Low Latency: Accelerated/Decelerated Playback

haudiobe commented 4 years ago

Background: For low-latency, to catchup with the desired latency or to avoid buffer underrun, the application may want to accelerate/decelerate playback of the media

Stimulus: Playback regular content and fill buffer. Then decelerate and accelerate content playback by a certain factor.

Expected Observation: Video is played at adjusted framerate. Audio is played properly - sounds good, for example applying pitch corrected. details are tbd

CMAF content: regular cmaf content, but may be media profile specific and should also be test for audio and video combined.

haudiobe commented 4 years ago

May be two tests, one with and one without pitch correction.

jpiesing commented 4 years ago

I agree with adding this but there are a lot of small variations and we need to think carefully what is important to avoid a combinatorial explosion.

How important is it to test video without audio and audio without video?
If we only test CMAF Presentations (video+audio) how does that work for the different codecs? Would it be reasonable to test each video media profile with (say) HE-AAC and each audio media profile with AVC?
Is there really a use-case for decelerated playback?

jpiesing commented 4 years ago

Duplicate of #71

haudiobe commented 2 years ago

accepted as duplicate.

cta-wave / device-playback-task-force

Low Latency: Accelerated/Decelerated Playback #79