Buffering ahead nonstop into the cache results in nonstop disk or network
activity to read stream data from wherever it may originate. Currently,
there's no way to configure the demuxer to back off once it's buffered
ahead enough data, since the cache limit will be perpetually not-reached as
a stream continues to play, until the entire stream is eventually buffered.
On a laptop with an i9-12900H with decoding performed by the iGPU,
watching a locally-saved 1080p video which hasn't been buffered into the
page cache consumes approximately 15 W even with caching enabled. When
configuring a hysteresis to make the demuxer back off, power consumption
drops to 9 W when watching the same video, resulting in a whopping 6 W of
power savings.
To make it possible to attain significant power savings via caching, add
a --demuxer-hysteresis-secs option to configure a hysteresis to make the
demuxer back off until there's only the configured number of seconds
remaining in the cache from the current playback position.
This feature is disabled by default.
Sultan Alsawaf
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