void Compression::AriVLD()
{
ac_decoder acd;
ac_model acm;
ac_decoder_init (&acd,(path + std::string(".ari")).c_str());
ac_model_init (&acm, NSYM1, NULL, ADAPT);
std::fstream rlc(path + std::string(".rlc"),std::ios::out);
while(loop_num){
char c = (char)ac_decode_symbol (&acd,&acm);
if(c == 'B'){
rlc << c;
rlc << std::endl;
}
else{
rlc << c;
}
--loop_num;
}
ac_decoder_done (&acd);
ac_model_done (&acm);
}
void mexFunction( int nlhs, mxArray *plhs[],
int nrhs, const mxArray*prhs[] )
{
/* retrive arguments */
if( nrhs<4 )
mexErrMsgTxt("4 input arguments are required.");
if( nlhs!=1 )
mexErrMsgTxt("1 output arguments are required.");
// first argument : input array
int n = mxGetM(prhs[0]);
int p = mxGetN(prhs[0]);
if( p>1 )
mexErrMsgTxt("Works only for vector arrays.");
int dir = (int) *mxGetPr(prhs[1]);
double* x = mxGetPr(prhs[0]);
if( mxGetM(prhs[3])!=2 && mxGetN(prhs[3])!=2 )
mexErrMsgTxt("known_bounds must be of size 2.");
int known_size = (int) *mxGetPr(prhs[2]);
// lower and upper bounds on the int to code
int known_a = (int) mxGetPr(prhs[3])[0];
int known_b = (int) mxGetPr(prhs[3])[1];
bool coding_size = true;
if( known_size>0 ) // the decoder will know the size and provide it
coding_size = false;
bool coding_bounds = false;
if( known_a==known_b && known_b==-1 )
coding_bounds = true; // the decoder will not know the bounds and provide it
if( dir==1 )
{
ac_encoder ace;
ac_model acm;
// compute range of the data
int a = 1<<20, b = -(1<<20);
for( int i=0; i<n; ++i )
{
if( x[i]<a )
a = (int) x[i];
if( x[i]>b )
b = (int) x[i];
}
int subrange = b-a+1;
// init
ac_encoder_init(&ace, filename);
ac_model_init(&acm, subrange, NULL, 1);
// code the size of the image and range
if( coding_size )
ac_encode_bytes(&ace, 4, &n);
else if( known_size!=n )
mexErrMsgTxt("The provided size does not match the real size.");
if( coding_bounds )
ac_encode_bytes(&ace, 4, &a);
else if( known_a>a )
mexErrMsgTxt("The provided bound does not match the real size.");
if( coding_bounds )
ac_encode_bytes(&ace, 4, &b);
else if( known_b<b )
mexErrMsgTxt("The provided bound does not match the real size.");
// perform coding
for( int i=0; i<n; ++i )
ac_encode_symbol(&ace, &acm, (int) (x[i]-a), 0);
// end coding
ac_encoder_done(&ace);
// reopen output file
FILE* fin = fopen( filename, "rb" );
if( fin==NULL )
mexErrMsgTxt("Cannot open file.");
int nbr_bytes = 0;
// compute number of bytes
while( getc(fin)!=EOF )
nbr_bytes++;
fclose(fin);
// retrieve results in byte
fin = fopen( filename, "rb" );
if( fin==NULL )
mexErrMsgTxt("Cannot open file.");
plhs[0] = mxCreateNumericMatrix( nbr_bytes, 1, mxDOUBLE_CLASS, mxREAL );
double* y = mxGetPr( plhs[0] );
for( int i=0; i<nbr_bytes; ++i )
{
y[i] = (double) getc(fin);
}
fclose(fin);
}
else
{
// write data to a file byte by byte
FILE* fin = fopen( filename, "wb" );
if( fin==NULL )
mexErrMsgTxt("Cannot open file.");
for( int i=0; i<n; ++i )
{
char c = (char) x[i];
fwrite( &c, sizeof(char), 1, fin );
}
fclose(fin);
// initialize coder
ac_decoder acd;
ac_model acm;
ac_decoder_init(&acd, filename);
// retrieve size of the data
int n, a, b;
if( coding_size )
ac_decode_bytes(&acd, 4, &n);
else
n = known_size;
if( coding_bounds )
ac_decode_bytes(&acd, 4, &a);
else
a = known_a;
if( coding_bounds )
ac_decode_bytes(&acd, 4, &b);
else
b = known_b;
int subrange = b-a+1;
ac_model_init(&acm, subrange, NULL, 1);
// retrieve the data
plhs[0] = mxCreateNumericMatrix( n, 1, mxDOUBLE_CLASS, mxREAL );
double* y = mxGetPr( plhs[0] );
for( int i=0; i<n; ++i )
y[i] = ac_decode_symbol(&acd, &acm, 0)+a;
}
}