View Full Version : Hey guys, I Need a QUICK response, please!


Bryan Wilkat
April 20th, 2008, 09:04 AM
I need some help!
I've gotta compress something for web delivery today, I shouldve tested this sooner but I was pressed for time.
Anyways, I have 16:9 1080i footage(editing on a mac) that needs to be compressed to under 100MB, what settings should I use? I tried the quicktime preset, "broadband high" but it stretches my image in a 4:3 frame OR makes it 4:3 letterboxed and I don't want either of those results. What settings/size do I select for true widescreen/almost no compression, but smaller?
Thanks in advance!

Edward Carlson
April 20th, 2008, 09:47 AM
If you're using Compressor, I've had good luck with the QuickTime 7 Web Streaming 300kbps. In the Inspector window of Compressor, you will need to click the Geometry tab and change Pixel Aspect and Constrain to display aspect to match your source.

Rob Wood
April 20th, 2008, 10:06 AM
here's some settings i use in QuickTime. i'm generally working at a range of 720x540 to 1920x1080 at either 24 or 30fps... btw, the "kbits" is where all the action is... my numbers may be completely out of line for your needs.. more on this below.


QUICKTIME SETTINGS
Export Movie to QuickTime Movie > Options


SETTINGS
Compression Type: H264
Frame Rate: Current
Key Frames: Automatic
Frame Reordering: checked
Compressor Encoding: Best quality (Multi-pass)
Data Rate: Restrict to 4096kbits

This last is where you're gonna have most concerns. Do a short render and check. If quality is great but size is large, drop to half or even a quarter (2048 / 1024) and try again... the content will determine how much the codec needs to do its thing satisfactorily. I've gone down to 384kpbs and as high as 8192kpbs, depending.

(btw, I use computer numbers (1024, 2048, etc) cuz I'm like that... its not like the extra few kbps is gonna make any serious difference. Doubling/halfing is the important idea... like colour correcting; go way beyond so you can reel it back in... keeping notes is a good idea til you got it)


FILTERS
none


SIZE
Use Current Size (or specify a precise size)


SOUND
AAC
Stereo (L R)
Rate: 48.000kHz
Target Bit Rate: 128kpbs, 160kpbs, 192kpbs

Personally I use 128kpbs unless there's a lot of detail in the high-end of the audio: cymbals, very close to the mic whispers, etc)


~


And there's more...

GAMMA, H264 & QUICKTIME
Gamma m-a-y go south on you. Do a test render and see if the content looks milky. If so, you'll have to adjust the Gamma OR the Pedestal/Gain/Saturation. I do the latter, but that's me. *

Gamma: shift to .88 (or .82 i can't remember)
OR
Pedestal/Gain/Saturation: Pedestal(-15%), Gain/Saturation (+15%)


REDUCING THE DATA
You may want to crush the blacks very slightly to reduce the amount of info there, allowing the codec to expend its limited resources on more important visual content. I'm figuring 1-3% IRE.

You may also want to apply a *very* mild unsharp mask (again we're talking small amounts; pick a light or mild preset, then do a check AFTER the render). This'll firm up edges that might be lost when using H264 and as a bonus, slightly reduce the amount of info per frame.

I do these to encourage H264 to toss out data from areas I consider less important.

~

You'll likely find it best to pick/choose from the above settings rather than follow it completely. And you'll definitely be tweaking the kbits before getting a result that suits your eye / 100 meg limit.

good luck
rob

* there's a third trick for correcting the gamma but i've had problems with playback so i don't recommend it... here it is anyway:

1) load the milky looking QuickTime file into QuickTime
2) QuickTime > Show Movie Properties
3) highlight Video Track
4) click Visual Settings tab
5) Open the Transparency dialogue-box (it'll say "Straight Alpha")
6) change it to Blend and move the Transparency Level from 50% to 100%
7) change the dialogue-box back to Straight Alpha
8) close Movie Properties
9) Save as a self-contained movie

...included for completeness but i really can't recommend this method...

Bryan Wilkat
April 20th, 2008, 10:22 AM
Thanks guys! I'm going to go give these settings a shot!

Bryan Wilkat
April 20th, 2008, 10:51 AM
all i can say is.. wow. that data rate thing makes a huuuuge difference! thanks Rob!