Close the latency gap on the Android client with per-SoC decoder tuning, an
event-driven decode loop, and full system integration.
- Decoder selection: rank MediaCodecList decoders in Kotlin (hardware/vendor
preferred, software avoided, FEATURE_LowLatency probed) and create the chosen
one by name. Per-SoC low-latency keys gated on the codec-name prefix: Qualcomm
picture-order + low-latency, Exynos (also Google Tensor), Amlogic, HiSilicon;
MediaTek vdec-lowlatency set unconditionally. operating-rate = MAX (Qualcomm)
vs priority = 0 (else) are mutually exclusive. NVIDIA/Rockchip/Realtek have no
vendor key — covered by ranking + the standard low-latency key.
- Async decode loop: AMediaCodec async-notify replaces the poll loop, presenting a
decoded frame the instant it is ready instead of waiting out a poll interval.
Behind USE_ASYNC_DECODE with the synchronous loop kept for A/B during bring-up.
- System integration: Wi-Fi FULL_LOW_LATENCY lock and HDMI ALLM
(setPreferMinimalPostProcessing) for the stream's lifetime; game_mode_config.xml
opting out of OEM downscaling / FPS overrides.
- Pipeline: boost the data-plane pump + audio thread priorities, AAudio usage=Game,
DSCP marking on by default on Android, ADPF setPreferPowerEfficiency(false),
and setFrameRateWithChangeStrategy(ALWAYS) to force the HDMI mode switch on TV.
- lowLatencyMode master toggle (default on) as the escape hatch; the stats HUD now
shows the resolved decoder name.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
enricobuehler
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