diff options
Diffstat (limited to 'media/libtheora/lib/decinfo.c')
| -rw-r--r-- | media/libtheora/lib/decinfo.c | 250 |
1 files changed, 250 insertions, 0 deletions
diff --git a/media/libtheora/lib/decinfo.c b/media/libtheora/lib/decinfo.c new file mode 100644 index 000000000..603b1f93e --- /dev/null +++ b/media/libtheora/lib/decinfo.c @@ -0,0 +1,250 @@ +/******************************************************************** + * * + * 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); + } +} |