Addresses items raised by the multi-agent code review of the 0.9.9
HW accel + first-start work:
- EncoderProfile now carries DecodeHwAccel so the demuxer `-hwaccel`
flag and the encoder argv derive from a single resolved profile.
Adding a new backend can no longer leave the two switches out of
sync.
- VAAPI no longer passes `-hwaccel_output_format vaapi`. That option
pinned decoded frames to GPU memory, but the filter chain (scale,
format, setparams) runs on CPU and would fail with "impossible to
convert between formats". Frames now decode HW + flow on CPU; the
encoder uploads back to GPU. Pre-existing bug, never reported because
no one had VAAPI auto-detected in practice.
- readyMax field comment + name: documented that it's a COUNT
(segments ready), not an index. The semantics were correct but the
comment read "highest index" which made `idx < readyMax` look like
an off-by-one to reviewers.
- probe_cache background janitor: 5-minute sweeper that drops expired
entries even when no lookup retouches the key. Lookup-only eviction
was fine for small libraries but unbounded for users who browse and
abandon thousands of files within a TTL window. Lazy + sync.Once.
- probe_cache TTL eviction now re-checks under the write lock so a
concurrent re-insert isn't accidentally evicted.
- probe_cache size-change test now Chtimes the file back to its
original mtime so only `size` differs between store and lookup
keys — properly exercises the size-check path.
- New TestProbeCache_SweepDropsExpired covers the janitor sweep.
- CHANGELOG: backfilled missing compare links 0.6.4 → 0.9.9.
- Stale "line ~1119" reference in VideoToolbox comment dropped; the
bitrate block moved a few lines and the comment was already wrong.
Two issues with the 0.9.9 preset retune:
1. applyDefaults was filling Preset="veryfast" before
ResolveEncoderProfile got to pick the latency-biased default, so the
"superfast" change never reached users with a freshly-generated
config.toml — only those who left the field empty saw it.
2. The configured preset was being passed through to every encoder.
That's only valid for libx264 (ultrafast…veryslow); NVENC uses p1-p7
and rejects anything else, QSV uses its own subset. A user with NVENC
+ preset="veryfast" would have ffmpeg reject the argv.
Now:
- TranscodeConfig.Preset documented as libx264-only with the full
range + advice on quality vs first-start latency.
- Default in applyDefaults is empty (was "veryfast") so the engine
fills in "superfast" on libx264.
- ResolveEncoderProfile ignores configuredPreset for vendor encoders
(NVENC sticks to p3, QSV to veryfast, VideoToolbox has no preset
knob). Test cases updated to lock in this behaviour.
Users who want better quality at slower first-play should set
download.transcode.preset = "veryfast" (previous default) / "faster" /
"fast" / "medium" in their config.toml.
Reduces first-segment latency on cache MISS so the player doesn't sit on
"preparando sesión". Three independent levers:
1. ProbeFile memoised by (path, mtime, size) for 30 min — second play of
the same source skips ffprobe (1-3 s on 50+ GB MKVs).
2. HLS encoder presets biased for latency over quality:
- libx264 default veryfast → superfast (~15-20% faster, marginal
quality loss at 5-25 Mbps target bitrates).
- NVENC: -preset p4 -tune hq → -preset p3 -tune ll. First-segment
~0.8 s on RTX-class GPUs (was ~1.5 s).
- QSV: -preset medium → -preset veryfast (keeps look_ahead=0).
- VideoToolbox: adds -realtime 1 (was unset). Bitrate args still
drive rate control; -q:v dropped to avoid the silent conflict
where ffmpeg ignored it under -b:v.
3. Per-session log surfaces encoder + accel + preset so "first-start
was slow" complaints can be triaged from the journal alone.
Diagnostic helpers (DetectHWAccelDiagnostic + HWAccelDiagnostic) added
for future wiring into daemon startup / agent register; users today can
already inspect via `unarr probe-hwaccel`.
Web: AgentsTab profile page now shows the agent's chosen encoder
(amber if software libx264, green if HW) plus the transcode-resolution
cap. Hidden for pre-0.9.9 agents that haven't reported hwAccel.
