Compression question – for film fest submission….

[Craig Seeman]

The short version:

High Profile, CABAC entropy, 2 pass VBR, x264 codec.
Squeeze should be able to do that. Compressor definitely not.

Keep in mind that data rate and file size are directly related. If 700kbps gives you more that 500MB then the duration of your movie might make that impossible. You’d then have to lower the data rate. You should be OK if your movie is under 100 minutes offhand. Of the H.264 encodes x264 is the most efficient, MainConcept a bit less, Apple’s not even in contention.

[Tom Laughlin]

Could you send me a screen grab of what you’re settings would be set up inside Sorenson? Thanks, Tom

Tom Laughlin
Producer/Editor
Digital Chop House
Salt Lake City, Utah

[Jeff Greenberg]

Screen won’t show it really.
Set it as QuickTime – go to the bottom to find x264
Then press the advanced button.
That’s where you’ll find the CABAC setting.

Best,

Jeff I. Greenberg
Author/Master Instructor/Speaker/Consulting
My contact info and more
New! Come see me speak @ NAB/Post Production World!

[Tom Laughlin]

Craig,

Is this correct, using Squeeze 8:

Tom Laughlin
Producer/Editor
Digital Chop House
Salt Lake City, Utah

[Tom Laughlin]

Jeff,

Is this correct, using Squeeze 8:

Tom Laughlin
Producer/Editor
Digital Chop House
Salt Lake City, Utah

[Jeff Greenberg]

Tom,

You’d mentioned x264, and right now at the top you have the MainConcepts h264 compressor chosen.

When you switch it to x264, it’ll reveal (under advanced) the CABAC choice – which is more complex, and may help the encode a bit.

Best,

Jeff I. Greenberg
Author/Master Instructor/Speaker/Consulting
My contact info and more
New! Come see me speak @ NAB/Post Production World!

[Tom Laughlin]

I did some tests and there was some artificating in a few spots, like a few areas with text, white text over a black background. And then there was one still image that came in blurry.

Test 1: Specs in Squeeze 8 (Final encode came out with ‘artifacts’)

Test 1: Problem areas: Artifacts

Test 2: Specs in Squeeze 8 (Came out clean, but data rate high.)

Test 2: Problem areas (and areas that encoded ok):

Test 3: Specs in Squeeze 8 (Clean video, but some video’ pulsing’ in few areas)

Test 3: Video clean, encoded ok, but data rate needs be at ‘700kps’, not 1000kps…:

So, there were some things I tried, and some things that worked, and some things that didn’t, but the “Test 2” (x 264, 1.1 Mbt/s data-rate) gave me best results, in comparison to the other tests, but I still need to see if someone could help me get this within 700kps data-rate.

Ultimately, I’d love to get this file to look as good as test 2, x.264, but with a lower datsa rate, so I’ll try this later. AVC Profile? Does this affect the encode? Square pixels display? Or, 3×3 or 16×9 display? Are there some other settings other than data-rate tha would help? CBR vs VBR? This video is mostly talking heads and pictures, so. No fast action.

If there is something I can tweak in my settings, please let me know. Squeeze is a lot more layered that others, so I’m still working to learn it more. If there is anything that needs to be changes, checked, un-checked, or any setting suggestions, please let me know.

I think the client will be ok with test 2, but the data-rate is a little higher, and this file was the “cleanest”.

But please let me know what more things I can try.

Thanks again everyone,

Tom

Tom Laughlin
Producer/Editor
Digital Chop House
Salt Lake City, Utah

[Craig Seeman]

You might want to analyze the encode with the free program Bitrate Viewer which is Windows only and one of the many reasons why all my recent Macs have Parallels and Bootcamp.

https://www.winhoros.de/docs/bitrate-viewer/

It may let you know if frames are a bit bit starved. Several things can impact that ranging from key frame rate or your Max data rate setting.

It’s been a while since I looked at the Squeeze interface but your Profile should be set to High and in some of those settings shots it doesn’t seem to be. x264 as similar settings should always be better than MainConcept.

You may want to do a little reading about what some of the key setting mean like, Profile, B-frames, Entropy etc.

[Tom Laughlin]

Yea, I noticed that when you switch from the codec “MainConcept H.264” to the “x.264” at the top of the Squeeze interface, the list of ‘specs to change’ changes in the window, and there are different prefs, some are there and are similar, but with the x.264 window, not all the prefs to change are there in the MC H.264 drop-down menu.

So some of these prefs I can’t change or switch. Can you send me a spec list of the main prefs that I need to ensure are set to what you are saying, using the x.264 drop-down, or if you want, use the screen shot in my post of test 2 for reference, but AVC profile, and a few other ‘main’ prefs, can you remind me once more what they all need to be set at? Since x.264 (test 2) gave me the cleanest encode at 1000kps, I may just not worry at all about the other tests that used MC H.264 and focus on lowering the bit-rate and continue testing using the x.264 drop-down. But let me know what you want me to change here on this screenshot:

Tom Laughlin
Producer/Editor
Digital Chop House
Salt Lake City, Utah

[Jeff Greenberg]

[Tom Laughlin] “Yea, I noticed that when you switch from the codec “MainConcept H.264” to the “x.264” at the top of the Squeeze interface, the list of ‘specs to change’ changes in the window, and there are different prefs, some are there and are similar, but with the x.264 window, not all the prefs to change are there in the MC H.264 drop-down menu.
“

This is because Squeeze has 3 different (really 4) different h.264 encoders; each have different capabilities – all will encode a h.264 viable file.
Sorenson has their own encoder that they built
Main Concepts is the one they licensed (that most of the other software – Episode & Adobe Media Encoder happen to use.)
They also are using the open source x264 implementation.

99% sure you don’t *really* need to work about 99% of those switches (that’s why there’s the Simple/Advanced) settings. OTOH I totally respect the desire to educate yourself as fully as possible.

Your original post said:
480×270 (16×9)
Bit-rate: 700kbps
Max file-size: 500 MB

Well, at that size (which should be okay-ish for h.264, you can get about 100 minutes of footage.
Not happy with it? As you increase the bit rate you get a larger file…and if you limit it to 500 megs, you get less minutes.

90% of quality is going to be the data rate.

SD: 640×360 @ 1000kbs is a good place to start.
As you reduce the file size, you can reduce the data rate.
If you reduce the FPS (to 2:1) you can cut the data rate in half.

A better question (one I think I asked in my first reply) was: how long is the video? Based on that, we can talk about increasing the data rate.