Animated PNG implementation

Animated PNG implementation


BUG=1171
BUG=437662

[MaxStepin, 2015-08-03 10:24:56]

maxstepin@gmail.com changed reviewers:
+ noel@chromium.org

[acterhd, 2015-08-21 18:54:00]

On 2015/08/03 10:24:56, MaxStepin wrote:
> mailto:maxstepin@gmail.com changed reviewers:
> + mailto:noel@chromium.org

Sad no subscribers. I'm up!

[Noel Gordon, 2015-08-25 06:02:26]

The CQ bit was checked by noel@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2015-08-25 06:02:36]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1250373006/40001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1250373006/40001

[commit-bot: I haz the power, 2015-08-25 06:16:00]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-08-25 06:16:00]

Dry run: Try jobs failed on following builders:
  mac_chromium_compile_dbg_ng on tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_comp...)

[Noel Gordon, 2015-08-25 13:12:29]

The CQ bit was checked by noel@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2015-08-25 13:12:42]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1250373006/60001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1250373006/60001

[commit-bot: I haz the power, 2015-08-25 14:06:26]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-08-25 14:06:26]

Dry run: Try jobs failed on following builders:
  mac_chromium_rel_ng on tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_rel_...)

[Noel Gordon, 2015-08-26 07:37:21]

The CQ bit was checked by noel@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2015-08-26 07:37:33]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1250373006/60001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1250373006/60001

[commit-bot: I haz the power, 2015-08-26 08:47:42]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-08-26 08:47:43]

Dry run: Try jobs failed on following builders:
  win_chromium_rel_ng on tryserver.chromium.win (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.win/builders/win_chromium_rel_...)

[Noel Gordon, 2015-08-27 06:45:50]

The CQ bit was checked by noel@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2015-08-27 06:45:57]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1250373006/80001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1250373006/80001

[commit-bot: I haz the power, 2015-08-27 08:24:06]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-08-27 08:24:07]

Dry run: Try jobs failed on following builders:
  win_chromium_rel_ng on tryserver.chromium.win (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.win/builders/win_chromium_rel_...)

[Noel Gordon, 2015-08-28 00:47:39]

The CQ bit was checked by noel@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2015-08-28 00:47:48]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1250373006/100001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1250373006/100001

[commit-bot: I haz the power, 2015-08-28 03:08:34]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-08-28 03:08:35]

Dry run: This issue passed the CQ dry run.

[acterhd, 2015-08-28 11:40:24]

On 2015/08/28 03:08:35, commit-bot: I haz the power wrote:
> Dry run: This issue passed the CQ dry run.

lgtm

[Noel Gordon, 2015-08-28 12:19:12]

@acterhd you are not a chromium committer, nor do you possess the right to
approve patches.

@max due to ^^^, please close this issue an re-open it in a new issue.

[Noel Gordon, 2015-08-28 12:21:04]

.. ahem, and reopen it in a new issue, also while we are here ...

[Noel Gordon, 2015-08-28 12:23:15]

https://codereview.chromium.org/1250373006/diff/100001/LayoutTests/canvas/phi...
File LayoutTests/canvas/philip/tests/2d.drawImage.animated.poster-expected.txt
(right):

https://codereview.chromium.org/1250373006/diff/100001/LayoutTests/canvas/phi...
LayoutTests/canvas/philip/tests/2d.drawImage.animated.poster-expected.txt:1:
Failed assertion: got pixel [255,0,0,255] at (50,25), expected [0,255,0,255] +/-
2
Better to find out why the test change behavior, rather than mark it failed.

[Noel Gordon, 2015-08-28 12:24:36]

noel@chromium.org changed reviewers:
- acterhd@gmail.com, noel@chromium.org

[MaxStepin, 2015-08-28 14:53:16]

On 2015/08/28 12:23:15, noel gordon wrote:
>
https://codereview.chromium.org/1250373006/diff/100001/LayoutTests/canvas/phi...
> File LayoutTests/canvas/philip/tests/2d.drawImage.animated.poster-expected.txt
> (right):
> 
>
https://codereview.chromium.org/1250373006/diff/100001/LayoutTests/canvas/phi...
> LayoutTests/canvas/philip/tests/2d.drawImage.animated.poster-expected.txt:1:
> Failed assertion: got pixel [255,0,0,255] at (50,25), expected [0,255,0,255]
+/-
> 2
> Better to find out why the test change behavior, rather than mark it failed.


OK, I will open the new issue.


The test behavior change was expected. 
Firefox gives the same result (since it supports APNG), as you can see here:
http://www.w3c-test.org/2dcontext/drawing-images-to-the-canvas/2d.drawImage.a...

There are two APNG files and one AGIF in LayoutTests/canvas/philip/images/
The tests make sure that canvas drawImage() will always render the first
(poster) frame.

But for APNG, the poster frame could be marked hidden, and not be part of the
animation.
In this case, PNG decoder will ignore it. To save memory and decoding time, it
will 
never decode it. So when canvas drawImage() will request the first/poster image,

the decoder will always return the first *visible* frame, aka
m_frameBufferCache[0]

This test expects that hidden poster frame of APNG.
But from practical point of view, serving the first visible frame is much
easier.

[MaxStepin, 2015-08-28 15:32:37]

Moved here:

https://codereview.chromium.org/1312843006/