GURU feedback needed: web server encoding and .flv size

[lucite]

Hi,

I know this is a complex question, so many thanks for taking the time to look into it. Also, because it's complex there are many parameters which aren't set yet: I've indicated those separately. And if my question just doesn't make sense, then please let me know what else I need to figure out.

I'm trying to get an estimate of the megabyte size of 1 minute of an .flv. for a "good" (i.e. '8.5 out of 10') playback quality (something closer to stage6 than youtube). The videos will be user generated content and will be encoded & compressed to .flv on our web server.

Ultimately, I know that I will need to run tests on all of this to figure out what works best in my situation; but right now I'm looking for a good estimate.

Here are my known parameters:

- talking head (no fast pans or movement)
- near solid bakground
- dimensions 560x420 (or 480x360 - it would be nice if you can provide an estimate for both)


Here are the parameters which aren't as clear:

- encoding will occur on a web server and thus will most likely be ffmpeg (I just don't know of any other solid encoder - are there other worthwhile solutions to look into?)

- the encoding time must be reasonable (we should be able to encode around 1000 videos a day; of course we can always farm the work to multiple servers, but still, we have to watch costs). In other words, I don't know whether doing 2-pass encoding is practical.

- Codec: AFAIK, ffmpeg uses .H263 to encode to .flv (and I don't know if that's ideal: would I get higher quality and a smaller file size with an another codec? .H264 is great, but not widely supported enough yet).

So what's your best estimate of MB size for 1 minute of an .flv of this kind? And/or do you know of any other web pages which discuss these issues - I've looked a fair bit but haven't found much that was truly relevant.

Many thanks

[mats.hogberg]

encoding will occur on a web server

Not a good idea. Have separate encoding server and web server.

/Mats

[lucite]

^ Yes, the term slipped my tongue. Of course: we will have servers specifically tuned for encoding and separate from our HTTP servers.

Thanks for clarifying that.

[45tripp]

the material you describe is undemanding.

one might say youtube quality is sufficient.

ffmpeg is good for flv1 and for h264,
in between is vp6,
which i guess would one would have to swing with the flix encoder. (which answers your alternative encoder question)

have people install flash9...
not that hard.

flv1 is easier though,
and i'd say
448x336 at 500k video and stero audio at 112k 44.1 kh (or mono audio if there's no specific need for stereo)
would be good enough for plenty.
that puts 1 min at about 4.5 MB

2-pass makes a difference...

if you want better estimates,
provide samples of what's to be typically encoded.

gl
tripp

[lucite]

the material you describe is undemanding.

I would think that coming up with a good estimate based on so few set parameters would be more difficult.

Thanks for your response and the alternative encoder ref.

1/ YouTube quality won't cut it; and if I was aiming for YouTube quality all I need to do to figure out MB/minute is download one and see its size. Problem is, I've been looking for better quality video, but I'm not finding it. Vimeo is better, but the dimensions are still not really comparable to our target dimensions.

So perhaps an easier way to ask my question is:

Does anyone know of a site with (preferably UGC) videos of dimensions of 560x420 (or 480x360) and with better video quality than YouTube (i.e. quality good enough that one can really see expressions on a face)?