playrate & templateimage

Martin Koob mkoob at
Thu Mar 31 09:28:15 EDT 2022

Hi Klaus

I have been meaning to test this but have to get my Windows machine up and running.   I have been using my Mac exclusively for a while.

I suspect I will get the same result as Paul but  I may get a chance to try it before this week Saturday.

I would be interested in how LC 10 works though.   

In LC 9 the player is using AVFoundation on Mac or DirectShow on Windows.

In LC 10  the player will use Windows Player Media Foundation.
Windows Player Media Foundation

The current player on Windows uses DirectShow – which only natively supports the WMV file format. Newer video formats (such as MP4) require third-party codecs to be installed. The move to Media Foundation will mean these are natively supported. MediaFoundation libraries support all the modern codecs such as mp4 natively – so mp4s will play in player objects without any thirdparty components needing to be installed in the OS.

Additionally, mirrored video playback will work correctly as well as non-standard playback rates.

This brings parity between Windows, macOS, Android and iOS video playback features in terms of supported video formats.

From what I remember the first DP of LC 10 did not include the new Windows Player Media foundation.

I don’t know if it has been added to recent DPs.   Once it is I plan to put it through its paces.

Hopefully that will resolve the issue with variable rate playback and result in parity for windows and the other platforms.


> On Mar 31, 2022, at 8:31 AM, Klaus major-k via use-livecode <use-livecode at> wrote:
> Hi Paul,
>> Am 31.03.2022 um 14:23 schrieb Paul Dupuis via use-livecode <use-livecode at>:
>> On 3/31/2022 3:40 AM, Klaus major-k via use-livecode wrote:
>>>> ...
>>> Well, that is the point, the PITCH does NOT change, only the speed of the playback,
>>> and even you might to be able to hear that. :-D
>> Okay, I made a test stack with a player and a slider with playRate from -2 to +2, current Thumb position 1 that on scrollBarDrag set the playRate to the thumbPosition and opened a mp4 video a tested.
>> 1) Under LC 9.6.6, changing the playRate can cause LC to hang, whether the video is playing or paused. Not every time, but some of the times it would just pop up an endless spinning windows cursor ball and Windows would declare that LiveCode 9.6.6. was "not responding" and a forced quit would be required.
>> 2) When it did work, I was able to change the playRate to 1.2 or 1.4 and while the video sped up, apparently my ears are better than I thought, as even I could tell the pitch got higher (the people's voices got higher pitched and "squeaky")
>> Windows 10 (latest build) LiveCode 9.6.6 STABLE.
> thank you very much for testing!
> So apparently it does not work on Windows as it does on a Mac, and thus currently not usable for me.
> Best
> Klaus
> --
> Klaus Major
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