VuoAvPlayerObject Class Reference

Description

https://b33p.net/kosada/node/9140

Internal video player implementation. Use VuoVideoPlayer to work with video.

Instance Methods
(id)	- init
	Initialize new instance.
(void)	- setPlayerCallback:target:
	tell this player where the decoder is so that it can invoke callbacks
(bool)	- setURL:
	Set the file path and begin loading assets.
(void)	- setPlaybackRate:
	unload the currently playing video
(bool)	- decodePreceedingVideoSamples
	decode a number of video samples prior to the current timestamp
(bool)	- seekToSecond:withRange:frame:
	seek playhead to point and time range to decode within. If range is < 0, duration - second is set as range.
(bool)	- canBeginPlayback
	Is the video ready to begin playback?
(bool)	- nextVideoFrame:
	Get the last decoded video frame.
(bool)	- nextAudioFrame:
	Get the last decoded audio frame.
(VuoReal)	- getCurrentTimestamp
	Get the last decoded video timestamp.
(bool)	- setAssetReaderTimeRange:
	reset the assetreader to a new range.
(bool)	- copyNextVideoSampleBuffer
	read the next video samplebuffer to store.
(unsigned int)	- getAudioChannelCount:
	Get the number of audio channels.
(bool)	- audioEnabled
	is audio playback enabled?
(VuoReal)	- getDuration
	get the total duration of this asset
(double)	- getFrameRate
	the ideal framerate
(bool)	- canPlayAudio
	true if no audio stream is found, or one is fonud and the decoder is capable of playing it
(unsigned int)	- audioChannels
	return the number of available audio channels

Class Methods
(void)	+ releaseAssetReader:
	Release an AVAssetReader after a 200 ms delay.

Protected Attributes
AVAsset *	asset
	The AVAsset currnetly loaded.
float	videoTimestamp
	AVPlayer object.
AVAssetReader *	assetReader
	asset reader
AVAssetReaderTrackOutput *	assetReaderVideoTrackOutput
	video reader output
AVAssetReaderTrackOutput *	assetReaderAudioTrackOutput
	audio reader output
volatile bool	isReady
	is the asset ready to begin playback
bool	playOnReady
	shoudl play once tracks are ready?
float	playbackRate
	the speed of playback (used to decide which direction to decode video in, and whether audio should be read or not)
float	nominalFrameRate
	the playback speed that this asset wants to be played at by default
void *	avDecoderCppObject
	A pointer to the C++ VuoAvDecoder object that's driving this thing. Used to fire callbacks into C++ land.
void(*	readyToPlayCallback )(void *decoderCppObject, bool canPlayMedia)
	A function pointer to a static C++ function that accepts a pointer to a VuoAvDecoder object to send an OnDecoderReady event.
NSMutableArray *	videoQueue
	list of video frames to be output
Float32 *	audioBuffer
	Holds audio extracted from copyNextSampleBuffer until an audio frame comes to collect it. Is interleaved.
float	audioTimestamp
	the last timestamp as reported by the audio asset reader.
size_t	audioBufferCapacity
	the capacity in byte size that the audioBuffer possesses
unsigned int	audioBufferChannelCount
	how many channels copyNextSampleBuffer gives the audio buffer.
unsigned int	audioBufferSamplesPerChannel
	the number of samples one channel of audio contains in the audioBuffer
unsigned int	audioBufferSampleIndex
	The current index that audio frames are copying samples from the audioBuffer.
unsigned int	audioChannelCount
	How many channels of audio are in the current asset track.
bool	containsUnplayableAudio
	True if there is an audio stream that cannot be played by AvFoundation. False otherwise.
CVOpenGLTextureCacheRef	textureCache
	GL_TEXTURE_RECTANGLEs from the movie.
VuoGlContext	glContext
	Context for textureCache

Method Documentation

- (unsigned int) audioChannels

return the number of available audio channels

- (bool) audioEnabled

is audio playback enabled?

- (bool) canBeginPlayback

Is the video ready to begin playback?

- (bool) canPlayAudio

true if no audio stream is found, or one is fonud and the decoder is capable of playing it

- (bool) copyNextVideoSampleBuffer

read the next video samplebuffer to store.

read the next video sample buffer

- (bool) decodePreceedingVideoSamples

decode a number of video samples prior to the current timestamp

- (unsigned int) getAudioChannelCount:

(AVAssetTrack*)

track

Get the number of audio channels.

- (VuoReal) getCurrentTimestamp

Get the last decoded video timestamp.

- (VuoReal) getDuration

get the total duration of this asset

- (double) getFrameRate

the ideal framerate

- (id) init

Initialize new instance.

Creates a new player.

- (bool) nextAudioFrame:

(VuoAudioFrame*)

frame

Get the last decoded audio frame.

this shouldn't ever happen, but if it does realloc samples and change the audioChannelCount size

- (bool) nextVideoFrame:

(VuoVideoFrame*)

frame

Get the last decoded video frame.

Returns the current frame's image.

+ (void) releaseAssetReader:

(AVAssetReader*)

reader

Release an AVAssetReader after a 200 ms delay.

- (bool) seekToSecond:		(float)	second
withRange:		(float)	range
frame:		(VuoVideoFrame *)	frame

seek playhead to point and time range to decode within. If range is < 0, duration - second is set as range.

- (bool) setAssetReaderTimeRange:

(CMTimeRange)

timeRange

reset the assetreader to a new range.

audio settings

- (void) setPlaybackRate:

(double)

rate

unload the currently playing video

Set the rate of playback.

playback is swapping directions, clear the caches

- (void) setPlayerCallback:		(void* functionPtr, bool canPlayMedia)	callback
target:		(void*)	decoderCppObject

tell this player where the decoder is so that it can invoke callbacks

- (bool) setURL:

(NSURL*)

url

Set the file path and begin loading assets.

Loads media at url.

prevent race condition when trying to seek right away by enabling playback after initial setrange.

try to load a few frames of video before declaring this asset ready to play. some codecs will load and successfully extract a single frame then crap out. cough mjpeg cough

calling on main thread prevents tests from compiling in the event that isReady is false.

Member Data Documentation

- (AVAsset*) asset

protected

The AVAsset currnetly loaded.

- (AVAssetReader*) assetReader

protected

asset reader

- (AVAssetReaderTrackOutput*) assetReaderAudioTrackOutput

protected

audio reader output

- (AVAssetReaderTrackOutput*) assetReaderVideoTrackOutput

protected

video reader output

- (Float32*) audioBuffer

protected

Holds audio extracted from copyNextSampleBuffer until an audio frame comes to collect it. Is interleaved.

- (size_t) audioBufferCapacity

protected

the capacity in byte size that the audioBuffer possesses

- (unsigned int) audioBufferChannelCount

protected

how many channels copyNextSampleBuffer gives the audio buffer.

- (unsigned int) audioBufferSampleIndex

protected

The current index that audio frames are copying samples from the audioBuffer.

- (unsigned int) audioBufferSamplesPerChannel

protected

the number of samples one channel of audio contains in the audioBuffer

- (unsigned int) audioChannelCount

protected

How many channels of audio are in the current asset track.

- (float) audioTimestamp

protected

the last timestamp as reported by the audio asset reader.

- (void*) avDecoderCppObject

protected

A pointer to the C++ VuoAvDecoder object that's driving this thing. Used to fire callbacks into C++ land.

- (bool) containsUnplayableAudio

protected

True if there is an audio stream that cannot be played by AvFoundation. False otherwise.

- (VuoGlContext) glContext

protected

Context for textureCache

- (volatile bool) isReady

protected

is the asset ready to begin playback

- (float) nominalFrameRate

protected

the playback speed that this asset wants to be played at by default

- (float) playbackRate

protected

the speed of playback (used to decide which direction to decode video in, and whether audio should be read or not)

- (bool) playOnReady

protected

shoudl play once tracks are ready?

- (void(* readyToPlayCallback)(void *decoderCppObject, bool canPlayMedia))

protected

A function pointer to a static C++ function that accepts a pointer to a VuoAvDecoder object to send an OnDecoderReady event.

- (CVOpenGLTextureCacheRef) textureCache

protected

GL_TEXTURE_RECTANGLEs from the movie.

- (NSMutableArray*) videoQueue

protected

list of video frames to be output

- (float) videoTimestamp

protected

AVPlayer object.

The current frame timestamp where start of video = 0.

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The documentation for this class was generated from the following files:

• node/vuo.video/VuoAvPlayerObject.h
• node/vuo.video/VuoAvPlayerObject.m