Starboard Module Reference: player.h

Defines an interface for controlling playback of media elementary streams.

Macros

SB_PLAYER_INITIAL_TICKET

The value of the initial ticket held by the player before the first seek. The player will use this ticket value to make the first call to SbPlayerStatusFunc with kSbPlayerStateInitialized.

SB_PLAYER_NO_DURATION

The value to pass into SbPlayerCreate's duration_pts argument for cases where the duration is unknown, such as for live streams.

kSbPlayerInvalid

Well-defined value for an invalid player.

Enums

SbPlayerDecoderState

An indicator of whether the decoder can accept more samples.

Values

• kSbPlayerDecoderStateNeedsData

  The decoder is asking for one more sample.

• kSbPlayerDecoderStateBufferFull

  The decoder is not ready for any more samples, so do not send them. Note that this enum value has been deprecated and the SbPlayer implementation should no longer use this value.

• kSbPlayerDecoderStateDestroyed

  The player has been destroyed, and will send no more callbacks.

SbPlayerState

An indicator of the general playback state.

Values

• kSbPlayerStateInitialized

  The player has just been initialized. It is expecting an SbPlayerSeek() call to enter the prerolling state.

• kSbPlayerStatePrerolling

  The player is prerolling, collecting enough data to fill the pipeline before presentation starts. After the first preroll is completed, there should always be a video frame to render, even if the player goes back to Prerolling after a Seek.

• kSbPlayerStatePresenting

  The player is presenting media, and it is either paused or actively playing in real-time. Note that the implementation should use this state to signal that the preroll has been finished.

• kSbPlayerStateEndOfStream

  The player is presenting media, but it is paused at the end of the stream.

• kSbPlayerStateDestroyed

  The player has been destroyed, and will send no more callbacks.

Typedefs

SbPlayer

An opaque handle to an implementation-private structure representing a player.

Definition

typedef struct SbPlayerPrivate* SbPlayer

SbPlayerDeallocateSampleFunc

Callback to free the given sample buffer data. When more than one buffer are sent in SbPlayerWriteSample(), the implementation only has to call this callback with sample_buffer points to the the first buffer.

Definition

typedef void(* SbPlayerDeallocateSampleFunc) (SbPlayer player, void *context, const void *sample_buffer)

SbPlayerDecoderStatusFunc

Callback for decoder status updates, called in response to a call to SbPlayerSeek() or SbPlayerWriteSample(). This callback will never be called until at least one call to SbPlayerSeek has occurred. ticket will be set to the ticket passed into the last received call to SbPlayerSeek() at the time this callback was dispatched. This is to distinguish status callbacks for interrupting seeks. These callbacks will happen on a different thread than the calling thread, and it is not valid to call SbPlayer functions from within this callback. After an update with kSbPlayerDecoderStateNeedsData, the user of the player will make at most one call to SbPlayerWriteSample() or SbPlayerWriteEndOfStream(). The player implementation should update the decoder status again after such call to notify its user to continue writing more frames.

Definition

typedef void(* SbPlayerDecoderStatusFunc) (SbPlayer player, void *context, SbMediaType type, SbPlayerDecoderState state, int ticket)

SbPlayerErrorFunc

Callback for player errors, that may set a message. error: indicates the error code. message: provides specific informative diagnostic message about the error condition encountered. It is ok for the message to be an empty string or NULL if no information is available.

Definition

typedef void(* SbPlayerErrorFunc) (SbPlayer player, void *context, SbPlayerError error, const char *message)

SbPlayerStatusFunc

Callback for player status updates. These callbacks will happen on a different thread than the calling thread, and it is not valid to call SbPlayer functions from within this callback.

Definition

typedef void(* SbPlayerStatusFunc) (SbPlayer player, void *context, SbPlayerState state, int ticket)

Structs

SbPlayerInfo2

Information about the current media playback state.

Members

• SbTime current_media_timestamp

  The position of the playback head, as precisely as possible, in microseconds.

• SbTime duration

  The known duration of the currently playing media stream, in microseconds.

• SbTime start_date

  The result of getStartDate for the currently playing media stream, in microseconds since the epoch of January 1, 1601 UTC.

• int frame_width

  The width of the currently displayed frame, in pixels, or 0 if not provided by this player.

• int frame_height

  The height of the currently displayed frame, in pixels, or 0 if not provided by this player.

• bool is_paused

  Whether playback is currently paused.

• double volume

  The current player volume in [0, 1].

• int total_video_frames

  The number of video frames sent to the player since the creation of the player.

• int dropped_video_frames

  The number of video frames decoded but not displayed since the creation of the player.

• int corrupted_video_frames

  The number of video frames that failed to be decoded since the creation of the player.

• double playback_rate

  The rate of playback. The video is played back in a speed that is proportional to this. By default it is 1.0 which indicates that the playback is at normal speed. When it is greater than one, the video is played in a faster than normal speed. When it is less than one, the video is played in a slower than normal speed. Negative speeds are not supported.

SbPlayerSampleInfo

Information about the samples to be written into SbPlayerWriteSample2.

Members

• const void * buffer

  Points to the buffer containing the sample data.

• int buffer_size

  Size of the data pointed to by buffer.

• SbTime timestamp

  The timestamp of the sample in SbTime.

• constSbMediaVideoSampleInfo* video_sample_info

  Information about a video sample. This value is required for video samples. Otherwise, it must be NULL.

• constSbDrmSampleInfo* drm_info

  The DRM system related info for the media sample. This value is required for encrypted samples. Otherwise, it must be NULL.

Functions

SbPlayerCreate

Creates a player that will be displayed on window for the specified video_codec and audio_codec, acquiring all resources needed to operate it, and returning an opaque handle to it. The expectation is that a new player will be created and destroyed for every playback.

This function returns the created player. Note the following:

• The associated decoder of the returned player should be assumed to not be in kSbPlayerDecoderStateNeedsData until SbPlayerSeek() has been called on it.

• It is expected either that the thread that calls SbPlayerCreate is the same thread that calls the other SbPlayer functions for that player, or that there is a mutex guarding calls into each SbPlayer instance.

• If there is a platform limitation on how many players can coexist simultaneously, then calls made to this function that attempt to exceed that limit must return kSbPlayerInvalid. Multiple calls to SbPlayerCreate must not cause a crash.

window: The window that will display the player. window can be kSbWindowInvalid for platforms where video is only displayed on a particular window that the underlying implementation already has access to.

video_codec: The video codec used for the player. If video_codec is kSbMediaVideoCodecNone, the player is an audio-only player. If video_codec is any other value, the player is an audio/video decoder.This can be set to kSbMediaVideoCodecNone to play a video with only an audio track. audio_codec: The audio codec used for the player. The value should never be kSbMediaAudioCodecNone. In addition, the caller must provide a populated audio_header if the audio codec is kSbMediaAudioCodecAac.This can be set to kSbMediaAudioCodecNone to play a video without any audio track. In such case audio_header must be NULL. drm_system: If the media stream has encrypted portions, then this parameter provides an appropriate DRM system, created with SbDrmCreateSystem(). If the stream does not have encrypted portions, then drm_system may be kSbDrmSystemInvalid.

audio_header: Note that the caller must provide a populated audio_header if the audio codec is kSbMediaAudioCodecAac. Otherwise, audio_header can be NULL. See media.h for the format of the SbMediaAudioHeader struct.Note that audio_specific_config is a pointer and the content it points to is no longer valid after this function returns. The implementation has to make a copy of the content if it is needed after the function returns.When audio_codec is kSbMediaAudioCodecNone, this must be set to NULL. sample_deallocator_func: If not NULL, the player calls this function on an internal thread to free the sample buffers passed into SbPlayerWriteSample().

decoder_status_func: If not NULL, the decoder calls this function on an internal thread to provide an update on the decoder's status. No work should be done on this thread. Rather, it should just signal the client thread interacting with the decoder.

player_status_func: If not NULL, the player calls this function on an internal thread to provide an update on the playback status. No work should be done on this thread. Rather, it should just signal the client thread interacting with the decoder.player_error_func: If not NULL, the player calls this function on an internal thread to provide an update on the error status. This callback is responsible for setting the media error message. context: This is passed to all callbacks and is generally used to point at a class or struct that contains state associated with the player.

output_mode: Selects how the decoded video frames will be output. For example, kSbPlayerOutputModePunchOut indicates that the decoded video frames will be output to a background video layer by the platform, and kSbPlayerOutputDecodeToTexture indicates that the decoded video frames should be made available for the application to pull via calls to SbPlayerGetCurrentFrame().

provider: Only present in Starboard version 3 and up. If not NULL, then when output_mode == kSbPlayerOutputModeDecodeToTexture, the player MAY use the provider to create SbDecodeTargets on the renderer thread. A provider may not always be needed by the player, but if it is needed, and the provider is not given, the player will fail by returning kSbPlayerInvalid.If NULL is passed to any of the callbacks (sample_deallocator_func, decoder_status_func, player_status_func, or player_error_func if it applies), then kSbPlayerInvalid must be returned.

Declaration

SbPlayer SbPlayerCreate(SbWindow window, SbMediaVideoCodec video_codec, SbMediaAudioCodec audio_codec, SbDrmSystem drm_system, const SbMediaAudioHeader *audio_header, SbPlayerDeallocateSampleFunc sample_deallocate_func, SbPlayerDecoderStatusFunc decoder_status_func, SbPlayerStatusFunc player_status_func, SbPlayerErrorFunc player_error_func, void *context, SbPlayerOutputMode output_mode, SbDecodeTargetGraphicsContextProvider *context_provider)

SbPlayerDestroy

Destroys player, freeing all associated resources. Each callback must receive one more callback to say that the player was destroyed. Callbacks may be in- flight when SbPlayerDestroy is called, and should be ignored once this function is called.

It is not allowed to pass player into any other SbPlayer function once SbPlayerDestroy has been called on that player.

player: The player to be destroyed.

Declaration

void SbPlayerDestroy(SbPlayer player)

SbPlayerGetCurrentFrame

Given a player created with the kSbPlayerOutputModeDecodeToTexture output mode, it will return a SbDecodeTarget representing the current frame to be rasterized. On GLES systems, this function must be called on a thread with an EGLContext current, and specifically the EGLContext that will be used to eventually render the frame. If this function is called with a player object that was created with an output mode other than kSbPlayerOutputModeDecodeToTexture, kSbDecodeTargetInvalid is returned.

Declaration

SbDecodeTarget SbPlayerGetCurrentFrame(SbPlayer player)

SbPlayerGetInfo2

Gets a snapshot of the current player state and writes it to out_player_info. This function may be called very frequently and is expected to be inexpensive.

player: The player about which information is being retrieved. out_player_info: The information retrieved for the player.

Declaration

void SbPlayerGetInfo2(SbPlayer player, SbPlayerInfo2 *out_player_info2)

SbPlayerGetMaximumNumberOfSamplesPerWrite

Writes a single sample of the given media type to player's input stream. Its data may be passed in via more than one buffers. The lifetime of sample_buffers, sample_buffer_sizes, video_sample_info, and sample_drm_info (as well as member subsample_mapping contained inside it) are not guaranteed past the call to SbPlayerWriteSample. That means that before returning, the implementation must synchronously copy any information it wants to retain from those structures.

player: The player for which the number is retrieved. sample_type: The type of sample for which the number is retrieved. See the SbMediaType enum in media.h.

Declaration

int SbPlayerGetMaximumNumberOfSamplesPerWrite(SbPlayer player, SbMediaType sample_type)

SbPlayerIsValid

Returns whether the given player handle is valid.

Declaration

static bool SbPlayerIsValid(SbPlayer player)

SbPlayerOutputModeSupported

Returns true if the given player output mode is supported by the platform. If this function returns true, it is okay to call SbPlayerCreate() with the given output_mode.

Declaration

bool SbPlayerOutputModeSupported(SbPlayerOutputMode output_mode, SbMediaVideoCodec codec, SbDrmSystem drm_system)

SbPlayerSetBounds

Sets the player bounds to the given graphics plane coordinates. The changes do not take effect until the next graphics frame buffer swap. The default bounds for a player is the full screen. This function is only relevant when the player is created with the kSbPlayerOutputModePunchOut output mode, and if this is not the case then this function call can be ignored.

This function is called on every graphics frame that changes the video bounds. For example, if the video bounds are being animated, then this will be called at up to 60 Hz. Since the function could be called up to once per frame, implementors should take care to avoid related performance concerns with such frequent calls.

player: The player that is being resized. z_index: The z-index of the player. When the bounds of multiple players are overlapped, the one with larger z-index will be rendered on top of the ones with smaller z-index. x: The x-coordinate of the upper-left corner of the player. y: The y-coordinate of the upper-left corner of the player. width: The width of the player, in pixels. height: The height of the player, in pixels.

Declaration

void SbPlayerSetBounds(SbPlayer player, int z_index, int x, int y, int width, int height)

SbPlayerSetPlaybackRate

Set the playback rate of the player. rate is default to 1.0 which indicates the playback is at its original speed. A rate greater than one will make the playback faster than its original speed. For example, when rate is 2, the video will be played at twice the speed as its original speed. A rate less than 1.0 will make the playback slower than its original speed. When rate is 0, the playback will be paused. The function returns true when the playback rate is set to playback_rate or to a rate that is close to playback_rate which the implementation supports. It returns false when the playback rate is unchanged, this can happen when playback_rate is negative or if it is too high to support.

Declaration

bool SbPlayerSetPlaybackRate(SbPlayer player, double playback_rate)

SbPlayerSetVolume

Sets the player's volume.

player: The player in which the volume is being adjusted. volume: The new player volume. The value must be between 0.0 and 1.0, inclusive. A value of 0.0 means that the audio should be muted, and a value of 1.0 means that it should be played at full volume.

Declaration

void SbPlayerSetVolume(SbPlayer player, double volume)

SbPlayerWriteEndOfStream

Writes a marker to player's input stream of stream_type indicating that there are no more samples for that media type for the remainder of this media stream. This marker is invalidated, along with the rest of the stream's contents, after a call to SbPlayerSeek.

player: The player to which the marker is written. stream_type: The type of stream for which the marker is written.

Declaration

void SbPlayerWriteEndOfStream(SbPlayer player, SbMediaType stream_type)

SbPlayerWriteSample2

Writes a single sample of the given media type to player's input stream. Its data may be passed in via more than one buffers. The lifetime of sample_buffers, sample_buffer_sizes, video_sample_info, and sample_drm_info (as well as member subsample_mapping contained inside it) are not guaranteed past the call to SbPlayerWriteSample. That means that before returning, the implementation must synchronously copy any information it wants to retain from those structures.

player: The player to which the sample is written. sample_type: The type of sample being written. See the SbMediaType enum in media.h. sample_buffers: A pointer to an array of buffers with number_of_sample_buffers elements that hold the data for this sample. The buffers are expected to be a portion of a bytestream of the codec type that the player was created with. The buffers should contain a sequence of whole NAL Units for video, or a complete audio frame. sample_buffers cannot be assumed to live past the call into SbPlayerWriteSample(), so it must be copied if its content will be used after SbPlayerWriteSample() returns. sample_buffer_sizes: A pointer to an array of sizes with number_of_sample_buffers elements. Each of them specify the number of bytes in the corresponding buffer contained in sample_buffers. None of them can be 0. sample_buffer_sizes cannot be assumed to live past the call into SbPlayerWriteSample(), so it must be copied if its content will be used after SbPlayerWriteSample() returns. number_of_sample_buffers: Specify the number of elements contained inside sample_buffers and sample_buffer_sizes. It has to be at least one, or the call will be ignored. sample_pts: The timestamp of the sample in 90KHz ticks (PTS). Note that samples MAY be written "slightly" out of order. video_sample_info: Information about a video sample. This value is required if sample_type is kSbMediaTypeVideo. Otherwise, it must be NULL. sample_drm_info: The DRM system related info for the media sample. This value is required for encrypted samples. Otherwise, it must be NULL.Writes samples of the given media type to player's input stream. The lifetime of sample_infos, and the members of its elements like buffer, video_sample_info, and drm_info (as well as member subsample_mapping contained inside it) are not guaranteed past the call to SbPlayerWriteSample2. That means that before returning, the implementation must synchronously copy any information it wants to retain from those structures.

player: The player to which the sample is written. sample_type: The type of sample being written. See the SbMediaType enum in media.h. sample_infos: A pointer to an array of SbPlayerSampleInfo with number_of_sample_infos elements, each holds the data for an sample, i.e. a sequence of whole NAL Units for video, or a complete audio frame. sample_infos cannot be assumed to live past the call into SbPlayerWriteSample2(), so it must be copied if its content will be used after SbPlayerWriteSample2() returns. number_of_sample_infos: Specify the number of samples contained inside sample_infos. It has to be at least one, and less than the return value of SbPlayerGetMaximumNumberOfSamplesPerWrite().

Declaration

void SbPlayerWriteSample2(SbPlayer player, SbMediaType sample_type, const SbPlayerSampleInfo *sample_infos, int number_of_sample_infos)