问题
I'm working with live MPEG-DASH streaming, and I would like to know if there exists a stardard terminology for a given functionality.
It's the "live-dvr" functionality. That is, a mix between a live stream and VOD features: a live stream with the seeking bar in the player allowing to watch past stream time. This involves a series of infrastructure tweaks.
The term "live-dvr" for this setup is kind of informal, and different parties call it in its own way: "live catch-up", "live-vod", "cached live", some vendors set the name for this based on their product lines, and so on. I would like to know if there's a standard term for this kind of setup. Specially because interpreting the standard in order to understand setup parameters for the manifests may be confusing or even misleading without proper terminology.
回答1:
The MPEG-DASH standard only mentions a timeShiftBufferDepth, which specifies how long after the availability of a segment it is still available on the server.
From the spec:
@timeShiftBufferDepth specifies the duration of the time shifting buffer for this Representation that is guaranteed to be available for a Media Presentation with type 'dynamic'.
There is no mention at all of DVR in the spec. So time shift seems to be the term used by MPEG-DASH. However, for example HLS does not mentioned DVR or time shift at all.
回答2:
DVR (Digital Video Recording, also known as nDVR - network DVR) is a functionality that allows recording the live stream and perform its playback from any moment of recorded period. Live stream can still run while the end-user may rewind it to any particular moment in past. Typically media servers (like our Nimble Streamer) also provide time-shift and time range selection - see our links for details.
来源：https://stackoverflow.com/questions/44950488/terminology-live-dvr-in-mpeg-dash-streaming