PHABRIX, a worldwide leader in test and measurement solutions, will present its new AV Delay software option for the popular Sx Series of handheld instruments at NAB 2019. This new feature, which accurately measures audio to video differential delay, will be available for demonstration on Stand N4508.

Although SDI feeds hold both video and audio data, this does not mean that the video and audio are automatically in-sync. Variously referred to as a lip sync error or AV delay, offsets can create a noticeable issue for the viewer. Any active processing equipment can introduce an error in AV timing, but compensation may only be possible at the system level. Understanding the AV delay through broadcast workflows is a priority.

PHABRIX’s AV Delay Generation and Analysis option offers an end-to-end solution for the measurement of audio to video differential delay through a broadcast chain. The tool not only provides a real-time update of the differential delay between the video content and the selected audio channel pair but can also be used to measure the propagation, or pipeline delay, of video and audio content.

The AV Delay option, with a combined Generator and Analyzer license, is available on the handheld SxA, SxD and SxE instruments. Uniquely, it can be used with all Sx supported video formats and frame rates on both SDI and AES interfaces.

Key features of the software include:

AV Delay Generator:

  • EBU Tech 3305 AV delay test pattern adapted for use with all Sx supported video formats
  • A cycle time of approximately two seconds
  • AV Delay audio insertion selectable on up to 16 embedded audio channels plus AES out
  • Audio delay control, allowing adjustment of audio to video generator timing in video frame step sizes


AV Delay Analyzer:

  • EBU and Lawo modes of operation providing compatibility with third party tools
  • Real time AV delay measurement up to +/-400ms in 0.1ms steps (accuracy = 1ms)
  • Audio source select for measurement – Embedded audio pair or AES
  • Fast measurement time

PHABRIX’s Managing Director, Phillip Adams, said, “Our Sx handheld instruments can be found in virtually every major broadcaster and OB truck around the world. This new AV Delay software option is a powerful addition to this ubiquitous tool, providing swift and accurate audio/video timing understanding.”