Bug 173403

Summary: ImageDecoder: Gifs with infinite animation only play once very often
Product: WebKit Reporter: Carlos Garcia Campos <cgarcia>
Component: PlatformAssignee: Nobody <webkit-unassigned>
Status: RESOLVED FIXED    
Severity: Normal CC: bugs-noreply, magomez, mcatanzaro, sabouhallawa, simon.fraser
Priority: P2 Keywords: Gtk
Version: WebKit Nightly Build   
Hardware: Unspecified   
OS: Unspecified   
Attachments:
Description Flags
Patch
none
Patch
none
Patch mcatanzaro: review+

Carlos Garcia Campos
Reported 2017-06-15 00:53:08 PDT
It doesn't always happen, it's easier to reproduce when loading big files from the network, but it also depends on every file. The problem is that ImageFrameCache is caching the repetition count value always when the size is already available. In the case of gif files, the loop count value can be at any point of the image stream, so having the size available doesn't mean we also have the loop count. So, if the value is queried before it's available, the default value is cached (repeat once) and then always used. So, we need a way to only cache that value when it's really available.
Attachments
Patch (9.82 KB, patch)
2017-06-15 00:57 PDT, Carlos Garcia Campos 		no flags
DetailsFormatted DiffDiff
Patch (10.59 KB, patch)
2017-06-15 01:17 PDT, Carlos Garcia Campos 		no flags
DetailsFormatted DiffDiff
Patch (2.05 KB, patch)
2017-07-11 06:40 PDT, Carlos Garcia Campos 		mcatanzaro: review+
DetailsFormatted DiffDiff
Show Obsolete (2) View All Add attachment proposed patch, testcase, etc.
Carlos Garcia Campos
Comment 1 2017-06-15 00:57:49 PDT
Created attachment 312958 [details] Patch
Carlos Garcia Campos
Comment 2 2017-06-15 01:17:04 PDT
Created attachment 312959 [details] Patch
Carlos Garcia Campos
Comment 3 2017-06-29 02:02:30 PDT
Ping reviewers.
Michael Catanzaro
Comment 4 2017-06-29 07:36:49 PDT
Said, is there another way you would prefer to do this?
Said Abou-Hallawa
Comment 5 2017-06-29 13:55:53 PDT
(In reply to Michael Catanzaro from comment #4) > Said, is there another way you would prefer to do this? I think this issue can be fixed by clearing m_repetitionCount in ImageFrameCache::clearMetadata(). This method is called from ImageSource::dataChanged() every time new data is incrementally added to the image source. ImageFrameCache::clearMetadata() clears all the cached metadata that may change their values with new data added to the image source.
Carlos Garcia Campos
Comment 6 2017-07-11 06:39:30 PDT
(In reply to Said Abou-Hallawa from comment #5) > (In reply to Michael Catanzaro from comment #4) > > Said, is there another way you would prefer to do this? > > I think this issue can be fixed by clearing m_repetitionCount in > ImageFrameCache::clearMetadata(). This method is called from > ImageSource::dataChanged() every time new data is incrementally added to the > image source. ImageFrameCache::clearMetadata() clears all the cached > metadata that may change their values with new data added to the image > source. Ah!, good point, I didn't know that, it's indeed a much simpler solution. I'll submit a new patch. Thanks!
Carlos Garcia Campos
Comment 7 2017-07-11 06:40:11 PDT
Created attachment 315102 [details] Patch
Michael Catanzaro
Comment 8 2017-07-11 08:37:18 PDT
Comment on attachment 315102 [details] Patch Much nicer! Thanks, Said.
Carlos Garcia Campos
Comment 9 2017-07-12 03:58:40 PDT
Committed r219389: <http://trac.webkit.org/changeset/219389>
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