Chapter 31. Configuring SDI Video Output

Broadcast, film, and video post production and digital cinema applications can require Serial Digital (SDI) or High Definition Serial Digital (HD-SDI) video output. SDI/HD-SDI is a digital video interface used for the transmission of uncompressed video signals as well as packetized data. SDI is standardized in ITU-R BT.656 and SMPTE 259M while HD-SDI is standardized in SMPTE 292M. SMPTE 372M extends HD-SDI to define a dual-link configuration that uses a pair of SMPTE 292M links to provide a 2.970 Gbit/second interface. SMPTE 424M extends the interface further to define a single 2.97 Gbit/second serial data link.

SDI and HD-SDI video output is provided through the use of the NVIDIA driver along with an NVIDIA SDI output daughter board. In addition to single- and dual-link SDI/HD-SDI digital video output, Frame Lock and Genlock synchronization are provided in order to synchronize the outgoing video with an external source signal (see Chapter 30, Configuring Frame Lock and Genlock for details on these technologies). This section describes the setup and use of the SDI video output.

Hardware Setup

Before you begin, you should check that your hardware has been properly installed. The following steps must be performed when the system is off:

  1. Insert the NVIDIA SDI Output card into any available expansion slot within six inches of the NVIDIA Quadro graphics card. Secure the card's bracket using the method provided by the chassis manufacturer (usually a thumb screw or an integrated latch).

  2. Connect one end of the 14-pin ribbon cable to the Quadro Sync connector on the NVIDIA Quadro graphics card, and the other end to the NVIDIA SDI output card.

  3. Connect the DVI-loopback connector by connecting one end of the DVI cable to the DVI connector on the NVIDIA SDI output card and the other end to the "north" DVI connector on the NVIDIA Quadro graphics card. The "north" DVI connector on the NVIDIA Quadro graphics card is the DVI connector that is the farthest from the graphics card PCIe connection to the motherboard. The SDI output card will NOT function properly if this cable is connected to the "south" DVI connector.

Once the above installation is complete, you may boot the system and configure the SDI video output using nvidia-settings. These instructions assume that you have already successfully installed the NVIDIA Linux Accelerated Graphics Driver. If you have not done so, see Chapter 4, Installing the NVIDIA Driver for details.

Clone Mode Configuration with nvidia-settings

SDI video output is configured through the nvidia-settings utility. See the nvidia-settings(1) man page, and the nvidia-settings online help (click the "Help" button in the lower right corner of the interface for per-page help information).

After the system has booted and X Windows has been started, run nvidia-settings as

    % nvidia-settings

When the NVIDIA X Server Settings page appears, follow the steps below to configure the SDI video output.

  1. Click on the Graphics to Video Out tree item on the side menu. This will open the Graphics to Video Out page.

  2. Go to the "Synchronization Options" subpage and choose a synchronization method. From the Sync Options drop down click the list arrow to the right and then click the method that you want to use to synchronize the SDI output.

    Sync Method Description
    Free Running The SDI output will be synchronized with the timing chosen from the SDI signal format list.
    Genlock SDI output will be synchronized with the external sync signal.
    Frame Lock The SDI output will be synchronized with the timing chosen from the SDI signal format list. In this case, the list of available timings is limited to those timings that can be synchronized with the detected external sync signal.

    Note that you must first choose the correct Sync Format before an incoming sync signal will be detected.

  3. From the top Graphics to Video Out page, choose the output video format that will control the video resolution, field rate, and SMPTE signaling standard for the outgoing video stream. From the Clone Mode drop down box, click the Video Format arrow and then click the signal format that you would like to use. Note that only those resolutions that are smaller or equal to the desktop resolution will be available. Also, this list is pruned according to the sync option selected. If Genlock synchronization is chosen, the output video format is automatically set to match the incoming video sync format and this drop down list will be grayed out preventing you from choosing another format. If Frame Lock synchronization has been selected, then only those modes that are compatible with the detected sync signal will be available.

  4. Choose the output data format from the Output Data Format drop down list.

  5. Click the Enable SDI Output button to enable video output using the settings above. The status of the SDI output can be verified by examining the LED indicators in the Graphics to SDI property page banner.

  6. To subsequently stop SDI output, simply click on the button that now says Disable SDI Output.

  7. In order to change any of the SDI output parameters such as the Output Video Format, Output Data Format as well as the Synchronization Delay, it is necessary to first disable the SDI output.

Configuration for TwinView or as a Separate X Screen

SDI video output can be configured through the nvidia-settings X Server Display Configuration page, for use in TwinView or as a separate X screen. The SDI video output can be configured as if it were a digital flat panel, choosing the resolution, refresh rate, and position within the desktop.

Similarly, the SDI video output can be configured for use in TwinView or as a separate X screen through the X configuration file. The supported SDI video output modes can be requested by name anywhere a mode name can be used in the X configuration file (either in the "Modes" line, or in the "MetaModes" option). E.g.,

 Option "MetaModes" "CRT-0:nvidia-auto-select, DFP-1:1280x720_60.00_smpte296"

The mode names are reported in the nvidia-settings Display Configuration page when in advanced mode.

As well, the initial output data format, sync mode and sync source can be set via the Option "GvoDataFormat" "string", Option "GvoSyncMode" "string", and Option "GvoSyncSource" "string". See Appendix B, X Config Options for instructions on how to set these X options.

Note that SDI "Clone Mode" as configured through the Graphics to Video Out page in nvidia-settings is mutually exclusive with using the SDI video output in TwinView or as a separate X screen.