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DASH trick mode support
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Parses DASH trick mode tracks and puts the extra trick mode Stream
into the manifest.  StreamingEngine can now use this info to optimize
streaming during trick play mode.

Includes:
 - a new demo asset with a trick mode track
 - updates to tests (we now require at least one audio or video stream
   and we require bandwidth attributes on them)
 - updates to the parser's trickmode test
 - a new StreamingEngine test

Closes #538

Change-Id: Id38264ca64bc7905a5c33a269269741cfd12dd4d
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@joeyparrish
joeyparrish committed Jan 5, 2017
1 parent e093ab2 commit c645169
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Showing 13 changed files with 423 additions and 80 deletions.
17 changes: 17 additions & 0 deletions demo/assets.js
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Original file line number Diff line number Diff line change
Expand Up @@ -73,6 +73,7 @@ shakaAssets.Feature = {
PSSH: 'embedded PSSH',
MULTIKEY: 'multiple keys',
MULTIPERIOD: 'multiple Periods',
TRICK_MODE: 'special trick mode track',

SUBTITLES: 'subtitles',
CAPTIONS: 'captions',
Expand Down Expand Up @@ -342,6 +343,22 @@ shakaAssets.testAssets = [
shakaAssets.Feature.WEBVTT
]
},
{
name: 'Sintel w/ trick mode (MP4 only, 720p)',
manifestUri: '//storage.googleapis.com/shaka-demo-assets/sintel-trickplay/dash.mpd', // gjslint: disable=110

encoder: shakaAssets.Encoder.SHAKA_PACKAGER,
source: shakaAssets.Source.SHAKA,
drm: [],
features: [
shakaAssets.Feature.HIGH_DEFINITION,
shakaAssets.Feature.MP4,
shakaAssets.Feature.SEGMENT_BASE,
shakaAssets.Feature.SUBTITLES,
shakaAssets.Feature.TRICK_MODE,
shakaAssets.Feature.WEBVTT
]
},
{
name: 'Sintel 4k (WebM only)',
manifestUri: '//storage.googleapis.com/shaka-demo-assets/sintel-webm-only/dash.mpd', // gjslint: disable=110
Expand Down
6 changes: 5 additions & 1 deletion externs/shaka/manifest.js
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Original file line number Diff line number Diff line change
Expand Up @@ -294,7 +294,8 @@ shakaExtern.GetSegmentReferenceFunction;
* keyId: ?string,
* language: string,
* type: string,
* primary: boolean
* primary: boolean,
* trickModeVideo: ?shakaExtern.Stream
* }}
*
* @description
Expand Down Expand Up @@ -373,6 +374,9 @@ shakaExtern.GetSegmentReferenceFunction;
* True indicates that the player should prefer this Stream over others
* in the same Period. However, the player may use another
* Stream to meet application preferences.
* @property {?shakaExtern.Stream} trickModeVideo
* <i>Video streams only.</i> <br>
* An alternate video stream to use for trick mode playback.
*
* @exportDoc
*/
Expand Down
137 changes: 91 additions & 46 deletions lib/dash/dash_parser.js
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Original file line number Diff line number Diff line change
Expand Up @@ -236,7 +236,8 @@ shaka.dash.DashParser.PeriodInfo;
* main: boolean,
* streams: !Array.<shakaExtern.Stream>,
* drmInfos: !Array.<shakaExtern.DrmInfo>,
* containsInband: boolean
* containsInband: boolean,
* trickModeFor: ?string
* }}
*
* @description
Expand All @@ -256,6 +257,10 @@ shaka.dash.DashParser.PeriodInfo;
* The DRM info for the AdaptationSet.
* @property {boolean} containsInband
* Signals whether AdaptationSet has inband content indicator on it.
* @property {?string} trickModeFor
* If non-null, this AdaptationInfo represents trick mode tracks. This
* property is the ID of the normal AdaptationSet these tracks should be
* associated with.
*/
shaka.dash.DashParser.AdaptationInfo;

Expand Down Expand Up @@ -700,53 +705,71 @@ shaka.dash.DashParser.prototype.parsePeriod_ = function(
.map(this.parseAdaptationSet_.bind(this, context))
.filter(shaka.util.Functional.isNotNull);

if (adaptationSets.length == 0) {
throw new shaka.util.Error(
shaka.util.Error.Category.MANIFEST,
shaka.util.Error.Code.DASH_EMPTY_PERIOD);
}
var normalAdaptationSets = adaptationSets
.filter(function(as) { return !as.trickModeFor; });

var trickModeAdaptationSets = adaptationSets
.filter(function(as) { return as.trickModeFor; });

// Attach trick mode tracks to normal tracks.
trickModeAdaptationSets.forEach(function(trickModeSet) {
// There may be multiple trick mode streams, but we do not currently
// support that. Just choose one.
var trickModeVideo = trickModeSet.streams[0];
var targetId = trickModeSet.trickModeFor;
normalAdaptationSets.forEach(function(normalSet) {
if (normalSet.id == targetId) {
normalSet.streams.forEach(function(stream) {
stream.trickModeVideo = trickModeVideo;
});
}
});
});

// see if any adaptation set has emsg indicator on it.
// See if any adaptation set has emsg indicator on it.
// If it does, we'll register a response filter later.
for (var i = 0; i < adaptationSets.length; i++) {
if (adaptationSets[i].containsInband) {
for (var i = 0; i < normalAdaptationSets.length; i++) {
if (normalAdaptationSets[i].containsInband) {
periodInfo.containsInband = true;
}
}
var videoSets = this.getSetsOfType_(adaptationSets, 'video');
var audioSets = this.getSetsOfType_(adaptationSets, 'audio');
var variants = [];

// TODO: Limit number of combinations. Come up with a heuristic
// to decide which audio tracks to combine with which video tracks.
for (var i = 0; i < audioSets.length; i++) {
for (var j = 0; j < videoSets.length; j++) {
variants.push.apply(variants,
this.createVariants_(audioSets[i], videoSets[j]));
}
var videoSets = this.getSetsOfType_(normalAdaptationSets, 'video');
var audioSets = this.getSetsOfType_(normalAdaptationSets, 'audio');

if (!videoSets.length && !audioSets.length) {
throw new shaka.util.Error(
shaka.util.Error.Category.MANIFEST,
shaka.util.Error.Code.DASH_EMPTY_PERIOD);
}

// In case of audio-only or video-only content, we create an array of one item
// containing a null. This way, the double-loop works for all kinds of
// content.
if (!audioSets.length) {
// Video only variants
for (var i = 0; i < videoSets.length; i++) {
variants.push.apply(variants,
this.createVariants_(null, videoSets[i]));
}
audioSets = [null];
}

if (!videoSets.length) {
// Audio only variants
for (var i = 0; i < audioSets.length; i++) {
variants.push.apply(variants,
this.createVariants_(audioSets[i], null));
videoSets = [null];
}

// TODO: Limit number of combinations. Come up with a heuristic
// to decide which audio tracks to combine with which video tracks.
var variants = [];
for (var i = 0; i < audioSets.length; i++) {
for (var j = 0; j < videoSets.length; j++) {
var audioSet = audioSets[i];
var videoSet = videoSets[j];
this.createVariants_(audioSet, videoSet, variants);
}
}

var textSets = this.getSetsOfType_(adaptationSets, 'text');
var textSets = this.getSetsOfType_(normalAdaptationSets, 'text');
var textStreams = [];
for (var i = 0; i < textSets.length; i++) {
textStreams.push.apply(textStreams, textSets[i].streams);
}

return {
startTime: periodInfo.start,
textStreams: textStreams,
Expand Down Expand Up @@ -774,14 +797,26 @@ shaka.dash.DashParser.prototype.getSetsOfType_ = function(
*
* @param {?shaka.dash.DashParser.AdaptationInfo} audio
* @param {?shaka.dash.DashParser.AdaptationInfo} video
* @return {!Array.<!shakaExtern.Variant>}
* @param {!Array.<shakaExtern.Variant>} variants New variants are pushed onto
* this array.
* @private
*/
shaka.dash.DashParser.prototype.createVariants_ = function(audio, video) {
var variants = [];
shaka.dash.DashParser.prototype.createVariants_ =
function(audio, video, variants) {
// Since both audio and video are of the same type, this assertion will catch
// certain mistakes at runtime that the compiler would miss.
goog.asserts.assert(!audio || audio.contentType == 'audio',
'Audio parameter mistmatch!');
goog.asserts.assert(!video || video.contentType == 'video',
'Video parameter mistmatch!');

/** @type {number} */
var bandwidth;
/** @type {shakaExtern.Variant} */
var variant;

if (!audio && !video) {
return variants;
return;
} else if (audio && video) {
// Audio+video variants
var DrmEngine = shaka.media.DrmEngine;
Expand All @@ -791,13 +826,21 @@ shaka.dash.DashParser.prototype.createVariants_ = function(audio, video) {

for (var i = 0; i < audio.streams.length; i++) {
for (var j = 0; j < video.streams.length; j++) {
var variant = {
// Explicit cast, followed by assertion. These should both be defined
// in the case of DASH, but the type of Stream.bandwidth allows for
// undefined in order to support HLS.
bandwidth = /** @type {number} */(
video.streams[j].bandwidth +
audio.streams[i].bandwidth);
goog.asserts.assert(bandwidth,
'Bandwidth must be defined and non-zero!');
variant = {
id: this.globalId_++,
language: audio.language,
primary: audio.main || video.main,
audio: audio.streams[i],
video: video.streams[j],
bandwidth: video.streams[j].bandwidth + audio.streams[i].bandwidth,
bandwidth: bandwidth,
drmInfos: drmInfos,
allowedByApplication: true,
allowedByKeySystem: true
Expand All @@ -811,13 +854,19 @@ shaka.dash.DashParser.prototype.createVariants_ = function(audio, video) {
// Audio or video only variants
var set = audio || video;
for (var i = 0; i < set.streams.length; i++) {
var variant = {
// Explicit cast, followed by assertion. These should both be defined
// in the case of DASH, but the type allows for undefined in order to
// support HLS.
bandwidth = /** @type {number} */(set.streams[i].bandwidth);
goog.asserts.assert(bandwidth,
'Bandwidth must be defined and non-zero!');
variant = {
id: this.globalId_++,
language: set.language || '',
primary: set.main,
audio: audio ? set.streams[i] : null,
video: video ? set.streams[i] : null,
bandwidth: set.streams[i].bandwidth,
bandwidth: bandwidth,
drmInfos: set.drmInfos,
allowedByApplication: true,
allowedByKeySystem: true
Expand All @@ -826,8 +875,6 @@ shaka.dash.DashParser.prototype.createVariants_ = function(audio, video) {
variants.push(variant);
}
}

return variants;
};


Expand Down Expand Up @@ -884,10 +931,6 @@ shaka.dash.DashParser.prototype.parseAdaptationSet_ = function(context, elem) {
trickModeFor = prop.getAttribute('value');
}
});
if (trickModeFor != null) {
// Ignore trick mode tracks until we support them fully.
return null;
}

var contentProtectionElems = XmlUtils.findChildren(elem, 'ContentProtection');
var contentProtection = shaka.dash.ContentProtection.parseFromAdaptationSet(
Expand Down Expand Up @@ -927,7 +970,8 @@ shaka.dash.DashParser.prototype.parseAdaptationSet_ = function(context, elem) {
main: main,
streams: streams,
drmInfos: contentProtection.drmInfos,
containsInband: containsInband
containsInband: containsInband,
trickModeFor: trickModeFor
};
};

Expand Down Expand Up @@ -1025,7 +1069,8 @@ shaka.dash.DashParser.prototype.parseRepresentation_ = function(
keyId: keyId,
language: language,
type: context.adaptationSet.contentType,
primary: isPrimary
primary: isPrimary,
trickModeVideo: null
};
};

Expand Down
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