echo

[geedsen]

I hase my Settopbox connected to a WDMI (Wireless HDMI transmitter) that sends the signal to a WDMI receiver at my TV.
the settopbox is also directly connected to my receiver (for audio). And as I expected, there are lip-sync problems between the TV and the audio coming from
my receiver. The video is delayed because of the wireless transmission. So I need to buy a receiver that allows audio delay. I have seen several ones but the maximum delay is different for example the onkyo TR608 has a 200ms delay max.

So before I buy a receiver I would like to know how much the delay currently is. So that is why I used Audacity, I was hoping that the recording of the sound of the receiver and the (delayed) sound of the TV would show me somehow how much delay there is. The delay is audible (echo) and th recording clearly shows where the echo starts, but I cannot figure out how much delay there is looking at the sinusses. Anyone have an idea of how to establish this? (I can make a recording for download available)

Thanks

Ben

[kozikowski]

The delay is not coming from the wireless. That's practically instantaneous. The delay is the digital processing. If the display system has internal video processing, they have to add sound delay in addition to all the rest of the processing delays.

Record something that has staccato sounds like hammering on "This Old House." Find one of the hammer strikes and then find the echo. They should both present with blue spikes on the timeline. Use the Zoom tools: Control-E, Control-F, Control-3, etc., etc., to see what you're doing.

Switch the middle time window at the bottom of the editor to "Length," and drag-select the area between the two spikes. Read the delay directly. You can customize the readout to appear in almost any clock system. Milliseconds, Drop Frame Timecode, US Movie Frames, etc.

Koz