fix(dgw): fix adaptive frame skipping during EOF waits in session shadowing by irvingoujAtDevolution · Pull Request #1678 · Devolutions/devolutions-gateway

irvingouj@Devolutions (irvingoujAtDevolution) · 2026-02-13T20:36:13Z

Fixes video playback freezing permanently during live session shadowing. After brief pauses in the recording stream (e.g., during network hiccups or slow file writes), the shadow player would stop rendering new frames entirely, requiring a session restart.

With this fix, shadow sessions now recover gracefully from temporary recording pauses, maintaining smooth video playback throughout the session.

Issue: DGW-341

github-actions · 2026-02-13T20:36:40Z

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crates/video-streamer/src/streamer/mod.rs

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Pull request overview

This PR fixes a critical bug in session shadowing where adaptive frame skipping would permanently stall video streaming after EOF retry waits. The issue occurred because the realtime ratio calculation (used to decide whether to skip frames) included idle time spent waiting for file growth, causing the ratio to drop far below the 1.0 threshold and triggering perpetual decode-only mode.

Changes:

Modified the realtime ratio calculation to track only active processing time, excluding EOF wait periods
Added a 3-second timeout to EOF waits to prevent indefinite stalls
Increased MAX_RETRY_COUNT from 3 to 25 to accommodate the new timeout-based retry strategy

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
crates/video-streamer/src/streamer/tag_writers.rs	Added processing_time tracking to measure only active processing (excluding idle waits), updated current_realtime_ratio to use processing_time instead of wall time, added Duration import
crates/video-streamer/src/streamer/mod.rs	Added 3-second timeout to EOF waits, increased MAX_RETRY_COUNT from 3 to 25 to accommodate timeout-based retries

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crates/video-streamer/src/streamer/mod.rs

crates/video-streamer/src/streamer/tag_writers.rs

Benoît Cortier (CBenoit) · 2026-02-19T15:46:22Z

irvingouj@Devolutions (@irvingoujAtDevolution) Is it ready?

Benoît Cortier (CBenoit)

I’m good with the changes, so I’m approving now. Feel free to merge when you are satisfied.

Before merging, make sure you follow these instructions for the PR / commit: https://github.com/Devolutions/devolutions-gateway/blob/b955082ef7f98c94ea24f37b83528b4e72a26f37/AGENTS.md#pr-body

Especially, the PR title/body:

Should include a user-oriented description (what users gain/notice)
Can include technical context for developers
Avoid internal implementation details
Focus on impact and benefits
This text appears in the changelog for feat/fix/perf

irvingouj@Devolutions (irvingoujAtDevolution) · 2026-03-02T15:40:07Z

Implementation Details

Root cause: The adaptive frame skip ratio (media_time / wall_time) was corrupted by idle time spent waiting for the recording file to grow during EOF retries. A 20-second EOF wait produced a ratio of ~0.006, far below the 1.0 threshold, causing all subsequent frames to be decode-only with no encoded output reaching the player.

Changes:

Changed ratio calculation to use accumulated active processing time (media_time / processing_time) instead of total wall time, excluding idle waits
Added 3-second timeout to EOF waits to limit maximum stall duration per retry
Increased MAX_RETRY_COUNT from 3 to 25 to accommodate the timeout-based retry strategy (worst case: 75s total, but downstream components enforce stricter overall timeouts)

…dowing Fixes playback failures in session shadowing where adaptive frame skipping permanently stalls video streaming after EOF retry waits. The ratio used for adaptive frame skip decisions (media_time / wall_time) was corrupted by time spent waiting for the recording file to grow during EOF retries. A 20-second EOF wait would result in a ratio of ~0.006, far below the 1.0 threshold, causing all subsequent frames to be decode-only with no encoded output reaching the player. The fix changes the ratio to only measure active processing time (media_time / accumulated_processing_time) instead of total wall time, excluding idle waits. Additionally, EOF waits now time out after 3 seconds to limit the maximum stall duration. Issue: DGW-341

Lower EOF timeout log from info! to trace!, add rationale comment for MAX_RETRY_COUNT, and document current_realtime_ratio() intent. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

irvingouj@Devolutions (irvingoujAtDevolution) · 2026-03-02T19:45:01Z

irvingouj@Devolutions (irvingouj@Devolutions (@irvingoujAtDevolution)) Is it ready?

Sorry, took a while, it's ready now

irvingouj@Devolutions (irvingoujAtDevolution) force-pushed the fix-adaptive-frame-skip-eof-ratio branch from a51ceca to 16733fc Compare February 13, 2026 20:36

Marc-André Moreau (awakecoding) approved these changes Feb 13, 2026

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Benoît Cortier (CBenoit) reviewed Feb 14, 2026

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Benoît Cortier (CBenoit) requested a review from Copilot February 14, 2026 01:30

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Benoît Cortier (CBenoit) approved these changes Feb 20, 2026

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irvingouj@Devolutions (irvingoujAtDevolution) force-pushed the fix-adaptive-frame-skip-eof-ratio branch 2 times, most recently from 0ea587a to b15648e Compare March 2, 2026 15:30

irvingouj@Devolutions (irvingoujAtDevolution) and others added 4 commits March 2, 2026 11:10

fix(dgw): address PR review comments on adaptive frame skip fix

2b6621f

Lower EOF timeout log from info! to trace!, add rationale comment for MAX_RETRY_COUNT, and document current_realtime_ratio() intent. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

cap fram skipped

66c4f54

style: apply nightly rustfmt formatting

c4fb2ca

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

irvingouj@Devolutions (irvingoujAtDevolution) force-pushed the fix-adaptive-frame-skip-eof-ratio branch from 344f94d to c4fb2ca Compare March 2, 2026 16:10

fix(dgw): improve comments on adaptive frame skip constants and methods

88efbbb

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

irvingouj@Devolutions (irvingoujAtDevolution) merged commit a1566fd into master Mar 2, 2026
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irvingouj@Devolutions (irvingoujAtDevolution) deleted the fix-adaptive-frame-skip-eof-ratio branch March 2, 2026 19:44

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fix(dgw): fix adaptive frame skipping during EOF waits in session shadowing#1678

fix(dgw): fix adaptive frame skipping during EOF waits in session shadowing#1678
irvingouj@Devolutions (irvingoujAtDevolution) merged 5 commits intomasterfrom
fix-adaptive-frame-skip-eof-ratio

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Pull request overview

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irvingouj@Devolutions (irvingoujAtDevolution) commented Mar 2, 2026

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