h a l f b a k e r y
Naturally low in facts.
add, search, annotate, link, view, overview, recent, by name, random
news, help, about, links, report a problem
or get an account
Please log in.
Before you can vote, you need to register.
Please log in or create an account.
audio delay lines are old tech as are regular video delay lines,
but as far as I can find, no-one makes an HDMI delay line for
home use in delaying the video to match the delayed audio
that comes from things like using bluetooth speakers. There
are very few HDMI products of any description out
because of the DRM mechanism, but I suspect it has not
occurred to manufacturers (until reading this post :-) ) that
you don't need to un-DRM an HDMI signal in order to delay it!
Simply store the DRM'd data packets in RAM for a short time
then pump them out the other side, still DRM'd. Video/audio
synch for HDMI is really becoming a problem nowadays with so
many systems inserting delays, especially in the audio path.
This kickstarter project seems to rely on the same principle of manipulating a DRM'd signal without actually decoding it. I think this confirms that the delay line idea would indeed be implementable. [gtoal, Jul 20 2019]
||I still have a leftover pair of HDMI-SDI and SDI-
HDMI cheapchinese converter boxes, which in an
undocumented sort of way manage to completely
skirt around DRM by not implementing it.
||Why is not possible for the audio track to include time-
markers that software can use to sync with corresponding
markers in the video track?
||You sure this hasn't been done ? The year is 2019 and I think that counts as the future. It would seem like childsplay for a protocol to survey a local network and time synchronize all devices.
||Bluetooth audio is generally not laggy with a v4 device. AppleTV and cheap v4 headphones works great. There are probably good $20 v4 converters if you have some quality cabled headphones.
||Actually, @bigsleep, it was after buying a v4 BT
transmitter/receiver pair that was advertised as having the
lowest latency available that I posted this suggestion. Some
people (such as my wife) don't hear the offset audio, but I
definitely do and it's enough to continually annoy me
whenever I watch TV on our projector. The lag may only be
2 or 3 frames but it's noticeable. And I looked around a lot
and could not find anything (other that super expensive
recording studio tech) that delayed the video - only the
||Does anyone know the name of the analog video effect where an image of say a dancing person is followed by a bunch of clones? I think it might have been used in the 1970's.
||The lag modifying HDMI thing reminded me of that.
||[beanangel] Stroboscopic motion? The waveform of dance in a mouse arrow tails sort of way.
||Dig into the menu systems of the appliance, sometimes there are timing features.
||// the same principle of manipulating a DRM'd signal
without actually decoding it //
||Additionally (or not, if that link is to the same thing I'm
remembering), I remember there was a few years ago some
kind of device (open-source/diy/?) that overlaid a generated
image (e.g. dashboard meters or the like) on top of an
HDCP-protected HDMI video signal, so the generated image
could be displayed superimposed on the video on an HDCP-