NextPVR Forums

Hi sub,

i have now a small problem playing back hd material within all npvr setups. Some hd channels are stuttering while watching live tv, while some others just are "black". Audio is available, but it sounds mechanical.
This happens ONLY within NPVR while watching Live TV or as normal videofile (copied into the media archive).
Playing back the recorded bufferfiles with Graphedit, VLC or Windows Media Player, there's absolutely no problem. Graphedit and Windows Media Player are using the same splitter (LAV 0.44), the same videodecoder (ffdshow -> libavcodec) and the same audiocodec.

This means: the recorded .ts files are fine and there's perhaps a bug on another place? Non hd material isn't a problem at all, it's just fine as usual.

Otherwise i could see a very high cpu usage while playing back the hd content; even with the microsoft dtv decoder. NextPVR @ ~48% cpu usage (npvr.exe is multithreading now?) on an i5-2500K @ 2,8 GHz.

It's not network related. I have just tested 3 simultaneous playbacks of the same channel. NextPVR on the left, Graphedit, VLC and Windows Media Player. They all played the same file and only NextPVR was stuttering.

Nothing has changed on this front. How much CPU is used, and how smooth playback is, will come down to the decoders and renderers.

What type of HD do you have there? H.264? If so, what decoder do you use? I use the ArcSoft decode for viewing H.264 video.

sub Wrote:What type of HD do you have there? H.264? If so, what decoder do you use?

VLC is recognizing the .ts files as H264 - MPEG-4AVC (part 10) (h264)

As written before, i am using ffdshow for h264. But for testing purposes i switched to Microsoft DTV-DVD Decoder too. The renderer is EVR.

Playback as LiveTV is stuttering. Playback as Recording is stuttering. The tone sounds as if it came from a tin can. But only within NextPVR Client.
I've opened the same videofile from the same location within wmp, graphstudio and vlc. They don't have any problem with the simultaneous(!) playback over lan.

I have some h264 files in my media archive too (mkv container), those files doesn't make any problem.

I am not sure, but it looks like as would npvr try to use only one cpu core for playback the livetv file and reaches all the time it's limit. But the taskmanager shows me, that npvr is using more cores.

Otherwise i could make a small movie to show you what i mean. If you're interested, just tell me what you want to see on the screen.

I'm not really sure. None of that should be any different from the previous release.

Maybe try copying one of the files directly onto the client pc, to take network out of mix, and see if it makes any difference.

Also try setting the audio renderer back to 'system default' to see if it helps with your stuttering.

I have just copied a bufferfile to this local machine and disabled npvr acting as client. I switched the audio renderer back to system default:

This makes no difference on video. Perhaps a little, little, little bit lesser stuttering. Audio is better now. Audio isn't stuttering anymore and it doesn't sound like a tin can.

If you want to let me know where to download small buffer file from one of these channels that show black, I'll take a look.

arte HD - captured with TechniSat CableStar HD2 -> stuttering video within npvr
ZDF HD - captured with TechniSat CableStar HD2 -> no/black video within npvr

Every file is around 30 MiB with an upload of around 128 Kib/s .

I tried those two clips here.

The arte HD one played fine on my machine (Q9550 processor with nvidia card). I tried with both the ArcSoft and Microsoft decoders. Both had CPU hovering between 5-10%. No sign of any stuttering.

The ZDF HD clip gave no video. I'm looking into why.

sub Wrote:The ZDF HD clip gave no video. I'm looking into why.

I have fullest confidence in your Abilities. (this one was translated with Lucy Software translator) *buck*

The arte HD one ... i get a headache. Perhaps it's just antipathy between digital tv and me. I am more the analog one.