Re: advice needed..

Tech-Archive recommends: Repair Windows Errors & Optimize Windows Performance

From: Jessie (jjohnson_at_soscctv.ie)
Date: 07/29/04 

Date: Thu, 29 Jul 2004 09:11:47 +0100

On Wed, 28 Jul 2004 18:23:12 -0500, Joe Flynn wrote:

> Jessie wrote:
>> I am trying to render multiple MPEG4 (XviD) files, and need to be able to
>> fast forward and reverse during playback.
>>
>> I have tried building a timeline and it plays successfully at normal speed.
>> However, any attempts to change the rate either fails or has no effect.
>> I've tried (put_Rate(), SetRate(), and SetOutputFPS()).
>>
>> I have also tried just building a normal graph (using RenderFile()) and
>> then changing positions manually with SetPositions(). That works well
>> enough when setting initial positions, but is not ideal when smooth video
>> rendering is needed.
>>
>> So my question to the experts is, if you needed to be able to play
>> sequential video clips and have the ability to FF/FB, which way would you
>> implement it? Would you use timelines, and if so, is there a way to change
>> the play rate dynamically (for example, variable increase/decrease using
>> values from a slider control)?
>>
>
>
> Have you tried IAMTimeline::SetDefaultFPS() ?
>
> For the calls that failed what HRESULT is returned?
>
Hi Joe,

Yes, I have tried SetDefaultFPS, but I would need to be able to change the
play rate dynamically (and smoothly) as the user requests instead of just
once during initialization (unless of course you mean I should try using
SetDefaultFPS at any time during playback).

The HRESULT I get is 80004001.

One thing that Thore mentioned in his reply was the use and possible
limtations of Xvid. So, just for laughs, I tried substituting Xvid for the
standard MS MPEG4 V2 encoder and everything started working.. SetRate does
what it should, GetRate returns the correct values, etc.

It's great that the rate changes work, but now it leaves me with more
questions. Why doesn't it work with Xvid. I'd really prefer to use Xvid
because the compression is so much better. I'm currently using
XviD-1.0-RC4-05042004 but I've also tried XviD-1.0.1-05062004 which seemed
unstable.

Is there a better, more stable release of Xvid that I'm not aware of or
have you had any similar experiences with setting the playback rates
specifically with Xvid?

I'll try switching back to Xvid to confirm that it's causing problems.
There may be an option or two that I need to set in order for it to work.

Thanks for your help,
J

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