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Subject: Re: Sync problems in grayscale lib?
From: BlueChip (
Date: 2004-05-23

At 12:23 23/05/04, you wrote:
>Tobi wrote:
>>I have an Archos Recorder with USB 2.0. All applications, that uses the
>>grayscale lib have some sort of a display error. It seems like a problem
>>with the lcd timing. A gray bar goes all along from the top of the
>>display to the bottom. It looks like you film a television. Is this a
>>common problem?
>Hi Tobi,
>this is because of a missing v-sync scheme of the display. Jukebox clock
>and display refresh rate are not synced. Grayscale refresh rate is
>somewhat really close to the display's framerate and tends to drift due to
>temperature effects/tolerances of the LCD timing oscillator. That drift
>causes bars/artefacts wandering along your screen. Your assumtion with an
>lcd timing issue is right.
>For every complex problem, there is a solution that is simple, neat, and
>H.L. Mencken (1880-1956)

So whilst looking for that solution - how simple, neat or wrong would it be
to add a user-controllable refresh timer to the greyscale stuff?


Page was last modified "Jan 10 2012" The Rockbox Crew