bitwise.c

mediastreamer2是开源的网络传输媒体流的库

  b->endbit++;
  if(b->endbit>7){
    b->endbit=0;
    b->ptr++;
    b->endbyte++;
  }
  return(ret);
}

long oggpackB_read1(oggpack_buffer *b){
  long ret;
  
  if(b->endbyte>=b->storage){
    /* not the main path */
    ret=-1L;
    goto overflow;
  }

  ret=(b->ptr[0]>>(7-b->endbit))&1;
  
 overflow:

  b->endbit++;
  if(b->endbit>7){
    b->endbit=0;
    b->ptr++;
    b->endbyte++;
  }
  return(ret);
}

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 <stdio.h>

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<vals;i++)
    oggpack_write(&o,b[i],bits?bits:ilog(b[i]));
  buffer=oggpack_get_buffer(&o);
  bytes=oggpack_bytes(&o);
  if(bytes!=compsize)report("wrong number of bytes!\n");
  for(i=0;i<bytes;i++)if(buffer[i]!=comp[i]){
    for(i=0;i<bytes;i++)fprintf(stderr,"%x %x\n",(int)buffer[i],(int)comp[i]);
    report("wrote incorrect value!\n");
  }
  oggpack_readinit(&r,buffer,bytes);
  for(i=0;i<vals;i++){
    int tbit=bits?bits:ilog(b[i]);
    if(oggpack_look(&r,tbit)==-1)
      report("out of data!\n");
    if(oggpack_look(&r,tbit)!=(b[i]&mask[tbit]))
      report("looked at incorrect value!\n");
    if(tbit==1)
      if(oggpack_look1(&r)!=(b[i]&mask[tbit]))
	report("looked at single bit incorrect value!\n");
    if(tbit==1){
      if(oggpack_read1(&r)!=(b[i]&mask[tbit]))
	report("read incorrect single bit value!\n");
    }else{
    if(oggpack_read(&r,tbit)!=(b[i]&mask[tbit]))
      report("read incorrect value!\n");
    }
  }
  if(oggpack_bytes(&r)!=bytes)report("leftover bytes after read!\n");
}

void cliptestB(unsigned long *b,int vals,int bits,int *comp,int compsize){
  long bytes,i;
  unsigned char *buffer;
  
  oggpackB_reset(&o);
  for(i=0;i<vals;i++)
    oggpackB_write(&o,b[i],bits?bits:ilog(b[i]));
  buffer=oggpackB_get_buffer(&o);
  bytes=oggpackB_bytes(&o);
  if(bytes!=compsize)report("wrong number of bytes!\n");
  for(i=0;i<bytes;i++)if(buffer[i]!=comp[i]){
    for(i=0;i<bytes;i++)fprintf(stderr,"%x %x\n",(int)buffer[i],(int)comp[i]);
    report("wrote incorrect value!\n");
  }
  oggpackB_readinit(&r,buffer,bytes);
  for(i=0;i<vals;i++){
    int tbit=bits?bits:ilog(b[i]);
    if(oggpackB_look(&r,tbit)==-1)
      report("out of data!\n");
    if(oggpackB_look(&r,tbit)!=(b[i]&mask[tbit]))
      report("looked at incorrect value!\n");
    if(tbit==1)
      if(oggpackB_look1(&r)!=(b[i]&mask[tbit]))
	report("looked at single bit incorrect value!\n");
    if(tbit==1){
      if(oggpackB_read1(&r)!=(b[i]&mask[tbit]))
	report("read incorrect single bit value!\n");
    }else{
    if(oggpackB_read(&r,tbit)!=(b[i]&mask[tbit]))
      report("read incorrect value!\n");
    }
  }
  if(oggpackB_bytes(&r)!=bytes)report("leftover bytes after read!\n");
}

int main(void){
  unsigned char *buffer;
  long bytes,i;
  static unsigned long testbuffer1[]=
    {18,12,103948,4325,543,76,432,52,3,65,4,56,32,42,34,21,1,23,32,546,456,7,
       567,56,8,8,55,3,52,342,341,4,265,7,67,86,2199,21,7,1,5,1,4};
  int test1size=43;

  static unsigned long testbuffer2[]=
    {216531625L,1237861823,56732452,131,3212421,12325343,34547562,12313212,
       1233432,534,5,346435231,14436467,7869299,76326614,167548585,
       85525151,0,12321,1,349528352};
  int test2size=21;

  static unsigned long testbuffer3[]=
    {1,0,14,0,1,0,12,0,1,0,0,0,1,1,0,1,0,1,0,1,0,1,0,1,0,1,0,0,1,1,1,1,1,0,0,1,
       0,1,30,1,1,1,0,0,1,0,0,0,12,0,11,0,1,0,0,1};
  int test3size=56;

  static unsigned long large[]=
    {2136531625L,2137861823,56732452,131,3212421,12325343,34547562,12313212,
       1233432,534,5,2146435231,14436467,7869299,76326614,167548585,
       85525151,0,12321,1,2146528352};

  int onesize=33;
  static int one[33]={146,25,44,151,195,15,153,176,233,131,196,65,85,172,47,40,
                    34,242,223,136,35,222,211,86,171,50,225,135,214,75,172,
                    223,4};
  static int oneB[33]={150,101,131,33,203,15,204,216,105,193,156,65,84,85,222,
		       8,139,145,227,126,34,55,244,171,85,100,39,195,173,18,
		       245,251,128};

  int twosize=6;
  static int two[6]={61,255,255,251,231,29};
  static int twoB[6]={247,63,255,253,249,120};

  int threesize=54;
  static int three[54]={169,2,232,252,91,132,156,36,89,13,123,176,144,32,254,
                      142,224,85,59,121,144,79,124,23,67,90,90,216,79,23,83,
                      58,135,196,61,55,129,183,54,101,100,170,37,127,126,10,
                      100,52,4,14,18,86,77,1};
  static int threeB[54]={206,128,42,153,57,8,183,251,13,89,36,30,32,144,183,
			 130,59,240,121,59,85,223,19,228,180,134,33,107,74,98,
			 233,253,196,135,63,2,110,114,50,155,90,127,37,170,104,
			 200,20,254,4,58,106,176,144,0};

  int foursize=38;
  static int four[38]={18,6,163,252,97,194,104,131,32,1,7,82,137,42,129,11,72,
                     132,60,220,112,8,196,109,64,179,86,9,137,195,208,122,169,
                     28,2,133,0,1};
  static int fourB[38]={36,48,102,83,243,24,52,7,4,35,132,10,145,21,2,93,2,41,
			1,219,184,16,33,184,54,149,170,132,18,30,29,98,229,67,
			129,10,4,32};

  int fivesize=45;
  static int five[45]={169,2,126,139,144,172,30,4,80,72,240,59,130,218,73,62,
                     241,24,210,44,4,20,0,248,116,49,135,100,110,130,181,169,
                     84,75,159,2,1,0,132,192,8,0,0,18,22};
  static int fiveB[45]={1,84,145,111,245,100,128,8,56,36,40,71,126,78,213,226,
			124,105,12,0,133,128,0,162,233,242,67,152,77,205,77,
			172,150,169,129,79,128,0,6,4,32,0,27,9,0};

  int sixsize=7;
  static int six[7]={17,177,170,242,169,19,148};
  static int sixB[7]={136,141,85,79,149,200,41};

  /* Test read/write together */
  /* Later we test against pregenerated bitstreams */
  oggpack_writeinit(&o);

  fprintf(stderr,"\nSmall preclipped packing (LSb): ");
  cliptest(testbuffer1,test1size,0,one,onesize);
  fprintf(stderr,"ok.");

  fprintf(stderr,"\nNull bit call (LSb): ");
  cliptest(testbuffer3,test3size,0,two,twosize);
  fprintf(stderr,"ok.");

  fprintf(stderr,"\nLarge preclipped packing (LSb): ");
  cliptest(testbuffer2,test2size,0,three,threesize);
  fprintf(stderr,"ok.");

  fprintf(stderr,"\n32 bit preclipped packing (LSb): ");
  oggpack_reset(&o);
  for(i=0;i<test2size;i++)
    oggpack_write(&o,large[i],32);
  buffer=oggpack_get_buffer(&o);
  bytes=oggpack_bytes(&o);
  oggpack_readinit(&r,buffer,bytes);
  for(i=0;i<test2size;i++){
    if(oggpack_look(&r,32)==-1)report("out of data. failed!");
    if(oggpack_look(&r,32)!=large[i]){
      fprintf(stderr,"%ld != %ld (%lx!=%lx):",oggpack_look(&r,32),large[i],
	      oggpack_look(&r,32),large[i]);
      report("read incorrect value!\n");
    }
    oggpack_adv(&r,32);
  }
  if(oggpack_bytes(&r)!=bytes)report("leftover bytes after read!\n");
  fprintf(stderr,"ok.");

  fprintf(stderr,"\nSmall unclipped packing (LSb): ");
  cliptest(testbuffer1,test1size,7,four,foursize);
  fprintf(stderr,"ok.");

  fprintf(stderr,"\nLarge unclipped packing (LSb): ");
  cliptest(testbuffer2,test2size,17,five,fivesize);
  fprintf(stderr,"ok.");

  fprintf(stderr,"\nSingle bit unclipped packing (LSb): ");
  cliptest(testbuffer3,test3size,1,six,sixsize);
  fprintf(stderr,"ok.");

  fprintf(stderr,"\nTesting read past end (LSb): ");
  oggpack_readinit(&r,"\0\0\0\0\0\0\0\0",8);
  for(i=0;i<64;i++){
    if(oggpack_read(&r,1)!=0){
      fprintf(stderr,"failed; got -1 prematurely.\n");
      exit(1);
    }
  }
  if(oggpack_look(&r,1)!=-1 ||
     oggpack_read(&r,1)!=-1){
      fprintf(stderr,"failed; read past end without -1.\n");
      exit(1);
  }
  oggpack_readinit(&r,"\0\0\0\0\0\0\0\0",8);
  if(oggpack_read(&r,30)!=0 || oggpack_read(&r,16)!=0){
      fprintf(stderr,"failed 2; got -1 prematurely.\n");
      exit(1);
  }

  if(oggpack_look(&r,18)!=0 ||
     oggpack_look(&r,18)!=0){
    fprintf(stderr,"failed 3; got -1 prematurely.\n");
      exit(1);
  }
  if(oggpack_look(&r,19)!=-1 ||
     oggpack_look(&r,19)!=-1){
    fprintf(stderr,"failed; read past end without -1.\n");
      exit(1);
  }
  if(oggpack_look(&r,32)!=-1 ||
     oggpack_look(&r,32)!=-1){
    fprintf(stderr,"failed; read past end without -1.\n");
      exit(1);
  }
  oggpack_writeclear(&o);
  fprintf(stderr,"ok.\n");

  /********** lazy, cut-n-paste retest with MSb packing ***********/

  /* Test read/write together */
  /* Later we test against pregenerated bitstreams */
  oggpackB_writeinit(&o);

  fprintf(stderr,"\nSmall preclipped packing (MSb): ");
  cliptestB(testbuffer1,test1size,0,oneB,onesize);
  fprintf(stderr,"ok.");

  fprintf(stderr,"\nNull bit call (MSb): ");
  cliptestB(testbuffer3,test3size,0,twoB,twosize);
  fprintf(stderr,"ok.");

  fprintf(stderr,"\nLarge preclipped packing (MSb): ");
  cliptestB(testbuffer2,test2size,0,threeB,threesize);
  fprintf(stderr,"ok.");

  fprintf(stderr,"\n32 bit preclipped packing (MSb): ");
  oggpackB_reset(&o);
  for(i=0;i<test2size;i++)
    oggpackB_write(&o,large[i],32);
  buffer=oggpackB_get_buffer(&o);
  bytes=oggpackB_bytes(&o);
  oggpackB_readinit(&r,buffer,bytes);
  for(i=0;i<test2size;i++){
    if(oggpackB_look(&r,32)==-1)report("out of data. failed!");
    if(oggpackB_look(&r,32)!=large[i]){
      fprintf(stderr,"%ld != %ld (%lx!=%lx):",oggpackB_look(&r,32),large[i],
	      oggpackB_look(&r,32),large[i]);
      report("read incorrect value!\n");
    }
    oggpackB_adv(&r,32);
  }
  if(oggpackB_bytes(&r)!=bytes)report("leftover bytes after read!\n");
  fprintf(stderr,"ok.");

  fprintf(stderr,"\nSmall unclipped packing (MSb): ");
  cliptestB(testbuffer1,test1size,7,fourB,foursize);
  fprintf(stderr,"ok.");

  fprintf(stderr,"\nLarge unclipped packing (MSb): ");
  cliptestB(testbuffer2,test2size,17,fiveB,fivesize);
  fprintf(stderr,"ok.");

  fprintf(stderr,"\nSingle bit unclipped packing (MSb): ");
  cliptestB(testbuffer3,test3size,1,sixB,sixsize);
  fprintf(stderr,"ok.");

  fprintf(stderr,"\nTesting read past end (MSb): ");
  oggpackB_readinit(&r,"\0\0\0\0\0\0\0\0",8);
  for(i=0;i<64;i++){
    if(oggpackB_read(&r,1)!=0){
      fprintf(stderr,"failed; got -1 prematurely.\n");
      exit(1);
    }
  }
  if(oggpackB_look(&r,1)!=-1 ||
     oggpackB_read(&r,1)!=-1){
      fprintf(stderr,"failed; read past end without -1.\n");
      exit(1);
  }
  oggpackB_readinit(&r,"\0\0\0\0\0\0\0\0",8);
  if(oggpackB_read(&r,30)!=0 || oggpackB_read(&r,16)!=0){
      fprintf(stderr,"failed 2; got -1 prematurely.\n");
      exit(1);
  }

  if(oggpackB_look(&r,18)!=0 ||
     oggpackB_look(&r,18)!=0){
    fprintf(stderr,"failed 3; got -1 prematurely.\n");
      exit(1);
  }
  if(oggpackB_look(&r,19)!=-1 ||
     oggpackB_look(&r,19)!=-1){
    fprintf(stderr,"failed; read past end without -1.\n");
      exit(1);
  }
  if(oggpackB_look(&r,32)!=-1 ||
     oggpackB_look(&r,32)!=-1){
    fprintf(stderr,"failed; read past end without -1.\n");
      exit(1);
  }
  oggpackB_writeclear(&o);
  fprintf(stderr,"ok.\n\n");


  return(0);
}  
#endif  /* _V_SELFTEST */

#undef BUFFER_INCREMENT