About frame duration for animation

[sha...@gmail.com]

Hi,

In the webp container spec, https://developers.google.com/speed/webp/docs/riff_container

Frame Duration: 24 bits (uint24)

The time to wait before displaying the next frame, in 1 millisecond units. In particular, frame duration of 0 is useful when one wants to update multiple areas of the canvas at once during the animation.

When frame duration is 0, how does the viewer display the frame?

For example, http://littlesvr.ca/apng/images/SteamEngine.webp

In this webp animation, all frame durations are 0.

When I view it in Chrome, it seems the duration of 0 is replaced with a default delay.

So, I feel the words in red does not keep consistent with the behavior of Chrome.

Does it mean we should delete these words, and frame duration of 0 means a default value (for example 100ms) ?

Regards,

Solan

[sha...@gmail.com]

Then I view this picture with vwebp, It seems vwebp conform this spec, with wierd display, and differ from Chrome

[James Zern]

Hi,

Thanks for the report, I filed a bug to track this:

https://bugs.chromium.org/p/webp/issues/detail?id=380

 

Regards,

Solan