ArdourCanvas::Image allow to set custom data instead of class pre-allocated memory.

gtk2_ardour/video_image_frame.cc

@@ -35,6 +35,13 @@
 using namespace std;
 using namespace ARDOUR;
 
+static void freedata_cb (uint8_t *d, void *arg) {
+	/* later this can be used with libharvid
+	 * the buffer/videocacheline instead of freeing it
+	 */
+	free (d);
+}
+
 VideoImageFrame::VideoImageFrame (PublicEditor& ed, ArdourCanvas::Group& parent, int w, int h, std::string vsurl, std::string vfn)
 	: editor (ed)
 	, _parent(&parent)
@@ -117,7 +124,7 @@ VideoImageFrame::draw_line ()
 	const int rowstride = img->stride;
 	const int clip_height = img->height;
 	uint8_t *pixels, *p;
-	pixels = img->data.get();
+	pixels = img->data;
 
 	int y;
 	for (y = 0;y < clip_height; y++) {
@@ -133,7 +140,7 @@ VideoImageFrame::fill_frame (const uint8_t r, const uint8_t g, const uint8_t b)
 	const int clip_height = img->height;
 	const int clip_width = img->width;
 	uint8_t *pixels, *p;
-	pixels = img->data.get();
+	pixels = img->data;
 
 	int x,y;
 	for (y = 0; y < clip_height; ++y) {
@@ -152,7 +159,7 @@ VideoImageFrame::draw_x ()
 	const int clip_width = img->width;
 	const int clip_height = img->height;
 	uint8_t *pixels, *p;
-	pixels = img->data.get();
+	pixels = img->data;
 
 	for (x = 0;x < clip_width; x++) {
 		y = clip_height * x / clip_width;
@@ -173,7 +180,7 @@ VideoImageFrame::cut_rightend ()
 	const int clip_height = img->height;
 	const int clip_width = img->width;
 	uint8_t *pixels, *p;
-	pixels = img->data.get();
+	pixels = img->data;
 	if (rightend > clip_width) { return; }
 
 	int x,y;
@@ -233,10 +240,9 @@ VideoImageFrame::http_download_done (char *data){
 		cut_rightend();
 		image->put_image(img);
 	} else {
-		img = image->get_image();
-		/* TODO - have curl write directly to the shared memory region */
-		memcpy((void*) img->data.get(), data, img->stride * img->height);
-		free(data);
+		img = image->get_image(false);
+		img->data = (uint8_t*) data;
+		img->destroy_callback = &freedata_cb;
 		draw_line();
 		cut_rightend();
 		image->put_image(img);

libs/canvas/canvas/image.h

@@ -25,27 +25,42 @@
 
 #include "canvas/item.h"
 
+typedef void (*ImageReleaseCallback)(uint8_t *d, void *arg);
+
 namespace ArdourCanvas {
 
+
 class Image : public Item
 {
 public:
     Image (Group *, Cairo::Format, int width, int height);
     
     struct Data {
-	Data (boost::shared_array<uint8_t> d, int w, int h, int s, Cairo::Format fmt)
+	Data (uint8_t *d, int w, int h, int s, Cairo::Format fmt)
 		: data (d)
 		, width (w)
 		, height (h)
 		, stride (s)
 		, format (fmt)
+		, destroy_callback(NULL)
+		, destroy_arg(NULL)
 	{}
 
-	boost::shared_array<uint8_t> data;
+	virtual ~Data () {
+		if (destroy_callback) {
+			destroy_callback(data, destroy_arg);
+		} else {
+			free(data);
+		}
+	}
+
+	uint8_t* data;
 	int width;
 	int height;
 	int stride;
 	Cairo::Format format;
+	ImageReleaseCallback  destroy_callback;
+	void* destroy_arg;
     };
 
     /** 
@@ -59,7 +74,8 @@ public:
      * ... to avoid collisions with Image deletion, some synchronization method
      * may be required or the use of shared_ptr<Image> or similar.
      */
-    boost::shared_ptr<Data> get_image ();
+    boost::shared_ptr<Data> get_image (bool allocate_data = true);
+
 
     /**
      * Queues a Data object to be used to redraw this Image item

libs/canvas/image.cc

@@ -36,7 +36,7 @@ void
 Image::render (Rect const& area, Cairo::RefPtr<Cairo::Context> context) const
 {
 	if (_need_render && _pending) {
-		_surface = Cairo::ImageSurface::create (_pending->data.get(),
+		_surface = Cairo::ImageSurface::create (_pending->data,
 							_pending->format,
 							_pending->width,
 							_pending->height,
@@ -59,14 +59,18 @@ Image::compute_bounding_box () const
 }
 
 boost::shared_ptr<Image::Data>
-Image::get_image ()
+Image::get_image (bool allocate_data)
 {
 	/* can be called by any thread */
 
 	int stride = Cairo::ImageSurface::format_stride_for_width (_format, _width);
-	boost::shared_ptr<Data> d (new Data (boost::shared_array<uint8_t> (new uint8_t[stride*_height]), _width, _height, stride, _format));
-
-	return d;
+	if (allocate_data)  {
+		boost::shared_ptr<Data> d (new Data (new uint8_t[stride*_height], _width, _height, stride, _format));
+		return d;
+	} else {
+		boost::shared_ptr<Data> d (new Data (NULL, _width, _height, stride, _format));
+		return d;
+	}
 }
 
 void