/** number of allowed filters */
#define NUM_FILTERS 2
-/** The maximum number of taps in either the IIR or FIR filter;
- * I believe MLP actually specifies the maximum order for IIR filters as four,
- * and that the sum of the orders of both filters must be <= 8.
-*/
-#define MAX_FILTER_ORDER 8
+/** The maximum number of taps in IIR and FIR filters. */
+#define MAX_FIR_ORDER 8
+#define MAX_IIR_ORDER 4
/** Code that signals end of a stream. */
#define END_OF_STREAM 0xd234d234
uint8_t order; ///< number of taps in filter
uint8_t shift; ///< Right shift to apply to output of filter.
- int32_t coeff[MAX_FILTER_ORDER];
- int32_t state[MAX_FILTER_ORDER];
+ int32_t coeff[MAX_FIR_ORDER];
+ int32_t state[MAX_FIR_ORDER];
} FilterParams;
/** sample data coding information */
unsigned int channel, unsigned int filter)
{
FilterParams *fp = &m->channel_params[channel].filter_params[filter];
+ const int max_order = filter ? MAX_IIR_ORDER : MAX_FIR_ORDER;
const char fchar = filter ? 'I' : 'F';
int i, order;
assert(filter < 2);
order = get_bits(gbp, 4);
- if (order > MAX_FILTER_ORDER) {
+ if (order > max_order) {
av_log(m->avctx, AV_LOG_ERROR,
"%cIR filter order %d is greater than maximum %d.\n",
- fchar, order, MAX_FILTER_ORDER);
+ fchar, order, max_order);
return -1;
}
fp->order = order;
unsigned int channel)
{
SubStream *s = &m->substream[substr];
- int32_t filter_state_buffer[NUM_FILTERS][MAX_BLOCKSIZE + MAX_FILTER_ORDER];
+ int32_t filter_state_buffer[NUM_FILTERS][MAX_BLOCKSIZE + MAX_FIR_ORDER];
FilterParams *fp[NUM_FILTERS] = { &m->channel_params[channel].filter_params[FIR],
&m->channel_params[channel].filter_params[IIR], };
unsigned int filter_shift = fp[FIR]->shift;
for (j = 0; j < NUM_FILTERS; j++) {
memcpy(&filter_state_buffer[j][MAX_BLOCKSIZE], &fp[j]->state[0],
- MAX_FILTER_ORDER * sizeof(int32_t));
+ MAX_FIR_ORDER * sizeof(int32_t));
}
for (i = 0; i < s->blocksize; i++) {
for (j = 0; j < NUM_FILTERS; j++) {
memcpy(&fp[j]->state[0], &filter_state_buffer[j][index],
- MAX_FILTER_ORDER * sizeof(int32_t));
+ MAX_FIR_ORDER * sizeof(int32_t));
}
}