CEA-861 Plug Fest #9 Tech Session Oct 31, Testing HDMI Lipsync Mark Stockfisch Vice President & CTO Quantum Data
CEA-861 Plug Fest #9 Tech Session Oct 31, Overview Lipsync problem (example) HDMI’s lipsync solution Lipsync test tools How to use these tools to measure lipsync
CEA-861 Plug Fest #9 Tech Session Oct 31, Good Lipsync
CEA-861 Plug Fest #9 Tech Session Oct 31, Bad Lipsync - Audio Leads
CEA-861 Plug Fest #9 Tech Session Oct 31, Bad Lipsync - Video Leads
CEA-861 Plug Fest #9 Tech Session Oct 31, What is HDMI lipsync? HDMI sinks and repeaters can now declare audio/video latency information in their EDIDs Lipsync-aware sources may delay audio or video to compensate for latencies in downstream devices
CEA-861 Plug Fest #9 Tech Session Oct 31, Example Without HDMI Lipsync
CEA-861 Plug Fest #9 Tech Session Oct 31, Same Example With HDMI Lipsync
CEA-861 Plug Fest #9 Tech Session Oct 31, New Lipsync Tools New data fields in EDID Editor New Signal Generator/Analyzer Features Lipsync Adapter (converts aural chirp, flash of light, non-HDMI analog/digital audio signals to simple digital pulses) Lipsync Calibrator (calibrated sound & light source for doing “sanity checks”)
CEA-861 Plug Fest #9 Tech Session Oct 31, EDID Editor - HDMI VSDB Lipsync Data Audio processing delay 0-500ms or INVALID Video processing delay 0-500ms or INVALID Maybe 2 nd value for interlace
CEA-861 Plug Fest #9 Tech Session Oct 31, Generator’s New Test Image “LipsyncB”
CEA-861 Plug Fest #9 Tech Session Oct 31, “LipsyncB” Test Image Specification Flashing full-white square 1/8th of major active axis Only appears in first field of interlaced formats Audio burst (2 to 3 cycles of sine positioned relative to center of flashing square plus or minus 500 ms
CEA-861 Plug Fest #9 Tech Session Oct 31, “LipsyncB” Test Image Controls
CEA-861 Plug Fest #9 Tech Session Oct 31, Analyzer’s Lipsync Meter - Relative Mode
CEA-861 Plug Fest #9 Tech Session Oct 31, Instrument (882EA emulating a STB) Measure Sink’s Latencies Lipsync Adapter Sink (DTV or AVR) Audio/Video (TMDS) Optical Sensor Audio/Video Digital Pulses “LipsyncB” Test Image Microphone or Analog/Digital Signal 2 - Lipsync adapter converts visual flash and (or) audible chirp into digital pulses 1 - Instrument outputs “LipsyncB” test image with latency set to zero 3 - Instrument measures delay between generator’s flash/chirp event and incoming pulses - then indicates sink’s audio and (or) video latencies 42ms HDMI Cable
CEA-861 Plug Fest #9 Tech Session Oct 31, Instrument (882EA emulating a STB) Functionally Test Sink’s EDID Lipsync Data Lipsync Adapter Sink (DTV or AVR) Audio/Video (TMDS) Optical Sensor Audio/Video Digital Pulses “LipsyncB” Test Image EDID (DDC) Microphone or Analog/Digital Signal 1 - Instrument reads latency data from the sink’s EDID 3 - Lipsync adapter converts visual flash & audible chirp into digital pulses 2 - Instrument outputs “LipsyncB” test image with latency-compensated audio/video 4 - Instrument measures delay between pulses and indicates latency error 0ms HDMI Cable
CEA-861 Plug Fest #9 Tech Session Oct 31, Instrument (882EA emulating a DTV) Functionally Test Source’s Lipsync Comp Audio/Video (TMDS) Source (DVD) 2 - Instrument generates hot-plug and source reads latency data from instrument’s EDID emulator 1 - Instrument’s EDID emulator presents audio/video latency test value to the source (+42ms) 3 - Source outputs test image (e.g. “LipsyncB” image from test DVD) with the requested audio/video latency compensation 4 - Instrument measures incoming audio/video lipsync, which should compensate the value presented in the EDID (-42ms) ms HDMI Cable EDID (DDC)
CEA-861 Plug Fest #9 Tech Session Oct 31, Instrument (882CA) Functionally Test Repeater’s Lipsync Comp 5 - Instrument measures delay between audio & video and indicates any latency error 2 - Repeater incorporates instrument’s latency data in its EDID 4 - Instrument outputs “LipsyncB” test image with corrected audio/video and repeater passes it back to the instrument Audio/Video (TMDS) Instrument generates hot-plug and repeater’s source reads latency data from instrument’s EDID emulator EDID (DDC) Repeater’s Source Repeater’s Sink Instrument’s Sink (emulating a DTV) Instrument’s Source (emulating a STB) Audio/Video (TMDS) Instrument’s Sink (emulating a DTV) EDID Repeater’s Sink EDID 0ms 3 - Repeater generates hot-plug and the instrument’s source reads latency data from repeater’s EDID Repeater
CEA-861 Plug Fest #9 Tech Session Oct 31, Summary Lipsync problems happen HDMI has new features that allow source devices to compensate for unmatched signal paths - when sink and repeater devices provide EDID latency data New tools now exist for testing these features
CEA-861 Plug Fest #9 Tech Session Oct 31, Questions?