void CompressFile( FILE *input, BIT_FILE *output, int argc, char *argv[] ){
/*
FILE *input;
BIT_FILE *output;
int argc;
char *argv[];
{
*/
int look_ahead[ BUFFER_SIZE ];
int index;
int i;
int run_length;
for ( i = 0 ; i < BUFFER_SIZE ; i++ )
look_ahead[ i ] = getc( input );
index = 0;
for ( ; ; ) {
if ( look_ahead[ index ] == EOF )
break;
/*
* If run has started, I handle it here. I sit in the do loop until
* the run is complete, loading new characters all the while.
*/
if ( silence_run( look_ahead, index ) ) {
run_length = 0;
do {
look_ahead[ index ++ ] = getc( input );
index &= BUFFER_MASK;
if ( ++run_length == 255 ) {
putc( SILENCE_CODE, output->file );
putc( 255, output->file );
run_length = 0;
}
} while ( !end_of_silence( look_ahead, index ) );
if ( run_length > 0 ) {
putc( SILENCE_CODE, output->file );
putc( run_length, output->file );
}
}
/*
* Eventually, any run of silence is over, and I output some plain codes.
* Any code that accidentally matches the silence code gets silently
* changed.
*/
if ( look_ahead[ index ]== SILENCE_CODE )
look_ahead[ index ]--;
putc( look_ahead[ index ], output->file );
look_ahead[ index++ ] = getc( input );
index = BUFFER_MASK;
}
while ( argc-- > 0 )
printf( "Unused argument: %s\n", *argv++ );
}
//void CompressFile( FILE *input, BIT_FILE *output, int argc, char *argv[] )
void CompressFile( FILE *input, BIT_FILE *output, int, char*[])
{
int look_ahead[ BUFFER_SIZE ];
int index;
int i;
int run_length;
//Update so Silence and Compand do not conflict
int silence_match[6] = { 31, 0, 31, 0, 30, 0 };
// Compand addition
int compress[ 256 ];
int steps;
int bits;
int value;
int k;
int j;
bits = 5;
steps = ( 1 << ( bits - 1 ) );
// OutputBits( output, (unsigned long) bits, 8 );
// OutputBits( output, (unsigned long) get_file_length( input ), 32 );
for ( k = steps ; k > 0; k-- ) {
value = (int)
( 128.0 * ( pow( 2.0, (double) k / steps ) - 1.0 ) + 0.5 );
for ( j = value ; j > 0 ; j-- ) {
compress[ j + 127 ] = k + steps - 1;
compress[ 128 - j ] = steps - k;
}
}
for ( i = 0 ; i < BUFFER_SIZE ; i++ )
look_ahead[ i ] = getc( input );
index = 0;
for ( ; ; )
{
if ( look_ahead[ index ] == EOF )
break;
/*
* If a run has started, I handle it here. I sit in the do loop until
* the run is complete, loading new characters all the while.
*/
if ( silence_run( look_ahead, index ) )
{
run_length = 0;
do {
look_ahead[ index++ ] = getc( input );
index &= BUFFER_MASK;
if ( ++run_length == 255 )
{
for( i=0; i<6; i++ )
{
OutputBits( output, (unsigned long) silence_match[i], bits );
}
OutputBits( output, (unsigned long) run_length, 8 );
}
} while ( !end_of_silence( look_ahead, index ) );
if ( run_length > 0 )
{
for( i=0; i<6;i++ )
{
OutputBits( output, (unsigned long) silence_match[i], bits );
}
OutputBits( output, (unsigned long) run_length, 8 );
}
}
/*
* Eventually, any run of silence is over, and I output some plain codes.
* Any code that accidentally matches the silence code gets silently changed.
*/
OutputBits( output, (unsigned long) compress[ look_ahead[ index ] ], bits );
look_ahead[ index++ ] = getc( input );
index &= BUFFER_MASK;
}
}
void codeSilence (void *inb, void *outb)
/***********************************************************************
Silence encoding, takes care of "silence" pieces
************************************************************************
inb input buffer
outb output buffer
***********************************************************************/
{
memBUFF *inbuff = (memBUFF *) inb;
memBUFF *outbuff = (memBUFF *) outb;
int look_ahead[LOOKAHSZ];
int index, i, run_length, flag;
/* preload the look ahead buffer */
for(i=0; i<LOOKAHSZ; i++)
if(buffGetc(inbuff, look_ahead[i]) == MEM_EOB)
break;
/* if not enough samples, no RLE */
if(i < LOOKAHSZ){
buffMerge(outbuff, inbuff);
return;
}
index = 0;
for(;;){
if(look_ahead[index] == MEM_EOB) break;
if(silence_run(look_ahead, index)){
run_length = 0;
do{
flag = buffGetc(inbuff, look_ahead[index]);
if(flag == MEM_EOB) look_ahead[index] = MEM_EOB;
index ++;
index &= LOOKAHMASK;
if(++run_length == MAXLENGTH){
buffPutc(outbuff, SILENCECODE);
buffPutc(outbuff, MAXLENGTH);
run_length = 0;
}
} while(!end_of_silence(look_ahead, index));
if(run_length > 0){
buffPutc(outbuff, SILENCECODE);
buffPutc(outbuff, run_length);
}
}
if(look_ahead[index] == MEM_EOB) break;
/* the silence code in the input get changed */
if(look_ahead[index] == SILENCECODE) look_ahead[index]++;
buffPutc(outbuff, look_ahead[index]);
/* get a new code */
flag = buffGetc(inbuff, look_ahead[index]);
if(flag == MEM_EOB) look_ahead[index] = MEM_EOB;
index ++;
index &= LOOKAHMASK;
}
}
void codeSilence (void *inb, void *outb)
/***********************************************************************
Silence encoding, takes care of "silence" pieces
************************************************************************
inb input buffer
outb output buffer
************************************************************************
Note: To avoid the inefficiency in encoding isolated 0's, I start a run
only when there are CODESTARTTHRSHOLD consective 0's. Therefore,
a look ahead buffer is needed. The run is stopped as soon as there
is a non-0 symbol.
***********************************************************************/
{
wpcBUFF *inbuff = (wpcBUFF *) inb;
wpcBUFF *outbuff = (wpcBUFF *) outb;
int look_ahead[CODELOOKAHSZ];
int index, i, run_length, flag;
/* preload the look ahead buffer */
for(i=0; i<CODELOOKAHSZ; i++)
if(buffGetc(inbuff, look_ahead[i]) == WPC_EOB)
break;
/* if not enough samples, no RLE */
if(i < CODELOOKAHSZ){
buffMerge(outbuff, inbuff);
return;
}
index = 0;
for(;;){
if(look_ahead[index] == WPC_EOB) break;
if(silence_run(look_ahead, index)){
run_length = 0;
do{
flag = buffGetc(inbuff, look_ahead[index]);
if(flag == WPC_EOB) look_ahead[index] = WPC_EOB;
index ++;
index &= CODELOOKAHMASK;
if(++run_length == CODEMAXLENGTH){
buffPutc(outbuff, CODESILENCECODE);
buffPutc(outbuff, CODEMAXLENGTH);
run_length = 0;
}
} while(!end_of_silence(look_ahead, index));
if(run_length > 0){
buffPutc(outbuff, CODESILENCECODE);
buffPutc(outbuff, run_length);
}
}
if(look_ahead[index] == WPC_EOB) break;
/* the silence code in the input get changed */
if(look_ahead[index] == CODESILENCECODE) look_ahead[index]++;
buffPutc(outbuff, look_ahead[index]);
/* get a new code */
flag = buffGetc(inbuff, look_ahead[index]);
if(flag == WPC_EOB) look_ahead[index] = WPC_EOB;
index ++;
index &= CODELOOKAHMASK;
}
}