HDMI & Audio – RasPi Show

Video Resolution

Sometimes you may find that the Raspberry Pi does not use the correct video resolution for your monitor. You can set it correctly.

tvservice -d edid.dat

1	tvservice -d edid.dat

edidparser edid.dat | grep 1080p
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Example output:
HDMI:EDID found CEA format: code 16, 1920x1080p @ 60Hz (native)
HDMI:EDID found CEA format: code 31, 1920x1080p @ 50Hz
HDMI:EDID CEA mode (16) 1920x1080p @ 60 Hz with pixel clock 148 MHz has a score of 211624
HDMI:EDID CEA mode (31) 1920x1080p @ 50 Hz with pixel clock 148 MHz has a score of 128680
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edidparser edid.dat | grep 1080p

=======================================

Example output:

HDMI:EDID found CEA format: code 16, 1920x1080p @ 60Hz (native)

HDMI:EDID found CEA format: code 31, 1920x1080p @ 50Hz

HDMI:EDID CEA mode (16) 1920x1080p @ 60 Hz with pixel clock 148 MHz has a score of 211624

HDMI:EDID CEA mode (31) 1920x1080p @ 50 Hz with pixel clock 148 MHz has a score of 128680

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“CEA” corresponds to hdmi_group=1
“DMT” corresponds to hdmi_group=2
The value inside () corresponds to hdmi_mode.

From the above result:
hdmi_group=1
hdmi_mode=16

The file /boot/config.txt has these lines:
#hdmi_group=1
#hdmi_mode=1

As in the case above use sudo nano /boot/config.txt and modify them as required. Don’t forget to remove the # from the lines.

Reboot.

Alternately:

sudo sed -i "s,#hdmi_group=1,hdmi_group=1," /boot/config.txt
sudo sed -i "s,#hdmi_mode=1,hdmi_mode=16," /boot/config.txt
sudo reboot

sudo sed -i "s,#hdmi_group=1,hdmi_group=1," /boot/config.txt

sudo sed -i "s,#hdmi_mode=1,hdmi_mode=16," /boot/config.txt

sudo reboot

No Audio via HDMI

If you find that there is no audio output via HDMI then:

sudo sed -i "s,#hdmi_drive=2,hdmi_drive=2," /boot/config.txt
sudo reboot

1 2	sudo sed -i "s,#hdmi_drive=2,hdmi_drive=2," /boot/config.txt sudo reboot

Omxplayer Errors

Set the GPU Memory size to 256MB

This is very important. Omxplayer will at times error if you do not do this,

sudo sed -i "s,gpu_mem=64,gpu_mem=256," /boot/config.txt
sudo reboot

1 2	sudo sed -i "s,gpu_mem=64,gpu_mem=256," /boot/config.txt sudo reboot

Alternately, use the Raspbian menu preferences>raspberry pi configuration>performance, increase the GPU Memory to 256.