Diagnosed mpv YouTube audio and playback failures

• Day: 2026-04-17
• Time: 10:25 to 10:40
• Project: Dev
• Workspace: WP 2: Operational
• Status: Completed
• Priority: MEDIUM
• Assignee: Matías Nehuen Iglesias
• Tags: Mpv, Yt-Dlp, Youtube, Audio-Debugging, Systemd, Linux

Description

Session Goal

Investigate why Matías’ YouTube playlist playback via mpv/yt-dlp was failing in different ways: no audio, duplicate audio, and HTTP 403 errors. The broader intent was to isolate whether the issue lived in the player, extractor, browser, or process orchestration layer.

Key Activities

• Reviewed troubleshooting flows for mpv playback with no audio, including process checks, log inspection, direct mpv tests, and audio backend validation (pipewire/pulseaudio).
• Analyzed a 403 failure path and traced it away from the scheduler/wrapper toward the YouTube → extractor → googlevideo.com URL chain.
• Compared yt-dlp/mpv integration behavior and identified version/runtime mismatches as likely contributors.
• Explored remediation options: updating yt-dlp, forcing mpv to use yt-dlp explicitly, testing verbose extraction, and considering Deno as a runtime for JavaScript-dependent extraction.
• Diagnosed duplicate/residual audio caused by concurrent mpv and Firefox playback, and refined the process-management approach using pgrep, pactl, and more aggressive stop scripts.
• Proposed a more production-ready orchestration model using systemd --user, timed playback, and curated profile-based YouTube link bags for ambient audio.

Achievements

• Narrowed the root cause of the 403 issue to the extraction/playback chain rather than the scheduler, wrapper script, or browser.
• Identified that lingering audio was due to coexistence of multiple mpv processes, not Firefox alone.
• Clarified that the immediate stabilization path is to clean up process state during tests and refresh the extraction/runtime stack before changing the overall playback architecture.
• Established a concrete direction for long-term automation: user-level systemd orchestration with scheduled playback profiles.

Pending Tasks

• Update and re-test yt-dlp extraction in verbose mode.
• Install or validate Deno if the extractor requires a JS runtime.
• Re-check mpv version compatibility and confirm audio output path behavior.
• Temporarily harden stop scripts to kill all mpv instances during debugging.
• Validate the proposed systemd --user ambient-audio orchestration design with real playlists and schedules.

Evidence

• source_file=2026-04-17.sessions.jsonl, line_number=7, event_count=0, session_id=15e193ce4fde669ec06f627d0b3db310707ba364a33be238ba3c2e93098b4a58
• event_ids: []