Tips on encoding video for Adobe Connect (plus some presets!)

Note: Adobe Connect supports FLV, F4V and MP4 video formats. Not sure which file format to use? Read this blog entry first. This article primarily applies to Flash Video (FLV).

If you're completely new to video, or Flash Video, a good place to start is this Learning Guide on Adobe Developer Connection, which includes a lot of great information.

If you're only interested in playing back video in Adobe Connect, the learning guide might actually be too comprehensive, so I thought it would be valuable to share some Connect-relevant tips.

There are three main factors that determine the overall size and quality of your video:

1. Frame size - width & height of your video. 
2. Bitrate (or data rate) - how many kilobits per second are needed to display video. 
3. Frame rate (or frames per second).

The trick is to figure out the right combination of these three factors that gives you the best video quality at an acceptable target bandwidth (or datarate/bitrate). Here are some general tips:

• Use uncompressed video: Remember the old 'garbage in, garbage out' principle. For best results, start with the highest quality video source that you have. Also, if you are actually capturing the video, be sure to check the tips on this page. 
• Frame size - In most cases, when sharing a video in an Adobe Connect meeting, the Share pod will likely share the available screen real estate with other pods, so keep that in mind when you're deciding how large (or small) of a video frame you want. Also, remember that Connect will automatically rescale the video up or down to fill your Share pod. Having a larger frame size than the size of the Share pod in your layout will just incur additional bandwidth, without any real quality benefit. 
• Bitrate: Unless you know that all of your participants will have a robust Internet connection, I wouldn't go much higher than 600kbps for a 360p frame. Because video in Connect is streamed to meeting participants (rather than progressive download), only a small part of the video is being buffered for each participant at any given time. If there is a drop in connectivity and the participant's buffer runs out, the video playback will stop until the buffer fills up again. 
• Frame rate: In most cases, you're likely going to leave the frame rate as-is. However, if you do need to reduce the frame rate, use a number that divides evenly into the original fps. For example, if your original video is 30fps, then your options would be 15, 10, 6, 5, etc. 
• 2-pass: If you have a choice between 1-pass and 2-pass encoding, go for 2-pass. It takes longer for the conversion process, but you'll get better results. 
• CBR: The other common option you will see is a choice between constant bit rate (CBR) and variable bit rate (VBR). Since video playback in Adobe Connect is streaming (vs progressive download), CBR is your best bet. 

There are a lot of options for actually converting your video files (future blog topic?) to Flash Video, but if you're using Adobe Media Encoder, feel free to download and use the attached presets:

• 480p (16:9 - widescreen) - 854x480 - 900kbps
• 360p (16:9 - widescreen) - 640x360 - 512kbps
• 240p (16:9 - widescreen) - 426x240 - 384kbps
• 360p (4:3 - standard) - 480x360 - 410kbps
• 240p (4:3 - standard) - 320x240 - 324kbps