View Full Version : encoding to flv


Michael Donne
January 15th, 2007, 11:27 AM
Hi,

Hoping for a quick steer before wasting any money.....

I need to encode a sequence from fce hd3.5 into FLV format.

1.Am i right in thinking this means i have to buy flash mx and then get the flv export plugin? I dont want to spend the money unnecessarily.

2.Even if i do buy it, as far as i can read it only quotes supporting fcp so have i likely got a further problem as i'm on fce.

3.If so would my next route be to encode to something like h264 and let the web designer convert it, or does that added step introduce a horrible quality drop. (does fce hd3.5 have a codec i could use that is better than h264 for subsequent conversion to flv)?

Many thanks.

Cale Rogers
January 15th, 2007, 12:46 PM
Hello,

It's always best to compress from the timeline or from an exported uncompressed video file. But, h264 compression could work if you keep the data rate high and the web designer is willing to accept the format. Our web designer has the ability to compress flash files himself. But, we determined that I should compress to flash from the timeline (FCP) to maintain the integrity of the finished output. We had to buy a flash compression tool ($199), but the final output and workflow benefits our client every time we have to go to flash (which is a lot). Besides, my duel G5 is much faster than his Pentium 4 machine so it saves time for both of us.

Good luck,

Evan Donn
January 15th, 2007, 06:09 PM
You can get On2's flix exporter ($99 - http://www.on2.com/consumer/flix-exporter) which is basically an export component for quicktime. This will let you go straight to flv using the Export>Using Quicktime Conversion and gives you higher quality than Flash's converter thanks to a 2-pass encoding option and the ability to preserve an alpha channel.

Stefano Folgaria
January 16th, 2007, 03:22 AM
Which product? I see there just codecs for Windows and Flash...

Michael Donne
January 16th, 2007, 05:37 AM
actually i found on2 yesterday after posting and downloaded the trial of the $39 flix standard which doesnt integrate into final cut, so you export a qt first then load that into flix standard and have it make an flv.

The downside to this $39 deal versus Flix eporter (actually $199, not $99) seems to be that it offers:

a. 1 pass not 2 pass encoding
b. constant not variable bitrate
c. an 'average quality' slidebar setting fixed at 75%

I'd love some insight into how significant these things potentially are for my situation...........reducing file size is my issue. Im getting a 45 second flv of 3.4mb of the quality i need (not stunning) by using bitrate 500, keyframe every 25 frames, vid sized at 480 x 270 with no audio, content is slow pannning home interiors with very textural decor. The full video is 5 mins long so i'm currently looking at 22.6mb, plus inevitably the web designer is gonna ask me to drop a twinkly bit of music onto it.

seems like a big thing to stick on a website but thats their bisiness so long as i can say i've delivered a perfectly reasonable file size relative to the material.

Anyone feel i should be aiming for a significantly different file size??

Evan Donn
January 16th, 2007, 01:32 PM
Which product? I see there just codecs for Windows and Flash...

If you click on the buy now or demo buttons on the right side of the page you'll see they give you the option of windows or mac versions - and Michael's right, it's $199 (not $99 as I stated).

I'd love some insight into how significant these things potentially are for my situation...........reducing file size is my issue.

Really it comes down to image size and bitrate, so my general approach is to choose the size I want and then run a few 10 second tests changing only the bitrate. 500kb sounds about right for that size but depending on the motion you may be able to go lower - I'd say test 100kb and 250kb to get a better feel for how low you can go.

VBR and 2-pass encoding can have a very noticeable effect on quality but their benefits depend greatly on the content you are encoding. VBR generally isn't recommended for streaming but if you're doing progressive download it should be fine and may give you a smaller file size - again, depends a lot on the motion. If your whole video is slow pans you aren't likely to see a huge difference, it's mostly of benefit when the motion varies a lot from shot to shot. 2-pass encoding isn't of any benefit unless you are using VBR, won't directly affect your file size, and may not improve your quality if the motion is fairly constant. However, if you have a mix of motion and static shots it can have a noticeable effect on quality during fast motion and can allow you to push the bitrate further down without losing too much picture quality.

So based on your description of the content I'd say you won't see a lot of benefit from the more expensive On2 product - but if you plan to be doing a lot of this and can't count on the video always consisting of smooth slow pans it may be worth getting the better encoder now.

seems like a big thing to stick on a website but thats their business so long as i can say i've delivered a perfectly reasonable file size relative to the material.

I know it may seem odd but when it comes to online video file size doesn't really matter - bitrate is the most important thing. You want to match your bitrate to your audience's bandwidth so that they don't have to wait for the video to start playing. If it starts playing right away and doesn't stop then the deciding factor in how long they'll keep downloading is how interesting your video is to them.

I have more detail on this type of thing in some class notes on my site:

http://divergentshadows.com/dv/web/web_compression1.shtml
http://divergentshadows.com/dv/web/web_compression2.shtml

Michael Donne
January 16th, 2007, 02:51 PM
that is a gold star response Evan.....shining example of why these forums are such a great place.......totally helps me out, thank you.
.............by the way, how did you lose your E from your surname?....hehe.

Evan Donn
January 19th, 2007, 12:24 AM
no problem, glad to help...and I'm pretty sure the e fell overboard on the boat ride over, long long ago...