vorbis-tools-1.2.0/ogginfo/theora.c

   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) 2002-2003                *
   9  * by the Xiph.Org Foundation http://www.xiph.org/                  *
  10  *                                                                  *
  11  ********************************************************************
  12
  13   function:
  14   last mod: $Id: toplevel.c,v 1.39 2004/03/18 02:00:30 giles Exp $
  15
  16  ********************************************************************/
  17
  18 #ifdef HAVE_CONFIG_H
  19 #include <config.h>
  20 #endif
  21
  22 #include <stdlib.h>
  23 #include <string.h>
  24 #include "theora.h"
  25
  26 #define theora_read(x,y,z) ( *z = oggpackB_read(x,y) )
  27
  28 static void _tp_readbuffer(oggpack_buffer *opb, char *buf, const long len)
  29 {
  30   long i;
  31   long ret;
  32
  33   for (i = 0; i < len; i++) {
  34     theora_read(opb, 8, &ret);
  35     *buf++=(char)ret;
  36   }
  37 }
  38
  39 static void _tp_readlsbint(oggpack_buffer *opb, long *value)
  40 {
  41   int i;
  42   long ret[4];
  43
  44   for (i = 0; i < 4; i++) {
  45     theora_read(opb,8,&ret[i]);
  46   }
  47   *value = ret[0]|ret[1]<<8|ret[2]<<16|ret[3]<<24;
  48 }
  49
  50 void theora_info_clear(theora_info *c) {
  51   memset(c,0,sizeof(*c));
  52 }
  53
  54 static int _theora_unpack_info(theora_info *ci, oggpack_buffer *opb){
  55   long ret;
  56
  57   theora_read(opb,8,&ret);
  58   ci->version_major=(unsigned char)ret;
  59   theora_read(opb,8,&ret);
  60   ci->version_minor=(unsigned char)ret;
  61   theora_read(opb,8,&ret);
  62   ci->version_subminor=(unsigned char)ret;
  63
  64   theora_read(opb,16,&ret);
  65   ci->width=ret<<4;
  66   theora_read(opb,16,&ret);
  67   ci->height=ret<<4;
  68   theora_read(opb,24,&ret);
  69   ci->frame_width=ret;
  70   theora_read(opb,24,&ret);
  71   ci->frame_height=ret;
  72   theora_read(opb,8,&ret);
  73   ci->offset_x=ret;
  74   theora_read(opb,8,&ret);
  75   ci->offset_y=ret;
  76
  77   theora_read(opb,32,&ret);
  78   ci->fps_numerator=ret;
  79   theora_read(opb,32,&ret);
  80   ci->fps_denominator=ret;
  81   theora_read(opb,24,&ret);
  82   ci->aspect_numerator=ret;
  83   theora_read(opb,24,&ret);
  84   ci->aspect_denominator=ret;
  85
  86   theora_read(opb,8,&ret);
  87   ci->colorspace=ret;
  88   theora_read(opb,24,&ret);
  89   ci->target_bitrate=ret;
  90   theora_read(opb,6,&ret);
  91   ci->quality=ret;
  92
  93   theora_read(opb,5,&ret);
  94   ci->granule_shift = ret;
  95
  96   theora_read(opb,2,&ret);
  97   ci->pixelformat=ret;
  98
  99   /* spare configuration bits */
 100   if ( theora_read(opb,3,&ret) == -1 )
 101     return (OC_BADHEADER);
 102
 103   return(0);
 104 }
 105
 106 void theora_comment_clear(theora_comment *tc){
 107   if(tc){
 108     long i;
 109     for(i=0;i<tc->comments;i++)
 110       if(tc->user_comments[i])_ogg_free(tc->user_comments[i]);
 111     if(tc->user_comments)_ogg_free(tc->user_comments);
 112     if(tc->comment_lengths)_ogg_free(tc->comment_lengths);
 113     if(tc->vendor)_ogg_free(tc->vendor);
 114   }
 115   memset(tc,0,sizeof(*tc));
 116 }
 117
 118 static int _theora_unpack_comment(theora_comment *tc, oggpack_buffer *opb){
 119   int i;
 120   long len;
 121
 122   _tp_readlsbint(opb,&len);
 123   if(len<0)return(OC_BADHEADER);
 124   tc->vendor=_ogg_calloc(1,len+1);
 125   _tp_readbuffer(opb,tc->vendor, len);
 126   tc->vendor[len]='\0';
 127
 128   _tp_readlsbint(opb,(long *) &tc->comments);
 129   if(tc->comments<0)goto parse_err;
 130   tc->user_comments=_ogg_calloc(tc->comments,sizeof(*tc->user_comments));
 131   tc->comment_lengths=_ogg_calloc(tc->comments,sizeof(*tc->comment_lengths));
 132   for(i=0;i<tc->comments;i++){
 133     _tp_readlsbint(opb,&len);
 134     if(len<0)goto parse_err;
 135     tc->user_comments[i]=_ogg_calloc(1,len+1);
 136     _tp_readbuffer(opb,tc->user_comments[i],len);
 137     tc->user_comments[i][len]='\0';
 138     tc->comment_lengths[i]=len;
 139   }
 140   return(0);
 141
 142 parse_err:
 143   theora_comment_clear(tc);
 144   return(OC_BADHEADER);
 145 }
 146
 147 static int _theora_unpack_tables(theora_info *c, oggpack_buffer *opb){
 148   /* NOP: ogginfo doesn't use this information */
 149   return 0;
 150 }
 151
 152 int theora_decode_header(theora_info *ci, theora_comment *cc, ogg_packet *op){
 153   long ret;
 154   oggpack_buffer *opb;
 155
 156   if(!op)return OC_BADHEADER;
 157
 158   opb = _ogg_malloc(sizeof(oggpack_buffer));
 159   oggpackB_readinit(opb,op->packet,op->bytes);
 160   {
 161     char id[6];
 162     int typeflag;
 163
 164     theora_read(opb,8,&ret);
 165     typeflag = ret;
 166     if(!(typeflag&0x80)) {
 167       free(opb);
 168       return(OC_NOTFORMAT);
 169     }
 170
 171     _tp_readbuffer(opb,id,6);
 172     if(memcmp(id,"theora",6)) {
 173       free(opb);
 174       return(OC_NOTFORMAT);
 175     }
 176
 177     switch(typeflag){
 178     case 0x80:
 179       if(!op->b_o_s){
 180         /* Not the initial packet */
 181         free(opb);
 182         return(OC_BADHEADER);
 183       }
 184       if(ci->version_major!=0){
 185         /* previously initialized info header */
 186         free(opb);
 187         return OC_BADHEADER;
 188       }
 189
 190       ret = _theora_unpack_info(ci,opb);
 191       free(opb);
 192       return(ret);
 193
 194     case 0x81:
 195       if(ci->version_major==0){
 196         /* um... we didn't get the initial header */
 197         free(opb);
 198         return(OC_BADHEADER);
 199       }
 200
 201       ret = _theora_unpack_comment(cc,opb);
 202       free(opb);
 203       return(ret);
 204
 205     case 0x82:
 206       if(ci->version_major==0 || cc->vendor==NULL){
 207         /* um... we didn't get the initial header or comments yet */
 208         free(opb);
 209         return(OC_BADHEADER);
 210       }
 211
 212       ret = _theora_unpack_tables(ci,opb);
 213       free(opb);
 214       return(ret);
 215
 216     default:
 217       free(opb);
 218       /* ignore any trailing header packets for forward compatibility */
 219       return(OC_NEWPACKET);
 220     }
 221   }
 222   /* I don't think it's possible to get this far, but better safe.. */
 223   free(opb);
 224   return(OC_BADHEADER);
 225 }