Synopsis
The ClearView® quality analyzer serves uncompressed audio/video output to an encoder, simultaneously captures the output via IP stream or video decoder, and aligns the resulting uncompressed sequences for testing. It uses highly accurate metrics to score the audio and video quality, or measure the absolute difference between what was sent and what was received and then plays the two sequences in many different comparative views onto a video display at full resolution.
ST 2110 Network Connectivity and Workflow
The SMPTE ST 2110 standard has been evolving to include encoding functionalities and the first applications are for testing encoding and decoding as applied in ST 2110-22 and also for testing picture and sound quality of encoders that process content from the ST 2110 to another network using MPEG or other compression types targeted for delivery over satellite, terrestrial broadcast transmission, or internet.
Applying the ClearView full reference test systems with new 4K capable ST 2110 network interfaces allows the user to perform a well known technique for testing the network path or encoder processing quality whether it be JPEG XS, HEVC, AV1, or any codec.
- The user may easily capture video, then feed the original source content chosen for testing into the network while, at the same time, recording the content that has been encoded and decoded as a fully uncompressed sequence to test for quality.
- Once captured, source and test sequences are automatically aligned with several selective automatic methods.
- A host of quality metrics may then be applied for testing picture and sound quality of separate vendor codec implementations or testing a varying set of bit rates through the encoding process in order to find the best quality for the required media content, delivery format, and potentially different receiver devices as additional variables.
Testing Workflow In A Hybrid SDI And IP Environment
- Record or Import Your A/V Source File or use a pre-loaded one
- Play the source test sequence to the device under test (DUT) as RGB or YUV
- Record the output of the DUT via MPEG IP network
- Automatically temporally and spatially align source and processed recordings
- Calculate quality score closely correlated to human perception
– VMAF, MS-SSIM (on DMOS and MS-SSIM scales), ΔEITP, and Sarnoff JND algorithms - Log and overlay graph each score type automatically with included Metric Log Grapher
- View the video sequences to verify the score