Merge pull request #91 from flangelo/jpeg_if_bmp_large_enough

GUAC-1365: Don't send JPEG image refreshes if the image size is less …
This commit is contained in:
Mike Jumper 2015-10-19 11:46:34 -07:00
commit 0f2041ee5c

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@ -91,6 +91,12 @@
*/
#define GUAC_COMMON_SURFACE_JPEG_FRAMERATE 3
/**
* Minimum JPEG bitmap size (area). If the bitmap is smaller than this threshold,
* it should be compressed as a PNG image to avoid the JPEG compression tax.
*/
#define GUAC_SURFACE_JPEG_MIN_BITMAP_SIZE 4096
/**
* The WebP image quality ('quantization') setting to use. Range 0-100 where
* 100 is the highest quality/largest file size, and 0 is the lowest
@ -408,14 +414,20 @@ static int __guac_common_surface_should_use_jpeg(guac_common_surface* surface,
/* Calculate the average framerate for the given rect */
int framerate = __guac_common_surface_calculate_framerate(surface, rect);
/* JPEG is preferred if framerate is high enough */
int rect_size = rect->width * rect->height;
/* JPEG is preferred if:
* - frame rate is high enough
* - image size is large enough
* - PNG is not more optimal based on image contents */
return framerate >= GUAC_COMMON_SURFACE_JPEG_FRAMERATE
&& rect_size > GUAC_SURFACE_JPEG_MIN_BITMAP_SIZE
&& __guac_common_surface_png_optimality(surface, rect) < 0;
}
/**
* Returns whether the given rectangle would be optimally encoded as WebP
* Returns whether the given rectangle would be optimally encoded as WebP
* rather than PNG.
*
* @param surface
@ -435,8 +447,14 @@ static int __guac_common_surface_should_use_webp(guac_common_surface* surface,
if (!guac_client_supports_webp(surface->client))
return 0;
/* Usage criteria are currently the same as JPEG */
return __guac_common_surface_should_use_jpeg(surface, rect);
/* Calculate the average framerate for the given rect */
int framerate = __guac_common_surface_calculate_framerate(surface, rect);
/* WebP is preferred if:
* - frame rate is high enough
* - PNG is not more optimal based on image contents */
return framerate >= GUAC_COMMON_SURFACE_JPEG_FRAMERATE
&& __guac_common_surface_png_optimality(surface, rect) < 0;
}