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myrao / libyuv

Automatically exported from code.google.com/p/libyuv
BSD 3-Clause "New" or "Revised" License
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I420Scale issue on iOS #312

Closed GoogleCodeExporter closed 9 years ago

GoogleCodeExporter commented 9 years ago 
What steps will reproduce the problem?
1. Call I420Scale from any iOS app (armv7 arch) 
2. Input 480X640 (width = 480, height = 640) and output 360X480 ( width = 360, 
height = 480)
3. Write the file to JPEG or PNG or rendering into screen.

What is the expected output? What do you see instead?
Expected clean scaled Image but see odd image output. See attached Image 

What version of the product are you using? On what operating system?
Device : iPhone 5 with iOS 7, Xcode 5 with Armv7 architecture. Latest trunk   

Please provide any additional information below.
 Below sample code can be use to reproduce the issue
https://gist.github.com/bsrao/8996355

Original issue reported on code.google.com by srid...@tokbox.com on 14 Feb 2014 at 5:54

Attachments:

GoogleCodeExporter commented 9 years ago 
A quick look at your code doesn't reveal anything obvious, but I would suspect 
the stride of the original is not what you think it is?

Original comment by fbarch...@chromium.org on 24 Feb 2014 at 7:31

GoogleCodeExporter commented 9 years ago 
We suspect these are the same issue:
https://code.google.com/p/webrtc/issues/detail?id=2478

Is there a requirement for input/output images to have dimensions with n % 16 
== 0?

Original comment by char...@tokbox.com on 26 Feb 2014 at 6:21

GoogleCodeExporter commented 9 years ago 
No requirements for functionality, but on arm most functions are optimized for 
multiple of 8 pixels.

On iOS some capture resolutions have 'extrawidth', especially on iphone5s. You 
should use that for the source stride.
The sample code included does not pass in stride and assumes it is a function 
or width.  Theres a good chance that is your issue.

Original comment by fbarch...@chromium.org on 17 Mar 2014 at 11:18

GoogleCodeExporter commented 9 years ago 
unittests on ios are still passing.
marking as invalid as there is no known issue with the libyuv end of things and 
would need more information on how to reproduce the issue.
File a new issue if you're still seeing an issue.

Original comment by phthor...@gmail.com on 7 Jul 2014 at 10:52