Canon CHDK User Manual page 17

Video Parameters
Video Mode
Video compression modes.
–
Bitrate
dictates a constant data rate.
Video compression (and hence, video quality) expands or
contracts as necessary to maintain the data rate constant.
Quality –
Sets a constant compression level, ensuring a defined level of quality regardless of
how much data that level requires.
Note: From owners reports of testing Quality overrides, it is evident that settings above the
standard Canon setting gain little if any higher quality, however file sizes will increase
significantly. Lower settings (minor), will lose little in quality but will reduce file size.
Excess Bitrate and Quality settings can cause memory buffer overload, and stop
recording, a red
Video Bitrate
The compression factor for Bitrate compression. 0.25 is the most compressed /least quality and
3 is the least compressed / best quality.
Video Quality
The compression factor for Quality compression. 1 is the most compressed / least quality and 99
is the least compressed / best quality. (Roughly ~70 - 80 is Canon equivalent).
Clear Video Params on Start?
When enabled this will clear all your custom video compression settings back to the camera's
own defaults on startup.
Fast Video Control
Only a few cameras are supported. Pause and unpause video by pressing
recording. Note: When using this function the remaining video-record time calculation is reset,
so the change is shown immediately in the OSD.
Video Quality Control ?
When enabled, using the
bit-rate (depends on which one is enabled in the Video Mode override) - While you are
recording.
Enable Optical Zoom
This feature allows you to use the camera's optical zoom during video recordings.
Mute During Zooming
To eliminate focus mechanism noise. Please note that the zoom mechanism sound is very loud in
video, which is probably why it was disabled by the manufacturer.
AF key
< Video Parameters < Main Menu
(Shutter button - half press, or
single autofocus scan.
< Main Menu
[ Bitrate or Quality ]
!
will show on the OSD.
[ 0.25, 0.5, 0.75, 1, 1.25, 1.5, 1.75, 2, 2.5, 3 ]
[ 1 - 99 ]
< Video Parameters < Main Menu
Enable [•] / Disable [ ]
Enable [•] / Disable [ ]
button will increase or decrease video quality or
UP / DOWN
Enable [•] / Disable [ ]
Enable [•] / Disable [ ]
FUNC.SET
Enable [•] / Disable [ ]
< Video Parameters
< Video Parameters
button) During video recording - camera makes a
while
LEFT / RIGHT
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