Raspberry Pi A User Manual page 128

112
P A R T I
framebuffer_ignore_alpha—Set to
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controls transparency in the console. Disabling the alpha channel is not normally
required, but it may correct graphical corruption caused when setting
to 32 bits per pixel.
depth
sdtv_mode—This value affects the analogue composite video output of the Pi, adjust-
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ing it to operate in various countries. By default, the Pi uses the North American ver-
sion of the NTSC video standard; users in other countries may need to change this
value to get a picture on an analogue TV. Possible values are:
•
0—NTSC, the North American video standard
•
1—NTSC-J, the Japanese video standard
•
2—PAL, the video standard for the UK and other countries
•
3—PAL-M, the Brazilian video standard
sdtv_aspect—Controls the aspect ratio of the analogue composite output. If the pic-
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ture looks stretched or squished, alter this to correspond to your TV's aspect ratio.
Possible values are:
•
1—4:3 aspect ratio, common on older sets
•
2—14:9 aspect ratio, common for smaller widescreen TVs
•
3—16:9 aspect ratio, common for modern widescreen TVs
hdmi_mode—In addition to setting the video mode for the analogue composite out-
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put, it's also possible to override automatic resolution detection on the HDMI port.
This is handy if you want to run your Pi at a lower resolution than the display's native
resolution in order to make things more readable from a distance. Appendix C, "HDMI
Display Modes", lists the possible values for this setting.
hdmi_drive—It's also possible to alter the voltage output by the HDMI port. This is
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important when you're using an HDMI to DVI adapter, because HDMI and DVI volt-
ages differ slightly. If you find that your picture is snowy or blown out with too bright
an image, try altering this setting. Possible values are:
•
1—DVI output voltages. In this mode, no audio is included on the HDMI cable.
•
2—HDMI output voltages. In this mode, audio is included on the HDMI cable.
hdmi_force_hotplug—Forces the Raspberry Pi to use the HDMI port, even if it
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doesn't detect a connected display. A value of
display, while a value of
C O N N E C T I N G T H E B O A R D
, this value disables the alpha channel, which
1
0
forces the Pi to use HDMI regardless.
1
framebuffer_
allows the Pi to attempt to detect the