On 6/20/23 11:16, James Knott via talk wrote:
On 2023-06-20 10:50, Lennart Sorensen wrote:
https://www.fpga4fun.com/files/HDMI_Demystified_rev_1_02.pdf gives a
nice explanation of how it worked in HDMI 1.3. 2.1 just got rid of the
dedicated clock to free up a 4th signal pair.
Other than a small bit about lip sync, there is nothing about syncing
the signal in that.
Sure but HDMI and compressed video of IP have nothing in common really.
Vastly different bandwidths and purposes.
First off, that RTP article mentions video, not just audio. While the
details may differ, the principles remain the same, that is the
framing is embedded in the data. Don't confuse transport with signal.
In the case of my IPTV, the exact same signal is delivered to my TV,
as I would receive over the old digital system. And they both use
HDMI to reach my TV.
IPTV is not at all like HDMI.
The give away is with the IP in IPTV.
HDMI does not require any of the overhead of IP because it is a direct
connect so there is no need for IP addresses, MAC addresses or ports.
IPTV has the video stream compressed using one complex codec or another
whereas HDMI has close to 0 encoding so that it can run on fairly
in-expensive hardware.
The fact that most TVs now days have powerful processors has nothing to
do with where HDMI came from as a way to display high quality video but
adding in the encryption to make it hard for people to easily decode
the video stream and publish it on the internet.
The bit rate going over HDMI would be something like:
Image height * Image width * pixel size * frame rate.
So for an example:2048*1024*24*60 = 3,019,898,880bits/s
Add on to that the overhead for some number of audio channels.
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Alvin Starr || land: (647)478-6285
Netvel Inc. || Cell: (416)806-0133
al...@netvel.net ||
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