Skip navigation

TV System option (also referred to as Video output mode) sets video display parameters of STB making possible properly displaying video on the TV screen, computer monitor, etc.
TV System option defines two main parameters - Display resolution, and TV scan method (i-interlaced or p-progressive). In addition, for each value of the TV system option, the Aspect ratio and Framerate parameters are defined by default. When STB works along with digital TV, Auto framerate mode can be activated on STB.
A list of TV System values is specified below in the Supported Video Output Modes section.

Graphic Resolution option sets which display resolution value should be used for "drawing" graphic objects (like text, images, etc.) on the TV screen. List of Graphics resolution values and specificity of graphics displaying, depending on TV System value, are considered in on the upper level of the screen resolution section.

STB connecting to TV receiver

TV system set on video outputs during and after STB booting

During the boot process (after STB power on or reset), one of Standard Definition (SD) modes is set at the STB video outputs: PAL(576i) or NTSC(480i) - the value is determined at the factory according to the region where STB is planned to be used (PAL region or NTSC region - see below).
SD video mode makes possible to display boot process (logo and boot process messages) on TV screen regardless of TV type (analog or digital). In addition, SD video mode is set during the Bootloader menu (for MAG250/254/270) or System Recovery Utility menu (MAG256/322 and all next STB models). During STB boot up, the video signal is transferred simultaneously to digital (HDMI) and analog composite (AV) video outputs. After the boot process completed and STB software loaded, STB switches to Video Output mode value defined in STB settings.

Note. As an indicator of boot completion, it can be considered start of media portal loading (Embedded or External) or Select a Portal for loading window displayed on the screen.

Absence of image on TV screen during STB boot (only for MAG250/254/270)

If nothing is displayed on the TV screen during STB boot up (black screen), a possible cause may be a mismatch between STB TV system and video display resolution supported by TV - PAL (480i) or NTSC (576i). To handle the issue user can change TV system mode (PAL / NTSC) using the Remote control unit (RC).

In case of absence of image on the screen try to do as follows:

  • Turn off STB (unplug the power connector).
  • Press and hold Menu on RC (direct your RC straight to STB front panel).
  • Turn on STB (plug the power connector in) while Menu key remains pressed.
  • Hold on Menu key for 10 seconds after turning on STB.
  • Switch PAL - NTSC with a single press Red key (F1) on RC (Bootloader menu screen should appear).
  • Exit from the Bootloader menu.

Incorrect connection/setting of video output (only for MAG250/254/270)

If STB TV system has been set to one of the HD modes, an alarm message is sent to analog video (AV) output:

Image Documentation

If you are watching this warning then:

  • if you intend to use AV video output then video output mode selected on STB is wrong (change TV system to SD mode supported by your TV - PAL (480i) or NTSC (576i);
  • if you intend to use HDMI video output, you need to change your video output connection to HDMI. If you also use HDMI connection in parallel with CVBS (AV) connection, change Source settings on TV (to HDMI input).

Information for developers. The warning text is located in the STB software image in file /home/default/SDmsg_en.

Screen resolution choice

Before first connecting STB to TV, the user should carefully read operating instructions for the TV. Make sure that the TV system and Graphic Resolution values set in STB conform with your TV screen resolution.
The factory settings of STB:

Video output mode:

  • PAL (480i) or NTSC (576i) - for STB models that don't support video output mode auto-detection (MAG250/270 and partly of MAG254);
  • Auto - for STB models that support video output mode auto-detection (partly MAG254, MAG256/3xx, and higher models).

Graphical resolution:

  • Same as video.

TV system parameters in STB settings must be compatible with your TV. In case of incompatibility, image quality deterioration is possible, up to the complete lack of image on the TV screen.

As a rule, on TV devices there is marking of supported modes like:

If instructions or markings are not available, the required information can be obtained from the TV manufacturer's support service.

Storing parameters

Video output mode and Graphic resolution values are stored in environment variables:

  • tvsystem - video output mode in STB software working mode*;
  • graphicres - graphics resolution which set in STB software working mode*.
    *  - STB software working mode implies that state when STB software has been loaded already (in opposite to boot stage).

How to change STB settings of TV system and Graphic resolution

TV system and Graphics resolution values can be auto-set (default setting value) or selected manually by user. An ordinary way to set these parameters is System Settings of Portal (Embedded or External). In some cases (for example, if there is no image on the TV screen after STB software loaded), the user may change these settings at the boot stage - from the Bootloader menu (for MAG250/254/270) or the System Recovery Utility menu (for other models).

Embedded portal settings

  • Enter System settings;
  • Go to Video;
  • Set the desired value of Video output mode;
  • Set the desired value of Graphic resolution;
  • Save data with Save (OK);
  • Confirm with OK - STB will automatically reboot.

Bootloader menu MAG250/254/270

  • Launch Bootloader menu;
  • Select TV System and set a required value (by pressing Right on RC);
  • Select Graphic Res. and set a required value (by pressing Right on RC);
  • Select Exit&Save and press Right on RC, confirm with OK.

System Recovery Utility menu MAG256/3xx and higher

  • Bring up System Recovery Utility menu;
  • Select TV System and press ОК on RC. In the appeared TV System menu choose a required value and press ОК on RC. Confirm selection - select Yes;
  • Select Graphic Resolution and press ОК on RC. In appeared Graphic resolution menu choose a required value and press ОК on RC;
  • Select Exit and Reboot and press ОК on RC. Confirm operation - select Yes.

Supported Video Output Modes (TV System)

Available TV Systems

In the STB software working mode the following video output modes are supported:

TV system (Video output mode)

Screen resolution*

Scanning mode**

Frame rate, frame/sec

Aspect ratio


Auto-detecting TV System
STB sets TV System, depending on the used type of video interface (AV/HDMI) as well as possibilities of the TV device.
PAL region (Europe, Australia, most of Asia and Africa, some countries in South America, etc.)
PAL (576i)
50 semi-frames/sec
Analog TV - 4:3
Digital TV - 16:9
Analog TV and digital SDTV standard. PAL color encoding system is used for analog TV.
HD / HD Ready
50 semi-frames/sec
Full HD
HD Ready 1080p / Full HD
4K Ultra HD
NTSC region (America, Japan, etc.)
NTSC (480i)
640 × 480
60 semi-frames/sec

Analog TV - 4:3
Digital TV - 16:9
Analog TV and digital SDTV standard. NTSC color encoding system is used for analog TV.
HD / HD Ready
60 semi-frames/sec
Full HD
HD Ready 1080p / Full HD
4K Ultra HD
- Screen resolutions are specified for digital TV standards.
** - Scanning mode: i - interlaced, p - progressive. To display interlaced video on progressive scan displays (contemporary TV types), playback applies deinterlacing to the video signal.

Making choice of TV System

The choice of required TV system (video output mode) depends on various factors, like that:

  • type of the TV device - for analog devices, modes with interlaced scanning are usually used, for digital devices - with progressive scanning are usually used;
  • region of use - broadcasting of television in different regions (in the table these regions are specified as NTSC and PAL) adapted to different frame rates (25/50 or 30/60 frames per second) and screen resolution (only in SD mode);
  • type of media content being played - depends on the TV platform used for broadcasting or the mode of creating the video;
  • etc.

Graphics Resolution (Graphic Res.)

Graphics Resolution options

In the STB software working mode the following graphics resolution options are supported:

Graphics resolution options Comment
TV System Resolution (Same as video) Autodetection of the graphics resolution, depending on the TV system setting.

Graphic Resolution setting

If the value of Graphic Res. option set in STB is greater than a permissible resolution of video output then the most appropriate resolution of the graphics window is selected by STB.

If value TV System Res. is selected then STB sets resolution value that is appropriate to current video output mode.

For example:

If you set TV System in 1080i-50 then a video will be played with resolution 1920×1080, and graphics can be "drawn" with one of the values: 720×576, 1280×720, 1920×1080. That is, the user may choose any resolution value for the graphics menu. In this case, graphics resolution values lower than video resolution will be scaled up to TV System value. 
If Graphic Resolution set to TV System Res, then the graphics resolution value will be set according to the current TV system value, which is 1920×1080.

Typical variant: If the user selects Video output mode (TV System) - 1080i-50 and Graphic resolution (Graphic Res) - 720×576 then the video will be displayed at the highest possible quality and graphics will be upscaled. In this case, the data traffic reduces and STB performance improves.

Possible variants:
TV System Video Resolution Graphic Resolution Type of graphics resolution
1080i/p-50/60 1920×1080 1920×1080, 1280×720, 720×576 HD
720p-50/60 1280×720 1280×720, 720×576 HD
576p-50/60 1024×576 720×576 ED
PAL (576i) 720×576 720×576 SD
NTSC (480i) 720×480 720×480 SD

Type of digital video output HDMI-DVI

Type of digital video output HDMI or DVI is chosen depending on the type of digital port used on the TV device. STB factory setting defines a type of digital video output as HDMI. If you need to switch over types of digital video output:

  • Enter System settings Video More;
  • Set HDMI/DVI required value:
    • HDMI - if your TV device connected to STB by HDMI port;
    • DVI - if your TV device connected to STB by DVI port.
  • Confirm with Save (OK);
  • Message Successfully saved should be appeared on the screen.

When you connect STB to TV device with HDMI-input then HDMI value must be set. If option DVI is set then no audio signal is given on STB HDMI output!

Auto frame rate

The Auto frame rate feature is intended to set the required Frame rate value for HDMI video output, depending on a video content being played. The required Frame rate value is selected from one of the pre-indicated variants. Thus, STB applies a frame rate value that best fits video content. This provides the TV device with the ability to process video by itself, making "smoothing" the video displaying - i.e. adjusting display refresh rate.

In the factory default setting of STB, the Auto frame rate feature is disabled and the Frame rate is set according to set TV system value.

To enable or disable Auto frame rate feature:

  • Enter System settings VideoMore;
  • Set Auto frame rate value:
    • Disabled - Auto frame rate feature is disabled (the frame rate will be set, depending on the TV system value);
    • 50/60 - a choice between frequency values of 50 Hz or 60 Hz;
    • 24/50/60 - a choice between frequency values of 24 Hz, 50 Hz or 60 Hz;
    • 24/50 - a choice between 24 Hz or 50 Hz;
    • 24/60 - a choice between 24 Hz or 60 Hz;
  • Confirm with Save (OK);
  • Message Successfully saved should be appeared on the screen.

Use the Auto frame rate feature carefully! When Auto frame rate is enabled, some video signal receivers might not display video signal:

1. Auto frame rate feature can be applied only with HD screen resolutions (720p/1080i/1080p). Before enabling this function in the STB, make sure that the TV supports specified screen resolution values.
2. Auto frame rate feature must be supported by the video signal receiver. For example, some digital computer monitors do not support this function.

Need Help

Dave is an expert on the MAG STB and the author of this article.

Was this article helpful?

Yes No

Sorry to hear that.
How can we improve this article?

We use cookies in order to optimise our website, provide you with the best possible user experience and help us promote our products. Please read our Cookie Policy to find out how we use cookies and how you can control cookies.
By using this website or closing this message, you acknowledge our Privacy Policy and agree to our use of cookies as described in our Cookie Policy.