obsproject / obsproject/obs-studio

Missing NACK response in WHIP Simulcast for medium/low layers (HIGH works fine)

Open
#13,161 0 comments 0 reactions 0 assignees View on GitHub

Nobody has claimed this yet.

Dominant language
C
Stars
76.4k
Forks
10.2k
Avg merge
4d 23h
Merged PRs (30d)
12

Description

Operating System Info

macOS 15

Other OS

No response

OBS Studio Version

32.1.0-rc1

OBS Studio Version (Other)

No response

OBS Studio Log URL

https://obsproject.com/logs/IWwBCGkdWWllnfAK

OBS Studio Crash Log URL

No response

Expected Behavior

It should respond to NACK requests for all layers, not just HIGH layer

Current Behavior

It responds to HIGH video layer for NACK requests, and ignores lower video layers/resolutions, making 3 layer simulcast video under packet loss frozen for lower quality video tracks.

Steps to Reproduce
  1. Publish Simulcast to a WHIP endpoint that accepts Simulcast from OBS
  2. Check NACK logs
  3. Verify OBS resends lost packets for HIGH video track
Anything else we should know?

Bug is related to https://github.com/obsproject/obs-studio/pull/10885

Contributor guide

Open the contributing guide

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start by reviewing the behavior described in the OBS log and the related pull request 10885, then reproduce the issue with a WHIP endpoint accepting OBS simulcast while monitoring NACKs. Done means lost packets are retransmitted for HIGH, medium, and low video layers rather than only HIGH.

Written by the indexing model from the issue text.

Assessment

Tech stack
c
Domain
audio-video-rtc, networking
Issue type
Bug
Difficulty
4/5
Estimated time
3-5 days
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
38/100

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.