when the previous frame does not specify dispose to background only the
current frame's rectangle should be cleared
related to bug #245
Change-Id: I2fc4f5be99057e0bf87d8fedec57b06859b070bd
Earlier, we stored a 1x1 frame for such frames. Now, we drop every such
frame and increase the duration of its previous frame instead.
Also, modify the anim_diff tool to handle animated images that are
equivalent, but have different number of frames.
Change-Id: I2688b1771e1f5f9f6a78e48ec81b01c3cd495403
This is designed for the simple use-case where one wants to decode all
frames one-by-one in order.
Also, use this API in anim_util library, which is in turn used by
anim_diff tool.
Change-Id: Ie8b653c04e867d40fd23321b3dd41b87689656c7
using a *tmp_plane buffer to split a/r/g/b planes up appeared to
be the easiest route, compared to copy-pasting the whole code and
making it x_stride aware...
Change-Id: I0898ef1df62bd3e1713b77187b31b5eeef3832fe
If this flag is not used, RGB is premultiplied before comparison.
Otherwise, the raw R/G/B values are compared, which can be a problem
in transparent area (alpha=0 R/G/B=anything)
Change-Id: I131cc10ec92414ad508b81f599a60d0097cac470
It can be used to test if given pair of animated images (GIF and/or
WebP) are identical in terms of pixel match and other animation
properties.
Change-Id: I84adea145e9d062be6ad06a0d4fcdc9658cf52d4
When converting from video sources, the duration of current frame
is often unavailable until the next frame. So, we internally convert
timestamps to durations.
Change-Id: I20ad86361c22e014be7eb91f00d5d40108281351
this is in line with the recommendation in the spec, cf.,
5603947 webp-container-spec: clarify background clear on loop
Change-Id: Id3910395b05a1a1f2804be841b61f97bd4bac593
Updated the near-lossless level mapping and make it correlated to lossy
quality i.e 100 => minimum loss (in-fact no-loss) and the visual-quality loss
increases with decrease in near-lossless level (quality) till value 0.
The new mapping implies following (PSNR) loss-metric:
-near_lossless 100: No-loss (bit-stream same as -lossless).
-near_lossless 80: Very very high PSNR (around 54dB).
-near_lossless 60: Very high PSNR (around 48dB).
-near_lossless 40: High PSNR (around 42dB).
-near_lossless 20: Moderate PSNR (around 36dB).
-near_lossless 0: Low PSNR (around 30dB).
Change-Id: I930de4b18950faf2868c97d42e9e49ba0b642960
previously the first frame would be redisplayed, which might be
unexpected if the final frame was meant to be a composite, for example.
Change-Id: I4da795623c71501e2fa426e8fba8fb2ffcbab58a
Enable the WebP near-lossless feature by pre-processing the image to smoothen
the pixels.
On a 1000 PNG image corpus, for which WebP lossless (default settings) gets
25% compression gains, following is the performance of near-lossless feature
at various '-near_lossless' levels:
-near_lossless 90: 30% (very very high PSNR 54-60dB)
-near_lossless 75: 38% (very high PSNR 48-54dB)
-near_lossless 50: 45% (high PSNR 42-48dB)
-near_lossless 25: 48% (moderate PSNR 36-42dB)
-near_lossless 10: 50% (PSNR 30-36dB)
WebP near-lossless is specifically useful for discrete-tone images like
line-art, icons etc.
Change-Id: I7d12a2c9362ccd076d09710ea05c85fa64664c38
add additional return checks and asserts to avoid:
C6102: Using 'XXX' from failed function call ...
Change-Id: I51f5fa630324e0cd7b2d9fceefecb4f4021474b1
width / height are unsigned; fixes a warning with msvs /analyze:
C6340: Mismatch on sign: 'const unsigned int' passed as _Param_(4) when
some signed type is required in call to 'fprintf'.
Change-Id: I5f1fad4c93745baf17d70178a5e66579ccd2b155
This is because, FlattenSimilarBlocks() replaces some opaque pixels by
transparent ones. This results in an equivalent output only if blending
is turned on for the current frame.
Change-Id: I05612c952fdbd4b3a6e0ac9f3a7d49822f0cfb9b
Snapping odd offsets in GIF to even offsets in WebP was causing extra row/column
being disposed in such cases.
Code is rewritten to maintain previous and current canvas (it used to maintain
previous canvas and current frame earlier). And we recompute change rectangles
as those from GIF may no longer apply.
Also, this renders methods like ReduceTransparency() and ConvertToKeyFrame()
redundant, as internally maintained current canvas is always independent of
previous canvases.
Disposal method choice: we pick the disposal method that results in the smallest
change rectangle.
Change-Id: Ic31186d98fe1a2a790a89d1571b17e3abd127e79
For some GIF images, the first frame is missing the corresponding
graphic control extension. For such cases, we were never calling
GetBackgroundColor(), and default background color value (white) was being used
incorrectly.
So, we call GetBackgroundColor() when we encounter the first image
descriptor instead, to make sure that it is always called.
Change-Id: I00fc8e943d8a0c1578dcd718f3e74dec7de4ed61
put WebPMuxConfig on the stack in main() rather than allocating it in
InitializeConfig(); removes a level of indirection there.
Change-Id: I81d386f7472ebbd322dd3fdbfda9d78dbeb62a66
