Shooting Content Suitable for Streaming
1. Start with clear objectives
If you shoot without clear objectives, editing will end up being difficult. In a worst case scenario, you may need to reshoot some scenes, which will thus lead you to lose valuable time. Start with a well developed shooting policy that clarifies what you want to deliver to your audience, picturing and realizing specific scenes in advance. Sketch out the scenes before you shoot them.
2. Use methods suitable for streaming
Streaming distribution has a limited bandwidth.
[Avoid quick panning and zooming]
The larger the differences between frames, the higher the compression ratio (degrading image quality). Keep camera motions smooth and avoid quick panning and zooming.
[Get close to your target]
The streaming replay screen is small (mostly around 320 x 240). Long shots make it hard for the audience to follow the action. Try to get as close as you can to your target when shooting.
[Use different camera angles]
Since you cannot use a lot of zooming when shooting for streaming distribution, you may tend to shoot from the same angle. The result will be a monotonous picture and the audience will soon get bored. It is better to shoot cuts from different angles.
[Tripod is a must]
Handheld shots are always blurry and shaky, hence uncomfortable to watch. Use a tripod as often as you can.
[Avoid detailed images]
Elaborate details with many colors will require considerable arithmetic processing when encoding, degrading the compression rate and reducing image quality.
Choose simple backgrounds. Actors should avoid wearing checked or striped costumes.
[Shoot with ample lighting]
If you encode for a small streaming screen, the result will be smaller and darker than the original. Shoot in bright locations or use artificial lighting for interior shots.
[Recording sound on location]
To ensure that sound is clear, use microphones or pinned mics instead of camera microphones. For lectures and seminars, retrieve the sound from the mixer used at the site.
Editing for Streaming
The following is the workflow for creating a streaming file.
1. Prepare or shoot the material.
2. Upload the movie into a PC.
3. Edit the movie using editing software.
4. Render into a file format that can be encoded (converted) to a streaming file.
5. Convert to a streaming file.
As you can see from above the workflow, after shooting you are working solely with a PC to create a streaming file. First, upload your material (movie footage) into your PC, which is a process called "capturing."
Specific steps will differ depending on your motion picture editing software; refer to the tutorial for your particular application.
Since each editing application operates in its own way, we cannot cover every detail. Here, however are a few tips when preparing a film for streaming.
1. Avoid frequent use of transitions (scene joining effects)
A transition is a very effective method to create a smooth change between scenes, but complicated transitions will increase the difference between frames. Sudden movements or block-noise may ruin scenes before and after the transition.
2. Do color correction at the editing stage.
The computer display shows color information in RGB (Red-Green-Blue), the three principle colors of light. On the other hand, NTSC uses YUV (Y stands for luminance, U for hue, V for color saturation). If YUV is applied to RGB, white becomes light gray and black becomes dark gray; the screen is darkened.
Most streaming files are viewed on a computer display. If you encode a movie without color correction, it will be darker than the original. To prevent this from happening apply color correction in advance, for example by increasing the contrast gamma (by using special effect or color correction filters) at the editing stage.
*If the encoder has software that enables you to apply color correction, it is better to do so in during the encoding process.
3. Adjusting audio gain
Most streaming files are viewed on a computer. Depending on the user environment, optimum volume is often unavailable due to sound card or speaker specifications. Set the decibel gain to +6 or more when editing.
When you have completed the editing, the last thing to do is to render it to a file format that is compatible for encoding into a streaming file. File formats compatible with the Windows Media Encoder include files with .wma, .wmv, .asf, .avi, .wav, .mpg, .mp3, .bmp and .jpg file extensions.
*When using a .mpg file as a source, the computer used for encoding must have a MPEG-2 compatible decoder installed.