H264 and mvpmcx2

[trummel]

Eeey by gum, I remember when I was a lad, I started programming on a Sinclair ZX80 built from a kit, it had 4k of RAM as it's primary storage and loaded its applications from a tape recorder. We thought we was lucky when we eventually built (yes including etching the circuit board) a 16k ram expansion card and my first V24bis modem. I remember being elated that the download speed was 1200 bps, even though upload was only 75bps.

And you tell the kids of today that and they don't believe you....

And yes, I am also old enough to have watched Monty Python live the first time around

I have noticed that the "normal" audio channel is quieter than the narrative one. Unsure as to whether this is the broadcaster, your downmixing, or my TV

Me too.

Ah, when I bought my first assembler and could stop coding by hand and guessing jump offsets

Surely Martin, you mean calculated not guessed )

[mvallevand]

I have noticed that the "normal" audio channel is quieter than the narrative one. Unsure as to whether this is the broadcaster, your downmixing, or my TV.

I can't answer since don't have a lot of samples with both ac3 and mp2 tracks outside these BBC samples (maybe they amplify audio at the source for the hearing impaired?) and a golf video where they whisper anyway. I do find the same volume difference when I use the the PCH player mono though. I would expect AC3 pass through will be louder if I get that working.

Martin

[mvallevand]

And yes, I am also old enough to have watched Monty Python live the first time around

Me too. Watching it, and "Carry On" movie reruns when I was a young teenager was my first exposure to British humour. I am still scarred.

Martin

[trummel]

I have noticed that the "normal" audio channel is quieter than the narrative one. Unsure as to whether this is the broadcaster, your downmixing, or my TV

For me at least, it's a non issue, simply an observation. It's especially not an issue now I don't have to switch between the streams.

What is the formal position on 1080p video? I seem to be using it OK with these BBC HD broadcasts on my PCH set to 1080p HDMI and a 1080p Sony LCD, but I seem to remember noticing references to it not being supported in PCH2 (because of software decoding????). I ask, because I do get an occaisional stutter mid way through playing back a recording. I dont want to waste anyones time (including my own of course) chasing a minor irritation in a system that I may be overstressing anyway.

[mvallevand]

Except for some encrypted satellite broadcasts I don't think 1080p streams are available right now so that is a non-issue. The true 1080p files from BluRay and other fully 1080p HD source will always go to the PCH player.

At the same time I will be looking at the hardware demux which does require a little less bandwidth. The software demux handles so many problems, I am reluctant to make commitments that I will make this change.

As for occasional problems, my opinion is that is to be expected in anything but perfect source. If you can reduce the load on the server or improve reception quality you would probably see some improvement and I can buffer more, which I will do once I am sure GBPVR is waiting long enough on a live tv recordings. But there is a point of diminishing return, some stutter is inevitable on a PC client or on mvpmcx2, it is just some much more noticeable with digital than it is with a poor analog signal.

This is not just GBPVR phenomena either, my wife and I were watch Hancock on the cable STB Saturday night and we had to stop when the AC3 started breaking up too much.

Martin

[trummel]

So are the BBC HD samples we have been looking at not 1080p then? In which case, would I be better setting my PCH to something lower and stressing things less for no loss in quality. Sorry if these are dumb questions, but I get very confused by too many acronym's, 1080px60, 720p, 1080i, DVB-S, DVB-S2, AC3, H.264 etc etc etc...

Yes, I know what they stand for, but how they relate to and intract with each other and is confusing for one of my meagre intellect.

[mvallevand]

Changing your monitor setting to a lower resolution won't change the fact that the BBC HD files are 1080i MBAFF blah blah blah format, the PCH will render them from PAL to 720p to 1080p whatever you prefer. I see no reason from a performance perspective not to use 1080p if your machine handles it, the same network traffic is required.

There really isn't a definitive answer on whether 1080i is "better" than 720p, but from an mvpmcx2 choice, I think that the OSD over video look better at 1080i.

Frequency can have an impact even though the PCH adjust 23.997/24/25/50/60 fps the quality can be noticeable to some but my opinion is it has the most impact on BluRay quality. You should try 50 and 60 settings to see if you can see the difference.

Martin