flash size vs bitrate

[Noa Put]

For my site I"m using a combination of exposureroom video embeds and flv files that are on my server. I have had complaints from clients telling me that my video's sometimes stutter and I have been doing some testing now but have not been able finding a good quality/size.

I'm using premiere pro to export to a flash video but does anyone know how to eliminate the stutter as much as possible but keeping a quality high enough.

As I understand the higher the bitrate the more demanding for a pc to play it, right? Does the size have any impact on that? Let's say you have 720p video size but with only a bitrate of below 1000kbs, that should work I guess?

I read on exposureroom that if you transcode to f.I. 480x270 you nee dto embed it in the same size again because if you use a smaller or larger embed size the pc processor will have to recalculate in realtime which can cause stuttering again?

I'd like to have larger size flv's but with an almost stutter free bitrate and good enough quality, is that even possible considering that not all my clients have fast pc's or internet connections?

[Seth Bloombaum]

Stuttering typically implies too high a bitrate for the internet connection to sustain, not processor load.

One, reduce bitrate as far as you possibly can, locally testing picture quality.

Two, avoid VBR encoding for best internet performance. CBR provides a constant stream to the player . Some players are adaptive in how much they cache before playing, but, if the bitrate varies, they'll be wrong. What player are you using?

Three, h.264 encoding does create more processor load to decode than VP6 encoding. However, at the sizes and bitrates you should be using, that shouldn't be an issue. Avoid the Spark codec - it takes way too many bits to look good.

Four, you can't satisfy high-speed users with fast computers with streaming content that also works for slower connections/computers. You either have to reduce to the lowest common denominator, or, provide multiple bitrates/sizes for users to select.

Five, where is your server? If it's in your house or place of business, how many video users will it take to exceed your upload capacity? This is another potential choke-point.

Six, if you have access to a "buffer" parameter in Premiere's encoder, try setting it higher. The default might be 3 or 5, try 8. This forces the player to buffer more video before starting play, which can help.

Seven, as you explore bitrates for other sizes, check out this cool bitrate calculator. It's really just a starting point, but do notice and use the "motion" pulldown.

[Sareesh Sudhakaran]

you could even try reducing the frame rate for the internet.

[Noa Put]

Thanks a lot Seth for your answer.

About the player I"m not sure, I use wordpress and the player for exposureroom is build in the theme I am using, it appears in a lightbox overlay window.
The video's I play from a server are also displayed with the use of a plugin.
The server I use is from a German website provider, as far as I can see it's fast enough to load video's on my pc. The complaint I got from clients was more for exposureroom video's in medium quality (640x340) but that I thought had to do with a too high bitrate and size (in mb)? For that reason I switched to the small size video's which seem to work better.
I think that providing multiple qualities depending on the clients internetconnection is a good idea, giving them a opportunity to choose if it would stutter.
I will try out the buffer settings you suggested and thanks for the link to the bitrate calculator! very usefull.

[Noa Put]

Originally Posted by Sareesh Sudhakaran

you could even try reducing the frame rate for the internet.

Thanks for the tip Sareesh, don't you think that will cause too much stuttering as well but then because of the "missing" frames?

[Sareesh Sudhakaran]

Mostly videos play at their native frame rates (30/25/24fps) but if size is an issue you can go to even 12fps depending on your footage...only you can decide what's acceptable but if 'frame quality' is at an absolute minimum and you still need to reduce size, there's no other way except - resolution and frame rate.

[Ervin Farkas]

Can you be more specific? The two videos on your home page play just fine... at that size you should not need more than 150-200 Kbps bitrate...

[Noa Put]

Those 2 are bigger in size to ensure a good quality when played in a bigger screen size (just click on the full screen button) but are embedded in a smaller size. I"m not sure but thought they are around 1500kbs, these 2 are located on my own server. It's also the exposureroom video's on my media page that I have gotten complaints about that stutter, I used to take 640x360 as display size but now switched to 470x280 which seems to work better but I prefer having them in a bigger screensize.

[Ervin Farkas]

I would suggest you stay away from all these online video sharing places - Youtube, Vimeo, ExposureRoom, Facebook and the kind. If you want an additional channel to promote your stuff, that's fine, then post them there as well, but only in addition to hosting them on your own server. There is just too much that you have no control over, they re-encode the video you upload, they decide on all of the parameters, they can even arbitrarily reduce bandwidth according to their needs, not yours.

I found that mpeg4/h.264 encoded video in a 640x360 window, at a bitrate of 500Kbps to 1Mbps depending on complexity, with an aac audio at 128 Kbps works fine for most situations when played with the Flash player embedded directly into your own website. Lately I have been even playing with x264 video (using the free Handbrake) and getting incredibly good results.

[Seth Bloombaum]

Originally Posted by Noa Put

Those 2 are bigger in size to ensure a good quality when played in a bigger screen size (just click on the full screen button) but are embedded in a smaller size. I"m not sure but thought they are around 1500kbs, these 2 are located on my own server..

Not sure whether it's better for European viewers, but here in the U.S. I usually consider 800k to be the minimum broadband connection. Quite a few of DSL customers have that as their max download, and cable systems customers can get throttled way back during peak hours (cable systems here run on shared bandwidth).

What would you consider to be the minimum connection speed of your audience? If you want smooth performance across that audience, consider not exceeding it!

Originally Posted by Ervin Farkas

...I found that mpeg4/h.264 encoded video in a 640x360 window, at a bitrate of 500Kbps to 1Mbps depending on complexity, with an aac audio at 128 Kbps works fine for most situations...

Ervin and I seem to have independently arrived at similar bitrates...

1500Kbps doubtless produces great quality, but you can't have it and broad distribution, unless you post additional files of lower bitrate for user selection, or, we're just starting to see some scripting for automagically switching between bitrates in response to network conditions, which uses the dynamic streaming function of FlashPlayer 10.

Here's one example of dynamic streaming. Here's a different approach. They require hosting on Flash Media Server. Very encouraging... we'll probably see this functionality showing up on CDNs before too long.

[Noa Put]

Internet speed is becoming an issue less and less in Belgium and the Netherlands, it's therefore hard to say what the best min bitrate should be. I noticed on 2 pc's at my fathers place, who has wireless internet that his 1 year old dualcore laptop plays my films just fine, only his 3 year old desktop pc not. I have tested the download speed on that thing and it's much slower which must be the result of the wireless receiver (I thought a usb wireless stick) that does not perform well. The laptop has a receiver build in.

I'm beginning to think that the problem can also be hardware related as many people use laptop these day's but if they buy a external usb receiver that's not so good, a fast internetconnection won't help you much.

Adding low res films beside high res films might be my best option to secure that everybody can watch.

Reg exposurerooms, vimeo and such, I would like to use video directly from my server but my wordpress site does not support it, I can embed the movies like on my frontpage that link to a server but not in my media page which displays the videos in a overlay lightbox window, untill now I only managed to embed external providers like exposureroom succesfully.