Adobe Premiere Pro CS6 - Manual (Page 479)

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frame rate of an FLA file, use the Advanced Video Encoding settings in the FLV Import wizard.
Select a frame size that fits your data rate and frame aspect ratio
At a given data rate (connection speed), increasing the frame size decreases video quality. When you select the frame size for your encoding
settings, consider frame rate, source material, and personal preferences. To prevent pillarboxing, choose a frame size of the same aspect ratio as
the frame aspect ratio of your source footage. For example, pillarboxing results when you encode NTSC footage to a PAL frame size.
Adobe Premiere Pro makes several FLV and F4V file presets available through the Export Settings dialog box. These include preset frame sizes
and frame rates for the different television standards at different data rates. Experiment with the various Adobe Media Encoder presets to find the
best setting for your project. Use the following list of common frame sizes (in pixels) as a guide:
Modem NTSC 4 x 3 162 x 120
Modem PAL 4 x 3 160 x 120
T1/DSL/Cable NTSC 4 x 3 648 x 480
T1/DSL/Cable PAL 4 x 3 768 x 576
Stream for best performance
You can stream FLV and F4V files to eliminate download time. FLV and F4V files also have deep interactivity and navigation capabilities when
they are streamed. Streaming FLV and F4V files allow you to monitor quality of service. You can stream FLV and F4V files with the Flash Media
Server. Alternatively, you can use a hosted service from one of the FLV/F4V Streaming Service partners available through the Adobe website. For
more information, see “Delivering Flash Video: Understanding the Difference Between Progressive Download and Streaming Video” on the Flash
Developer Center website.
Cover progressive download times
Learn how long it takes to download enough of your video so that it can play to the end without pausing to finish downloading. While the first part
of your video clip downloads, you can display other content that disguises the download. For short clips, use the following formula: Pause =
download time – play time + 10% of play time. For example, if your clip is 30 seconds long and it takes 1 minute to download, give your clip a
33-second buffer. The applied formula is 60 seconds – 30 seconds + 3 seconds = 33 seconds.
Remove noise and interlacing
For the best encoding, remove noise and interlacing.
The higher the quality of the original, the better the final result. Frame rates and sizes of Internet video are smaller than frame rates and sizes of
television video. However, computer monitors typically have color fidelity, saturation, sharpness, and resolution at least as good as high-definition
televisions. Even with a small window, image quality can be as important for digital video as for HDTV. Artifacts and noise are at least as obvious
on a computer screen as on a television screen.
FLV files, F4V files, and SWF files are intended for progressive display on computer screens and other devices. Interlaced displays such as TVs
do not typically play FLV or F4V files. Interlaced footage viewed on a progressive display can exhibit alternating vertical lines in high-motion areas.
Thus, all the FLV and F4V file presets in the Adobe Media Encoder have deinterlacing turned on by default.
Follow the same guidelines for audio
The same considerations apply to audio production as to video production. To achieve good audio compression, begin with clean audio. If your
project contains audio from a CD, transfer the audio files directly from the CD to your hard disk. Do not record the sound through the analog input
of your sound card. The sound card introduces an unnecessary digital-to-analog and analog-to-digital conversion that can create noise in your
source audio. Direct digital transfer tools are available for Windows and Macintosh® platforms. To record from an analog source, use the highest-
quality sound card available.
Tips for creating video for mobile devices
Use these tips when shooting content for mobile devices:
Tight shots are better. Try to keep the subject separated from the background; the colors and values between background and subject
should not be too similar.
Be aware of lighting. Poor lighting is a greater problem with mobile devices and can reduce visibility on small screens. Shoot and adjust with
this limitation in mind.
Avoid excessive panning or rolling.
Use the following tips when editing video with Adobe Premiere Pro and After Effects:
Set the frame rate for the output movie according to output device or output type. For example, a commercial in After Effectsmight be
rendered at 15 frames per second (fps) for distribution on mobile devices, but at 29.97 fps for broadcast television in the USA. In general,
use a lower frame rate. A frame rate of 22 fps is a good compromise for reducing file size without losing quality
Make the movie as small as possible and remove any extraneous content, especially empty frames. Many actions can be done pre-encoding
to limit file size. Some of them apply to shooting techniques, while others (for instance, using motion-stabilization tools in After Effects or
applying a noise-reduction or blur effect) are post-production tasks that facilitate the compression portion of the encoder.
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