Z9X Pro Stuttering (Solved)

Thanks to all that are working on this trying to figure out the problem!

@cucnz Thanks for the infos but I don't think the stuttering problem discussed here is related to overheating. My Z9X Pro is completely open and is not hot at all while the stuttering occurs.

I've seen some videos with DV profile 7 + Atmos TrueHD direct from disc using MakeMKV stutter, like "The Flash" and some others using the same method with no stutters like "Aquaman", I listened to quite some part of Aquaman and I didn't see stuttering. So I'm not sure it's "bad files" that's causing this.

 

My HDDs got very low heating and ventilation and we're winter, then it's not the case of this period. It's related to bitrate/frame rate of video (some time over 30fps stuttering appear) and audio TrueHD contents (tried another channel and disappear). IMO firmware must be optimized.

 

Again, this issue is not caused by bitrate or framerate, it is caused by certain TrueHD soundtracks.

 

I'm sorry but my own experience (Z9X) is also framerate of my own made MKV movie: 60, 50 and 40 fps shows stuttering, 30 fps none.

 

Yes, I understand that, but your installation is very specific and definitely not designed for high bitrate delivery.

The problem people are having here is to do with TrueHD soundtracks and the more the waters get muddied by either file specific or environment specific issues, the longer it will take to fix.

At the moment the devs are saying they can't replicate the problem. If they can't replicate it, they can't fix it, so if we get away from the true issue, the devs are likely to think that perhaps it's just finger trouble, there is no issue, and ignore it.

 

No, the issue of framerate is not related to my specific installation. It happens with file saved in HD connected to Zidoo. I’ve replicated same bug in different files with same result.

 

Can you post a short (2 minute) example to Mega of a file that does this.

 

Yes, but not now since that's a personal movie. I'll produce another one and send the example to Mega.

 

Great - can you PM the link.

I think the issue of personal movies is not worth pursuing - there are too many variables depending how the movie was produced - iPhone, Android phone, GoPro etc etc - this box is not really designed for that.

 

Probably yes as it created by Wondershare Filmora v13, a quite stable and popular video editing software

 

One movie where (for me and others) the UHD, TrueHD issue is repeatable is the movie Elemental. Right at the start where the Disney castle is shown, the camera pans up a waterfall and judder is seen - 100% repeatable. This happens with the full UHD bluray - either played from Blu-ray menu or direct play. It also happens on the MKV remux of the main movie.

 

Yeah I sent a clip of that one to the devs too but I'm not convinced they know what they're looking for. Had very little feedback about this other than they can't replicate.

 

So cant we enable some deep debugging and send you the logs instead?

 

Not sure what deep debugging is, but already done.

 

That batmobile clip stutters every time on my end at the end of the vertical panning on the batmobile. I'm surprised they can't reproduce the problem with that clip?

For added information, my setup is simple and is the following:
Z9X Pro -> Yamaha A8A AVR -> Sony X95K TV

I send RAW audio (RAW selected in the settings) and the video to the AVR and then the AVR decodes the TrueHD Atmos audio and only sends the video to the TV.

Avatar: Way of Water stutters a lot also even at the beginning (time 1:15 on the panning in the forest with the animal moving on the tree branch and a little later when he plays with the kids, etc.).

I am thinking about getting an Z9X but I really don't want to downgrade if this can be fixed at some point as the Z9X Pro is better in every way except for this problem.

Thanks for talking with the devs about this problem and if I can help, tell me what I can do!

 

problem with sound stuttering also occurs on the Z20 Pro when playing 4K movies with TrueHD/Atmos.

Additionally, I noticed that after some time, the sound automatically switches from TrueHD/Dolby Atmos to Multi Ch Stereo and stutters. Re-selecting the TrueHD/Dolby Atmos track fixes the problem, but after some time, the issue returns.

 

i Just watched that ,swapping between hd7.1 and 2 ch audio and couldnt see any difference ,on my system ..tried multiple times ,too .... both ways being free from any dicernable stutter

 

Have we looked at which tv/reciever brands are having the most issue with this stutter ? ie is their one two or all brands seeing this issue

IE OLEDs naturally have some stutter issues due to their superfast oled response times vs lower frame rate material

Im on a Panasonic L1500Z/Denon 3700h Rec and am seeing almost zero stutter issues even when time frames are being reported as an issue

 

Thanks for mentioning goral, i was wondering whether other Zidoo's (with the RTD1619BPD) would als have the stutter problem.

 

Yep, The Flash batmobile clip is probably the best and most reliable example - stutters at exactly the same point each time.

I've said this previously, but I replaced my trusty old Z9X with a Z9X Pro in my cinema room recently but decided quite quickly to swap back to the Z9X - the Pro just isn't stable enough for me yet.