Distorted Audio

[magnetar]

I'm giving NextPVR a try and am having an issue I'm hoping someone can assist with. When playing several OTA stations (their IPTV versions as well) the video plays for 5-10 sec, pauses, then resumes but with the audio distorted. It almost sounds as if it's slowed down but remains in sync with the video.

I'm running NextPVR in docker on an Unraid server. I've tried transcoding via CPU and VAAPI but it has the same results. I also tried linking NextPVR to my Emby server and running it through that but it has the same results.

Any ideas what is going on? Thanks.

[mvallevand]

Did you try with a direct play client like Kodi to see if you server is having trouble keeping up. Uploading your zipped logs would be the only way to diagnose this further, it is not a general problem.

Martin

[magnetar]

I have using Emby, assuming I'm doing it right. I think the problem might have to do with VAAPI transcoding. Emby was breaking up a lot when I had that set as the default transcoder, but when I switched it to Quicksync it cleaned up. Is there a way to use Quicksync with NextPVR? I'm not seeing anything in the FAQ or wiki.

[mvallevand]

VAAPI is the only supported format on Linux including Docker. However NextPVR sends the raw stream to Emby without transcoding in most cases so it appears to be an Emby issue. Without logs or testing in a true NextPVR direct play client we can't help further.

Martin

[BigTA78]

I have the same issue. 
I've a custom xml that uses ffmpeg to encode the stream from a USB capture of my STB, allowing me to watch anywhere on my network. It was working a few months back, but now I get this audio issue with a couple of seconds of good audio, before it switches to this weird distorted version (like someone's using a voice distorter to demand a ransom over the phone). I'm not sure what changed.
The same ffmpeg script and settings works with good audio if I just run it in command line to capture an mp4 file. It also appears to work if I set it up through my Jellyfin server with the NextPVR plugin. It's just the NextPVR web browser that's the issue.

Logs attached

[mvallevand]

First this is a Docker sub forum so don't assume your Windows server has anything to do with this thread.

The audio I see coming from you script is pass through so the issue is the source. Perhaps you need to force transcoded audio to 2.0 AAC

Martin

[BigTA78]

I'm happy to move to a new sub it this is easier.
I seem to get pass through on both video and audio whenever I specify any audio parameters. If I specify just video parameters, then it seems to transcode video, and provides audio in aac 2 channels 192k.
See attached XML. the "Sky Stream" channel seems to transcode video and "Sky Stream Audio" has [H264] COPY & [AAC] COPY under the "i" information box.

[BigTA78]

I'm happy to move to a new sub it this is easier.
I seem to get pass through on both video and audio whenever I specify any audio parameters. If I specify just video parameters, then it seems to transcode video, and provides audio in aac 2 channels 192k.
See attached XML. the "Sky Stream" channel seems to transcode video and "Sky Stream Audio" has [H264] COPY & [AAC] COPY under the "i" information box.

Just to update, I've just tried through the Silk browser on my Amazon Echo Show and I don't get distorted audio. Seem to only be in Chrome on my Windows PC and laptop - so this looks like it's browser related.

[mvallevand]

Extras are supposed to create web ready media, maybe try mp3 audio since that will be 2.0 Sorry I don't support extras or ffmpeg, I don't see how "Sky Stream" is even passing audio.

My experience with cheap USB grabbers is they do get worse the longer they play.

Martin