- Format can represent both container and sample formats.
If a container contains a single track (as is true in
DASH and SmoothStreaming) then the container Format can
also contain sufficient information about the samples
to allow for track selection. This avoids the Format to
MediaFormat conversions that we were previously doing in
ChunkSource implementations.
- One important result of this change is that adaptive
format evaluation and static format selection now use the
same format objects, which is a whole lot less confusing
for someone who wants to implement both initial selection
and subsequent adaptation logic. It's not in the V2 doc,
but it may well make sense if the TrackSelector not only
selects the tracks to enable for an adaptive playback, but
also injects a FormatEvaluator when enabling them that will
control the subsequent adaptive selections. That would make
it so that all format selection logic originates from the
same place.
- As part of this change, the adaptiveX variables are removed
from the format object; they don't really correspond to a
single format. This also saves on having to inject the max
video dimensions through a bunch of classes.
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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=114546777
[Step 4 - Partial, of []
- The capabilities checks previously performed in VideoFormatSelectorUtil
are now performed in MediaCodecVideoTrackRenderer. This means they'll be
useful for non-chunk use cases (e.g. when using ExtractorSampleSource).
- Added capabilities checks for audio in MediaCodecAudioTrackRenderer. We
didn't check audio capabilities previously.
- Added functionality to allow a TrackRenderer to indicate the extent of
its adaptive support.
The idea here is that a TrackSelector (to be introduced) will have access to:
(a) TrackGroups from the SampleSource that indicate whether they support
adaptive playbacks and the formats of each individual track.
(b) TrackRenderers that indicate whether they support adaptive playbacks as
well as how capable they are of rendering formats of individual tracks.
This is everything that a TrackSelector needs from the player components in
order to decide how to wire things up. Note that a TrackSelector may opt to
treat FORMAT_EXCEEDS_CAPABILITIES as FORMAT_HANDLED at its own risk, if it
thinks that it (or the user) knows better. This is a request that we've seen
from third parties for better handling cases where capabilities aren't
accurately reported by the underlying platform.
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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=114427428
GitHub note - Apologies for the cryptic change descriptions,
they relate to a design doc that's not externally visible.
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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=113043764
When a seek is performed, renderers currently perform the
actions that they need to take in two places: Some changes
are performed in seekTo implementations. Other changes are
performed when discontinuities are read from the source.
In HLS we need to perform what is effectively a seek
originating in the source. To support this, this CL allows
discontinuities read from the source to modify the playback
position. All actions that renderers perform as a result
of a seek are moved to be performed when a discontinuity is
received.
Best way to understand CL:
- Look at SampleSource interface change and then at the
concrete implementations, to make sure they've been
changed properly.
- Look at SampleSourceTrackRenderer change.
- Look at concrete renderers. The general pattern is that
code previously performed in seekTo and READ_DISCONTINUITY
is merged into onDiscontinuity().
Note: This will be further untangled in V2.
Issue #676
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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=112720746
- The old approach was technically incorrect, because the checks
were "capacity < sampleSize" and hence neglected the fact that
the buffer position may be greater than 0 (e.g. if the caller
wants to prefix the sample with some additional data).
- Also proactively throw an exception if the buffer is too small,
rather than wait for the failure when we actually do the write.
- Generalize rendererEnabledFlags to be selected track indices through
ExoPlayerImpl/ExoPlayerImplInternal.
- Selecting an out-of-bound track index (e.g. -1) is equivalent to
disabling a renderer prior to the generalization.
- A prepared TrackRenderer that exposes 0 tracks is equivalent to a
TrackRenderer in the STATE_IGNORE state prior to the generalization.
Issue #514.
1. Remove requirement for TrackRenderer implementations to report
current position, unless they are time sources.
2. Expose whether renderers have media to play. The immediate benefit
of this is to solve the referenced GitHub issue, and also to only
display the appropriate Audio/Video/Text buttons in the demo app
for the media being played. This is also a natural step toward
multi-track support.
Github issue: #541
This makes it so that it's no longer necessary to specify the number
of downstream renderers to HlsSampleSource, FrameworkSampleSource and
ExtractorSampleSource, by forcing the downstream renderers to register
with the SampleSource instances in their constructors. This eliminates
a common source of subtle client bugs where the passed value is incorrect.
This also fixes a technical mistake where HlsChunkSource is fed
seekPositionUs=-1 when obtaining the first chunk. This is wrong,
but the usage of this variable within HlsChunkSource enforces that
the seek must stay within bounds, so we get away with it.
Issue: #385
For fields encoded using UTF-16 or UTF-16BE charsets when looking for
termination character we have to look for two zero consecutive bytes.
Otherwise, as many characters encoded with UTF-16 or UTF-16BE has one
of their 2 bytes set with the value zero, we will be truncating text
fields.
- Added support for ID3 frames of types GEOB and PRIV.
- GEOB type is commonly used by dynamic ads provider to include in the
stream information about the ads to be played.
- PRIV type is commonly used for time synchronization (example:
synchronizing playback of a live stream and its webvtt captions) and
also by analytics companies to include tracking information in the
stream.
- Added a sample stream from Apple that contains ID3 metadata.
- TsExtractor is now based on ParsableByteArray rather than BitArray.
This makes is much clearer that, for the most part, data is byte
aligned. It will allow us to optimize TsExtractor without worrying
about arbitrary bit offsets.
- BitArray is renamed ParsableBitArray for consistency, and is now
exclusively for bit-stream level reading.
- There are some temporary methods in ParsableByteArray that should be
cleared up once the optimizations are in place.
Issue: #278
This is the start of a sequence of changes to fix the ref'd
github issue. Currently TsExtractor involves multiple memory
copy steps:
DataSource->Ts_BitArray->Pes_BitArray->Sample->SampleHolder
This is inefficient, but more importantly, the copy into
Sample is problematic, because Samples are of dynamically
varying size. The way we end up expanding Sample objects to
be large enough to hold the data being written means that we
end up gradually expanding all Sample objects in the pool
(which wastes memory), and that we generate a lot of GC churn,
particularly when switching to a higher quality which can
trigger all Sample objects to expand.
The fix will be to reduce the copy steps to:
DataSource->TsPacket->SampleHolder
We will track Pes and Sample data with lists of pointers into
TsPackets, rather than actually copying the data. We will
recycle these pointers.
The following steps are approximately how the refactor will
progress:
1. Start reducing use of BitArray. It's going to be way too
complicated to track bit-granularity offsets into multiple packets,
and allow reading across packet boundaries. In practice reads
from Ts packets are all byte aligned except for small sections,
so we'll move over to using ParsableByteArray instead, so we
only need to track byte offsets.
2. Move TsExtractor to use ParsableByteArray except for small
sections where we really need bit-granularity offsets.
3. Do the actual optimization.
Issue: #278
