Confused over streaming compression settings

[Craig Seeman]

[david Eadenhall] “When I ask advice from people, they all say that my bitrate settings are too high and should be about 600-800kbps!!! “

What do they all have in common?
What internet connection speed?
What computer specs?

If they have a download speed of around 3000kbps and have reasonably new computers that can decode H.264 then there shouldn’t be a problem but if they’re all on older or cheap computers and slow download that’s another story.

A good test might be if they can play a YouTube video in HD (NOT HQ) mode.
YouTube HD for example is about 2000kbps.

Superficially your frame size and data rate is reasonable given the above.

[Chris Blair]

Craig SeemanSuperficially your frame size and data rate is reasonable given the above.

It’s reasonable for SOME people with new computers and very fast internet connections.

As an example…we have workstation class computers at our facility, most with at least dual processors and several gigs of RAM…along with a T1 line. Yet if only one person is on the internet, we have a hard time playing YouTube HD files without buffering, pausing and stuttering…regardless of the power of the workstation.

At home I have a pretty standard cable connection and a 4 year old laptop with 512MB RAM…yet I can play YouTube HD video without issue.

There are so many potential issues that affect streaming video that bumping up against the boundaries of it’s capabilities in pixel size and data rates means that a large percentage of your audience likely won’t be able to reliably play your video.

Forget the fact that they SHOULD be able to play it, the simple fact is that many will not be able to. We’ve always advised clients that it’s better for their video to play at good quality, than it is for it to look pristine but pause and stutter…or not play at all.

Chris Blair
Magnetic Image, Inc.
Evansville, IN
http://www.videomi.com

[Craig Seeman]

David/Dan needs to define his own market.

In my neck of the woods I rarely see anyone with less than 3000kbps and that’s even on heavy trafficked lines. Consumer cable modems are 10,000, 15,000, 30,000 and now 100,000kbps.

My point is you MUST know your target market.

David/Dan has described both his encoding specs and anecdotal response. Those viewing may or may NOT be his target. He has to decide. I’m providing a means so he can make that decision.

[David Eadenhall]

Hi there Craig

Thank you so much for your response – I am so thankful that you have taken the time to respond and help.

My target audience is quite hard to sum up as it will be made up of so many individuals that will be accessing the videos on our servers from different backgrounds of computers. By that I mean some users will be computer fanatics and some will have basic set ups. I guess that makes things so complicated.

I have seen so many sites that embed these HD videos and they stream so well and smoothly. I just want to find a happy medium that allow as many users successfully watch these videos and be satisfied.

I have since learnt that the bit rate that I encode a video by relates to the minimum requirement that my user must have in his internet connection speed. I was able to get a fairly decent result with bit rates of about 1500kbps upwards but was being told by so many people that my bit rate was way too high and that I should be looking more towards 600-800kbps. Either I am doing something very wrong but I cannot for the life of me get anything even barely acceptable looking at that bit rate. It just looks totally blocky and jerky.

By my tests in compression, I am getting file sizes to be about 10mb per minute. Is that sounding high to you?

Craig, again thank you for all your help and I hope im not taking up too much of your time.

Dan

[Daniel Low]

David? Dan? I’m confused.

More confusion:

There’s streaming and there’s progressive download. Many confuse the two.

YouTube is progressive download, sometimes called ‘HTTP streaming’

Flash (in 95% of cases) is progressive download.

Therefore, regardless of connection speed, all people see the same video at the same quality only that those on slower connections need to wait longer for the clip to buffer/download before it will play.

If the clip is stuttering, wait until it has downloaded more and then play it back. If it still stutters then your computer is simply not capable of playing it back properly.

@Chris:
“As an example…we have workstation class computers at our facility, most with at least dual processors and several gigs of RAM…along with a T1 line. Yet if only one person is on the internet, we have a hard time playing YouTube HD files without buffering, pausing and stuttering…regardless of the power of the workstation. ”

T1 is only 1500kbps, as Craig pointed out, YouTube HD is approx 2000kbps

“At home I have a pretty standard cable connection and a 4 year old laptop with 512MB RAM…yet I can play YouTube HD video without issue. ”

Your cable connection is likely to be faster than the T1, even with contention.

For a proper HD experience, regardless of connection speed (but requiring a semi powerful computer at least) this is the ultimate:

HD/a>

Like with youtube, these are progressive download so you can view them even on a 56k connection. You’ll just have to wait.

__________________________________________________________________
Two years from now, spam will be solved. – Bill Gates, World Economic Forum 2004

[Chris Blair]

Guys,

We get clients who want to put the highest quality video on their internet sites and aren’t satisfied until we output videos compressed between 1000-2000kbs.

The video plays great on new computers with fast connections, but on many, it takes quite a while to buffer before it starts playing, and even then, it will buffer several more times during playback.

What do most site visitors do when this happens? They either don’t watch the video or they move on to a new page..or worse..a new website. If David’s site is strictly for watching his videos, then by all means, do them at the highest quality you can get away with or that customers will tolerate.

But if it’s a typical business website where people go to get information as well as watch video, it’s better to make the videos smaller (both in pixel and file size), and make sure they’ll play continuously.

The 10MB/minute file size doesn’t sound outrageous, but from the clients we work with, it’s certainly on the upper end of what’s going to play reliably across a wide range of users. We shoot for 6-8MB/minute at a smaller size of 640×360 (depending on the content) or even 512×288 at 5-6MB/minute.

If quality and showing the video at a large size is important, then he’ll have to live with the fact that likely half his audience will have buffering issues during playback.

The servers the videos are on also make a difference.

We have one client that uses Limelight for their CDN, which caches video on their servers, (theoretically improving playback), yet we’ve been unable to get 640×360 video at 10MB/min to play reliably on a large number of connections. The client settled on 512×288 at around 8MB/minute as their default because it plays reliably and still looks very good.

If you’re hosting the videos on your web sever, you’re not going to get the same performance as you would from hosting them on a Content Delivery Network separate from your website.

And to clarify, my home cable connection tests at about half the speed of our office T1 line. This illustrates that more than just the connection speed impacts playback. Your CPU, RAM, graphic card and its settings, Flash versions, etc. all can impact performance. After the video is delivered, your CPU still has to decompress it and your graphic card still has to process it.

Chris Blair
Magnetic Image, Inc.
Evansville, IN
http://www.videomi.com

[Daniel Low]

[Chris Blair] “then he’ll have to live with the fact that likely half his audience will have buffering issues during playback. “

Depending on what format you are delivering, there are ways of calculating the viewers connection speed and tailoring the buffer settings to match there are loads of resources that will explain how to do this, most for Flash, which should be fine for David/Dan

__________________________________________________________________
Two years from now, spam will be solved. – Bill Gates, World Economic Forum 2004

[David Eadenhall]

Hi there Daniel

Thank you so much for your response. I have chosen to use mp4 format for both streaming and download. I would love to know how its possible to calculate the viewer’s connection speed. Can you point me anywhere – this sounds just what i need!

Thank you again

Dan

[Daniel Low]

If you deliver the download files as Flash (F4V) then you’ll find a load of useful information here:

https://www.adobe.com/devnet/flashcom/articles/dyn_buffering.html

or

https://www.betriebsraum.de/blog/2007/02/27/flash-video-tip-1-calculating-an-optimal-buffer-size/

__________________________________________________________________
Two years from now, spam will be solved. – Bill Gates, World Economic Forum 2004

[David Eadenhall]

Thank you so much Chris and Daniel for all this amazing information advice and knowledge. I am incredibly appreciative that you have spent the time in explaining all this to me.

Its so good to actually speak to people who are experts in this field as I was getting so desperate of what to do.

One last thing if I may: What is the difference between progressive download and streaming. When i am compressing my video, how do I know what type of download I am compressing for (progressive or streaming)? I have a streaming server set up so that my users can use the ‘seek’ function, will both these types of download be compatible with this, or is there one in particular that i should go for?

I really feel that now I can start doing proper tests on my videos and know what my parameters are finally.

Thank you so, so much again

Daniel