Stack sizes for ASRC and SSRC in tests/examples seem incorrect.

[xross]

Stack sizes set as, for example:

int iSSRCStack[SRC_CHANNELS_PER_INSTANCE][SSRC_STACK_LENGTH_MULT * SRC_N_IN_SAMPLES]; // Buffers between processing stages

e.g.

lib_src/tests/ssrc_test/dut/ssrc_test.xc

Line 40 in 693ae0f

int ssrc_stack[SSRC_CHANNELS_PER_INSTANCE][SSRC_STACK_LENGTH_MULT * SSRC_N_IN_SAMPLES]; //Buffers between processing stages

Based on

lib_src/lib_src/src/multirate_hifi/ssrc/src_mrhf_ssrc.h

Line 34 in 693ae0f

#define SSRC_STACK_LENGTH_MULT (SSRC_N_CHANNELS * SSRC_N_IN_SAMPLES) // Multiplier for stack length (stack length = this value x the number of input samples to process)

I think they should just be:

int iSSRCStack[SRC_CHANNELS_PER_INSTANCE][SSRC_STACK_LENGTH_MULT]; // Buffers between processing stages

@ed-xmos any thoughts? I wonder if this crept in when adding support for multiple instances. Its unclear to me why each instance would need stack space related to the total channel count, not just the instance channel count.

[xross]

Following from this,

lib_src/tests/ssrc_test/dut/ssrc_test.xc

Line 14 in 693ae0f

#define SSRC_N_CHANNELS 2 //Total number of audio channels to be processed by SRC (minimum 1)

Should be set to CHANNELS_PER_INSTANCE as a separate define should be used for total SRC channel count.

[ed-xmos]

Stack sizes set as, for example:

int iSSRCStack[SRC_CHANNELS_PER_INSTANCE][SSRC_STACK_LENGTH_MULT * SRC_N_IN_SAMPLES]; // Buffers between processing stages

e.g.

lib_src/tests/ssrc_test/dut/ssrc_test.xc

Line 40 in 693ae0f

int ssrc_stack[SSRC_CHANNELS_PER_INSTANCE][SSRC_STACK_LENGTH_MULT * SSRC_N_IN_SAMPLES]; //Buffers between processing stages

Based on

lib_src/lib_src/src/multirate_hifi/ssrc/src_mrhf_ssrc.h

Line 34 in 693ae0f

#define SSRC_STACK_LENGTH_MULT (SSRC_N_CHANNELS * SSRC_N_IN_SAMPLES) // Multiplier for stack length (stack length = this value x the number of input samples to process)

I think they should just be:

int iSSRCStack[SRC_CHANNELS_PER_INSTANCE][SSRC_STACK_LENGTH_MULT]; // Buffers between processing stages

@ed-xmos any thoughts? I wonder if this crept in when adding support for multiple instances. Its unclear to me why each instance would need stack space related to the total channel count, not just the instance channel count.

I think you are right. Making the buffers too big silently cost some memory without causing any logical problems.