From bee2dc17af04285d02120013a1d046da8219305c Mon Sep 17 00:00:00 2001
From: Mark Thompson <129641948+NotherNgineer@users.noreply.github.com>
Date: Sat, 22 Jul 2023 09:12:35 -0500
Subject: [PATCH] Fixes to C8 capture support (#1290)

* Use divide vs shift in C16->C8 and C32->C16 conversion
* Color cyan for .C32 files
---
 firmware/application/apps/ui_fileman.hpp |  1 +
 firmware/application/io_convert.cpp      | 12 ++++++++----
 2 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/firmware/application/apps/ui_fileman.hpp b/firmware/application/apps/ui_fileman.hpp
index 13bd43b0..306a6354 100644
--- a/firmware/application/apps/ui_fileman.hpp
+++ b/firmware/application/apps/ui_fileman.hpp
@@ -76,6 +76,7 @@ class FileManBaseView : public View {
         {u".BMP", &bitmap_icon_file_image, ui::Color::green()},
         {u".C8", &bitmap_icon_file_iq, ui::Color::dark_cyan()},
         {u".C16", &bitmap_icon_file_iq, ui::Color::dark_cyan()},
+        {u".C32", &bitmap_icon_file_iq, ui::Color::dark_cyan()},
         {u".WAV", &bitmap_icon_file_wav, ui::Color::dark_magenta()},
         {u".PPL", &bitmap_icon_file_iq, ui::Color::white()},  // PPL is the file extension for playlist app
         {u"", &bitmap_icon_file, ui::Color::light_grey()}     // NB: Must be last.
diff --git a/firmware/application/io_convert.cpp b/firmware/application/io_convert.cpp
index 2c780804..00a09c78 100644
--- a/firmware/application/io_convert.cpp
+++ b/firmware/application/io_convert.cpp
@@ -34,9 +34,11 @@ void c16_to_c8(const void* buffer, File::Size bytes) {
     complex16_t* src = (complex16_t*)buffer;
     complex8_t* dest = (complex8_t*)buffer;
 
+    // Shift isn't used here because it would amplify noise at center freq since it's a signed number
+    // i.e. ((-1 >> 8) << 8) = -256, whereas (-1 / 256) * 256 = 0
     for (File::Size i = 0; i < bytes / sizeof(complex16_t); i++) {
-        auto re_out = src[i].real() >> 8;
-        auto im_out = src[i].imag() >> 8;
+        auto re_out = src[i].real() / 256;
+        auto im_out = src[i].imag() / 256;
         dest[i] = {(int8_t)re_out, (int8_t)im_out};
     }
 }
@@ -64,9 +66,11 @@ void c32_to_c16(const void* buffer, File::Size bytes) {
     complex32_t* src = (complex32_t*)buffer;
     complex16_t* dest = (complex16_t*)buffer;
 
+    // Shift isn't used here because it would amplify noise at center freq since it's a signed number
+    // i.e. ((-1 >> 16) << 16) = -65536, whereas (-1 / 65536) * 65536 = 0
     for (File::Size i = 0; i < bytes / sizeof(complex32_t); i++) {
-        auto re_out = src[i].real() >> 16;
-        auto im_out = src[i].imag() >> 16;
+        auto re_out = src[i].real() / 65536;
+        auto im_out = src[i].imag() / 65536;
         dest[i] = {(int8_t)re_out, (int8_t)im_out};
     }
 }