[Spice-devel] [PATCH 2/2] Fix LZ4 supported image formats.

[Javier Celaya]

- Read the original image format from the LZ4 stream. Only RGB formats
  are supported.
- Expand 24bit to 32bit image format.
---
 common/canvas_base.c | 48 +++++++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 43 insertions(+), 5 deletions(-)

diff --git a/common/canvas_base.c b/common/canvas_base.c
index bb7a424..d1a714c 100644
--- a/common/canvas_base.c
+++ b/common/canvas_base.c
@@ -554,22 +554,42 @@ static pixman_image_t *canvas_get_lz4(CanvasBase *canvas, SpiceImage *image, int
     int stride;
     int stride_abs;
     uint8_t *dest, *data, *data_end;
-    int width, height, direction;
+    int width, height, top_down;
     LZ4_streamDecode_t *stream;
+    uint8_t spice_format;
+    pixman_format_code_t format;
+    uint32_t * dest32, xrgb;
+    int i32, i24;
 
     spice_chunks_linearize(image->u.lz4.data);
     data = image->u.lz4.data->chunk[0].data;
     data_end = data + image->u.lz4.data->chunk[0].len;
     width = image->descriptor.width;
     height = image->descriptor.height;
-    direction = *(data++);
+    top_down = *(data++);
+    spice_format = *(data++);
+    switch (spice_format) {
+        case SPICE_BITMAP_FMT_16BIT:
+            format =  PIXMAN_x1r5g5b5;
+            break;
+        case SPICE_BITMAP_FMT_24BIT:
+        case SPICE_BITMAP_FMT_32BIT:
+            format =  PIXMAN_x8r8g8b8;
+            break;
+        case SPICE_BITMAP_FMT_RGBA:
+            format =  PIXMAN_a8r8g8b8;
+            break;
+        default:
+            spice_error("Unsupported bitmap format %d with LZ4\n", spice_format);
+            return NULL;
+    }
 
     surface = surface_create(
 #ifdef WIN32
                              canvas->dc,
 #endif
-                             PIXMAN_a8r8g8b8,
-                             width, height, direction == 0);
+                             format,
+                             width, height, top_down);
     if (surface == NULL) {
         spice_warning("create surface failed");
         return NULL;
@@ -580,7 +600,7 @@ static pixman_image_t *canvas_get_lz4(CanvasBase *canvas, SpiceImage *image, int
     stride = pixman_image_get_stride(surface);
     stride_abs = abs(stride);
     available = height * stride_abs;
-    if (direction == 1) {
+    if (!top_down) {
         dest -= (stride_abs * (height - 1));
     }
 
@@ -602,6 +622,24 @@ static pixman_image_t *canvas_get_lz4(CanvasBase *canvas, SpiceImage *image, int
     } while (data < data_end);
 
     LZ4_freeStreamDecode(stream);
+
+    if (spice_format == SPICE_BITMAP_FMT_24BIT) {
+        // Expand 24 to 32 bits
+        dest = (uint8_t *)pixman_image_get_data(surface);
+        if (!top_down) {
+            dest -= (stride_abs * (height - 1));
+        }
+        dest32 = (uint32_t *)dest;
+        i32 = height * width;
+        i24 = (height * stride_abs * 3) / 4;
+        while (i32 > 0) {
+            xrgb = dest[--i24] << 16;  // R
+            xrgb += dest[--i24] << 8;  // G
+            xrgb += dest[--i24];       // B
+            dest32[--i32] = xrgb;
+        }
+    }
+
     return surface;
 }
 #endif
-- 
1.9.3