Compression for HD delivery

[Nick Ambrose]

Hi guys,

I am a bit concerned with my ability to deliver/playback HD footage.

Right now, most of my delivery is DVD (easy as I just convert to SD) and web.

For web, the sweet-spot for me is to compress to a pretty low res file and use H.264 which gives really really nice results for small file sizes.

However, I am reaching the point where I might need to deliver full HD-sized files for some short films.

I tried encoding H.264 at 1920x1080 (although for some reason, FCE reports it as 1880x1060 or something odd). I chose a bitrate of 10,000 bps (average) and high quality.

OK, so I get an 88M file for my 1.5 min movie (not wretched) but when I try to play it back on a dual 2.0G Mac G5 with a 24" LCD, I dont think I have the horsepower to actually play it at full frame rate -- the footage looks very jerky and disorienting.

When I play back the smaller files, they look great.

So does anyone have any suggestions on how to encode for great playback on machines with reasonable CPU power? (Or maybe I am just doing something wrong with the encoding)

[Rob Yannetta]

Originally Posted by Nick Ambrose

I tried encoding H.264 at 1920x1080 (although for some reason, FCE reports it as 1880x1060 or something odd). I chose a bitrate of 10,000 bps (average) and high quality.

At that bitrate, the filesizes will be way too large for online distribution. Try ~3000k to ~4000k for 1920x1080 distribution.

If you check sites like Apple, that's what they're encoding their 1920x1080 downloads at. See http://www.apple.com/quicktime/guide/hd/

[Nick Ambrose]

Originally Posted by Rob Yannetta

At that bitrate, the filesizes will be way too large for online distribution. Try ~3000k to ~4000k for 1920x1080 distribution.

If you check sites like Apple, that's what they're encoding their 1920x1080 downloads at. See http://www.apple.com/quicktime/guide/hd/

Hmmm, I will give that a try and see if it reduces my CPU requirements any.

I am still a bit baffled by the 1880x1060 weirdness from FCE, but then I am used to having to take a Phd everytime I want to export something that actually looks right.

[Jarrod Whaley]

Originally Posted by Nick Ambrose

I am still a bit baffled by the 1880x1060 weirdness from FCE

This is just a guess because I normally work with neither HD material nor Final Cut, but maybe the encoding process exports to a slightly more narrow resolution (maybe with a slightly widened PAR to compensate) in order to squeeze out a little extra bandwidth for bit rate purposes?

[Nick Ambrose]

Originally Posted by Jarrod Whaley

This is just a guess because I normally work with neither HD material nor Final Cut, but maybe the encoding process exports to a slightly more narrow resolution (maybe with a slightly widened PAR to compensate) in order to squeeze out a little extra bandwidth for bit rate purposes?

Hmmm, possibly.
I "found" some more options.

Apparently I have 1920x1080 HD and 1920x1080 HD "16:9"

It is the 16:9 that gives the odd resolution, the regular HD is OK (but not encoded yet, so I will see)

Trying it now with 4500Kbps and key frames set to "auto", but it takes 60 mins to encode just 1.5 mins :(

[Nick Ambrose]

Originally Posted by Nick Ambrose

Hmmm, possibly.
I "found" some more options.

Apparently I have 1920x1080 HD and 1920x1080 HD "16:9"

It is the 16:9 that gives the odd resolution, the regular HD is OK (but not encoded yet, so I will see)

Trying it now with 4500Kbps and key frames set to "auto", but it takes 60 mins to encode just 1.5 mins :(

Darn -- replying to myself here.
I think my mac is just too slow to play H.264 at those resolutions :(