All,
With the significant improvement in video coding quality and the availability of MPEG-4 (H264) equipment (Portsdown) I think it's time we considered the specification of our repeater inputs - the current recommendations were made in 2002.
Most of us are running 4Ms (~4.5MHz) on 23cms and 2Ms (~2.25MHz on 70cms) and I think it's realistic to drop these to 2Ms on 23cms and 1Ms H264 on 70cms.
The instant benefit is a 3 dB gain - try getting that from improved antennas - and by using H264 there is no drop in video quality!
The reason for suggesting it now (and it is a suggestion) is that the new Portsdown 2019 with a LimeSDR Mini struggles to do MPEG2 above 1.5 Ms but will do H264 in 2Ms.
So the big question is can anyone recommend an H264 / MPEG-2 receiver which they have completed lock indicator mods on that we can all use?
73
Noel - G8GTZ
Repeater input bandwidths
Re: Repeater input bandwidths
Hi All
GB3ZZ has MPEG-4 H264 receivers as an option, maybe others?
i would have thought adding an Rx or two might be a start,
and give users of MPEG-2 equipment, maybe only MPEG-2 a chance to accept the change,
Maybe we don't need another excuse not to come on
I'm sure Ivor and Shaun would show us how it's done.
Peter
GB3ZZ has MPEG-4 H264 receivers as an option, maybe others?
i would have thought adding an Rx or two might be a start,
and give users of MPEG-2 equipment, maybe only MPEG-2 a chance to accept the change,
Maybe we don't need another excuse not to come on
I'm sure Ivor and Shaun would show us how it's done.
Peter
Re: Repeater input bandwidths
Found this article from 2013, shows what Noel was saying about the ""improvement in video coding quality"".
We have had several Batc talks over the years on this subject, but a useful read, regarding video standards.
https://wolfcrow.com/understanding-mpeg ... and-h-265/
Peter
We have had several Batc talks over the years on this subject, but a useful read, regarding video standards.
https://wolfcrow.com/understanding-mpeg ... and-h-265/
Peter
Re: Repeater input bandwidths
Re: LimeSDR-Mini Problems with DATV-Express Thread...
It's so easy to loop through another sat rx on 23 or 70, etc.
I've just ordered a HDMI switch to mod to work on lock light, as an experiment, just in-case needed.
Ivor and Shaun have done lots on GB3ZZ.
I say add not take away, put in extra receivers, then all are happy, well if only we could be
It's so easy to loop through another sat rx on 23 or 70, etc.
I've just ordered a HDMI switch to mod to work on lock light, as an experiment, just in-case needed.
Ivor and Shaun have done lots on GB3ZZ.
I say add not take away, put in extra receivers, then all are happy, well if only we could be