Eric Cheng

View Original optimal video encoding - mp4 vs flash

Jason and John over on the Kyte team have been really helpful over e-mail; I've figured out how to produce great video on Kyte. At the moment, they tell me that optimal resolution is 424x318 pixels. Also, a Flash (FLV) video encoded at less than 700kbps will not be re-encoded by Kyte.

Here are two examples of the same video hosted as a show on Kyte (a white-tip reef shark being cleaned by gobies -- I shot it in Cocos last year):

1. 424 x 318 pixels, MP4, High VBR using Compressor (9.3 MB upload)

2. 424 x 318 pixels, Flash (FLV), 650kbps using VisualHub (4.3 MB upload)

I put the windows next to each other and played them simultaneously. The difference is obvious: the Flash version looks much better even though it was half the upload size.

Here is a comparison of partial screenshots: uploads: flv on left, mp4 on right

Note that I used VisualHub instead of ffmpegX to do the Flash transcode because ffmpegX requires that width and height be divisible by 16. The closest to 424x318 is 432x320, which I thought might not be ideal.

Also, I had to produce a letterboxed version of the original video before the output to Flash, since Kyte isn't smart enough to retain aspect ratios. I hope they support that soon.

So it looks like I'll have two broadcast workflows:

If I have time, I will output a 424x318 version of my show in Apple Intermediate format using Compressor, and then run it through VisualHub to Flash before uploading.

If I don't have time, I will use the Flip Ultra and just upload the video. :)