SDK / exoplayer

- Made enabledRenderers an array to avoid loads of method calls.
- Made if so that enabled renderers are always called in a consistent
  order, rather than their order changing if they're enabled/disabled
  over time. This is likely to make performance more predictable.
- Split out reading of resets into a separate method. This method is
  now called directly after seeking on the source, so as to ensure
  instant propagation of the new position from source->renderers in
  the common case.
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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=117225639

Issue: #1287
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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=117225449

Issue #801
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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=117225377

Some devices fail to decode an avc3 stream that doesn't start with an SPS (for
example, if an access unit delimiter appears first). Workaround the issue by
discarding input sample data up to the first SPS on those devices.
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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=117224602

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=117224468

When reading unknown duration files with CBR seeking, the Mp3Extractor could
try to read sample data from 0. This happened because synchronization did not
skip over the ID3 data when it immediately found valid frames. When the invalid
sample data is read, the extractor tries to resynchronize from the next byte
(at offset 1), and this fails because the ID3 data at the start of the file is
longer than the synchronization search distance.
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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=117224270

This is needed to support fully demuxed audio in HLS. For the
sample I have the video (only) variant still declares an AAC
stream. I suspect there's at least one toolchain out there that
hardcodes H264 and AAC streams in TS output.
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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=117224224

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=117224172

The idea here is that you'll be able to feed data through an extractor
to a FakeExtractorOutput, then do the same again with some or all of the
simulated flakiness settings toggled on FakeExtractorInput, and then
assert that the output was the same in both cases.
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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=117224019

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=117220851

The upstream source (or its stream) should always provide data
starting from a sync frame, so this logic shouldn't be necessary.
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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=117220759

allow "center".
This value (and not "middle") is listed in
https://w3c.github.io/webvtt/ ( WebVTT: The Web Video Text Tracks Format, Draft
Community Group Report, 21 December 2015).

Leaving the behavior for "middle" unchanged.
It was the value listed in older drafts, e.g.
https://www.w3.org/TR/2014/WD-webvtt1-20141113/ ( W3C First Public Working
Draft 13 November 2014 )
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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=117220612

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=117220536

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=117220482

Failing to parse a UUID from a ContentProtection should only
result in filtering if there was actually a cenc:pssh element
there for us to get it from.

Issue: #1256
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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=117220417

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=117220360

This avoids accessing PtsTimestampAdjuster through a thunk method,
and allows the PesReader classes to be static, which is nice in
general.
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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=117220139

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=117220082

- Use it to simplify a bunch of tests.
- Will also replace RecordableExtractorInput in a subsequent CL.
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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=117220030

Issue: #497
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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=117219944

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=117219856

Issue: #1195
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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=117155301

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=117149421

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=117148015

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=117141509

Set the duration to the sum of the final period's start
+ duration (if available) if MPD@mediaPresentationDuration
isn't set in the manifest.
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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=117141391

Issue: #1193
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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=117136800

Issue: #1185
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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=117136646

Issue #1181
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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=117136370

Issue: #1235
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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=117131149

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=117131005

- readFully calls when reading a string or varint may have 0 length.
  The behavior of a 0 length read isn't well defined either at the
  ExtractorInput or DataSource level, particularly when the read may
  also coincide with EOS. We'll work on defining these cases properly
  going forward, but in the meantime this fix avoids attempting 0
  length reads.
- [Aside] UTF8 the is guaranteed default charset on Android.
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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=117130356

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=117129870

DTS Express (which is DTS LBR according to http://www.mp4ra.org/codecs.html) is
not supported for passthrough playback currently. Associate a different MIME
type with it so that we don't try to use DTS passthrough for playing DTS
Express.

The MIME type for DTS Express is just vnd.dts.hd, with a profile parameter
indicating that it's DTS Express rather than one of the other formats.
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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=117129583

Handle minor timing difference between the different media content
and the available range values as specified in the MPD.

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=117127112

The logic in the platform was causing captions and the reported
playback position to gradually drift out of sync with respect to
audio and video.
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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=117126970

Issue: #1197
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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=117125081

Notes:

- The way this works is that every time the player needs to
  select some tracks it invokes the TrackSelector. When a
  track selection is actually activated (i.e. "hits the
  screen") it gets passed back to the TrackSelector, which
  allows it to expose the current tracks through an API that
  it may choose to define. Since playlist support doesn't exist
  yet, it's currently the case that the pass-back always occurs
  immediately.
- A TrackSelector can invalidate its previous selections if its
  selection criteria changes. This will force the player to invoke
  it again to make a new selection. If the new selection is the
  same as the previous one for a renderer then the player handles
  this efficiently (i.e. turns it into a no-op).
- DefaultTrackSelector supports disabling/enabling of renderers.
  Separately, it supports overrides to select specific formats.
  Since formats may change (playlists/periods), overrides are
  specific to not only the renderer but also the set of formats
  that are available to it. If the formats available to a renderer
  change then the override will no longer apply. If the same set
  of formats become available at some point later, it will apply
  once more. This will nicely handle cases like ad-insertion where
  the ads have different formats, but all segments of main content
  use the same set of formats.
- In general, in  multi-period or playlist cases, the preferred
  way of selecting formats will be via constraints (e.g. "don't play
  HD", "prefer higher quality audio") rather than explicit format
  selections. The ability to set various constraints on
  DefaultTrackSelector is future work.

Note about the demo app:

- I've removed the verbose log toggle. I doubt anyone has
  ever used it! I've also removed the background audio option.
  Without using a service it can't be considered a reference
  implementation, so it's probably best to leave developers to
  figure this one out. Finally, listening to AudioCapabilities
  has also gone. This will be replaced by having the player
  detect and handle the capabilities change internally in a
  future CL. This will work by allowing a renderer to invalidate
  the track selections when its capabilities change, much like
  how a selector is able to invalidate the track selections in
  this CL.
- It's now possible to enable ABR with an arbitrary subset of
  tracks.
- Unsupported tracks are shown grayed out in the UI. I'm not
  showing tracks that aren't associated to any renderer, but we
  could optionally add that later.
- Every time the tracks change, there's logcat output showing
  all of the tracks and which ones are enabled. Unassociated
  tracks are displayed in this output.
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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=117122202

- I don't think the length is useful in hashCode; if the length
  is different then Arrays.hashCode should account for that.
- "this." just for consistency across these classes.
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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=116641142

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=116638211