Downconvert
 

Hi all,

i have shot in UK 1080p 25p and one shot in 720p 25

I need to down convert to SD.

what is the best route? has there been any problems before, want to try and keep the best quality possible :)

Thanks :)

Re: Downconvert
 

I've had the best luck with Apple's Compressor software. But you don't say what platform or software you're using.

Re: Downconvert
 

Premier CS5.5 with the new Media Encoder does a very good job, have just done a couple of productions with this.

Re: Downconvert
 

As a minor player - I find reading these forums very educational - so it's in this vein I ask the question - "what audience is the SD project targeting? Is it the DVD market or web?" With the answer/s I will be able to distinguish maybe areas that I could / should downconvert - where perhaps I am not already.

A possible benefit maybe the resultant file size? I look forward to reading further...

Thanks
Dave

Re: Downconvert
 

@Dave:

converting to SD only makes sense when it has to be put on DVD or DV-tape (for whatever reason: a filmfestival, a (local) TV-station, etc).
For web you can export to (for example) H.264 to make the filesize acceptable for uploading to YouTube, Vimeo, etc. When you want to use your own player and your own server: don't scale down to SD. Than it's better to downsize to a 'geometric-size' like 1280x720 (2/3 of HD), 960x540 (1/2 of HD), 640x360 (1/3 of HD), 480x270 (1/4 of HD). When you shoot interlaced it's probably better to stick with 1/2 and 1/4 of HD, because you'll need to deinterlace the footage.
(SD PAL is 53,333% of the height of SD, but only 37,5% of the width, thanks to non-square pixels: so from a math-perspective SD is not the best way to preserve quality for the web.)

Re: Downconvert
 

Best route?
That's the number one discussion with these cameras. Search this forum and others for a myriad of suggestions. So far, no "best" method. No perfect solution.

John

Re: Downconvert
 

Some articles you might want to review:


XDCAM-USER.COM Getting good SD from an HD camera.
XDCAM-USER.COM Getting SD from HD and the problems of oversampling.

Re: Downconvert
 

Probably for the best quality you need a hardware solution, like an AJA Kona LHi (if you are on Mac). The downconversion quality on this is really excellent. Either play out to tape or 2nd system, then re-digitise at 4.2.2 ProRes (SD). Bit of a faff, but the results are great.

Re: Downconvert
 

I would second Adobe's media encoder.

It does a great job ripping stuff back and forth - I would just set up a custom profile that you want, and just load it twice for both the different kinds of footage. As a matter of fact, I ripped some 1080i footage to 1080p with it yesterday, and it cleaned up the interlaced look pretty well.

Re: Downconvert
 

Don't forget to try QuickTime as well. I've had very good results scaling 1080 to 576 in QT - seems to produce less aliasing artefacts probably due to a slight softening.

The best route will depend somewhat on your subject matter.