Audio is ahead of video when streaming via RIST or SRT

[NeepOwO]

Before you file

• I searched existing issues (including closed ones) and this is not already reported.
• I am on the latest release and the problem still happens there.
• I restarted OBS after installing or updating the plugin.
• I checked the README's Stats reference and, if this is an audio or latency problem, the audio pipeline notes.
• I tried the same URL with a fresh IRL Source at default settings (Target Buffer 120ms, Hardware Decode Auto), to rule out my own settings.
• If it is a video or decoding problem, I tried Hardware Decode set to Off, to find out whether it is the hardware decoder.
• If audio sounds sped up, slowed down, pitchy or chipmunky, or skips ahead: I checked Use OBS Low-Latency Async Audio Mode in the source's advanced settings. That mode drains the buffer immediately instead of holding the jitter cushion and caps backlog by skipping audio, so it is the usual cause. Turn it off unless you specifically need it.
• If audio still runs fast after a stall, I checked my Catch-Up Speed setting. Playing back at up to +5% until latency returns to target is by design (nothing is skipped); the default is audible on music, so lower it if you would rather the recovery take longer than be heard.

What happened

Audio is ahead of video when streaming via RIST

Environment

• Source: iPhone 13 mini
• Connection protocol: RIST
• Video codec: H.265 / HEVC
• Resolution: 1920 × 1080
• Frame rate: 60 FPS
• Streaming path: iPhone → moblin → RIST → IRL Source → OBS
• OBS version: 32.2.2 (64-bit, Windows)
• IRL Source version: 2.1.5
• Bonding: 3 SIM cards

Problem

The audio is ahead of the video when streaming from an iPhone 13 mini to OBS through IRL Source.

Actual behavior

The audio plays ahead of the video, causing noticeable audio-video desynchronization.

Troubleshooting already tried

• Adjusted the Target Buffer setting in IRL Source.
• Toggled Hardware Decode on and off.
• Enabled OBS’s Low Latency Audio Buffering Mode.
• Switched the connection protocol from RIST to SRT.

Result: The audio is still ahead of the video.

Additional information

The issue occurs with a bonded connection using 3 SIM cards. I can provide logs, configuration details, or a sample recording if needed.

Steps to reproduce

1. Open Moblin and add a new RIST stream.

2. Enable Adaptive Bitrate (ABR) and Bonding for the stream.

3. Configure the video settings as follows:

   • Resolution: 1920 × 1080 (1080p)
   • Frame rate: 60 FPS
   • Video codec: H.265 / HEVC
   • Rate control: ABR
   • Bitrate: 5 Mbps
   • Keyframe interval: 2 seconds
   • Adaptive resolution: Enabled

4. Configure the audio settings:

   • Audio codec: AAC or Opus
   • Audio bitrate: 128 kbps

5. timestamps enabled or disabled.

6. Start the RIST stream from Moblin.

7. In OBS, receive the stream through IRL Source and monitor the audio and video.

8. Check whether the audio and video are synchronized during playback. The reported issue is that audio plays ahead of video.

OBS log

https://obsproject.com/logs/iUZsJ8BGx3NjUMyw

[irl-source] log lines

IRL Source version

2.1.5

OBS Studio version

32.2.2

Operating system

Windows

GPU / hardware

Nvidia rtx 3070

Stream setup

srt://0.0.0.0:port?mode=listener or rist://@0.0.0.0:port

Anything else

https://drive.google.com/file/d/1NurckdskUEqTFtdMMkCVUNot6VdUwkbr/view?usp=sharing