refactor(session): decode RFX to RgbX

Decode to the desired format, instead of converting from BgrX to the
DecodedImage format (typically RgbA) when applying the tile / drawing.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>

crates/ironrdp-graphics/src/color_conversion.rs

@@ -2,7 +2,7 @@ use std::io;
 
 use yuvutils_rs::{
     rdp_abgr_to_yuv444, rdp_argb_to_yuv444, rdp_bgra_to_yuv444, rdp_rgba_to_yuv444, rdp_yuv444_to_argb,
-    rdp_yuv444_to_bgra, BufferStoreMut, YuvPlanarImage, YuvPlanarImageMut,
+    rdp_yuv444_to_rgba, BufferStoreMut, YuvPlanarImage, YuvPlanarImageMut,
 };
 
 use crate::image_processing::PixelFormat;
@@ -24,7 +24,7 @@ pub fn ycbcr_to_argb(input: YCbCrBuffer<'_>, output: &mut [u8]) -> io::Result<()
     rdp_yuv444_to_argb(&planar, output, len).map_err(io::Error::other)
 }
 
-pub fn ycbcr_to_bgra(input: YCbCrBuffer<'_>, output: &mut [u8]) -> io::Result<()> {
+pub fn ycbcr_to_rgba(input: YCbCrBuffer<'_>, output: &mut [u8]) -> io::Result<()> {
     let len = u32::try_from(output.len()).map_err(io::Error::other)?;
     let width = len / 4;
     let planar = YuvPlanarImage {
@@ -37,7 +37,7 @@ pub fn ycbcr_to_bgra(input: YCbCrBuffer<'_>, output: &mut [u8]) -> io::Result<()
         width,
         height: 1,
     };
-    rdp_yuv444_to_bgra(&planar, output, len).map_err(io::Error::other)
+    rdp_yuv444_to_rgba(&planar, output, len).map_err(io::Error::other)
 }
 
 #[allow(clippy::too_many_arguments)]

crates/ironrdp-session/src/image.rs

@@ -9,8 +9,6 @@ use ironrdp_pdu::geometry::{InclusiveRectangle, Rectangle as _};
 use crate::SessionResult;
 
 const TILE_SIZE: u16 = 64;
-const SOURCE_PIXEL_FORMAT: PixelFormat = PixelFormat::BgrX32;
-const SOURCE_STRIDE: u16 = TILE_SIZE * SOURCE_PIXEL_FORMAT.bytes_per_pixel() as u16;
 
 pub struct DecodedImage {
     pixel_format: PixelFormat,
@@ -470,6 +468,7 @@ impl DecodedImage {
     pub(crate) fn apply_tile(
         &mut self,
         tile_output: &[u8],
+        pixel_format: PixelFormat,
         clipping_rectangles: &Region,
         update_rectangle: &InclusiveRectangle,
     ) -> SessionResult<InclusiveRectangle> {
@@ -481,6 +480,7 @@ impl DecodedImage {
         for region_rectangle in &update_region.rectangles {
             let source_x = region_rectangle.left - update_rectangle.left;
             let source_y = region_rectangle.top - update_rectangle.top;
+            let stride = u16::from(pixel_format.bytes_per_pixel()) * TILE_SIZE;
             let source_image_region = ImageRegion {
                 region: InclusiveRectangle {
                     left: source_x,
@@ -488,9 +488,9 @@ impl DecodedImage {
                     right: source_x + region_rectangle.width() - 1,
                     bottom: source_y + region_rectangle.height() - 1,
                 },
-                step: SOURCE_STRIDE,
-                pixel_format: SOURCE_PIXEL_FORMAT,
                 data: tile_output,
+                step: stride,
+                pixel_format,
             };
 
             let mut destination_image_region = ImageRegionMut {

crates/ironrdp-session/src/rfx.rs

@@ -1,6 +1,7 @@
 use core::cmp::min;
 
 use ironrdp_graphics::color_conversion::{self, YCbCrBuffer};
+use ironrdp_graphics::image_processing::PixelFormat;
 use ironrdp_graphics::rectangle_processing::Region;
 use ironrdp_graphics::{dwt, quantization, rlgr, subband_reconstruction};
 use ironrdp_pdu::codecs::rfx::{self, EntropyAlgorithm, Headers, Quant, RfxRectangle, Tile};
@@ -150,6 +151,7 @@ impl DecodingContext {
 
             let current_update_rectangle = image.apply_tile(
                 &self.decoding_tiles.tile_output,
+                PixelFormat::RgbA32,
                 &clipping_rectangles,
                 &update_rectangle,
             )?;
@@ -195,7 +197,7 @@ fn decode_tile(
         cr: ycbcr_temp[2].as_slice(),
     };
 
-    color_conversion::ycbcr_to_bgra(ycbcr_buffer, output).map_err(|e| custom_err!("decode_tile", e))?;
+    color_conversion::ycbcr_to_rgba(ycbcr_buffer, output).map_err(|e| custom_err!("decode_tile", e))?;
 
     Ok(())
 }

crates/ironrdp-testsuite-core/tests/graphics/color_conversion.rs

@@ -38,7 +38,7 @@ fn ycbcr_to_rgb_converts_one_element_buffer() {
     let expected = [128, 127, 128, 255];
 
     let mut actual = vec![0; 4];
-    ycbcr_to_bgra(ycbcr, actual.as_mut()).unwrap();
+    ycbcr_to_rgba(ycbcr, actual.as_mut()).unwrap();
     assert_eq!(expected.as_ref(), actual.as_slice());
 }