/******************************************************************** * * * THIS FILE IS PART OF THE Ogg CONTAINER 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 OggVorbis SOURCE CODE IS (C) COPYRIGHT 1994-2010 * * by the Xiph.Org Foundation http://www.xiph.org/ * * * ******************************************************************** function: packing variable sized words into an octet stream last mod: $Id: bitwise.c 18051 2011-08-04 17:56:39Z giles $ ********************************************************************/ /* We're 'LSb' endian; if we write a word but read individual bits, then we'll read the lsb first */ #include #include #include #include "ogg.h" #define BUFFER_INCREMENT 256 static const unsigned long mask[]= {0x00000000,0x00000001,0x00000003,0x00000007,0x0000000f, 0x0000001f,0x0000003f,0x0000007f,0x000000ff,0x000001ff, 0x000003ff,0x000007ff,0x00000fff,0x00001fff,0x00003fff, 0x00007fff,0x0000ffff,0x0001ffff,0x0003ffff,0x0007ffff, 0x000fffff,0x001fffff,0x003fffff,0x007fffff,0x00ffffff, 0x01ffffff,0x03ffffff,0x07ffffff,0x0fffffff,0x1fffffff, 0x3fffffff,0x7fffffff,0xffffffff }; static const unsigned int mask8B[]= {0x00,0x80,0xc0,0xe0,0xf0,0xf8,0xfc,0xfe,0xff}; void oggpack_writeinit(oggpack_buffer *b){ memset(b,0,sizeof(*b)); b->ptr=b->buffer=_ogg_malloc(BUFFER_INCREMENT); b->buffer[0]='\0'; b->storage=BUFFER_INCREMENT; } void oggpackB_writeinit(oggpack_buffer *b){ oggpack_writeinit(b); } int oggpack_writecheck(oggpack_buffer *b){ if(!b->ptr || !b->storage)return -1; return 0; } int oggpackB_writecheck(oggpack_buffer *b){ return oggpack_writecheck(b); } void oggpack_writetrunc(oggpack_buffer *b,long bits){ long bytes=bits>>3; if(b->ptr){ bits-=bytes*8; b->ptr=b->buffer+bytes; b->endbit=bits; b->endbyte=bytes; *b->ptr&=mask[bits]; } } void oggpackB_writetrunc(oggpack_buffer *b,long bits){ long bytes=bits>>3; if(b->ptr){ bits-=bytes*8; b->ptr=b->buffer+bytes; b->endbit=bits; b->endbyte=bytes; *b->ptr&=mask8B[bits]; } } /* Takes only up to 32 bits. */ void oggpack_write(oggpack_buffer *b,unsigned long value,int bits){ if(bits<0 || bits>32) goto err; if(b->endbyte>=b->storage-4){ void *ret; if(!b->ptr)return; if(b->storage>LONG_MAX-BUFFER_INCREMENT) goto err; ret=_ogg_realloc(b->buffer,b->storage+BUFFER_INCREMENT); if(!ret) goto err; b->buffer=ret; b->storage+=BUFFER_INCREMENT; b->ptr=b->buffer+b->endbyte; } value&=mask[bits]; bits+=b->endbit; b->ptr[0]|=value<endbit; if(bits>=8){ b->ptr[1]=(unsigned char)(value>>(8-b->endbit)); if(bits>=16){ b->ptr[2]=(unsigned char)(value>>(16-b->endbit)); if(bits>=24){ b->ptr[3]=(unsigned char)(value>>(24-b->endbit)); if(bits>=32){ if(b->endbit) b->ptr[4]=(unsigned char)(value>>(32-b->endbit)); else b->ptr[4]=0; } } } } b->endbyte+=bits/8; b->ptr+=bits/8; b->endbit=bits&7; return; err: oggpack_writeclear(b); } /* Takes only up to 32 bits. */ void oggpackB_write(oggpack_buffer *b,unsigned long value,int bits){ if(bits<0 || bits>32) goto err; if(b->endbyte>=b->storage-4){ void *ret; if(!b->ptr)return; if(b->storage>LONG_MAX-BUFFER_INCREMENT) goto err; ret=_ogg_realloc(b->buffer,b->storage+BUFFER_INCREMENT); if(!ret) goto err; b->buffer=ret; b->storage+=BUFFER_INCREMENT; b->ptr=b->buffer+b->endbyte; } value=(value&mask[bits])<<(32-bits); bits+=b->endbit; b->ptr[0]|=value>>(24+b->endbit); if(bits>=8){ b->ptr[1]=(unsigned char)(value>>(16+b->endbit)); if(bits>=16){ b->ptr[2]=(unsigned char)(value>>(8+b->endbit)); if(bits>=24){ b->ptr[3]=(unsigned char)(value>>(b->endbit)); if(bits>=32){ if(b->endbit) b->ptr[4]=(unsigned char)(value<<(8-b->endbit)); else b->ptr[4]=0; } } } } b->endbyte+=bits/8; b->ptr+=bits/8; b->endbit=bits&7; return; err: oggpack_writeclear(b); } void oggpack_writealign(oggpack_buffer *b){ int bits=8-b->endbit; if(bits<8) oggpack_write(b,0,bits); } void oggpackB_writealign(oggpack_buffer *b){ int bits=8-b->endbit; if(bits<8) oggpackB_write(b,0,bits); } static void oggpack_writecopy_helper(oggpack_buffer *b, void *source, long bits, void (*w)(oggpack_buffer *, unsigned long, int), int msb){ unsigned char *ptr=(unsigned char *)source; long bytes=bits/8; bits-=bytes*8; if(b->endbit){ int i; /* unaligned copy. Do it the hard way. */ for(i=0;iendbyte+bytes+1>=b->storage){ void *ret; if(!b->ptr) goto err; if(b->endbyte+bytes+BUFFER_INCREMENT>b->storage) goto err; b->storage=b->endbyte+bytes+BUFFER_INCREMENT; ret=_ogg_realloc(b->buffer,b->storage); if(!ret) goto err; b->buffer=ret; b->ptr=b->buffer+b->endbyte; } memmove(b->ptr,source,bytes); b->ptr+=bytes; b->endbyte+=bytes; *b->ptr=0; } if(bits){ if(msb) w(b,(unsigned long)(ptr[bytes]>>(8-bits)),bits); else w(b,(unsigned long)(ptr[bytes]),bits); } return; err: oggpack_writeclear(b); } void oggpack_writecopy(oggpack_buffer *b,void *source,long bits){ oggpack_writecopy_helper(b,source,bits,oggpack_write,0); } void oggpackB_writecopy(oggpack_buffer *b,void *source,long bits){ oggpack_writecopy_helper(b,source,bits,oggpackB_write,1); } void oggpack_reset(oggpack_buffer *b){ if(!b->ptr)return; b->ptr=b->buffer; b->buffer[0]=0; b->endbit=b->endbyte=0; } void oggpackB_reset(oggpack_buffer *b){ oggpack_reset(b); } void oggpack_writeclear(oggpack_buffer *b){ if(b->buffer)_ogg_free(b->buffer); memset(b,0,sizeof(*b)); } void oggpackB_writeclear(oggpack_buffer *b){ oggpack_writeclear(b); } void oggpack_readinit(oggpack_buffer *b,unsigned char *buf,int bytes){ memset(b,0,sizeof(*b)); b->buffer=b->ptr=buf; b->storage=bytes; } void oggpackB_readinit(oggpack_buffer *b,unsigned char *buf,int bytes){ oggpack_readinit(b,buf,bytes); } /* Read in bits without advancing the bitptr; bits <= 32 */ long oggpack_look(oggpack_buffer *b,int bits){ unsigned long ret; unsigned long m; if(bits<0 || bits>32) return -1; m=mask[bits]; bits+=b->endbit; if(b->endbyte >= b->storage-4){ /* not the main path */ if(b->endbyte > b->storage-((bits+7)>>3)) return -1; /* special case to avoid reading b->ptr[0], which might be past the end of the buffer; also skips some useless accounting */ else if(!bits)return(0L); } ret=b->ptr[0]>>b->endbit; if(bits>8){ ret|=b->ptr[1]<<(8-b->endbit); if(bits>16){ ret|=b->ptr[2]<<(16-b->endbit); if(bits>24){ ret|=b->ptr[3]<<(24-b->endbit); if(bits>32 && b->endbit) ret|=b->ptr[4]<<(32-b->endbit); } } } return(m&ret); } /* Read in bits without advancing the bitptr; bits <= 32 */ long oggpackB_look(oggpack_buffer *b,int bits){ unsigned long ret; int m=32-bits; if(m<0 || m>32) return -1; bits+=b->endbit; if(b->endbyte >= b->storage-4){ /* not the main path */ if(b->endbyte > b->storage-((bits+7)>>3)) return -1; /* special case to avoid reading b->ptr[0], which might be past the end of the buffer; also skips some useless accounting */ else if(!bits)return(0L); } ret=b->ptr[0]<<(24+b->endbit); if(bits>8){ ret|=b->ptr[1]<<(16+b->endbit); if(bits>16){ ret|=b->ptr[2]<<(8+b->endbit); if(bits>24){ ret|=b->ptr[3]<<(b->endbit); if(bits>32 && b->endbit) ret|=b->ptr[4]>>(8-b->endbit); } } } return ((ret&0xffffffff)>>(m>>1))>>((m+1)>>1); } long oggpack_look1(oggpack_buffer *b){ if(b->endbyte>=b->storage)return(-1); return((b->ptr[0]>>b->endbit)&1); } long oggpackB_look1(oggpack_buffer *b){ if(b->endbyte>=b->storage)return(-1); return((b->ptr[0]>>(7-b->endbit))&1); } void oggpack_adv(oggpack_buffer *b,int bits){ bits+=b->endbit; if(b->endbyte > b->storage-((bits+7)>>3)) goto overflow; b->ptr+=bits/8; b->endbyte+=bits/8; b->endbit=bits&7; return; overflow: b->ptr=NULL; b->endbyte=b->storage; b->endbit=1; } void oggpackB_adv(oggpack_buffer *b,int bits){ oggpack_adv(b,bits); } void oggpack_adv1(oggpack_buffer *b){ if(++(b->endbit)>7){ b->endbit=0; b->ptr++; b->endbyte++; } } void oggpackB_adv1(oggpack_buffer *b){ oggpack_adv1(b); } /* bits <= 32 */ long oggpack_read(oggpack_buffer *b,int bits){ long ret; unsigned long m; if(bits<0 || bits>32) goto err; m=mask[bits]; bits+=b->endbit; if(b->endbyte >= b->storage-4){ /* not the main path */ if(b->endbyte > b->storage-((bits+7)>>3)) goto overflow; /* special case to avoid reading b->ptr[0], which might be past the end of the buffer; also skips some useless accounting */ else if(!bits)return(0L); } ret=b->ptr[0]>>b->endbit; if(bits>8){ ret|=b->ptr[1]<<(8-b->endbit); if(bits>16){ ret|=b->ptr[2]<<(16-b->endbit); if(bits>24){ ret|=b->ptr[3]<<(24-b->endbit); if(bits>32 && b->endbit){ ret|=b->ptr[4]<<(32-b->endbit); } } } } ret&=m; b->ptr+=bits/8; b->endbyte+=bits/8; b->endbit=bits&7; return ret; overflow: err: b->ptr=NULL; b->endbyte=b->storage; b->endbit=1; return -1L; } /* bits <= 32 */ long oggpackB_read(oggpack_buffer *b,int bits){ long ret; long m=32-bits; if(m<0 || m>32) goto err; bits+=b->endbit; if(b->endbyte+4>=b->storage){ /* not the main path */ if(b->endbyte > b->storage-((bits+7)>>3)) goto overflow; /* special case to avoid reading b->ptr[0], which might be past the end of the buffer; also skips some useless accounting */ else if(!bits)return(0L); } ret=b->ptr[0]<<(24+b->endbit); if(bits>8){ ret|=b->ptr[1]<<(16+b->endbit); if(bits>16){ ret|=b->ptr[2]<<(8+b->endbit); if(bits>24){ ret|=b->ptr[3]<<(b->endbit); if(bits>32 && b->endbit) ret|=b->ptr[4]>>(8-b->endbit); } } } ret=((ret&0xffffffffUL)>>(m>>1))>>((m+1)>>1); b->ptr+=bits/8; b->endbyte+=bits/8; b->endbit=bits&7; return ret; overflow: err: b->ptr=NULL; b->endbyte=b->storage; b->endbit=1; return -1L; } long oggpack_read1(oggpack_buffer *b){ long ret; if(b->endbyte >= b->storage) goto overflow; ret=(b->ptr[0]>>b->endbit)&1; b->endbit++; if(b->endbit>7){ b->endbit=0; b->ptr++; b->endbyte++; } return ret; overflow: b->ptr=NULL; b->endbyte=b->storage; b->endbit=1; return -1L; } long oggpackB_read1(oggpack_buffer *b){ long ret; if(b->endbyte >= b->storage) goto overflow; ret=(b->ptr[0]>>(7-b->endbit))&1; b->endbit++; if(b->endbit>7){ b->endbit=0; b->ptr++; b->endbyte++; } return ret; overflow: b->ptr=NULL; b->endbyte=b->storage; b->endbit=1; return -1L; } long oggpack_bytes(oggpack_buffer *b){ return(b->endbyte+(b->endbit+7)/8); } long oggpack_bits(oggpack_buffer *b){ return(b->endbyte*8+b->endbit); } long oggpackB_bytes(oggpack_buffer *b){ return oggpack_bytes(b); } long oggpackB_bits(oggpack_buffer *b){ return oggpack_bits(b); } unsigned char *oggpack_get_buffer(oggpack_buffer *b){ return(b->buffer); } unsigned char *oggpackB_get_buffer(oggpack_buffer *b){ return oggpack_get_buffer(b); } /* Self test of the bitwise routines; everything else is based on them, so they damned well better be solid. */ #ifdef _V_SELFTEST #include static int ilog(unsigned int v){ int ret=0; while(v){ ret++; v>>=1; } return(ret); } oggpack_buffer o; oggpack_buffer r; void report(char *in){ fprintf(stderr,"%s",in); exit(1); } void cliptest(unsigned long *b,int vals,int bits,int *comp,int compsize){ long bytes,i; unsigned char *buffer; oggpack_reset(&o); for(i=0;i