static PyObject*
CPPMDecoder_decode(decoders_CPPMDecoder *self, PyObject *args) {
char* input_buffer;
#ifdef PY_SSIZE_T_CLEAN
Py_ssize_t input_len;
#else
int input_len;
#endif
uint8_t* output_buffer;
int output_len;
PyObject* decoded;
if (!PyArg_ParseTuple(args, "s#", &input_buffer, &input_len))
return NULL;
if (input_len % DVDCPXM_BLOCK_SIZE) {
PyErr_SetString(PyExc_ValueError,
"encoded block must be a multiple of 2048");
return NULL;
}
output_len = input_len;
output_buffer = malloc(sizeof(uint8_t) * output_len);
memcpy(output_buffer, input_buffer, input_len);
cppm_decrypt(&(self->decoder),
output_buffer,
output_len / DVDCPXM_BLOCK_SIZE,
1);
decoded = PyString_FromStringAndSize((char *)output_buffer,
(Py_ssize_t)output_len);
free(output_buffer);
return decoded;
}
static int
read_sector(DVDA_Sector_Reader* reader,
struct bs_buffer* sector)
{
if (reader->current.sector <= reader->end_sector) {
DVDA_AOB* aob = reader->current.aob;
static uint8_t sector_data[SECTOR_SIZE];
const size_t bytes_read = fread(sector_data,
sizeof(uint8_t),
SECTOR_SIZE,
aob->file);
buf_write(sector, sector_data, (uint32_t)bytes_read);
if (bytes_read == SECTOR_SIZE) {
/*sector read successfully*/
#ifdef HAS_UNPROT
/*unprotect if necessary*/
if (reader->cppm_decoder != NULL) {
cppm_decrypt(reader->cppm_decoder,
sector_data, 1, 1);
}
#endif
/*then move on to next sector*/
reader->current.sector++;
if (reader->current.sector > aob->end_sector) {
/*move on to next AOB in set, if any*/
if (reader->current.sector <= reader->end_sector) {
seek_sector(reader, reader->current.sector);
}
}
return 0;
} else {
/*I/O error reading sector*/
return 1;
}
} else {
/*no more sectors to read, so return EOF*/
return 0;
}
}
