Hi Experts,
This is with reference to my earlier post on filtering with buffered DMAs: e2e.ti.com/.../536748
After plugging in the filter routine using DSPF_sp_fir_gen API, i get filtered outputs as expected in some cases. However there are periodic bleeps that happens in the background. Also, the filter routine (DSPF_sp_fir_gen + updating filter state ) works fine in non-real time. The issue is when the routine is plugged into the DMA based code.
I need clarification on a couple of questions, could you kindly help:
1] I see that the format of data in the buffer pointed to by rxBufPtr[lastFullRxBuf] is of the form [xxxx,0, xxxx,0, xxxx, 0, xxxx, 0...] considering 16 bit short array and "xxxx" being valid values. It's these values that i use as input to the filter routine DSPF_sp_fir_gen. Is this correct or do is there additional data interleaving of left and right channels that needs to be taken into consideration. The rest of the code the the mcaspPlayBk module remains "as-is" (i.e, WORDSIZE 16, SLOT_SIZE 16, NUM_I2S_CHANNELS 2)
2] The taps that are input to the filter DSPF_sp_fir_gen API are right now in the range [-1 to 1] floating point values. Are there any restrictions here.
3] Any inputs on why periodic bleeps appear in background? I presume the filter is meeting real-time as i do see predicted outputs for cases as well.
Thanks and any pointers/insights would be helpful.
Regards
Smita