Sound is peaking during playback, particularly low-end sound

[Zelbinian 4]

This could be a mistake I'm making ripping the movies or it could be a mistake I made setting up Emby... not sure which. (When I rip I tend to choose the passthrough option for audio.) All I know right now is explosions and thuds get all crackly, regardless of whether I'm watching from the Roku app on my TV or via a browser on my PC. I attached the logs that were created during a movie I watched last night, hopefully someone here can decipher them and help me figure out which part of my chain I need to debug.

ffmpeg-transcode-0968c10d-76bb-4120-936f-e84dcd40b8a4_1.txt ffmpeg-transcode-ea8f917b-a412-45d6-9aee-55edc6d03595_1.txt ffmpeg-remux-914c1dca-ab5c-40fa-9224-745bccc470b9_1.txt ffmpeg-remux-3e00af4d-cc42-407b-a2fd-dda7754905f7_1.txt

[speechles 2055]

Are you using "Volume Mode" set to anything but OFF on your Roku?

https://support.roku.com/article/226802507

 

To fix this press the HOME button on your Roku remote to get to the Roku homescreen. Then go to Settings >> Audio. Make sure "Audio Output" is Auto. Preferred streaming format is Auto. Digital Output format should be Auto. Is that what yours shows?

When the audio is clipped the issue is usually due to either Volume Mode being turned ON to (Leveling or Night). To use "Volume Mode" without audible clipping you must choose Auto or Stereo. The Emby app on Roku will detect these changes correctly. But the clipping issue is always with the Roku itself trying to downmix 5.1 surround to stereo. Whenever Volume Mode is used it will downmix to stereo.

With the Volume Mode set to OFF and the above audio changes made does the problem still occur?

Edited June 7, 2023 by speechles

[Zelbinian 4]

Interesting. It happens on playback in Brave (a chromium browser) as well. I assume it's also a 5.1 -> stereo downmixing issue but how do I handle that in the browser?

Thanks for helping me figure this out. When ripping myself I can make sure there are separate tracks for 5.1 and stereo to have options but when if I get a file from somewhere else I won't always be able to control that.

[Luke 42078]

Can we please see a Roku example? Thanks.

[Zelbinian 4]

I have done the following things:

• Re-ripped the movie with tracks for both 5.1 and stereo audio
• Tried playing the movie on VLC on Windows with both settings at 100% VLC volume just to confirm. No issues.
• Tried playing the movie at 30% volume in the Emby webplayer (using Brave browser on Windows)
  • When the 5.1 track was playing, distortion present
  • When the stereo track was playing, the distortion went away BUT suddenly I started getting video stuttering - and even sometimes the video stream would stop altogether
• Tried playing the movie on Roku via Emby
  • After fiddling with my sound settings on my speaker system I was able to remove the distortion. Playing a movie with Emby via Roku just seems to be a lot louder by default than playing a movie from, say, the Prime or Disney+ apps.

So Emby via Roku is working ok. The sound being sent seems to be a little "hot" but seeing as I intend for Emby to be pretty much the only app I use for watching movies and shows, that's fine.

However, the web playback - my primary use case - still isn't great. I have no idea why switching to a different audio track would cause video trouble, but it did. And the 5.1 transcoding was very distorted in the bass-ier parts.

Also my 5 minutes of playing around in browser generated 14 log files and my 5 minutes of playing around in the Roku app generated... none. Wild.  

I waited a bit and re-played the first ~8 minutes of the movie I've been testing with in browser with the 5.1 audio track selected. I have attached the two files generated during that playback. I stopped playback within a few seconds of the distorted audio appearing.

ffmpeg-transcode-2026688f-414f-4434-aa2b-a5f4cd452bc8_1.txt ffmpeg-remux-a46001f2-7aed-40f0-8ab6-fdf8fac38957_1.txt

Edited June 8, 2023 by Zelbinian
grammar

[Luke 42078]

Hi, we’ll take a look at it. Thanks for reporting.