MLECO-2723: Updating RNNoise to use 512 frame size

* CMSIS-DSP acceleration will now be used for FFT in RNNoise pre-processing
* PESQ scores tested and similar

Signed-off-by: Richard Burton <richard.burton@arm.com>
Change-Id: Ifeebc041f58867909b27c948950e08f8f39ef276
diff --git a/source/use_case/noise_reduction/usecase.cmake b/source/use_case/noise_reduction/usecase.cmake
index 14cff17..60f92ae 100644
--- a/source/use_case/noise_reduction/usecase.cmake
+++ b/source/use_case/noise_reduction/usecase.cmake
@@ -53,8 +53,8 @@
     kaiser_best
     STRING)
 
-USER_OPTION(${use_case}_AUDIO_MIN_SAMPLES "Specify the minimum number of samples to use. Default is 480, if the audio is shorter it will be automatically padded."
-    480
+USER_OPTION(${use_case}_AUDIO_MIN_SAMPLES "Specify the minimum number of samples to use. Default is 512, if the audio is shorter it will be automatically padded."
+    512
     STRING)
 
 # Generate input files from audio wav files
@@ -69,8 +69,8 @@
 
 set(EXTRA_MODEL_CODE
     "/* Model parameters for ${use_case} */"
-    "extern const int        g_FrameLength         = 480"
-    "extern const int        g_FrameStride         = 480"
+    "extern const int        g_FrameLength         = 512"
+    "extern const int        g_FrameStride         = 512"
     "extern const uint32_t   g_NumInputFeatures    = 42*1"  # Single time-step input of 42 features.
     )