The Tor Browser: media/libtheora/lib/internal.c@b8a032363ba2

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

     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  ********************************************************************

    13   function:

    14     last mod: $Id: internal.c 17506 2010-10-13 02:52:41Z tterribe $

    16  ********************************************************************/

    18 #include <stdlib.h>

    19 #include <limits.h>

    20 #include <string.h>

    21 #include "internal.h"

    25 /*A map from the index in the zig zag scan to the coefficient number in a

    26    block.

    27   All zig zag indices beyond 63 are sent to coefficient 64, so that zero runs

    28    past the end of a block in bogus streams get mapped to a known location.*/

    29 const unsigned char OC_FZIG_ZAG[128]={

    30    0, 1, 8,16, 9, 2, 3,10,

    31   17,24,32,25,18,11, 4, 5,

    32   12,19,26,33,40,48,41,34,

    33   27,20,13, 6, 7,14,21,28,

    34   35,42,49,56,57,50,43,36,

    35   29,22,15,23,30,37,44,51,

    36   58,59,52,45,38,31,39,46,

    37   53,60,61,54,47,55,62,63,

    38   64,64,64,64,64,64,64,64,

    39   64,64,64,64,64,64,64,64,

    40   64,64,64,64,64,64,64,64,

    41   64,64,64,64,64,64,64,64,

    42   64,64,64,64,64,64,64,64,

    43   64,64,64,64,64,64,64,64,

    44   64,64,64,64,64,64,64,64,

    45   64,64,64,64,64,64,64,64

    46 };

    48 /*A map from the coefficient number in a block to its index in the zig zag

    49    scan.*/

    50 const unsigned char OC_IZIG_ZAG[64]={

    51    0, 1, 5, 6,14,15,27,28,

    52    2, 4, 7,13,16,26,29,42,

    53    3, 8,12,17,25,30,41,43,

    54    9,11,18,24,31,40,44,53,

    55   10,19,23,32,39,45,52,54,

    56   20,22,33,38,46,51,55,60,

    57   21,34,37,47,50,56,59,61,

    58   35,36,48,49,57,58,62,63

    59 };

    61 /*A map from physical macro block ordering to bitstream macro block

    62    ordering within a super block.*/

    63 const unsigned char OC_MB_MAP[2][2]={{0,3},{1,2}};

    65 /*A list of the indices in the oc_mb.map array that can be valid for each of

    66    the various chroma decimation types.*/

    67 const unsigned char OC_MB_MAP_IDXS[TH_PF_NFORMATS][12]={

    68   {0,1,2,3,4,8},

    69   {0,1,2,3,4,5,8,9},

    70   {0,1,2,3,4,6,8,10},

    71   {0,1,2,3,4,5,6,7,8,9,10,11}

    72 };

    74 /*The number of indices in the oc_mb.map array that can be valid for each of

    75    the various chroma decimation types.*/

    76 const unsigned char OC_MB_MAP_NIDXS[TH_PF_NFORMATS]={6,8,8,12};

    78 /*The number of extra bits that are coded with each of the DCT tokens.

    79   Each DCT token has some fixed number of additional bits (possibly 0) stored

    80    after the token itself, containing, for example, coefficient magnitude,

    81    sign bits, etc.*/

    82 const unsigned char OC_DCT_TOKEN_EXTRA_BITS[TH_NDCT_TOKENS]={

    83   0,0,0,2,3,4,12,3,6,

    84   0,0,0,0,

    85   1,1,1,1,2,3,4,5,6,10,

    86   1,1,1,1,1,3,4,

    87   2,3

    88 };

    92 int oc_ilog(unsigned _v){

    93   int ret;

    94   for(ret=0;_v;ret++)_v>>=1;

    95   return ret;

    96 }

   100 void *oc_aligned_malloc(size_t _sz,size_t _align){

   101   unsigned char *p;

   102   if(_align-1>UCHAR_MAX||(_align&_align-1)||_sz>~(size_t)0-_align)return NULL;

   103   p=(unsigned char *)_ogg_malloc(_sz+_align);

   104   if(p!=NULL){

   105     int offs;

   106     offs=((p-(unsigned char *)0)-1&_align-1);

   107     p[offs]=offs;

   108     p+=offs+1;

   109   }

   110   return p;

   111 }

   113 void oc_aligned_free(void *_ptr){

   114   unsigned char *p;

   115   p=(unsigned char *)_ptr;

   116   if(p!=NULL){

   117     int offs;

   118     offs=*--p;

   119     _ogg_free(p-offs);

   120   }

   121 }

   124 void **oc_malloc_2d(size_t _height,size_t _width,size_t _sz){

   125   size_t  rowsz;

   126   size_t  colsz;

   127   size_t  datsz;

   128   char   *ret;

   129   colsz=_height*sizeof(void *);

   130   rowsz=_sz*_width;

   131   datsz=rowsz*_height;

   132   /*Alloc array and row pointers.*/

   133   ret=(char *)_ogg_malloc(datsz+colsz);

   134   if(ret==NULL)return NULL;

   135   /*Initialize the array.*/

   136   if(ret!=NULL){

   137     size_t   i;

   138     void   **p;

   139     char    *datptr;

   140     p=(void **)ret;

   141     i=_height;

   142     for(datptr=ret+colsz;i-->0;p++,datptr+=rowsz)*p=(void *)datptr;

   143   }

   144   return (void **)ret;

   145 }

   147 void **oc_calloc_2d(size_t _height,size_t _width,size_t _sz){

   148   size_t  colsz;

   149   size_t  rowsz;

   150   size_t  datsz;

   151   char   *ret;

   152   colsz=_height*sizeof(void *);

   153   rowsz=_sz*_width;

   154   datsz=rowsz*_height;

   155   /*Alloc array and row pointers.*/

   156   ret=(char *)_ogg_calloc(datsz+colsz,1);

   157   if(ret==NULL)return NULL;

   158   /*Initialize the array.*/

   159   if(ret!=NULL){

   160     size_t   i;

   161     void   **p;

   162     char    *datptr;

   163     p=(void **)ret;

   164     i=_height;

   165     for(datptr=ret+colsz;i-->0;p++,datptr+=rowsz)*p=(void *)datptr;

   166   }

   167   return (void **)ret;

   168 }

   170 void oc_free_2d(void *_ptr){

   171   _ogg_free(_ptr);

   172 }

   174 /*Fills in a Y'CbCr buffer with a pointer to the image data in the first

   175    buffer, but with the opposite vertical orientation.

   176   _dst: The destination buffer.

   177         This can be the same as _src.

   178   _src: The source buffer.*/

   179 void oc_ycbcr_buffer_flip(th_ycbcr_buffer _dst,

   180  const th_ycbcr_buffer _src){

   181   int pli;

   182   for(pli=0;pli<3;pli++){

   183     _dst[pli].width=_src[pli].width;

   184     _dst[pli].height=_src[pli].height;

   185     _dst[pli].stride=-_src[pli].stride;

   186     _dst[pli].data=_src[pli].data

   187      +(1-_dst[pli].height)*(ptrdiff_t)_dst[pli].stride;

   188   }

   189 }

   191 const char *th_version_string(void){

   192   return OC_VENDOR_STRING;

   193 }

   195 ogg_uint32_t th_version_number(void){

   196   return (TH_VERSION_MAJOR<<16)+(TH_VERSION_MINOR<<8)+TH_VERSION_SUB;

   197 }

   199 /*Determines the packet type.

   200   Note that this correctly interprets a 0-byte packet as a video data packet.

   201   Return: 1 for a header packet, 0 for a data packet.*/

   202 int th_packet_isheader(ogg_packet *_op){

   203   return _op->bytes>0?_op->packet[0]>>7:0;

   204 }

   206 /*Determines the frame type of a video data packet.

   207   Note that this correctly interprets a 0-byte packet as a delta frame.

   208   Return: 1 for a key frame, 0 for a delta frame, and -1 for a header

   209            packet.*/

   210 int th_packet_iskeyframe(ogg_packet *_op){

   211   return _op->bytes<=0?0:_op->packet[0]&0x80?-1:!(_op->packet[0]&0x40);

   212 }

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