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View Full Version : QT Compression for web - AGAIN - I know


JurajMolcak
02-17-2006, 09:17 PM
Hi folks,

this is really nightmare for me. I am about to make my first reasonable render for web hosted video. I checked few threads about this sort of task and still canīt get good result.
I have 33 sec. video with PAL resolution. My workflow is:
1. New composition with stretched footage (640 x 480)
2. Render queue
3. Lossless menu - QT movie
4. Format option - Sorenson video 3, 25 FPS, key every 25, data rate 768 kbps, High quality
5. 32,000 kHz 16 bit stereo

with this settings I have filesize around 23 MB ( just looks too big for 30 sec )
I have videos of similar settings with size around 1,8 MB - 30sec. / 320 x 240 px

What should I do? Could complexity of graphics make it hard to compress?

evanfotis
02-21-2006, 10:05 AM
Why are you using lossless? that is not compressed for web...
And keyframes not every 25 but every 250.
Or
Try the H.264 format, or wmv for pc, or ... resize to 320X240!
That's why you get this difference is mb sizes-If you're rendering Pal 768X576 its about 4 times larger than 320X240...

JurajMolcak
02-21-2006, 01:11 PM
evanfotis: thanx for reply. What is compressed for web than? The Export menu? Well, just made little test with EXPORT to QuickTime. I have bigger file than one rendered from render queue based on Lossless. So far, I have 600 x 450 px with 40.056 kHz Stereo in 11,1 MB file. I canīt use 320x240 because of sensitive gfx.

evanfotis
02-21-2006, 01:31 PM
From what I know, AE has preset web output modules.
The other thing you can do is slice the fps from 25 to 15 or so, and downres the sound from 44Khz to 22Khz
Output modules can be found in the Render Que dialogue in the output options, or in Edit>Templates>Output modules. You can create your own, name them andset the default one of your taste.

JurajMolcak
02-21-2006, 02:51 PM
evanfotis: Now I got it. I think we are talking about the same. There is no difference between "to create new Output module" and "to change parameters within existing one". I changed almost everything within Lossless setup, so its new one. I just did it in crazy way :) BTW, there is no preset offer for web output in my 6.5 STD output module.

igorstshirts
02-21-2006, 11:26 PM
Oweron,
What's up man... I was born in Bratislava... Watching us in the olympics kick ass in hockey. I think we play the Czech rep. next... Go Slovakia!


Hey,
Flash is the solution for you bro... I think. If you are working 24 fps, I would drop the frame rate to 12 or maybe even 8. If your comp is 30 fps, drop it to 15 or maybe even 10. It will still look nice, sometimes looking like old 8mm. You just have to play with the size of the frames (dimension wise) and compression of each frame to get your target size.

Export a .PSD image sequence out of Aftereffects like every other frame or third frame. Compress each frame in Photoshop to like a 60 quality JPEG. This used to be a pain in the ass in latter versions of PS but I think CS has a batch compression option now. Flash will recompose all of the frames instantly and sound/music is super simple... Anyway, my suggestion. Ahoj.

P.S. You can even re-compress the movie in Flash when done... I think.

igorstshirts
02-21-2006, 11:36 PM
I did a little math...

I compressed a pretty colorful 640 by 480 frame to 60 quality JPEG and got around a 33k file size. So, dropping it to 10 frames per second at 33 seconds would be somewhere a little over 9 megs or so.

JurajMolcak
02-22-2006, 09:00 AM
Hey Igor!

Tonight is a night :love: Heh, we should beat the Czech or I am going to be very bad... We won 2 times, we lost 2 times and we had 1 draw in our history SVK vs. CZE
Looking at your homesite, I was working for similar shop during my J-1 in OceanCity. Heh.
BTW: "HOSTEL the movie" SUCKS! You were born in Bratislava... What do you think about that shit?

Ah, thanx for your suggestion about compression. The animation is already on_line :
http://forums.cgsociety.org/showthread.php?t=320074

igorstshirts
02-22-2006, 08:56 PM
Let's hope the Czech vs. Slovak hockey game ain't as ugly as that movie.:surprised

Nice job on the animation. I like the chalkboard texture look of it alot.

jussing
02-23-2006, 08:01 AM
Yo hockey boys..... sorry to interrupt. ;)

Here's a quicktime settings tut (http://forums.cgsociety.org/showthread.php?t=180825) with the settings I use.

Cheers,
- Jonas

beenyweenies
02-24-2006, 03:01 AM
Why are you using lossless? that is not compressed for web...
And keyframes not every 25 but every 250.
Or
Try the H.264 format, or wmv for pc, or ... resize to 320X240!
That's why you get this difference is mb sizes-If you're rendering Pal 768X576 its about 4 times larger than 320X240...

Just to add to evanfotis' point, the "keyframes" setting is actually crucial to understand when using those codecs that offer this setting, and the ideal setting is different for every codec. The ideal "keyframes" setting with Sorenson compression is typically 5-10 times the frame rate of the source file. This would mean 25fps video should keyframe every 125-250 frames as evanfotis mentioned. Set your keyframes accordingly (with Sorenson, anyway) depending on the frame rate of your source video.

Keyframes affect both the quality and playback of the file. Codecs like Sorenson compress data by checking for differences in your footage between keyframes, only recording new data where it is absolutely needed to preserve detail. The less frequent the keyframes, the fewer "reference points" the codec uses to determine how much compression to apply. Set more keyframes, and the codec preserves more detail, but at the cost of way bigger files. This is why Sorenson is hands-down better than Cinepak. While Sorenson only needs a keyframe every 250 frames or so to give good results, Cinepak's outdated algorithm is tuned to give best results with keyframes every 5 frames, resulting in much larger file size (sometimes as much as 4 times larger!) for the same or lesser quality.

Another gotcha - if you use far too FEW keyframes in some codecs, when someone tries to skip ahead in your video the playbar will indicate the movie is playing, but in a lot of cases the video won't actually play back until the next keyframe occurs. Therefore, setting a keyframe every 20 seconds would bad because people may miss large chunks of your movie, or even think something is wrong when the video freezes up for several seconds every time they try to skip ahead. The problem is made worse by dropouts in internet bandwidth, network congestion etc. This particular issue may not occur with some codecs, but I notice it most on some Divx encoded movies.
Using poorly chosen keyframe settings can (and will) cause the final product to be less than ideal, including odd playback behavior that most people struggle to identify only to find out it is their keyframe settings.

The important thing is to know that most codecs are created with ideal keyframe ranges in mind, and may deliver unexpected results if you stray too far from their recommended settings. Select a codec, then read up at their website for recommended settings!

Kutkin
02-24-2006, 10:04 PM
Hey Igor!

Tonight is a night :love: Heh, we should beat the Czech or I am going to be very bad... We won 2 times, we lost 2 times and we had 1 draw in our history SVK vs. CZE


We have beaten you again.:wip: But you were great. But anyway, we lost in th semifinal match.:banghead: So nover mind, just a game;)
I'm having issues with exporting videos from AE too. It seems i survived turning down the size, but i still do have some strange cracking noise in the sound. The quality of sound is 44k. It just do some crack sound.
I can't figure out what's going on with it.
Bye for now, folks!

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