Commit Graph

5 Commits

Author SHA1 Message Date
KongQun Yang 1223694249 Do not force earliest_presentation_time to 0 for VOD
Instead, the actual earliest presentation time is used except for
the first segment if there is an offset between presentation time
(pts) and decoding time (dts).

Chrome (as of v66) reports dts instead of pts in buffered ranges in
MSE API. To avoid breaking Chrome, the earliest_presentation_time
of the first segment is set to its dts as Chrome does not like negative
values for
  adjusted dts = dts + Period@start (0 for the first period)
                 - presentationTimeOffset (earliest_presentation_time).

Fixes #303.

Change-Id: I5ca80e05d5570961400499436f2bcc01f06e69e0
2018-04-20 13:58:01 -07:00
KongQun Yang 668335c647 Generate a more accurate time in Period@duration
Chrome internally uses time accurate to microseconds, which is
implemented per MSE spec (https://www.w3.org/TR/media-source/).

Generate Period@duration with better precision to avoid possible
buffered range gaps in Chrome (possibly other browsers too), which
may lead to other problems like playback stall.

b/74238961
Fixes #368.

Change-Id: I357a0f62b67f75c7ca044bb99ea4e3c8bbb6fecd
2018-04-20 13:39:40 -07:00
KongQun Yang f8a1cb66ad Calculate presentationTimeOffset and Period@duration from segments
Prefer timestamps from Video AdaptationSets if available - this avoids
possible video playback jitters due to gaps.

presentationTimeOffset is not applied to the first period as it may in
negative dts which Chrome does not like: https://crbug.com/398141.

It is safe to apply to subsequent periods as the actual offset applied
takes Period@start into consideration:

    offset = Period@start - presentationTimeOffset

The result timestamp with offset applied is close to Period@start, so
it is unlikely to result in a negative dts value.

Closes b/73899306.

Change-Id: If8361f5469610093b3aac6675754536ad7e83c4c
2018-03-01 22:25:55 -08:00
Haoming Chen da8877d8a2 Rename trick play rate to trick play factor.
- Add a "tpf" abbreviation in stream descriptor for
  trick_play_factor.

Change-Id: Ia09313bb9778456b53bdb0a8cc46d2ba8caa2ac2
2017-05-17 21:51:34 +00:00
Haoming Chen 4ba5bec660 Integrate trick play.
- Add trick play adaptation in mpd. This addresses #178.

Change-Id: Id6cc08c788eda074c261d0274768051837b84541
2017-05-09 13:33:11 -07:00