1/********************************************************************
2 * *
3 * THIS FILE IS PART OF THE OggTheora SOFTWARE CODEC SOURCE CODE. *
4 * USE, DISTRIBUTION AND REPRODUCTION OF THIS LIBRARY SOURCE IS *
5 * GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *
6 * IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING. *
7 * *
8 * THE Theora SOURCE CODE IS COPYRIGHT (C) 2002-2009 *
9 * by the Xiph.Org Foundation and contributors http://www.xiph.org/ *
10 * *
11 ********************************************************************
12
13 function:
14 last mod: $Id$
15
16 ********************************************************************/
17
18#include <stdlib.h>
19#include <string.h>
20#include <limits.h>
21#include "decint.h"
22
23/*Only used for fuzzing.*/
24#if defined(HAVE_MEMORY_CONSTRAINT)
25static const int MAX_FUZZING_WIDTH = 16384;
26static const int MAX_FUZZING_HEIGHT = 16384;
27#endif
28
29
30/*Unpacks a series of octets from a given byte array into the pack buffer.
31 No checking is done to ensure the buffer contains enough data.
32 _opb: The pack buffer to read the octets from.
33 _buf: The byte array to store the unpacked bytes in.
34 _len: The number of octets to unpack.*/
35static void oc_unpack_octets(oc_pack_buf *_opb,char *_buf,size_t _len){
36 while(_len-->0){
37 long val;
38 val=oc_pack_read(_opb,8);
39 *_buf++=(char)val;
40 }
41}
42
43/*Unpacks a 32-bit integer encoded by octets in little-endian form.*/
44static long oc_unpack_length(oc_pack_buf *_opb){
45 long ret[4];
46 int i;
47 for(i=0;i<4;i++)ret[i]=oc_pack_read(_opb,8);
48 return ret[0]|ret[1]<<8|ret[2]<<16|ret[3]<<24;
49}
50
51static int oc_info_unpack(oc_pack_buf *_opb,th_info *_info){
52 long val;
53 /*Check the codec bitstream version.*/
54 val=oc_pack_read(_opb,8);
55 _info->version_major=(unsigned char)val;
56 val=oc_pack_read(_opb,8);
57 _info->version_minor=(unsigned char)val;
58 val=oc_pack_read(_opb,8);
59 _info->version_subminor=(unsigned char)val;
60 /*verify we can parse this bitstream version.
61 We accept earlier minors and all subminors, by spec*/
62 if(_info->version_major>TH_VERSION_MAJOR||
63 (_info->version_major==TH_VERSION_MAJOR&&
64 _info->version_minor>TH_VERSION_MINOR)){
65 return TH_EVERSION;
66 }
67 /*Read the encoded frame description.*/
68 val=oc_pack_read(_opb,16);
69 _info->frame_width=(ogg_uint32_t)val<<4;
70 val=oc_pack_read(_opb,16);
71 _info->frame_height=(ogg_uint32_t)val<<4;
72 val=oc_pack_read(_opb,24);
73 _info->pic_width=(ogg_uint32_t)val;
74 val=oc_pack_read(_opb,24);
75 _info->pic_height=(ogg_uint32_t)val;
76 val=oc_pack_read(_opb,8);
77 _info->pic_x=(ogg_uint32_t)val;
78 val=oc_pack_read(_opb,8);
79 _info->pic_y=(ogg_uint32_t)val;
80 val=oc_pack_read(_opb,32);
81 _info->fps_numerator=(ogg_uint32_t)val;
82 val=oc_pack_read(_opb,32);
83 _info->fps_denominator=(ogg_uint32_t)val;
84 if(_info->frame_width==0||_info->frame_height==0||
85 _info->pic_width+_info->pic_x>_info->frame_width||
86 _info->pic_height+_info->pic_y>_info->frame_height||
87 _info->fps_numerator==0||_info->fps_denominator==0){
88 return TH_EBADHEADER;
89 }
90#if defined(HAVE_MEMORY_CONSTRAINT)
91 if(_info->frame_width>=MAX_FUZZING_WIDTH&&_info->frame_height>=MAX_FUZZING_HEIGHT){
92 return TH_EBADHEADER;
93 }
94#endif
95 /*Note: The sense of pic_y is inverted in what we pass back to the
96 application compared to how it is stored in the bitstream.
97 This is because the bitstream uses a right-handed coordinate system, while
98 applications expect a left-handed one.*/
99 _info->pic_y=_info->frame_height-_info->pic_height-_info->pic_y;
100 val=oc_pack_read(_opb,24);
101 _info->aspect_numerator=(ogg_uint32_t)val;
102 val=oc_pack_read(_opb,24);
103 _info->aspect_denominator=(ogg_uint32_t)val;
104 val=oc_pack_read(_opb,8);
105 _info->colorspace=(th_colorspace)val;
106 val=oc_pack_read(_opb,24);
107 _info->target_bitrate=(int)val;
108 val=oc_pack_read(_opb,6);
109 _info->quality=(int)val;
110 val=oc_pack_read(_opb,5);
111 _info->keyframe_granule_shift=(int)val;
112 val=oc_pack_read(_opb,2);
113 _info->pixel_fmt=(th_pixel_fmt)val;
114 if(_info->pixel_fmt==TH_PF_RSVD)return TH_EBADHEADER;
115 val=oc_pack_read(_opb,3);
116 if(val!=0||oc_pack_bytes_left(_opb)<0)return TH_EBADHEADER;
117 return 0;
118}
119
120static int oc_comment_unpack(oc_pack_buf *_opb,th_comment *_tc){
121 long len;
122 int i;
123 /*Read the vendor string.*/
124 len=oc_unpack_length(_opb);
125 if(len<0||len>oc_pack_bytes_left(_opb))return TH_EBADHEADER;
126 _tc->vendor=_ogg_malloc((size_t)len+1);
127 if(_tc->vendor==NULL)return TH_EFAULT;
128 oc_unpack_octets(_opb,_tc->vendor,len);
129 _tc->vendor[len]='\0';
130 /*Read the user comments.*/
131 _tc->comments=(int)oc_unpack_length(_opb);
132 len=_tc->comments;
133 if(len<0||len>(LONG_MAX>>2)||len<<2>oc_pack_bytes_left(_opb)){
134 _tc->comments=0;
135 return TH_EBADHEADER;
136 }
137 _tc->comment_lengths=(int *)_ogg_malloc(
138 _tc->comments*sizeof(_tc->comment_lengths[0]));
139 _tc->user_comments=(char **)_ogg_malloc(
140 _tc->comments*sizeof(_tc->user_comments[0]));
141 if(_tc->comment_lengths==NULL||_tc->user_comments==NULL){
142 _tc->comments=0;
143 return TH_EFAULT;
144 }
145 for(i=0;i<_tc->comments;i++){
146 len=oc_unpack_length(_opb);
147 if(len<0||len>oc_pack_bytes_left(_opb)){
148 _tc->comments=i;
149 return TH_EBADHEADER;
150 }
151 _tc->comment_lengths[i]=len;
152 _tc->user_comments[i]=_ogg_malloc((size_t)len+1);
153 if(_tc->user_comments[i]==NULL){
154 _tc->comments=i;
155 return TH_EFAULT;
156 }
157 oc_unpack_octets(_opb,_tc->user_comments[i],len);
158 _tc->user_comments[i][len]='\0';
159 }
160 return oc_pack_bytes_left(_opb)<0?TH_EBADHEADER:0;
161}
162
163static int oc_setup_unpack(oc_pack_buf *_opb,th_setup_info *_setup){
164 int ret;
165 /*Read the quantizer tables.*/
166 ret=oc_quant_params_unpack(_opb,&_setup->qinfo);
167 if(ret<0)return ret;
168 /*Read the Huffman trees.*/
169 return oc_huff_trees_unpack(_opb,_setup->huff_tables);
170}
171
172static void oc_setup_clear(th_setup_info *_setup){
173 oc_quant_params_clear(&_setup->qinfo);
174 oc_huff_trees_clear(_setup->huff_tables);
175}
176
177static int oc_dec_headerin(oc_pack_buf *_opb,th_info *_info,
178 th_comment *_tc,th_setup_info **_setup,ogg_packet *_op){
179 char buffer[6];
180 long val;
181 int packtype;
182 int ret;
183 val=oc_pack_read(_opb,8);
184 packtype=(int)val;
185 /*If we're at a data packet...*/
186 if(!(packtype&0x80)){
187 /*Check to make sure we received all three headers...
188 If we haven't seen any valid headers, assume this is not actually
189 Theora.*/
190 if(_info->frame_width<=0)return TH_ENOTFORMAT;
191 /*Follow our documentation, which says we'll return TH_EFAULT if this
192 are NULL (_info was checked by our caller).*/
193 if(_tc==NULL)return TH_EFAULT;
194 /*And if any other headers were missing, declare this packet "out of
195 sequence" instead.*/
196 if(_tc->vendor==NULL)return TH_EBADHEADER;
197 /*Don't check this until it's needed, since we allow passing NULL for the
198 arguments that we're not expecting the next header to fill in yet.*/
199 if(_setup==NULL)return TH_EFAULT;
200 if(*_setup==NULL)return TH_EBADHEADER;
201 /*If we got everything, we're done.*/
202 return 0;
203 }
204 /*Check the codec string.*/
205 oc_unpack_octets(_opb,buffer,6);
206 if(memcmp(buffer,"theora",6)!=0)return TH_ENOTFORMAT;
207 switch(packtype){
208 /*Codec info header.*/
209 case 0x80:{
210 /*This should be the first packet, and we should not already be
211 initialized.*/
212 if(!_op->b_o_s||_info->frame_width>0)return TH_EBADHEADER;
213 ret=oc_info_unpack(_opb,_info);
214 if(ret<0)th_info_clear(_info);
215 else ret=3;
216 }break;
217 /*Comment header.*/
218 case 0x81:{
219 if(_tc==NULL)return TH_EFAULT;
220 /*We shoud have already decoded the info header, and should not yet have
221 decoded the comment header.*/
222 if(_info->frame_width==0||_tc->vendor!=NULL)return TH_EBADHEADER;
223 ret=oc_comment_unpack(_opb,_tc);
224 if(ret<0)th_comment_clear(_tc);
225 else ret=2;
226 }break;
227 /*Codec setup header.*/
228 case 0x82:{
229 oc_setup_info *setup;
230 if(_tc==NULL||_setup==NULL)return TH_EFAULT;
231 /*We should have already decoded the info header and the comment header,
232 and should not yet have decoded the setup header.*/
233 if(_info->frame_width==0||_tc->vendor==NULL||*_setup!=NULL){
234 return TH_EBADHEADER;
235 }
236 setup=(oc_setup_info *)_ogg_calloc(1,sizeof(*setup));
237 if(setup==NULL)return TH_EFAULT;
238 ret=oc_setup_unpack(_opb,setup);
239 if(ret<0){
240 oc_setup_clear(setup);
241 _ogg_free(setup);
242 }
243 else{
244 *_setup=setup;
245 ret=1;
246 }
247 }break;
248 default:{
249 /*We don't know what this header is.*/
250 return TH_EBADHEADER;
251 }break;
252 }
253 return ret;
254}
255
256
257/*Decodes one header packet.
258 This should be called repeatedly with the packets at the beginning of the
259 stream until it returns 0.*/
260int th_decode_headerin(th_info *_info,th_comment *_tc,
261 th_setup_info **_setup,ogg_packet *_op){
262 oc_pack_buf opb;
263 if(_op==NULL)return TH_EBADHEADER;
264 if(_info==NULL)return TH_EFAULT;
265 oc_pack_readinit(&opb,_op->packet,_op->bytes);
266 return oc_dec_headerin(&opb,_info,_tc,_setup,_op);
267}
268
269void th_setup_free(th_setup_info *_setup){
270 if(_setup!=NULL){
271 oc_setup_clear(_setup);
272 _ogg_free(_setup);
273 }
274}
275