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Re: Smooth Transition Effect between Video Tracks over Firewire

At a guess, William, what format are your tracks? If they're, for instance,
DV, it's possible the Quicktime player is keeping them in a YUV type format
to play them back. In that case, when the transition begins, both video
tracks have to be converted to RGB, then the transition is applied, with the
extra time that implies. I think both the tracks might have to be pre-sized
the same so the transition works also. *Then* the resulting frame has to be
converted back to YUV and compressed out to DV.

The basic problem is that all the Apple transitions and effects are
currently RGB, at least, as far as Quicktime is concerned.

Using decklink stuff, you should be better off. Their components are
realtime and accept YUV. If you see a stutter with their stuff (when you
specifically choose their transitions and effects and no others), then the
problem may be elsewhere.

I'm not sure if the Decklink components will even work as software only.
Maybe. In that case they may work to help with firewire output.

Bruce Wheaton




Both tracks need

On 3/29/04 9:20 AM, "William Maluf Loureiro" <email@hidden> wrote:

>> <<AddEffectSegment.c>>
>>
>> Hi All,
>>
>> I have written some code to do real-time transitions between 2 video
>> tracks on
>> the same movie and improve video output over Firewire / Decklink
>> components.
>>
>> I got a AddEffectSegment.c example code at Apple Web Site to start my
>> application development. Attached is the file.
>>
>> I created a new movie in memory from NewMovie and
>> included 2 video tracks and one audio track. The video tracks had the
>> exact same
>> type, dimensions, etc . I would like to do a transition between these 2
>> videos
>> tracks. In my case the effect overlaps the end of the first track with the
>>
>> beginnig of the second track.
>>
>> My problem is : My playback stutte (flick) when the effect begins.
>>
>> I have lost a week trying to find out any solution that can help me with
>> that
>> but the main result is the same. Stutter the output when transition
>> begins.
>>
>> Is possible to do a smoothly playback transitions with a output over
>> firewire
>> component?
>>
>> I don't know if Apple example code does not work properly over firewire or
>> if
>> multiple tracks over output component is not allowed by QuickTime.
>>
>> Did anyone see anything about that ?
>>
>> I really appreciate any kind of help.
>>
>> Thanks in advance for your attention and sorry about the e-mail's size.
>>
>> William Maluf Loureiro
>
> [demime 0.98b removed an attachment of type application/octet-stream which had
> a name of AddEffectSegment.c]
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