Display Resolutions

From BATC Wiki
Revision as of 13:24, 14 July 2017 by G8GKQ (talk | contribs)
Jump to navigation Jump to search

This page details the various display formats and resolutions used in the Portsdown Transmitter.

Pi Camera

The native resolution of the Version 1 Pi Camera is 2592x1944. The version 2 camera is 3280x2464. These resolutions are always downscaled in the Portsdown Transmitter.

Video from EasyCap

The Fusicai EasyCap (as sold by the BATC Shop) outputs 720x576 in PAL mode, and 720x480 in NTSC mode. This mode can be switched by making selections on the Portsdown Console Menu or the Touchscreen menu. The PAL/NTSC selection on these menus ONLY adjusts this input mode; no other settings are changed.

Raspberry Pi Framebuffer

The Framebuffer on the Raspberry Pi 3 is 720x576 when set to PAL output mode. If set to NTSC output mode (by manually editing /boot/config.txt) the resolution is 720x480. Note that all the graphics, test cards and image overlays are sized to work correctly in PAL output mode. Some overlays will spill out of the picture in NTSC output mode. NTSC output mode is not tested or supported.

Raspberry Pi Analog Video Output

As of Software Release 201707120, The Raspberry Pi Analog video output (available on the 4-way 3.5mm jack) is set to output PAL at 720x576@50i. If set to NTSC mode (by manually editing /boot/config.txt) the resolution is 720x480@60i. Some overlays will spill out of the picture in NTSC output mode. NTSC output mode is not tested or supported.

Waveshare 3.5 inch Screen

The Waveshare 3.5 inch screen is 480x320. Note that this is a 3x2 aspect ratio, not 4x3, so some vertical compression (flattening and widening) of the transmitted image occurs.

Element 14 7 inch screen

The Element 14 7 inch display is 800x480 pixels.

Transmitted Resolution

The transmitted resolution depends on the mode, FEC and SR:

Default CAMH264 resolution is 720x576@25p Default CAMMPEG-2 resolution is 768x576. Note that this is currently generated from a stretched 720x576 picture.

Receiver Compatibility

There is no concept of a "PAL" or an "NTSC" DVB-S or DVB-S2 receiver. When PAL or NTSC is used in the receiver description it may refer to an analog video output from the receiver. What has been noticed is that some DVB-S receivers designed for use in North America do not decode 576x720 resolution and were manufactured on the basis that they would only ever receive 480x720 signals; as such they are not fully DVB-s compliant.