AJ_Status AJ_ASN1DecodeElement(DER_Element* der, uint8_t tag, DER_Element* out)
{
uint8_t tmp;
AJ_InfoPrintf(("AJ_ASN1DecodeElement(der=%p, tag=%x, out=%p)\n", der, tag, out));
if ((NULL == der) || (NULL == out)) {
return AJ_ERR_INVALID;
}
if ((NULL == der->data) || (0 == der->size)) {
return AJ_ERR_INVALID;
}
/*
* Decode tag and check it is what we expect
*/
tmp = *(der->data)++;
der->size--;
if (ASN_CONTEXT_SPECIFIC != (tmp & ASN_CONTEXT_SPECIFIC)) {
tmp &= 0x1F;
}
if (tmp != tag) {
return AJ_ERR_INVALID;
}
/*
* Decode size
*/
if (AJ_OK != DecodeLength(der, out)) {
return AJ_ERR_INVALID;
}
der->data += out->size;
der->size -= out->size;
return AJ_OK;
}
void DecodeAPP0(void) {
int length;
length = DecodeLength();
if(length < 14) {
if(debug>-1)
fprintf(stderr,"APP0 marker too short\n");
} else {
if(buf[0] == 0x4A && buf[1] == 0x46 &&
buf[2] == 0x49 && buf[3] == 0x46 &&
buf[4] == 0) {
found_jfif = 1;
}
}
SKIP(length-2);
}
void DecodeAPP14(void) {
int length;
length = DecodeLength();
if(length < 12) {
if(debug>-1)
fprintf(stderr,"APP14 marker too short\n");
} else {
if(buf[0] == 0x41 && buf[1] == 0x64 &&
buf[2] == 0x6F && buf[3] == 0x62 &&
buf[4] == 0x65) {
found_adobe = 1;
adobe_transform = buf[11];
}
}
SKIP(length-2);
}
void DecodeSOF(void) {
int length; int i;
length = DecodeLength();
imgh = Decode16(buf+1);
imgw = Decode16(buf+3);
comp = buf[5];
if(comp*3+8 != length) {
if(debug>-1)
fprintf(stderr,"SOF marker length mismatch\n");
} else {
for(i=0; i<__MIN(comp,4); i++) {
compid[i] = *(buf+6+i*3); // -2 bytes for length field
}
}
SKIP(length-2);
}
void SkipMarker(void) {
int length;
length = DecodeLength();
SKIP(length-2);
}