Commit Graph

21 Commits

Author SHA1 Message Date
KongQun Yang 3c26dfbd53 Estimate target duration in bandwidth calculation from initial blocks
We used to use the target segment duration provided by the user.
Unfortunately that does not work for iframe only playlist which
the target duration is effectively equal to the GOP duration.

In the new approach, we estimate the target duration from the initial
few blocks (10 blocks right now).

Fixes #610.

Change-Id: Ie8bf943e157149ca7ed3b9382fe0a1088d0774e2
2019-07-11 17:45:55 -07:00
KongQun Yang b85e5c9368 Use segment duration in buffer depth calculation
Segment start,end time was used previously, which could result in
problems if there are discontinuity in the streams. E.g. if the
stream has timestamp, 10000, 10001, 10002 and then next segment
comes in with timestamp 1. With the previous logic, all the segments
would remain in the time shift buffer until after 10000 segments
even with a small time shift buffer depth of 10.

This could also happen when timestamp wraps around, which could
happen during long time of live streaming.

This change will also be useful to support multi-period live DASH.

Fixes #563.

Change-Id: Ie078d76c6e4af13ade9ad46191c8e3529069ed4d
2019-04-17 22:47:10 +00:00
KongQun Yang 74df8d30cc Exclude short segments from peak bandwidth computation
https://tools.ietf.org/html/rfc8216#section-4.1
The peak segment bit rate of a Media Playlist is the largest bit rate
of any contiguous set of segments whose total duration is between 0.5
and 1.5 times the target duration.

Fixes #498.

Change-Id: I1f28972b9cc5977735e47906bdcd88ba3942db5a
2018-11-26 20:02:09 +00:00
KongQun Yang 5dd21179ec Do not use harmonic mean in bandwidth calculation
Instead, caclulating average bandwidth by dividing the sum of the
sizes of every segment by the sum of the durations of every segment.
This aligns with the requirement in HLS spec:
https://tools.ietf.org/html/draft-pantos-http-live-streaming-23 4.1.

BandwidthEstimator is also simplified to handle all blocks only.

Fixes #361

Change-Id: I89e7d415a841f4d4048f199de8dae7ffa250467b
2018-07-12 10:46:47 -07:00
KongQun Yang b4256bf040 [Cleanup] Use int64_t for time for consistency
Change-Id: I408f3fe7c98320be4e43ca2a5bcb9b22cc8a2012
2018-06-29 22:53:06 +00:00
KongQun Yang 418e741f7f [DASH] Fix potential text Segment Timeline not grouped
This happens when --allow_approximate_segment_timeline_ is set.

Fixes #417.

Change-Id: Idf938ad4e0f7788a00c7485b7eeda43358a94178
2018-06-22 00:45:00 +00:00
KongQun Yang 55cc50baa0 Use new vp09 codec string for WebM by default
Configurable under flag --use_legacy_vp9_codec_string, which defaults
to false as all major browsers and platforms support new style vp09
codec string already.

Closes #406.

Change-Id: I22e917777f9d66db815ff9d55eb47b6d55806269
2018-06-12 23:31:28 +00:00
KongQun Yang 37d4ff017f Support removing segments outside of live window in HLS
Issue: #223

Change-Id: Ib91c60268d8df9adbaf5f6cac77eaebd6a3edb6e
2018-04-30 17:25:39 -07:00
KongQun Yang 224b597b48 Support approximate SegmentTimeline
It is not always possible to align segment duration to target duration
exactly. For example, for AAC with sampling rate of 44100, there are
always 1024 audio frames per sample, so the sample duration is
1024/44100. For a target duration of 2 seconds, the closest segment
duration would be 1.984 or 2.00533.

This feature allows MPD generator to treat these segments as having
the same duration, thus allows MPD generator to generate less
SegmentTimeline entries and potentially no SegmentTimeline entries
(replaced with SegmentTemplate@duration instead if
  --segment_template_constant_duration flag is enabled).

Under flag --allow_approximate_segment_timeline. Disabled by default.

Fixes #330.

Change-Id: I5044eaa348ebbf45bf792a2af53fc95a115ae21b
2018-04-30 17:15:47 -07:00
KongQun Yang adc9549e2d Add new URL fields in MediaInfo
The file_name fields will be used to solely indicate file paths on the
designated file system, and they are used to do normal file operations,
including file creation, file updating and file removal if needed;
added new xxx_url fields, for the URLs that should appear on DASH
manifest or HLS playlists.

xxx_url are the URIs of the media in the manifest. The fields are
converted from file_name fields but adjusted to be relative to DASH
manifest path or HLS playlist path, optionally with base_url prepended.

Previously the file_name fields are converted in place to indicate
URLs when passing to manifest / playlist builders. The original file
names were lost, which made it difficult to remove files outside of
live window.

Now that the input file names are preserved. File system APIs can
operate on the original file names while manifest / playlist generation
functions can operate on URLs.

Issue: #233

Change-Id: I36a64f16e3d1261ce91783a86588f24ad1371662
2018-04-23 22:49:47 +00:00
KongQun Yang 43be3c8e8b Use max bitrate in Representation@bandwidth instead of average bitrate
According to DASH spec (23009-1:2014):

Consider a hypothetical constant bitrate channel of
bandwidth with the value of this attribute in bits per second
(bps). Then, if the Representation is continuously delivered
at this bitrate, starting at any SAP that is indicated either by
@startwithsap or by any Segment Index box, a client can
be assured of having enough data for continuous playout
providing playout begins after @minbuffertime *
@bandwidth bits have been received (i.e. at time
@minbuffertime after the first bit is received).
For dependent Representations this value specifies the
bandwidth according to the above definition for the
aggregation of this Representation and all complementary
Representations.

This suggests that max bitrate should be used instead of average
bitrate.

Also cleaned up BandwidthEstimator code.

Fixes #376.

Change-Id: Ibf5896394c5c6bb820849771a2129c59202d2273
2018-04-17 22:39:58 +00:00
KongQun Yang 64c2ad7d6e Support removing segments outside of live window in DASH
Issue: #223

Change-Id: Ie2d98a8f1553862532f1bdd074ca022d8904f0ea
2018-04-13 14:15:58 -07:00
KongQun Yang 4549b1d569 Remove pto_adjustment flag
This flag was introduced to workaround a rounding error in Chrome
(probably in other browsers too).

Also although this flag avoids the first frame of a Period to be
dropped due to rounding error but it could cause the last frame of a
Period to be dropped.

Now that we use a high precision Period@duration, we do not expect to
see rounding errors any more. The player would be a better place for
the workaround even if it is still needed.

Related issue: #368.

Change-Id: I3bd517ecc6d548ff62e0c13394edb49d4bc68e8f
2018-04-13 20:07:47 +00:00
KongQun Yang 4e9aadcb15 Write @startNumber for SegmentTemplate with $Time$ too
Change-Id: I8d55d81e7114e02b511656e73ecc0ad3bb1aa74f
2018-03-30 20:35:27 +00:00
KongQun Yang ee9b7f6392 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 08:55:10 -08:00
Aaron Vaage 30b5fdf19f Add Text Codec To Codec String
This change has the hls master playlist add the text codec string
to the list of codecs in a variant.

Bug: 72942756

Change-Id: Ib25bb2064a291d10d7b1d261a4307991df62220c
2018-02-28 19:23:36 +00:00
KongQun Yang d76ccea46f [DASH] Support multiple period
Change-Id: Ifd17bf0eabbd61ec7a1d35f0b864b5aa6666aa87
2018-01-11 21:44:18 +00:00
KongQun Yang ef2c424876 Implement Representation::GetDurationSeconds
Also added Period::GetAdaptationSets and
AdaptationSet::GetRepresentations.

Instead of implementing GetDurationSeconds in all MpdBuilder classes
(MpdBuilder/Period/Adaptation/Representation) like what we used to do
with GetEarliestTimestamp, the two new functions allows MpdBuilder to
iterate through the Representations to get durations.

Also updates GetEarliestTimestamp functions to use the same iteration
method.

Change-Id: I682b70c07c248c0f6511ec3d9019086f986ee10e
2018-01-09 01:03:05 +00:00
KongQun Yang 718fce068d Refactor DashIopMpdNotifier Part 2
Move AdaptationSet related functions to the new Period class, which
maps to <Period> element and provides methods to add AdaptationSets.

Change-Id: I0fee290769fbe9a6355cc1b8c86baec8fbc4b4fd
2017-12-22 13:24:38 -08:00
KongQun Yang 55edaf0bea Move SegmentTemplateTest and TimeShiftBufferDepthTest too
Moved from mpd_unittest.cc to representation_unittest.cc.

Also removed unused test data files in packager/mpd/test/data.

Change-Id: I23811390b4b1ffbfac3e69c1ffcf92544099a53d
2017-12-15 20:05:32 +00:00
KongQun Yang cacdab2209 Split mpd_unittest.cc into three files
Move AdaptationSet related tests to adaptation_set_unittest.cc and
Representation related tests to representation_unittest.cc.

Change-Id: I360e9aea3ba08a32e5ba3b0e8b34345f2b3f0b20
2017-12-15 20:05:15 +00:00