HDV and Jitter

Jul 26, 2006 at 7:52pm

HDV and Jitter

What is the current status of inputting HDV (1080i) into Jitter? We
are considering the use of HDV for a video installation, with minimal
Jitter processing, outputing the signal at 16:9 to a 1024 X 768 data
projector using a dual 2 Gig Mac.

Thanks,

Randall Packer

#26937
Jul 26, 2006 at 8:27pm

On Jul 26, 2006, at 12:52 PM, Randall Packer wrote:

> What is the current status of inputting HDV (1080i) into Jitter? We
> are considering the use of HDV for a video installation, with
> minimal Jitter processing, outputing the signal at 16:9 to a 1024 X
> 768 data projector using a dual 2 Gig Mac.

Unfortunately, there is no QT input component for HDV. iMovie and FCP
make use of a private API to interface with these cameras. We may
investigate HDV input at some point in the future, but certainly
won’t have it available anytime soon, unless some other software
developer makes an HDV QT input component. Also note that there will
possibly be greater latency with HDV which uses interframe (temporal)
compression, unlike DV or DVCPro HD.

I have had success using the QT input component for DVCPro HD
(provided with FCP) with the Panasonic AG-HVX200. However, note that
over firewire any 720 DVCProHD signal is delivered on top of a 1080
DVCProHD signal. Since Jitter doesn’t have special DVCPro HD code to
unpack this data, it looks like digital barf if streaming at 720
DVCProHD into Jitter. I am able to stream and draw to a window the
1080 DVCPro HD signal, however, in Jitter even on a 1.67GHz G4
AluBook. These cameras are obviously more expensive than the HDV
cameras out there, but they provide better quality images, with
higher quality chroma sampling (4:2:2 instead of 4:2:0), less
intraframe (spatial) compression, and no interframe (temporal)
compression.

Also of note, if I do capture DVCPro HD data for playback (I use FCP
to grab the 720p data), I typically convert to high quality photo
jpeg for significantly faster playback performance (30fps for photo
jpeg vs 8 fps in a slab based patch I use on my 1.67 G4 AluBook), and
compatibility on machines without FCP installed. If you are trying to
playback DVCPro HD in jit.qt.movie, make sure you either have the
highquality attribute enabled or have set it in the media file
itself, just as you would for DV. Otherwise it renders as preview
quailty.

I believe you might need to also export to Photo JPEG for HDV data
just to play in Jitter, and even if it’s not a requirement, you might
get faster framerates if you do.

For future reference, this is better suited for the Jitter list.

-Joshua

#81097
Jul 26, 2006 at 9:53pm

Moving this thread to Jitter, as per Joshua’s suggestion…

#81098

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