replace with more inclusive terms or remove the comment entirely if the
meaning was already clear.
Bug: webp:507
Change-Id: Ica3bbf751ebf79f6668df6e6209af770248ff4ca
enc is allocated with WebPSafeCalloc so there's no need to clear the
pointers afterward.
this has the side-effect of removing a non-inclusive term.
Bug: webp:507
Change-Id: I82f82954936638c4c15d33b2d6f0497a6a13571f
calculate the file duration using unsigned math. this could still result
in an incorrect average duration calculation if there were multiple
rollovers. caching the duration is an option if it was desirable to
support such an extreme case.
Change-Id: I3875d94d081fec947c03a857055df6e27ff5351d
This is to prepare the inclusion of <windows.h>
FrameRect => FrameRectangle
CLIP_MASK => CLIP_8b_MASK
Change-Id: Ia4b1fa4ac06137b4102c91e232206a1fb7159ce0
Documentation says: "if kmin == 0, then key-frame insertion is disabled;
and if kmax == 0, then all frames will be key-frames."
Reading this, you'd expect that if kmax == 0, then with any kmin <= 0
all frames will be key-frames. But actually the kmin <= 0 test is caught
first and you get the opposite (no keyframes but the first). You'd have
instead to set kmax == 0 and any value kmin > 0, which is absolutely
counter-intuitive (reversing order).
Moreover kmax == 1 has no valid kmin (kmin == 1 conflicts with the
`kmax > kmin` rule and kmin == 0 conflicts with `kmin >= kmax / 2 + 1`).
So it should be considered an exception too.
Instead I propose this new logic:
- kmax == 1 means that all frames are keyframes (you are explicitly
requesting a keyframe every 1 frame at most, i.e. all frames).
- kmax == 0 means no keyframes (you ask for a keyframe every 0 frames,
i.e. never).
This is more "logical" language-wise, and also does not involve any
conflicts about what if both kmax and kmin are 0, since now a single
property value is meaningful for the 2 exceptional cases.
Change-Id: Ia90fb963bc26904ff078d2e4ef9f74b22b13a0fd
In GenerateCandidates(), when candidate_ll->evaluate_ and
candidate_lossy->evaluate_ are both true, if lossless encoding
exits on error, candidate_ll->evaluate_ would not be correctly
reset. This will cause freeing uninitialized memory pointer in
SetFrame().
BUG=webp:322
Change-Id: I481b49a186e4fa3607ce71b4543a481083edf444
Set enc->prev_candidate_undecided_ as 0 when a frame is not chosen
as a possible keyframe, so that the dispose method can be
dispose-to-background.
Change-Id: If2899f5dbc06fb53705fb8240072ab6440a6de12
if src_{r,g,b} = 0, any value of src_a or dst_a such that
abs(src_a - dst_a) <= max_allowed_diff
was making the test pass, despite being very different-looking pixels.
The fix is to require same values for src_a and dst_a before attempting
an r/g/b comparison.
Change-Id: If3a55a229eab3904ed454f20065e49e35c39f25c
This improves compression by ~5% at default quality.
If only 'allow_mixed' is on (but 'minimize_size' isn't), we continue to
use a heuristic to try one of the two or both.
Change-Id: Ia573a73ea26ad25f9debff759eed69d2b0449e82
This was defined (slightly differently) at two places. Created a common
method and moved to utils/utils.[hc].
Change-Id: I66c3ac6dea24e0cd2c0eaa5440f3142b4dbbe23b
This reverts commit 169004b1d558c4767f110dde8f7824e59f9f3024.
this changes the ABI, so should bump versions and add a note to NEWS
when we're ready to expose it
Change-Id: Ic5bbd0aee2b6fd0f9d438a9effedf22fe0cec4bf
tl;dr
We do the following:
- Start with transparent value of 0x00000000 instead of 0x00ffffff, so that
WebPCleanupTransparentAreaLossless() is a no-op.
- Restore the original canvas after lossy encoding, to discard changes made by
WebPCleanupTransparentArea() before the next encode.
Explanation of why:
In the mixed mode, anim_encoder tries to encode using both lossless and lossy
compression. In fact, when "min_size" option is enabled, there are at most 4
encodes that can happen in this order:
- lossless with dispose none
- lossy with dispose none
- lossless with dispose background
- lossy with dispose background
But both lossless and lossy both potentially modify the canvas during encode
(for better compression):
- Lossless: WebPCleanupTransparentAreaLossless() turns all transparent pixels
to 0x00000000
- Lossy: WebPCleanupTransparentArea() flattens some transparent pixels
So, the result is that, sometimes we feed the modified canvas to the encoder
instead of the original one, which isn't the right thing to do.
This also applies to just lossless or just lossy encoding, as multiple encodes
happen (with the two dispose methods) in those cases too.
Change-Id: Idfa8ce831a1627014785ba7d0316c42f72594455
This was defined (slightly differently) at two places. Created a common
method and moved to utils/utils.[hc].
Change-Id: I19adc9c48f2a4e2ec9d995e78add6f25172774c2
not exactly same.
Based on lossy WebP quality setting, ignore minor differences when
flattening
similar blocks.
For 6k set, at default quality with '-min_size' option, improves
compression by 0.3%
Change-Id: Ifcb64219f941e869eb2643e231220b278aad4cd4
When FlattenSimilarBlocks() was making some blocks transparent with
averaged RGB values, filtering in lossy compression was causing
blockiness just outside the edge of these blocks.
Disabling filtering for that particular case avoid these block
artifacts.
The total encoded size of the 6k GIF set remains roughly the same (in
fact, reduces a bit).
Change-Id: Ida71cbabd59d851e16d871f53d19473312b3cc77
We pick a mapping with quality 0 mapping to max diff 32, to quality 100
mapping to max_diff 1.
For 6k GIF image set, this improves compression by:
4% at quality 0
0.05% at quality 75
Benefits the MovingThumbnailer test videos too.
Change-Id: I6838ce864d41e1e65311d26b9b8115a12390a253
This way we can ignore some noisy pixels and get tighter frame
rectangles.
Some results:
- Correctness:
Tested that anim_diff reports all images are identical for lossless, and
similar min_psnr value for lossy and mixed modes.
Also checked output images visually to make sure there weren't any
obvious kinks.
- Compression:
A very tiny improvement for 6000 image GIF set we have (0.03%) for lossy
and mixed mode. For some of these images, frames get dropped
automatically as they have a very small diff from previous frame.
10 images from test_video_frames_png show a clear improvement in
compression though. This CL leads to 7 out of 9 lossy WebPs getting
smaller -- for one of them, this leads to a higher quality being picked
(as that’s still < 150 KB).
Change-Id: If539b9e77e1375aa15edc8f926933593a9865f1c
Pass them along to internal 'pic' object, so that progress can be reported back
and user data can also be inspected.
Change-Id: Idb5d0d4a76d07283d704a86c5892e1ad7bda09fa
We now get error string instead of printing it.
The verbose option is now only used to print info and warnings.
Change-Id: I985c5acd427a9d1973068e7b7a8af5dd0d6d2585
It was needed earlier for WebPAnimEncoder API when it was using structs
like WebPConfig, but it only uses pointers to those now.
Change-Id: Ic0c144966421c678e8ef54b3fa81574bb2c9cd08
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
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
Some frames that were previously selected as key-frames were incorrectly
being reset to sub-frames.
Change-Id: Iee342dbb9a9aec144b8185c3b54ca56aa7038bfb
SanitizeEncoderOptions() was changing kmin to 2 too, which resulted in a
bad state with kmin == kmax.
Change-Id: Ie7273f1949bac469e7e6c8efbc98b154caf6de0f
As 'curr_canvas_mod' is being modified during calls to IncreaseTransparency()
and FlattenSimilarBlocks(), GetSubRect() should get the sub-frame from
'curr_canvas_mod' as well.
Earlier, GetSubRect() was computed from 'curr_canvas', so modifying
'curr_canvas_mod' had no effect on encoding.
Change-Id: Ia847503007b66364817fe57def5a9e3c37d1b3cc
We set the parameters even if there is just one frame. This is to make sure
assembly is correct even if single frame animation is NOT converted to a full
frame later.
Change-Id: If79e6aa5e2575cb0f3cd229f16c655b3663c35b0
Given that we decided to only handle frame disposal for output WebP
internally,
only current and previous canvas need to be maintained.
Change-Id: I625293bed5aeb5aabf4eca779f6ec3ee84c9ff2a
A separate API to generate animated WebP images.
It will eventually replace the internal gif2webp_util methods.
Also: update makefiles.
Change-Id: Idf61dfc1016c10b24fea70425d1a2323cffba515
