From c85d8206e209bcb69ebb6db08d5731be3f3d7bf4 Mon Sep 17 00:00:00 2001
From: louis <louis@xmos.com>
Date: Mon, 13 Feb 2017 08:37:07 +0000
Subject: [PATCH] Re-add support for I2S_DOWNSAMPLE_MONO_IN.

---
 module_usb_audio/audio_io/audio_io.xc | 9 ++++-----
 module_usb_audio/devicedefines.h      | 4 +---
 2 files changed, 5 insertions(+), 8 deletions(-)

diff --git a/module_usb_audio/audio_io/audio_io.xc b/module_usb_audio/audio_io/audio_io.xc
index f7f3d621..c7884a5f 100755
--- a/module_usb_audio/audio_io/audio_io.xc
+++ b/module_usb_audio/audio_io/audio_io.xc
@@ -507,11 +507,10 @@ unsigned static deliver(chanend c_out, chanend ?c_spd_out,
     {
         long long doubleWordAlignmentEnsured;
         /* [Number of I2S channels][Number of samples/phases][Taps per phase] */
-        /* TODO: Fix for mono */
-        int32_t delayLine[I2S_CHANS_ADC][USB_TO_AUD_RATIO][24];
+        int32_t delayLine[I2S_DOWNSAMPLE_CHANS_IN][USB_TO_AUD_RATIO][24];
     } i2sInDs3;
     memset(&i2sInDs3.delayLine, 0, sizeof i2sInDs3.delayLine);
-    int64_t i2sInDs3Sum[I2S_CHANS_ADC];
+    int64_t i2sInDs3Sum[I2S_DOWNSAMPLE_CHANS_IN];
 
     union i2sOutUs3
     {
@@ -854,7 +853,7 @@ unsigned static deliver(chanend c_out, chanend ?c_spd_out,
 
                     sample = bitrev(sample);
                     int chanIndex = ((frameCount-1)&(I2S_CHANS_PER_FRAME-1))+i; // channels 1, 3, 5.. on each line.
-#if (USB_TO_AUD_RATIO > 1)
+#if (USB_TO_AUD_RATIO > 1 && !I2S_DOWNSAMPLE_MONO_IN)
                     if ((USB_TO_AUD_RATIO - 1) == usbToAudioRatioCounter)
                     {
                         samplesIn[buffIndex][chanIndex] =
@@ -875,7 +874,7 @@ unsigned static deliver(chanend c_out, chanend ?c_spd_out,
                     }
 #else
                     samplesIn[buffIndex][chanIndex] = sample;
-#endif /* (USB_TO_AUD_RATIO > 1) */
+#endif /* (USB_TO_AUD_RATIO > 1) && !I2S_DOWNSAMPLE_MONO_IN */
                 }
 #endif
 
diff --git a/module_usb_audio/devicedefines.h b/module_usb_audio/devicedefines.h
index eebb42ae..12a5058c 100644
--- a/module_usb_audio/devicedefines.h
+++ b/module_usb_audio/devicedefines.h
@@ -154,7 +154,6 @@
  * @brief Only downsample one channel per input I2S frame.
  *
  * Default: 0 i.e. mono mode is disabled, all input channels will be downsampled.
- * TODO: Remove this define or reintroduce support in audio_io.xc
  */
 #ifndef I2S_DOWNSAMPLE_MONO_IN
 #define I2S_DOWNSAMPLE_MONO_IN (0)
@@ -164,7 +163,6 @@
  * @brief Number of incoming (device to host) I2S channels to downsample.
  *
  * Default: The number of I2S incoming channels, or half this if mono downsampling is enabled.
- * TODO: Remove this define or reintroduce support in audio_io.xc
  */
 #if (I2S_DOWNSAMPLE_MONO_IN == 1)
     #define I2S_DOWNSAMPLE_CHANS_IN (I2S_CHANS_ADC / 2)
@@ -172,7 +170,7 @@
         #error Mono I2S input downsampling is not avaliable in TDM mode
     #endif
 #else
-#define I2S_DOWNSAMPLE_CHANS_IN I2S_CHANS_ADC
+    #define I2S_DOWNSAMPLE_CHANS_IN I2S_CHANS_ADC
 #endif
 
 /**