Tiny Tiny streams in a lossy network

Compression Techniques

Tiny Tiny streams in a lossy network

Posted by Steve Modica on March 15, 2011 at 5:48 pm

Hi All
I have an interesting problem I’m trying to help with.
I have a somewhat lossy, meshy, resilient network that can move data at maybe 128Kbits/sec.
I want to take any arbitrary video and encode it into something that will be useful over that network. The display devices are phones. Very small screens, very little processing power.
My first thought is to use H.264 and 3GP files. However I don’t think B and P frames are a good idea. I’ve noticed that under lossy conditions, I frames are lost and the B and P frames are useless. So I’m thinking I need lots of Iframes and maybe no B and P frames (or very few).
Questions:
1. Is there a good encoder to use for this stuff that lets one easily make conversions like this?
2. Should I be looking at another format?
3. Is there something that will let me look at an encoded file and tell how many B and P frames are in there?
Steve

Steve Modica
CTO, Small Tree Communications

Steve Modica replied 15 years, 1 month ago 2 Members · 3 Replies
3 Replies

Michael Kammes
March 18, 2011 at 2:45 pm

Hey Steve! Many thanks for all of the info you share on here, perhaps I can help you this time!

h.264 or MP4 are the files typically used for proxy video. weaker computers and 128kb/s – wow, that’s rough. Your 3GP may be the correct assumption.

On the high end, you can get into some serious tweaking (Digital Rapids, Inlet, Root6, Telestream, etc). Products like Telestream’s Vantage & Root6’sa Content Agent also allow for boolean logic, so if a file exceeds a certain bitrate, it can redo it,and also offer a bunch of file analytical tools.

You may want to start out with Telestream Episode. V6 is out, and there is a free trial on the website. Puts a watermark on the file, but you can really dig into codecs and bitrates. It may give you just what you need, a or a basis from which to look into something higher end. It’s huge bang for the buck and nothing else at it’s price point is as good, IMHO.

Digital Rapids Stream Software uses many of the Main Concept codecs, which are pretty darn good – and the GUI allows for serious B, P and I frame tweaking, as well.

I do not know of an app that counts how many I frames are in a file. I use MediaInfo (or a variant) on the Mac to see the innards of a file when Quicktime’s “Get Info” isn’t enough. Then again, if YOU create a file, and specify the encoding parameters you then know the frequency they appear. So, works for engineering a file, just not reverse engineering it. Maybe someone else has a solution for this one.

~Michael

.: michael kammes mpse
.: senior applications editor . post workflow consultant
.: audio specialist . act fcp . acsr
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Michael Kammes
March 18, 2011 at 3:01 pm

Just did a test here. Can be done!

Episode 6, MPEG 4 in a 3GP wrapper. I bastardized one of the presets.
Manually set the data rate to 100kbit/s, manually altered the packet size, fps, frame size, keyframes, etc. For what it is, not to shabby.

~Michael

.: michael kammes mpse
.: senior applications editor . post workflow consultant
.: audio specialist . act fcp . acsr
.: michaelkammes.com
.: twitter: @michaelkammes
.: facebook: /mkammes

Hear me pontificate: Speaking Schedule .
Steve Modica
March 18, 2011 at 9:29 pm

You rock man.
I think we’re going to be streaming with VLC for android. I have to go build it cause it’s not released yet.
I’m going to use streamclip for now and cross my fingers.

They are going to tweak my radio network to get my bandwidth up. I think I’ll have 100KB/sec now (that’s Bytes!). Of course, now they want two way video chat too 🙂

Steve

Steve Modica
CTO, Small Tree Communications

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