Optimizing web videos has become very important as the use and size of videos has increased on the Web. Here are some practices used prominently by many people.
While streaming-media files make up only a small portion of the total web objects on the average web page. YouTube is responsible for about 10% of all traffic on the Internet (Nowak 2007) and is growing at over 162% a year (see Table 1). Consequently the optimization of streaming media, movies in particular, is important to minimize load times, reduce bandwidth bills, and maximize web page speed.Site | Unique Visitors (1000s) (Jan 2010) | Year-over-year growth |
1. YouTube | 66,378 | 162% |
2. Google Video | 23,759 | 137% |
3. AOL Video | 18,687 | 114% |
4. Yahoo! Video | 17,473 | 405% |
5. vids.myspace.com | 14,281 | 69% |
6. MSN Video | 19,967 | 8% |
Video Production Tips
To create highly optimizable videos you've got to have high quality originals videos. Video creation is like a war for your promotion of product. Use a high quality digital video camera to make your video, as there will be less noise in your video content. Minimize pans, zooms, and subject motion and make sure your subject is well oriented and visible and loud for the audiences to catch their attention. Use a simple background and a solid tripod for the camera. Avoid hand-held shots, but if a tripod is not an option use a gyroscopic stabilizer or an image stabilized lens. The lower the noise, movement, and fine detail in the background the smaller the video. Smaller the video the less space it will need on the web server and the faster it will be available to the user.- Minimize camera motion with a tripod
- Minimize subject motion
- Use a lot of light
- Use a simple background
- Avoid camera pans and zooms
- Use professional equipment
- Use a digital format
Video Optimization for the Web
Movies optimized for the web should be short in duration, small in dimension, and optimized with the appropriate codec. I have seen movies that are 12 to 20 minutes long auto-loaded on home pages some 90-150MB in file size! People are more accepting of temporal compression (over time) than spatial compression (frame per frame). You can cut the frame rate from 15fps to 10fps or even 8fps, each frame will have 50 percent more data per frame for the same file size, which will increase the quality of the picture. The minimum dimensions should be 320x240 pixels, anything much smaller has less impact and is hard to view. For users with a high speed connection you can offer a 400x300 pixel video. To maintain quality, up the data rate in proportion to the image size. Remember that doubling image size (320x240 to 640x480) requires a 4X (not 2X) increase in data rate.Use this data rate formula to help target your movie for the right delivery medium (especially with H.264).
Data Rate = (frames per second) X (movie width) X (movie height) divided by 29000
This translates to DR = FPS * W * H / 29000.
For example: A 320x240 movies with 15 frames per second needs to be compressed to about 39.7K of data per second.
After you've captured your video while minimizing noise edit any unnecessary frames and add titles and effects. The key to optimizing movies on the web is to break them up into smaller segments that are a few minutes long at most. Edit out the parts of the movie that aren't essential to your message, crop fuzzy edges, and reduce the dimensions to keep them to a reasonable file size. Use the minimum frame rate that gives an acceptable playback. Finally after editing out nonessential content, reducing dimensions and frame rate, optimize your videos with different codecs to see which creates the smallest acceptable file.
- Crop the fuzzy edges
- Reduce video noise (with filters)
- Adjust contrast
- Adjust gamma level (for cross-platform viewing)
- Restore black and white
- Deinterlace
Compressing Videos for the Web
Now that you've got your video prepared and adjusted it's time to compress it. This is called "encoding" in the jargon of the industry. You must compress the size of your video so it can be successfully streamed (or downloaded) to your target audience. Encoding is the process where this compression happens, and it is full of hard interdependent decisions:- Streaming Media Format - QuickTime versus RealMedia versus Windows Media
- Supported playback platforms - Microsoft Windows versus Macintosh, or both
- Delivery method - True real-time streaming versus HTTP streaming
- Overall data rate - Compression versus quality versus bandwidth required
- Audio quality - Mono versus stereo.
- Codec - H.264, Sorenson and WMV are the current champs.
- You'll need to make some decisions here to give the best compromise between quality and size. QuickTime Pro is a fast and convenient way to create optimized videos. For more control you can use Cleaner, a product made by Discreet (http://www.discreet.com). Sorenson Video Pro can sometimes make smaller videos than H.264 at similar quality. Finally Episode Pro offers maximum control over video compression with the ability to compress to H.264, Flash, ipod, and other formats.
CHEERS!!! ENJOY VIDEO OPTIMIZING
