This patch fixes the compatibility for loop-count handling.
This aims at addressing the change in Chrome handling of loop-count
prior to M63.
Before M63: loop-count interpretation was aligned to GIF's behaviour in
Chrome, but incompatible with WebP's spec. In particular, you couldn't
loop exactly once.
Post-M63: loop-count in WebP is really the total number of loops. Gif2webp
will convert correctly from a GIF source by adjusting the loop count.
Note: The Chrome version can be retrieved from the User-Agent
string (chrome://version).
An M63 version will contain the pattern:
Chrome/63.x.xxxx.xx
for instance.
Change-Id: Ie6dc13227e6498f4d7af2f09247913648997648a
DGifGetExtension() may successfully return, but the data pointer should
still be validated
BUG=webp:310
Change-Id: I6cfe617871fef2fe07887e5f48bb20f7ab7cfb35
decoding and file i/o have been split to imageio, all that remains is
some string routines used for parameter parsing in the examples
Change-Id: I77386cd8aa39124b9e14c95fdbaa17ea4ab5bb24
We now get error string instead of printing it.
The verbose option is now only used to print info and warnings.
Change-Id: I985c5acd427a9d1973068e7b7a8af5dd0d6d2585
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
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
* try to avoid trailing '.'
* rationalize capitalization
missed in:
0a8b886 dust up the help message
Change-Id: I6f80736cc8a2ff4f185f63d463a57d5bbf88a0db
previously, the final canvas size was adjusted tightly from the
animation frames. Now, it can be specified separately (to be larger, in particular).
calling WebPMuxSetCanvasSize(mux, 0, 0) triggers the 'adjust tightly' behaviour.
This can be useful after calling WebPMuxCreate() if further image addition
is expected.
-> Fixed gif2webp accordingly.
also: made WebPMuxAssemble() more robust by systematically zero-ing WebPData.
Change-Id: Ib4f7eac372cf9dbf6e25cd686a77960e386a0b7f
Similarly to Chrome, we then use the first sub-rectangle
to set the canvas size.
Also: add check for too-large GIF dimensions (>MAX_CANVAS_SIZE)
Change-Id: Idce55f1e6f6982a8f0e082aac540e16b530e023e
We align with Blink/Chromium code by:
- checking for ANIMEXTS1.0 signature too
- using ByteCount >= 3 instead of requiring ByteCount==3
Change-Id: Idc484ca62878517df3dccb1fdb3bb45104a5e066
see: http://odur.let.rug.nl/kleiweg/gif/netscape.html
this change has the side-effect of using directory names in the
include, silencing a lint warning.
Change-Id: Ib91cf63a90534e32fadfa5c2372bfdb29f854d02
* allow reading from stdin for dwebp / vwebp
* allow writing to stdout for gif2webp
by introducing a new function ExUtilReadFromStdin()
Example use: cat in.webp | dwebp -o - -- - > out.png
Note that the '-- -' option must appear *last*
(as per general fashion for '--' option parsing)
Change-Id: I8df0f3a246cc325925d6b6f668ba060f7dd81d68
this would require a PRIuS or similar macro for proper platform
compatibility (Visual Studio for instance would be variants of %lu)
Change-Id: I2b9fcb1639db024775fb47dbcf79a2240f3d98f2
This is to discourage generation of animated WebP images with ICC
profile, as
the real-world use-case for such images is rare at best.
Output of ICC/XMP metadata is now controlled by the '-metadata' option.
Change-Id: I8e3e29878c32bf46cbc661f50661bac602603c43
When '-mixed' option is given, each frame would be heuristically chosen
to be
encoded using lossy or lossless compression.
The heuristic is based on the number of colors in the image:
- If num_colors <= 31, pick lossless compression
- If num_colors >= 194, pick lossy compression
- Otherwise, try both and pick the one that compresses better.
Change-Id: I908c73493ddc38e8db35b7b1959300569e6d3a97
This is to conform to man/gif2webp.1
Earlier, one needed to give both '-kmin 0' and '-kmax 0' for this to
work.
Also, suppress further warnings for kmin = 0 and/or kmax = 0 case.
Change-Id: I6f5eeb609aeffc159d0252a40a5734162f7e4e7d
Specifically:
- Merge OptimizeAndEncodeFrame with WebPFrameCacheAddFrame: they use the same
if-else structure.
- Move maintenance of 'prev_canvas' and 'curr_canvas' to util.
- Move ReduceTransparency() and FlattenPixels() calls to SetFrame(): This is in
preparation for the next patch: which will try try lossless encoding for
each frame, even when '-lossy' option is given.
- Make most methods static inside util.
No changes to output expected.
Change-Id: I1f65af25246665508cb20f0f6e338f9aaba9367b
quite rarely, it gives a different output
then without the HINT, but that's often for
a smaller size (tested with default -m and -m 6)
Change-Id: I51d221ab61f8e007983325031345728e8d80b241
helps during lossless compression.
10% average saving, but that's mostly on what was previously
'difficult' cases, where the gain is ~30-50% actually.
Non-difficult cases are mostly unchanged.
Tested over ~7k random web gifs.
Change-Id: I09db4560e4ab09105d1cad28e6dbf83842eda8e9
We reduce transparency by turning some transparent pixels into
corresponding RGB values from previous canvas.
This improves compression by about 23%.
Change-Id: I02d70a43a1d0906ac09a7e2dc510be3b2d38f593
