Colossus recording at very low bitrate since updating to 2.5.9

[Radhard]

Hi, I have been using npvr for a few years now, and recording 720p from the analog output of my decoder to the colossus card for over a year with great results.

For no good reason I decided in early december to upgrade to npvr 2.5.9, since I noticed I was a few versions behind (It was 2.3.6).

I like the new EPG warnings for conflicts but apart from that, havent used any new features.

Today I finally had time to watch some (recorded) TV and immediately noticed something was wrong. Very apparent compression artifacts, especially around text and in dark or fast-moving scenes. I've looked through my recordings and the degradation started on december 8. December 1st recordings are fine. I have nothing in-between. Looking at the files, I was shocked by the small size and bitrate. 1700-1800 kbps, instead of the usual 7-8000. Resulting in a .ts file of 1.8GB for a 2 hour recording, instead of the usual 7.5-9.5GB. Codec is still H.264 AVC.

I looked to the HDPVR settings in config.xml and they havent changed (compared to config.old.xml and my remembrance).
720p settings are 9000000 and peak13500000 VBR. I believe these are the defaults.

Is there another place where the recording bitrate for the colossus card is set?

I must admit I am quite stumped.

Any help greatly appreciated as always.

Simon

[sub]

It's probably something like the Colossus not reporting it's resolution, and it's default to 480i or something similar.

Do a recording, then post the nrecord.log and I'll take a look.

[mvallevand]

Have you got fixed rate set on your STB, NextPVR will fix on the bit rate of the first resolution at locks in on. Something is wrong with your estimated recording size too. I use VBR 13.5-16Mbs and my recordings are ~ 2.6 GB an hour

Martin

[Radhard]

My set top box is set to output 720p, I do not have further controls. Also, to my knowledge, no other parameter has changed but the npvr version.

I have hundreds of recordings that are between 6.5 and 9.5GB for 2 hours, so I believe my estimate is OK. Back of the envelope suggest a size of 6 GB/hour for (constant) 13.5 Mbps sor I find your 2.6GB rather astonishing myself, even for VBR. But maybe your feed is much higher quality than my crappy provider and thus compresses better.

Also, the recorded low bit-rate files are still 1280x720 resolution, so resolution detection might be working fine.

I'll try to get an nrecord.log and post it asap.

[Radhard]

I am sorry the log is rather long, but I don't know where to cut it.

It seems that npvr sets the bitrate to 3000000 VBR with 5000000 peak. These are the settings for SDMode in config.xml.

I will try to change those to match 720p and record something else as a workaround.

What could cause npvr to detect SDMode?

[mvallevand]

Yes that looks like NRecord is setting too low a max. peak

Code:

2013-01-05 15:15:02.226    [DEBUG][7]    device reports current bitrate as: 3000000
2013-01-05 15:15:02.232    [DEBUG][7]    device reports current peak bitrate as: 5000000
2013-01-05 15:15:02.232    [DEBUG][7]    About to set BITRATE MODE
2013-01-05 15:15:02.239    [DEBUG][7]    requesting variable encoding
2013-01-05 15:15:02.245    [DEBUG][7]    trying to request bitrate: 3000000
2013-01-05 15:15:02.251    [DEBUG][7]    device confirms bitrate as: 3000000
2013-01-05 15:15:02.251    [DEBUG][7]    About to set PEAK BITRATE
2013-01-05 15:15:02.252    [DEBUG][7]    device minimum peak bitrate: 1000000
2013-01-05 15:15:02.252    [DEBUG][7]    device maximum peak bitrate: 24000000
2013-01-05 15:15:02.252    [DEBUG][7]    device peak bitrate step size: 500000
2013-01-05 15:15:02.252    [DEBUG][7]    trying to request peak bitrate: 5000000
2013-01-05 15:15:02.258    [DEBUG][7]    device confirms bitrate as: 5000000

Martin

[sub]

Yep, that was pretty much my reading of it. The colossus isn't reporting its number of lines for some reason, so it's defaulting to the SD bitrate. We've seen this a few times for Colossus users. I'm not sure why, but the HDPVR and HDPVR2 are more reliable at reporting this info.

I was going to suggest the workaround you've already suggested.

[Radhard]

Have set config.xml SDMode bitrates to match 720p as a workaround.

Device still reports very low bitrates, but npvr overrides it and video quality is fine.

I can live with that, but I still wonder why the device started reporting low bit rates after the 2.5.9 update.

How does that reporting works? Card API queries?

And Thanks mvallevand and sub for your very quick response with this matter. Much appreciated.

[sub]

How does that reporting works? Card API queries?

Yes, calls an API to ask how many vertical lines there are.