problem with Sorenson 3 codec

Question

Level 1

0 points

problem with Sorenson 3 codec

When I left the "insert keyframe every ___ frames" on AUTO, every second or so there was a pulse of artifact-laden footage, like a burst of pixelation. I went back and changed this setting to 24 (the default) and now the pulsing is gone but I'm have other issues.

At certain parts of my video, the same parts every time regardless of bit rate (unless I turn it WAY up), turn very pixelated. These are not necessarily complex parts, but it is true that most of the fades exhibit this problem. I imagine it's due to the fact that it's one-pass (no two-pass is available), but if anyone has any advice I'd appreciate it. Our goal is to make the file size as small as possible so turning the bit rate way up (which would be inefficient anyway) is not an option. If we MUST use two-pass, we may know someone who can do it for us.

We have made Sorenson 3 videos before at very low bit rates and not had these problems.

PowerMac G5, Mac OS X (10.4.9)

Posted on May 15, 2007 8:36 PM

Reply

Answer 1

Mikey M.

Level 4

1,180 points

May 15, 2007 9:18 PM in response to subnubilus

Hey subnubilus,

Sorenson3 is an awesome web codec!

however, depending on what you want to deliver it is what codec i would advise to you.

you did say you have delivered many sorenson3 files before, but was it the same type of delivery?

i have noticed that for example, email deliveries, sorenson3 is the WORST codec, since i have resolutions of 320x240 and frame rates of 29.97fps (i even go as low as 10fps with no luck). what i would use for email deliveries for example: good old *.mpg, using mpeg1 with mpeg1-layer2 audio, or mp3 if available.

the above example is for email, and i have more codec preferences for other deliverables, so let us know what you are doing with the file, and i am sure there's someone here that will be able to help you.

Mikey M. 🙂

Reply

Answer 2

subnubilus Author

Level 1

0 points

May 15, 2007 10:00 PM in response to Mikey M.

How is receiving a file in your e-mail any different than receiving it via a website or disc or anything else?

I'm finishing up a very large international project, part of which is a website. We expect thousands of people to view this movie and we need it to be as compatible as possible. People who do not have Quicktime 5 or later (which is able to play Sorenson 3 video) will be served an FLV version instead. We have a large H.264 version as well but that will be optional.

I believe I'm pretty decided on what codecs to use.

Reply

Answer 3

Mikey M.

Level 4

1,180 points

May 15, 2007 10:24 PM in response to subnubilus

Hey subnubilus,

your first question is very easy to answer:
you have bandwidth limitations in an email that more likely you wont on a download or streaming video via web.

as far as wanting to be the most compatible out there, why wouldnt you go *.mpg? it will play on all major decoders, including lesser known decoders in both mac and windows.

to be honest sub, it is a little difficult to help you when you don't provide enought information of your originating file, such as codec used (even if it came from tape, you have had to turn it into data to work with it on your computer), the duration and complexity of the file (as in motion).

in the sorenson3 settings, are you limiting your data rate or do you have it at automatic? depending on the complexity of the scenes, defines how many keyframes you will need, so please tell us what kind of video it is. where is your quality slider at?
obviously you are using compressor, so there are not many options within the *.mov export, but you can compensate for that by using compressor's settings, but i would need more info to help.

Mikey M. 🙂

Reply

Answer 4

subnubilus Author

Level 1

0 points

May 16, 2007 10:29 AM in response to Mikey M.

If you could give me a thorough explanation of how you would go about making super compatible .mpg files and why you think that would be better for our project, I'll certainly listen. So far everyone has told me I was on the right track but I don't know much about these things. It is my understanding the Sorenson 3 will cover anyone with Quicktime (because I don't think anyone is still using Quicktime 4 or earlier) and anyone who doesn't have Quicktime at all will see an FLV. No one has ever mentioned using an .mpg, and though I'm familiar with them I don't know the advantages or the codecs or anything.

Our video is nearly five minutes long, is mostly a talking head but there are a lot of 12 to 24 frame cross-dissolves. Some of these dissolves segue into a clip that has some Motion, never a whole lot but sometimes it is full screen. Overall the video is simple enough that my 2-pass VBR compressions (for DVD) tend to be much, much tighter than Compressor estimates before the job. However, the cross-dissolves and a few random (seemingly non-complex) parts are choking Sorenson 3.

Our footage is 1080i HDV converted in FCP to Apple Intermediate Codec footage, then exported as a non-independent Quicktime file and fed into Compressor. This has worked extremely well for our DVD and for larger H.264 videos (of the same video).

I limit the data rate manually, not using the quality slider. With the settings 600kbps it looks good except for the aforementioned artifacting at the cross-dissolves and random other sections. I realize this is quite a low bit rate, but to eliminate the artifacting throughout the dissolves and other sections requires that I turns the bit rate up a few 1000kbps, which leads to unacceptable file sizes.

I do include compression markers with the exported Quicktimes so I'm not sure why Compressor doesn't see the cross-dissolves coming. If I need to manually at the compression markers let me know.

Reply

Answer 5

Doug Metz

Level 2

360 points

May 16, 2007 1:14 PM in response to subnubilus

I can't say that I'm in agreement with MPEG-1. I don't like to use it unless the end-users are forced to stick with a stock Windows installation. It's old and inefficient, which results in larger file sizes than most everything else for similar quality. Ugh.

I've had my best luck with Sorenson 3 using the Pro version. That second encoding pass makes all the difference. It might be worth the investment if you think you'll use it a bunch.

Something to consider, though, would be delivering .flv as your intermediate file instead of SV3. Just bump up your dimensions and data rate... it sure does make pretty pictures. ;o)

Reply

Answer 6

subnubilus Author

Level 1

0 points

May 16, 2007 1:22 PM in response to Doug Metz

We know someone who has a Compression program (I forget which, I think it's Episode) which may allow us to make Sorenson 3 in 2-pass VBR, which we'll try to do this weekend. We aren't going to make a bunch of these files but the few we do make are extremely important.

Doug, I'm not following what you mean in your last line. What makes pretty pictures? Sorenson 3 or FLV? I was under the impression FLV looked horrible, but I haven't tried it yet (was going to do that tonight). Do you think it'd be better to JUST have FLV by default, and then an option large H.264 version? We were planning on going through the hassle of coding scripts and whatnot to redirect users based on what software they had only because we figured the quality difference in FLV and Sorenson 3 would be significant. Our priority is for the most users possible to see the best quality possible and, perhaps more importantly, for the download to be quick for users with slow connections. Unfortunately those users generally choke on H.264 even if they DO have Quicktime 7, so we figured Sorenson 3 was the best way to cover our bases with an FLV backup.

Anyhow, it's not a black-and-white issue, but I'd like to hear your opinion on it. Tonight I have to make some decisions.

Reply

Answer 7

Mikey M.

Level 4

1,180 points

May 16, 2007 1:43 PM in response to subnubilus

Hey Sub,

i will give you anexplantion is a minute. but to answer another question, sorenson3 is definitely a mac codec (manufacturd by another company of course) and goes as far back as QT 4 i believe. the beauty of Sorenson3 is that it's backward compatible with the older builds of the Sorenson decoder. the only catch is, what if the end user doesnt have a mac? they wont be able to play your sorenson3 file. obviously if the downloaded QT they would be able, but that already is asking to much of them :S

what about flash? flash is definitely the next gen codec! it is small, efficient in encoding and decoding and is HTML and flash compatible! so you would just need an updated web browser. what if your end user has an older web browser for specific needs? then they wont be able to play your embedded flash file. there other option to this is downloading a flash player, once again asking to much of the end user.

i am definitely not trying to play devil's advocate here, it's just when i create any file, i go staright to the lowest common denominator. the people that are using mac os 9, the people still running windown 95. i do understand that this are the minority, but why limit your audience at all.
just like when you considered the older web browsers when you created your websites, its the same with digital video (streaming or download).

now with that said, the pro's of *.mpg:
-supports true progressive frames at 29.97
-shines at resolutions of 320x240
-is cabaple of obtain great reults of less than 1.5Mb combined
-accepts mpeg1 layer 2 audio AND mpeg1 layer 3 (mp3) audio

i will continue this in a while, i have to get going...

Mikey M. 🙂

Reply

Answer 8

subnubilus Author

Level 1

0 points

May 16, 2007 7:22 PM in response to Mikey M.

Thanks for going into such detail. I'll wait for the rest and for whatever Doug has to say before commenting further.

Reply