1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/media/libtheora/lib/decinfo.c Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,250 @@
1.4 +/********************************************************************
1.5 + * *
1.6 + * THIS FILE IS PART OF THE OggTheora SOFTWARE CODEC SOURCE CODE. *
1.7 + * USE, DISTRIBUTION AND REPRODUCTION OF THIS LIBRARY SOURCE IS *
1.8 + * GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *
1.9 + * IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING. *
1.10 + * *
1.11 + * THE Theora SOURCE CODE IS COPYRIGHT (C) 2002-2009 *
1.12 + * by the Xiph.Org Foundation and contributors http://www.xiph.org/ *
1.13 + * *
1.14 + ********************************************************************
1.15 +
1.16 + function:
1.17 + last mod: $Id: decinfo.c 17276 2010-06-05 05:57:05Z tterribe $
1.18 +
1.19 + ********************************************************************/
1.20 +
1.21 +#include <stdlib.h>
1.22 +#include <string.h>
1.23 +#include <limits.h>
1.24 +#include "decint.h"
1.25 +
1.26 +
1.27 +
1.28 +/*Unpacks a series of octets from a given byte array into the pack buffer.
1.29 + No checking is done to ensure the buffer contains enough data.
1.30 + _opb: The pack buffer to read the octets from.
1.31 + _buf: The byte array to store the unpacked bytes in.
1.32 + _len: The number of octets to unpack.*/
1.33 +static void oc_unpack_octets(oc_pack_buf *_opb,char *_buf,size_t _len){
1.34 + while(_len-->0){
1.35 + long val;
1.36 + val=oc_pack_read(_opb,8);
1.37 + *_buf++=(char)val;
1.38 + }
1.39 +}
1.40 +
1.41 +/*Unpacks a 32-bit integer encoded by octets in little-endian form.*/
1.42 +static long oc_unpack_length(oc_pack_buf *_opb){
1.43 + long ret[4];
1.44 + int i;
1.45 + for(i=0;i<4;i++)ret[i]=oc_pack_read(_opb,8);
1.46 + return ret[0]|ret[1]<<8|ret[2]<<16|ret[3]<<24;
1.47 +}
1.48 +
1.49 +static int oc_info_unpack(oc_pack_buf *_opb,th_info *_info){
1.50 + long val;
1.51 + /*Check the codec bitstream version.*/
1.52 + val=oc_pack_read(_opb,8);
1.53 + _info->version_major=(unsigned char)val;
1.54 + val=oc_pack_read(_opb,8);
1.55 + _info->version_minor=(unsigned char)val;
1.56 + val=oc_pack_read(_opb,8);
1.57 + _info->version_subminor=(unsigned char)val;
1.58 + /*verify we can parse this bitstream version.
1.59 + We accept earlier minors and all subminors, by spec*/
1.60 + if(_info->version_major>TH_VERSION_MAJOR||
1.61 + _info->version_major==TH_VERSION_MAJOR&&
1.62 + _info->version_minor>TH_VERSION_MINOR){
1.63 + return TH_EVERSION;
1.64 + }
1.65 + /*Read the encoded frame description.*/
1.66 + val=oc_pack_read(_opb,16);
1.67 + _info->frame_width=(ogg_uint32_t)val<<4;
1.68 + val=oc_pack_read(_opb,16);
1.69 + _info->frame_height=(ogg_uint32_t)val<<4;
1.70 + val=oc_pack_read(_opb,24);
1.71 + _info->pic_width=(ogg_uint32_t)val;
1.72 + val=oc_pack_read(_opb,24);
1.73 + _info->pic_height=(ogg_uint32_t)val;
1.74 + val=oc_pack_read(_opb,8);
1.75 + _info->pic_x=(ogg_uint32_t)val;
1.76 + val=oc_pack_read(_opb,8);
1.77 + _info->pic_y=(ogg_uint32_t)val;
1.78 + val=oc_pack_read(_opb,32);
1.79 + _info->fps_numerator=(ogg_uint32_t)val;
1.80 + val=oc_pack_read(_opb,32);
1.81 + _info->fps_denominator=(ogg_uint32_t)val;
1.82 + if(_info->frame_width==0||_info->frame_height==0||
1.83 + _info->pic_width+_info->pic_x>_info->frame_width||
1.84 + _info->pic_height+_info->pic_y>_info->frame_height||
1.85 + _info->fps_numerator==0||_info->fps_denominator==0){
1.86 + return TH_EBADHEADER;
1.87 + }
1.88 + /*Note: The sense of pic_y is inverted in what we pass back to the
1.89 + application compared to how it is stored in the bitstream.
1.90 + This is because the bitstream uses a right-handed coordinate system, while
1.91 + applications expect a left-handed one.*/
1.92 + _info->pic_y=_info->frame_height-_info->pic_height-_info->pic_y;
1.93 + val=oc_pack_read(_opb,24);
1.94 + _info->aspect_numerator=(ogg_uint32_t)val;
1.95 + val=oc_pack_read(_opb,24);
1.96 + _info->aspect_denominator=(ogg_uint32_t)val;
1.97 + val=oc_pack_read(_opb,8);
1.98 + _info->colorspace=(th_colorspace)val;
1.99 + val=oc_pack_read(_opb,24);
1.100 + _info->target_bitrate=(int)val;
1.101 + val=oc_pack_read(_opb,6);
1.102 + _info->quality=(int)val;
1.103 + val=oc_pack_read(_opb,5);
1.104 + _info->keyframe_granule_shift=(int)val;
1.105 + val=oc_pack_read(_opb,2);
1.106 + _info->pixel_fmt=(th_pixel_fmt)val;
1.107 + if(_info->pixel_fmt==TH_PF_RSVD)return TH_EBADHEADER;
1.108 + val=oc_pack_read(_opb,3);
1.109 + if(val!=0||oc_pack_bytes_left(_opb)<0)return TH_EBADHEADER;
1.110 + return 0;
1.111 +}
1.112 +
1.113 +static int oc_comment_unpack(oc_pack_buf *_opb,th_comment *_tc){
1.114 + long len;
1.115 + int i;
1.116 + /*Read the vendor string.*/
1.117 + len=oc_unpack_length(_opb);
1.118 + if(len<0||len>oc_pack_bytes_left(_opb))return TH_EBADHEADER;
1.119 + _tc->vendor=_ogg_malloc((size_t)len+1);
1.120 + if(_tc->vendor==NULL)return TH_EFAULT;
1.121 + oc_unpack_octets(_opb,_tc->vendor,len);
1.122 + _tc->vendor[len]='\0';
1.123 + /*Read the user comments.*/
1.124 + _tc->comments=(int)oc_unpack_length(_opb);
1.125 + len=_tc->comments;
1.126 + if(len<0||len>(LONG_MAX>>2)||len<<2>oc_pack_bytes_left(_opb)){
1.127 + _tc->comments=0;
1.128 + return TH_EBADHEADER;
1.129 + }
1.130 + _tc->comment_lengths=(int *)_ogg_malloc(
1.131 + _tc->comments*sizeof(_tc->comment_lengths[0]));
1.132 + _tc->user_comments=(char **)_ogg_malloc(
1.133 + _tc->comments*sizeof(_tc->user_comments[0]));
1.134 + if(_tc->comment_lengths==NULL||_tc->user_comments==NULL){
1.135 + _tc->comments=0;
1.136 + return TH_EFAULT;
1.137 + }
1.138 + for(i=0;i<_tc->comments;i++){
1.139 + len=oc_unpack_length(_opb);
1.140 + if(len<0||len>oc_pack_bytes_left(_opb)){
1.141 + _tc->comments=i;
1.142 + return TH_EBADHEADER;
1.143 + }
1.144 + _tc->comment_lengths[i]=len;
1.145 + _tc->user_comments[i]=_ogg_malloc((size_t)len+1);
1.146 + if(_tc->user_comments[i]==NULL){
1.147 + _tc->comments=i;
1.148 + return TH_EFAULT;
1.149 + }
1.150 + oc_unpack_octets(_opb,_tc->user_comments[i],len);
1.151 + _tc->user_comments[i][len]='\0';
1.152 + }
1.153 + return oc_pack_bytes_left(_opb)<0?TH_EBADHEADER:0;
1.154 +}
1.155 +
1.156 +static int oc_setup_unpack(oc_pack_buf *_opb,th_setup_info *_setup){
1.157 + int ret;
1.158 + /*Read the quantizer tables.*/
1.159 + ret=oc_quant_params_unpack(_opb,&_setup->qinfo);
1.160 + if(ret<0)return ret;
1.161 + /*Read the Huffman trees.*/
1.162 + return oc_huff_trees_unpack(_opb,_setup->huff_tables);
1.163 +}
1.164 +
1.165 +static void oc_setup_clear(th_setup_info *_setup){
1.166 + oc_quant_params_clear(&_setup->qinfo);
1.167 + oc_huff_trees_clear(_setup->huff_tables);
1.168 +}
1.169 +
1.170 +static int oc_dec_headerin(oc_pack_buf *_opb,th_info *_info,
1.171 + th_comment *_tc,th_setup_info **_setup,ogg_packet *_op){
1.172 + char buffer[6];
1.173 + long val;
1.174 + int packtype;
1.175 + int ret;
1.176 + val=oc_pack_read(_opb,8);
1.177 + packtype=(int)val;
1.178 + /*If we're at a data packet and we have received all three headers, we're
1.179 + done.*/
1.180 + if(!(packtype&0x80)&&_info->frame_width>0&&_tc->vendor!=NULL&&*_setup!=NULL){
1.181 + return 0;
1.182 + }
1.183 + /*Check the codec string.*/
1.184 + oc_unpack_octets(_opb,buffer,6);
1.185 + if(memcmp(buffer,"theora",6)!=0)return TH_ENOTFORMAT;
1.186 + switch(packtype){
1.187 + /*Codec info header.*/
1.188 + case 0x80:{
1.189 + /*This should be the first packet, and we should not already be
1.190 + initialized.*/
1.191 + if(!_op->b_o_s||_info->frame_width>0)return TH_EBADHEADER;
1.192 + ret=oc_info_unpack(_opb,_info);
1.193 + if(ret<0)th_info_clear(_info);
1.194 + else ret=3;
1.195 + }break;
1.196 + /*Comment header.*/
1.197 + case 0x81:{
1.198 + if(_tc==NULL)return TH_EFAULT;
1.199 + /*We shoud have already decoded the info header, and should not yet have
1.200 + decoded the comment header.*/
1.201 + if(_info->frame_width==0||_tc->vendor!=NULL)return TH_EBADHEADER;
1.202 + ret=oc_comment_unpack(_opb,_tc);
1.203 + if(ret<0)th_comment_clear(_tc);
1.204 + else ret=2;
1.205 + }break;
1.206 + /*Codec setup header.*/
1.207 + case 0x82:{
1.208 + oc_setup_info *setup;
1.209 + if(_tc==NULL||_setup==NULL)return TH_EFAULT;
1.210 + /*We should have already decoded the info header and the comment header,
1.211 + and should not yet have decoded the setup header.*/
1.212 + if(_info->frame_width==0||_tc->vendor==NULL||*_setup!=NULL){
1.213 + return TH_EBADHEADER;
1.214 + }
1.215 + setup=(oc_setup_info *)_ogg_calloc(1,sizeof(*setup));
1.216 + if(setup==NULL)return TH_EFAULT;
1.217 + ret=oc_setup_unpack(_opb,setup);
1.218 + if(ret<0){
1.219 + oc_setup_clear(setup);
1.220 + _ogg_free(setup);
1.221 + }
1.222 + else{
1.223 + *_setup=setup;
1.224 + ret=1;
1.225 + }
1.226 + }break;
1.227 + default:{
1.228 + /*We don't know what this header is.*/
1.229 + return TH_EBADHEADER;
1.230 + }break;
1.231 + }
1.232 + return ret;
1.233 +}
1.234 +
1.235 +
1.236 +/*Decodes one header packet.
1.237 + This should be called repeatedly with the packets at the beginning of the
1.238 + stream until it returns 0.*/
1.239 +int th_decode_headerin(th_info *_info,th_comment *_tc,
1.240 + th_setup_info **_setup,ogg_packet *_op){
1.241 + oc_pack_buf opb;
1.242 + if(_op==NULL)return TH_EBADHEADER;
1.243 + if(_info==NULL)return TH_EFAULT;
1.244 + oc_pack_readinit(&opb,_op->packet,_op->bytes);
1.245 + return oc_dec_headerin(&opb,_info,_tc,_setup,_op);
1.246 +}
1.247 +
1.248 +void th_setup_free(th_setup_info *_setup){
1.249 + if(_setup!=NULL){
1.250 + oc_setup_clear(_setup);
1.251 + _ogg_free(_setup);
1.252 + }
1.253 +}
