Automotive multimedia test example: Multi-screen synchronization

The increasing size and complexity of automotive testing has begun to focus on evaluating the performance of multimedia components in the system. From rear-view cameras or 360° panoramic cameras to multi-screen high-definition infotainment systems, ensuring the quality of these products requires high-performance test equipment and integrating the testing of multiple parts of the system to an unprecedented degree. NI provides test equipment that includes all automotive system I/Os through an integrated and flexible platform that has been widely proven in the industry.

1. Example: Testing the synchronization of multiple infotainment screen signals

 

Figure 1. The infotainment system and example test system consists of an NI PXIe-8135 controller, NI PXIe-1085 chassis, and five NI PXIe-1491 HDMI/DVI analyzers. Note that you can also test LVDS interfaces using PXI modules from NI Alliance partners.

Here is an example of automotive testing that requires a comprehensive, high-performance solution to ensure synchronization of multiple screens in an infotainment system. Human senses can detect slight lags between multiple screens and lip-sync delays between audio and video. Testing these aspects of a system continuously is very challenging. Test systems to detect these issues require multi-sync high-definition acquisition, synchronization, and automation capabilities.

The PXI test system consists of the following parts:

• NI PXIe-1085 Chassis
• NI PXIe-8135 controller
• NI PXIe-1491 HDMI and Mobile HD Analyzer—one for each multimedia link in the system under test
• (Optional) Alfamation VA-01 LVDS Analyzer - required if the interface is LVDS instead of DVI or HDMI

Each test requires putting the infotainment system on a specific output and having the PXI system automatically run the test. Lip sync is a consideration here.

Figure 2. A video event (white box) is followed by an audio event (single sound playback).
Using this type of structured content, the lag between audio and video can be automatically detected.

By automating the device under test, the infotainment system, a lip sync delay is generated as shown in Figure 2. The PXI test system then uses the NI PXIe-1491 to acquire the data stream and runs a lip sync test using NI Image Quality Analysis software to obtain milliseconds of audio-video lag.

Figure 3. You can use NI Image Quality Analysis software to test lip sync, analyze image quality using measurements such as the Structural Similarity Index (SSIM), and test multiscreen synchronization using user-defined processors.

Major infotainment system manufacturers are now realizing the growing importance of automation for these applications, as the complexity and frequency of testing entire infotainment systems are increasing. Without automation, fully testing an infotainment system can take weeks and many man-hours. A software team might be able to compile a new software stack for an infotainment system every two to three weeks, but it would be impossible for a company to conduct comprehensive testing that frequently due to the resources required. An automated infotainment test system can complete testing that previously took weeks in a matter of hours. As a result, companies can test each software stack as soon as it is compiled, rather than waiting for months. In addition, because the system can be easily replicated and adapted, the testing process for different software stacks can be executed in parallel, whether for high-pressure development or high-throughput production testing.