17
NC
18
GND
19
NC
20
GND
PLAYING MULTIMEDIA
The default installation includes a command-line multimedia player. To
play audio or video start the media player giving the media files as
command line arguments:
mplayer song1.ogg
mplayer myvideo.avi
The sound volume can be controlled either from the GUI or by the
command-line ALSA application:
alsamixer
Volume channels are selected by the left and right arrow keys, values can
be changed with the up and down arrow keys, mute is controlled by the M
key, and the ESC key exits the application. Note that certain terminal
emulation programs cannot cope with the
alsamixer
output. HyperTerminal
is known not to work. PuTTY is known to work.
WARNING:
By default MPlayer uses the OSS sound interface. But
sometimes the OSS-emulation layer in ALSA does not work properly,
particularly in situations when the original sound stream must be down-
sampled. In these cases the sound will be distorted. MPlayer can be forced
to use ALSA with the
-ao alsa
command line argument:
mplayer -ao alsa song1.ogg
WARNING:
If colors seem to be messed up then MPlayer is not using 24bpp
color depth for the frame buffer. Fix that by forcing the video output driver
to SDL:
export DISPLAY=:0.0
# in case we're on the ttyS0 console
mplayer -vo sdl myvideo.avi
USING THE SD/MMC SLOT
A few limitations arise when using the SD/MMC slot:
1. AT73C213 sound cannot work in Linux.
2. ADS7843 touchscreen cannot work in Linux.
3. Generic SPI cannot work in Linux.
4. Before and during booting the jumper AT/SD must be in position
“AT”. After Linux kernel is loaded and running, this jumper must be
placed at the “SD” position.
5. The SMD jumpers WP_E and CP_E must be soldiered.
6.
A specially configured version of the Linux kernel must be used. A
precompiled binary can be found in the
“sam9-l9261-samba-
sdmmc.zip” archive
. The configuration for this kernel can be loaded
in the kernel source tree with the following command
make sam9_l9261_sdmmc_defconfig
CAVEAT:
The AT91SAM9261 MCI controller has a few bugs which can
prevent it from working properly with some SD/MMC cards. Please consult
the chip errata for more information.
COMPILING USER APPLICATIONS FOR EMBEDDED LINUX
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