Flash Video Support Information
Make your Flash Video Deployment Flawless

Video Conversion Basics

To convert video files to FLV format you will need a conversion application, referred to as an encoder. Converters are fairly straightforward to use — you simply import a file, choose a preset or customize the settings if required, then export as FLV. Good converters have additional features such as batch processing options.

There are numerous applications available to perform this encoding function, but three are the most prominent:

• Adobe Flash Professional: The official Flash authoring program comes bundled with a utility called Flash 8 Video Encoder. Flash itself is very powerful (and correspondingly expensive) but the encoder doesn't actually produce the best quality FLV files. If you already own Flash, this is a good way to begin making FLV files but if you want the best possible quality you should try other options.
• On2 Flix : Flix is a collection of encoders by On2 Technologies, the company which makes the VP6 codec used in Flash 8. There are various options including low-budget versions.
• Sorenson Squeeze : A powerful and versatile conversion application.

If you are not familiar with these applications or do not have professional video production equipment, feel free to contact us to create and convert your videos for you.

Flash Player Compatibility
Only Flash Player 8 supports both publishing and the playback of On2 VP6 video. You are able, in your web page, to include html code that will check for the latest Flash Player plugin and give the viewer the choice to install is without leaving your page.

Use the original source video whenever possible. Encoding an already compressed video source, like Windows Media, Quicktime or other compressed format will result in a much more degraded finished product than working with an uncompressed formet. Good quality DVD's (MPG2), Digital Video (DV) can produce exceptional results, since compression is not nearly as great as with other compression schemes.

Best Practices For Encoding Flash Videos

When you encode flash videovideo, you must take into consideration a number of factors, including amount of motion in the video, the target file size, target bandwidth, frame rate, keyframe interval, and theoverall dimensions of the video.

You may specify the settings for these factors when you encode Flash video.

The following are some general guidelines to follow when compressing video to Flash video for delivery over the Internet.

• A higher target bandwidth (also known as data rate) allows for more motion in the video, larger files, better frame rates, and larger pixel dimensions.

• The less motion there is in your video, the smaller the file size, which lowers the target bandwidth you can reach.

• As the target bandwidth decreases, reduce the keyframe rate. A lower keyframe rate (such as one keyframe every six seconds) will result in a softer or blurrier image but reduces the bandwidth demand.

• As motion increases, you must increase the keyframe rate, the frame rate, and the data rate. High-motion clips require more information to flow to the player. They are not good for low-bandwidth delivery because they require additional uncompressed keyframes to be encoded in the file.

• Reduce frame size when bandwidth is limited and frame rate and quality are important.

• If the video source you are encoding comes directly from a video camera, always enable de-interlacing and set the Flash Video Encoder to the upper field. If your video is interlaced, selecting this option increases the performance of the video encoding and playback.

Broadband Bit Rates
The bit rate you set the video at during encoding is the amount of data that will be transferred per second. When you encode Flash video, you specify a bit rate for the encoding. myFLASHSTREAM servers are robust and can handle broadband streams with ease. For DSL and Cable Modem subcribers, can normally view a very high-quality stream of 512 kbps with ease and offers an excellent balance of file size and quality.

Keyframes are important too!
Flash video is encoded as a sequence of keyframes (full-frame uncompressed images taken from the video at regular intervals), each of which is followed by information about how to change the pixels of the keyframe to produce the delta frames between that keyframe and the next. During playback, the decoder recreates the delta frames based on the keyframes.

With Flash video, keyframes are particularly important if your presentation approach provides a seek or scrub feature, which allows a user to advance the stream during playback. Keyframes set at every 15 - 30 frames result in a more more fluidly searchable (scrubbable) video for the end-user.

Streaming vs. Progressive Download

Progressive Download
On a broadband connection (Cable, DSL, T1) will see a status bar on the bottom of the video player as the video loads. Flash video is designed to calculate the speed at which the video is downloading and wait until enough of the video has been cached to begin playback without interruption. If the progressive stream slows during download, the video will pause until enough of it has loaded to allow playback to continue. DIal-up users may still choose to view the high quality video, but they will need to wait for a portion of the video to load before playing, and the video may pause during playback to allow it to continue loading. The quality of the video remains the same for both users.

Streaming
Streaming video is slightly more complicated. You may offer high and low bandwidth versions of the flash video. Each one would be compressed at different rates that will target either high or low-speed users. When a user attempts to view streaming video, flash will detect their bandwidth and stream the appropriate video for their connection speed. This means users on a low bandwidth connection will automatically receive a smaller, lower quality video and the braodband user will be streamed the higher-quality version. Thus, the end-user's bandwidth becomes the limiting factor in the video quality they receive.

Startup Time
Both Progressive and Streaming methods will load at about the same rate, especially for the bulk of your audience - the braodband users. One delays in polling the end-user's connection, the other dealys in caching just enough video to begin playback. For any braodband user, a 512 kpbs bit rate file will stream in almost immediately.

Seeking the Video
Progressive and streaming video have seek and navigation abilities. Progressive video can not seek video segments which have yet to be downloaded, while streaming video can, however, as fast as video is likely to be cached, this will rarely if ever be a concern or even noticed. Once a video file is completely cached, progressive files can be seeked or "scrubbed" back and forth fluidly. Streaming content must be re-sent from the server each time a new portion of the video is sought out.

Web Delivery
As mentioned befoire, progressively downloaded videos are stored in the user's cache. For customers who must maintain strict control over their content, streaming offers the advantage that it is extremely difficult to save the viewed content on the viewer's computer. With progressive download, a user could possibly locate the video content from their computer's cache. It is not a simple process for most, but possible. With streaming video, saving the content locally is very difficult to nearly impossible - and therefore offers more security with the content.

Compatability
If you need to support Flash Player 6 or below, you will need to choose a streaming account. Flash player 7 and above can handle progressive and streaming files which the bulk of users already have. You may place the code to automatically inform the viewer of the need to install an updated player and to view the material. This is a very simple snippet of code you can place in your web page.

Server Differences
Progressive download is easier to setup, and does not require special server software to run. Streaming requires this unique server software.

Conclusion
Both streaming and progressive download have their particular advantages and you should base your decision on your needs. If your video is very long, in excess of 10 minutes for instance, you should probably choose a streaming account. Otherwise, your content will play just fine with progressive download.

As a customer, we will try to answer any of the questions you may have as to what service best fits your needs, contact a customer service representative and we will be happy to assist you.

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