GUAC-240: Add function for streaming JPEG images via img instruction.

src/libguac/client.c

@@ -24,6 +24,7 @@
 
 #include "client.h"
 #include "client-handlers.h"
+#include "encode-jpeg.h"
 #include "encode-png.h"
 #include "error.h"
 #include "instruction.h"
@@ -397,3 +398,24 @@ void guac_client_stream_png(guac_client* client, guac_socket* socket,
 
 }
 
+void guac_client_stream_jpeg(guac_client* client, guac_socket* socket,
+        guac_composite_mode mode, const guac_layer* layer, int x, int y,
+        cairo_surface_t* surface, int quality) {
+
+    /* Allocate new stream for image */
+    guac_stream* stream = guac_client_alloc_stream(client);
+
+    /* Declare stream as containing image data */
+    guac_protocol_send_img(socket, stream, mode, layer, "image/jpeg", x, y);
+
+    /* Write JPEG data */
+    guac_jpeg_write(socket, stream, surface, quality);
+
+    /* Terminate stream */
+    guac_protocol_send_end(socket, stream);
+
+    /* Free allocated stream */
+    guac_client_free_stream(client, stream);
+
+}
+

src/libguac/guacamole/client.h

@@ -661,6 +661,39 @@ void guac_client_stream_png(guac_client* client, guac_socket* socket,
         guac_composite_mode mode, const guac_layer* layer, int x, int y,
         cairo_surface_t* surface);
 
+/**
+ * Streams the image data of the given surface over an image stream ("img"
+ * instruction) as JPEG-encoded data at the given quality. The image stream
+ * will be automatically allocated and freed.
+ *
+ * @param client
+ *     The Guacamole client from which the image stream should be allocated.
+ *
+ * @param socket
+ *     The socket over which instructions associated with the image stream
+ *     should be sent.
+ *
+ * @param mode
+ *     The composite mode to use when rendering the image over the given layer.
+ *
+ * @param layer
+ *     The destination layer.
+ *
+ * @param x
+ *     The X coordinate of the upper-left corner of the destination rectangle
+ *     within the given layer.
+ *
+ * @param y
+ *     The Y coordinate of the upper-left corner of the destination rectangle
+ *     within the given layer.
+ *
+ * @param surface
+ *     A Cairo surface containing the image data to be streamed.
+ */
+void guac_client_stream_jpeg(guac_client* client, guac_socket* socket,
+        guac_composite_mode mode, const guac_layer* layer, int x, int y,
+        cairo_surface_t* surface, int quality);
+
 /**
  * The default Guacamole client layer, layer 0.
  */