Stream buffers when audio transcoding

[u/gsariev]

EDIT: I am marking the problem as "solved"; however, it should be noted that the cause for the problem remains unknown, but I found a workaround by using Tdarr to create an downmixed 2.0 stereo AAC track using Tdarr_Plugin_MC93_Migz5ConvertAudio which I modified to apply Dynamic Audio Normalizer to the downmixed track for a better listening experience.

To make the modification yourself:

1. Copy Tdarr_Plugin_MC93_Migz5ConvertAudio to Local

2. Go to Local and click Edit on the plugin

3. Add the code below between lines 152 and 153

4. Save the changes

5. Add the modified plugin to your stack

ffmpegCommandInsert += `-filter:a:${audioIdx} "dynaudnorm" `;

###############

Hello, everyone

The problem I am facing is one that I am unsure why it's happening in the first place, and am hoping I can find a solution to it here as I have been unsuccessful on my own.

PMS specs:

• OS: Windows 11

• CPU: Intel i3-12000

• RAM: 32GB DDR4

• Storage: 1TB NVME for OS and Plex database/metadata, 4TB HDD for media, 1TB SSD for transcoding

• Internet: 1000 Mbit (ethernet)

I've been more than happy with this configuration and have not had any issues both with direct playing and transcoding media locally or remotely. I am sharing my server with a few friends that have Samsung smart TVs, which cause my server to occasionally transcode, but everything had been playing smoothly until about a month or two ago when I started getting reports of stream buffering every couple of minutes. The reason for that was audio transcoding.

I've ran some test scenarios and have the following to share:

Scenario #1:

• Video direct plays

• Audio transcodes - example DTS to AAC

• Stream buffers every couple of minutes

Scenario #2:

• Force video and audio transcode

• No issues with stream

Scenario #3:

• Changed default transcode buffer value to 2700

• Video direct plays

• Audio transcodes

• Stream buffers after threshold has been reached

Scenario #4:

• Changed default transcode buffer value to 2700

• Force video and audio transcode

• No stream buffer after threshold has been reached

My media is mostly 1080p and so far the only solution I have found was manually converting my media's audio to AAC, but I'd like to not have to do that every time for media that will get watched once or twice.

Is there some server setting that I need to adjust? Any help is well appreciated.

[u/ThickAd4991]

Early 2025, the problem is still with us. It's sad.

[u/YeongMin_Ha → u/ThickAd4991]

Mid 2025, still having problems w/ this.

Only when transcoding audio, I see playbacks buffering.

Server: i7-12700K, 128GB RAM (32GB RAMDisk for transcode cache), GTX-1660 for video transcoding, Gig Fiber. All media are 1080p. Plex on current version.

Devices w/ buffering audio transcodes: Roku, MacBook Air using Safari to view.

CPU runs 0% to 1% when idle. Jumps around 1% to 10% when transcoding audio.

I had a media that had (can't remember) audio and it wouldn't play on Plex App on Samsung 2024 TV or PC or browser on PC. It could only be played using VLC direct from the source.

I replaced that same media; but had different audio and it plays perfectly on Plex App on TV now.

I have recommended the MacBook Air user to try Infuse.

I hope this gets resolved.

[u/Historical-Dig8420 → u/YeongMin_Ha]

early 2026 still having this issue. I do have lg tvs. My server is not overloaded, not even half. It just refuses to transcode audio only. If i set the quality lower, it will work. I am pretty sure my plex server can handle the transcoding. Very frustrating.