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Here’s how I go about predicting what my video will look like once it is uploaded.
I have yet to find a video sharing site that doesn’t encode video in the Flash format (or FLV) for streaming. The biggest difference is the rate the signal is delivered at. To give you an idea of what’s typical, I checked playback rates of my videos on several sites.
Remember, all the files are served, streamed or played back in the same format, .FLV or flash video. On MySpace, the file streamed at 463Kbps (Kilobytes per second.) Then CNN iReports stream at 512Kbps. YouTube now has a normal and a high quality mode, normal streams at 378Kbps while HQ doubles it to 763Kbps. I also have an account on Spike TV’s site and it streams at 764Kbps. And finally to provide some real contest, my demo reels on Reel Exchange start at 1024Kbps (or 1 meg per second) and go up to 1396Kbps.
So when you upload to a particular site, they pick the band width (of the Kbps rate) they will playback your flv file at. So to see roughly what you will get, save a preview file at the bit rate as the site you’ve selected. Now that quality of image will be the best it can look streaming from that site. Using my examples, Spike TV and the HQ stream on YouTube will give the best quality playback of the video sharing sites. (But the professional Reel Exchange demo reels blow them out of the water.)
The other variable in the quality of the playback stream is how large (and what kind) of a file you can start with. If you are limited to a mere 100 Mb file, make sure the bit rate you use is at least as high as the site will convert to. If you have to compress your file to 256Kbps to make it fit, the sites I investigated could be recompressing at the higher rate by adding to or reusing your data. I prefer to upload to YouTube, since they accept files up to 1 gigabyte in size. My experience has been that I get better results when I use files with intra-frame rather than inter-frame compression. AVI is the classic intra-frame compression format while H.264 uses a great deal of inter-frame compression. (BTW, intra-frame compresses on each frame separately, inter-frame compress across several frames, know as GOP’s.) As may already know, AVI’s take around 1 gigabyte for every 5 minutes of video. So for videos shorter than 5 minutes and uploaded to YouTube, I will use the AVI format that Vegas uses.
My experience with the other standard rendering formats in Vegas can be fairly easily summarized. MPEG-2 translates well into an FLV stream. But if it is too large, I’ve also used MPEG-1 with good results. I have also played with Quicktime MOV’s but find they are always larger than the same compression using the WMV format. (This is something Vegas does, I’m fairly certain it isn’t true of all MOV renders.) So that’s what I’ve been doing to get fairly predictable results.
Hope this helps and Good Luck with posting your videos.