH_EBADHEADER;
+ val=oc_pack_read(_opb,3);
+ if(val!=0||oc_pack_bytes_left(_opb)<0)return TH_EBADHEADER;
+ return 0;
+}
+
+static int oc_comment_unpack(oc_pack_buf *_opb,th_comment *_tc){
+ long len;
+ int i;
+ /*Read the vendor string.*/
+ len=oc_unpack_length(_opb);
+ if(len<0||len>oc_pack_bytes_left(_opb))return TH_EBADHEADER;
+ _tc->vendor=_ogg_malloc((size_t)len+1);
+ if(_tc->vendor==NULL)return TH_EFAULT;
+ oc_unpack_octets(_opb,_tc->vendor,len);
+ _tc->vendor[len]='\0';
+ /*Read the user comments.*/
+ _tc->comments=(int)oc_unpack_length(_opb);
+ len=_tc->comments;
+ if(len<0||len>(LONG_MAX>>2)||len<<2>oc_pack_bytes_left(_opb)){
+ _tc->comments=0;
+ return TH_EBADHEADER;
+ }
+ _tc->comment_lengths=(int *)_ogg_malloc(
+ _tc->comments*sizeof(_tc->comment_lengths[0]));
+ _tc->user_comments=(char **)_ogg_malloc(
+ _tc->comments*sizeof(_tc->user_comments[0]));
+ if(_tc->comment_lengths==NULL||_tc->user_comments==NULL){
+ _tc->comments=0;
+ return TH_EFAULT;
+ }
+ for(i=0;i<_tc->comments;i++){
+ len=oc_unpack_length(_opb);
+ if(len<0||len>oc_pack_bytes_left(_opb)){
+ _tc->comments=i;
+ return TH_EBADHEADER;
+ }
+ _tc->comment_lengths[i]=len;
+ _tc->user_comments[i]=_ogg_malloc((size_t)len+1);
+ if(_tc->user_comments[i]==NULL){
+ _tc->comments=i;
+ return TH_EFAULT;
+ }
+ oc_unpack_octets(_opb,_tc->user_comments[i],len);
+ _tc->user_comments[i][len]='\0';
+ }
+ return oc_pack_bytes_left(_opb)<0?TH_EBADHEADER:0;
+}
+
+static int oc_setup_unpack(oc_pack_buf *_opb,th_setup_info *_setup){
+ int ret;
+ /*Read the quantizer tables.*/
+ ret=oc_quant_params_unpack(_opb,&_setup->qinfo);
+ if(ret<0)return ret;
+ /*Read the Huffman trees.*/
+ return oc_huff_trees_unpack(_opb,_setup->huff_tables);
+}
+
+static void oc_setup_clear(th_setup_info *_setup){
+ oc_quant_params_clear(&_setup->qinfo);
+ oc_huff_trees_clear(_setup->huff_tables);
+}
+
+static int oc_dec_headerin(oc_pack_buf *_opb,th_info *_info,
+ th_comment *_tc,th_setup_info **_setup,ogg_packet *_op){
+ char buffer[6];
+ long val;
+ int packtype;
+ int ret;
+ val=oc_pack_read(_opb,8);
+ packtype=(int)val;
+ /*If we're at a data packet...*/
+ if(!(packtype&0x80)){
+ /*Check to make sure we received all three headers...
+ If we haven't seen any valid headers, assume this is not actually
+ Theora.*/
+ if(_info->frame_width<=0)return TH_ENOTFORMAT;
+ /*Follow our documentation, which says we'll return TH_EFAULT if this
+ are NULL (_info was checked by our caller).*/
+ if(_tc==NULL)return TH_EFAULT;
+ /*And if any other headers were missing, declare this packet "out of
+ sequence" instead.*/
+ if(_tc->vendor==NULL)return TH_EBADHEADER;
+ /*Don't check this until it's needed, since we allow passing NULL for the
+ arguments that we're not expecting the next header to fill in yet.*/
+ if(_setup==NULL)return TH_EFAULT;
+ if(*_setup==NULL)return TH_EBADHEADER;
+ /*If we got everything, we're done.*/
+ return 0;
+ }
+ /*Check the codec string.*/
+ oc_unpack_octets(_opb,buffer,6);
+ if(memcmp(buffer,"theora",6)!=0)return TH_ENOTFORMAT;
+ switch(packtype){
+ /*Codec info header.*/
+ case 0x80:{
+ /*This should be the first packet, and we should not already be
+ initialized.*/
+ if(!_op->b_o_s||_info->frame_width>0)return TH_EBADHEADER;
+ ret=oc_info_unpack(_opb,_info);
+ if(ret<0)th_info_clear(_info);
+ else ret=3;
+ }break;
+ /*Comment header.*/
+ case 0x81:{
+ if(_tc==NULL)return TH_EFAULT;
+ /*We shoud have already decoded the info header, and should not yet have
+ decoded the comment header.*/
+ if(_info->frame_width==0||_tc->vendor!=NULL)return TH_EBADHEADER;
+ ret=oc_comment_unpack(_opb,_tc);
+ if(ret<0)th_comment_clear(_tc);
+ else ret=2;
+ }break;
+ /*Codec setup header.*/
+ case 0x82:{
+ oc_setup_info *setup;
+ if(_tc==NULL||_setup==NULL)return TH_EFAULT;
+ /*We should have already decoded the info header and the comment header,
+ and should not yet have decoded the setup header.*/
+ if(_info->frame_width==0||_tc->vendor==NULL||*_setup!=NULL){
+ return TH_EBADHEADER;
+ }
+ setup=(oc_setup_info *)_ogg_calloc(1,sizeof(*setup));
+ if(setup==NULL)return TH_EFAULT;
+ ret=oc_setup_unpack(_opb,setup);
+ if(ret<0){
+ oc_setup_clear(setup);
+ _ogg_free(setup);
+ }
+ else{
+ *_setup=setup;
+ ret=1;
+ }
+ }break;
+ default:{
+ /*We don't know what this header is.*/
+ return TH_EBADHEADER;
+ }break;
+ }
+ return ret;
+}
+
+
+/*Decodes one header packet.
+ This should be called repeatedly with the packets at the beginning of the
+ stream until it returns 0.*/
+int th_decode_headerin(th_info *_info,th_comment *_tc,
+ th_setup_info **_setup,ogg_packet *_op){
+ oc_pack_buf opb;
+ if(_op==NULL)return TH_EBADHEADER;
+ if(_info==NULL)return TH_EFAULT;
+ oc_pack_readinit(&opb,_op->packet,_op->bytes);
+ return oc_dec_headerin(&opb,_info,_tc,_setup,_op);
+}
+
+void th_setup_free(th_setup_info *_setup){
+ if(_setup!=NULL){
+ oc_setup_clear(_setup);
+ _ogg_free(_setup);
+ }
+}