Summary

Camera liveview stutters / is not smooth over the cloud relay (remote mode). Console shows continuous BambuTunnel::GetMsg(N) plus repeated ffmpeg mjpeg decode errors — frames from the relay arrive intermittently corrupt/truncated, are dropped, and cause stutter.

Logs

BambuTunnel::GetMsg(89)
[mjpeg @ 0x...] unable to decode APP fields: Invalid data found when processing input
[swscaler @ 0x...] deprecated pixel format used, make sure you did set range correctly

Analysis

• BambuTunnel::GetMsg(...) comes from the closed-source networking plugin (libBambuSource) — not in our source, cannot be fixed in this fork.
• Our open decoder (src/slic3r/GUI/AVVideoDecoder.cpp) behaves correctly and skips undecodable frames.
• Root cause is relay frame delivery (cloud path / closed plugin). LAN mode is smooth.

Status

• Reported upstream: Cloud-relay liveview stutters / drops frames (remote mode); decoder rejects some MJPEG frames bambulab/BambuStudio#11077 (the relay/plugin is theirs).
• Not fixable in this fork. Workaround for users: enable LAN mode + wired printer; keep one camera open.

Possible open-side follow-up (optional)

We could quiet the ffmpeg console spam in AVVideoDecoder (av_log_set_level) and clean the deprecated-pixel-format warning (YUVJ420P → YUV420P + color_range) — cosmetic only, does not fix the stutter.

Environment

BambuStudio 02.07.00.11732 (Linux .deb), Debian trixie, 2 printers, remote camera.