summaryrefslogtreecommitdiff
path: root/media/libtheora/lib/decinfo.c
blob: 603b1f93e46a65e2379560dcff30c0e82e004b6a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
/********************************************************************
 *                                                                  *
 * 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: decinfo.c 17276 2010-06-05 05:57:05Z tterribe $

 ********************************************************************/

#include <stdlib.h>
#include <string.h>
#include <limits.h>
#include "decint.h"



/*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;
  }
  /*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 and we have received all three headers, we're
     done.*/
  if(!(packtype&0x80)&&_info->frame_width>0&&_tc->vendor!=NULL&&*_setup!=NULL){
    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);
  }
}