GtkMediaStream

GtkMediaStream — Display media in GTK

Properties

gint64 duration Read
gboolean ended Read
GError * error Read
gboolean has-audio Read
gboolean has-video Read
gboolean loop Read / Write
gboolean muted Read / Write
gboolean playing Read / Write
gboolean prepared Read / Write
gboolean seekable Read
gboolean seeking Read
gint64 timestamp Read
gdouble volume Read / Write

Types and Values

Object Hierarchy

    GObject
    ╰── GtkMediaStream
        ╰── GtkMediaFile

Implemented Interfaces

GtkMediaStream implements GdkPaintable.

Includes

#include <gtk/gtk.h>

Description

GtkMediaStream is the integration point for media playback inside GTK.

Apart from application-facing API for stream playback, GtkMediaStream has a number of APIs that are only useful for implementations and should not be used in applications: gtk_media_stream_prepared(), gtk_media_stream_unprepared(), gtk_media_stream_update(), gtk_media_stream_ended(), gtk_media_stream_seek_success(), gtk_media_stream_seek_failed(), gtk_media_stream_gerror(), gtk_media_stream_error(), gtk_media_stream_error_valist().

Functions

gtk_media_stream_is_prepared ()

gboolean
gtk_media_stream_is_prepared (GtkMediaStream *self);

Returns whether the stream has finished initializing and existence of audio and video is known.

Parameters

self

a GtkMediaStream

 

Returns

TRUE if the stream is prepared


gtk_media_stream_get_error ()

const GError *
gtk_media_stream_get_error (GtkMediaStream *self);

If the stream is in an error state, returns the GError explaining that state. Any type of error can be reported here depending on the implementation of the media stream.

A media stream in an error cannot be operated on, calls like gtk_media_stream_play() or gtk_media_stream_seek() will not have any effect.

GtkMediaStream itself does not provide a way to unset an error, but implementations may provide options. For example, a GtkMediaFile will unset errors when a new source is set with ie gtk_media_file_set_file().

Parameters

self

a GtkMediaStream

 

Returns

NULL if not in an error state or the GError of the stream.

[nullable][transfer none]


gtk_media_stream_has_audio ()

gboolean
gtk_media_stream_has_audio (GtkMediaStream *self);

Returns whether the stream has audio.

Parameters

self

a GtkMediaStream

 

Returns

TRUE if the stream has audio


gtk_media_stream_has_video ()

gboolean
gtk_media_stream_has_video (GtkMediaStream *self);

Returns whether the stream has video.

Parameters

self

a GtkMediaStream

 

Returns

TRUE if the stream has video


gtk_media_stream_play ()

void
gtk_media_stream_play (GtkMediaStream *self);

Starts playing the stream. If the stream is in error or already playing, do nothing.

Parameters

self

a GtkMediaStream

 

gtk_media_stream_pause ()

void
gtk_media_stream_pause (GtkMediaStream *self);

Pauses playback of the stream. If the stream is not playing, do nothing.

Parameters

self

a GtkMediaStream

 

gtk_media_stream_get_playing ()

gboolean
gtk_media_stream_get_playing (GtkMediaStream *self);

Return whether the stream is currently playing.

Parameters

self

a GtkMediaStream

 

Returns

TRUE if the stream is playing


gtk_media_stream_set_playing ()

void
gtk_media_stream_set_playing (GtkMediaStream *self,
                              gboolean playing);

Starts or pauses playback of the stream.

Parameters

self

a GtkMediaStream

 

playing

whether to start or pause playback

 

gtk_media_stream_get_ended ()

gboolean
gtk_media_stream_get_ended (GtkMediaStream *self);

Returns whether the streams playback is finished.

Parameters

self

a GtkMediaStream

 

Returns

TRUE if playback is finished


gtk_media_stream_get_timestamp ()

gint64
gtk_media_stream_get_timestamp (GtkMediaStream *self);

Returns the current presentation timestamp in microseconds.

Parameters

self

a GtkMediaStream

 

Returns

the timestamp in microseconds


gtk_media_stream_get_duration ()

gint64
gtk_media_stream_get_duration (GtkMediaStream *self);

Gets the duration of the stream. If the duration is not known, 0 will be returned.

Parameters

self

a GtkMediaStream

 

Returns

the duration of the stream or 0 if not known.


gtk_media_stream_is_seekable ()

gboolean
gtk_media_stream_is_seekable (GtkMediaStream *self);

Checks if a stream may be seekable.

This is meant to be a hint. Streams may not allow seeking even if this function returns TRUE. However, if this function returns FALSE, streams are guaranteed to not be seekable and user interfaces may hide controls that allow seeking.

It is allowed to call gtk_media_stream_seek() on a non-seekable stream, though it will not do anything.

Parameters

self

a GtkMediaStream

 

Returns

TRUE if the stream may support seeking


gtk_media_stream_is_seeking ()

gboolean
gtk_media_stream_is_seeking (GtkMediaStream *self);

Checks if there is currently a seek operation going on.

Parameters

self

a GtkMediaStream

 

Returns

TRUE if a seek operation is ongoing.


gtk_media_stream_seek ()

void
gtk_media_stream_seek (GtkMediaStream *self,
                       gint64 timestamp);

Start a seek operation on self to timestamp . If timestamp is out of range, it will be clamped.

Seek operations may not finish instantly. While a seek operation is in process, the GtkMediaStream:seeking property will be set.

When calling gtk_media_stream_seek() during an ongoing seek operation, the new seek wil override any pending seek.

Parameters

self

a GtkMediaStream

 

timestamp

timestamp to seek to.

 

gtk_media_stream_get_loop ()

gboolean
gtk_media_stream_get_loop (GtkMediaStream *self);

Returns whether the stream is set to loop. See gtk_media_stream_set_loop() for details.

Parameters

self

a GtkMediaStream

 

Returns

TRUE if the stream should loop


gtk_media_stream_set_loop ()

void
gtk_media_stream_set_loop (GtkMediaStream *self,
                           gboolean loop);

Sets whether the stream should loop, ie restart playback from the beginning instead of stopping at the end.

Not all streams may support looping, in particular non-seekable streams. Those streams will ignore the loop setting and just end.

Parameters

self

a GtkMediaStream

 

loop

TRUE if the stream should loop

 

gtk_media_stream_get_muted ()

gboolean
gtk_media_stream_get_muted (GtkMediaStream *self);

Returns whether the audio for the stream is muted. See gtk_media_stream_set_muted() for details.

Parameters

self

a GtkMediaStream

 

Returns

TRUE if the stream is muted


gtk_media_stream_set_muted ()

void
gtk_media_stream_set_muted (GtkMediaStream *self,
                            gboolean muted);

Sets whether the audio stream should be muted. Muting a stream will cause no audio to be played, but it does not modify the volume. This means that muting and then unmuting the stream will restore the volume settings.

If the stream has no audio, calling this function will still work but it will not have an audible effect.

Parameters

self

a GtkMediaStream

 

muted

TRUE if the stream should be muted

 

gtk_media_stream_get_volume ()

double
gtk_media_stream_get_volume (GtkMediaStream *self);

Returns the volume of the audio for the stream. See gtk_media_stream_set_volume() for details.

Parameters

self

a GtkMediaStream

 

Returns

volume of the stream from 0.0 to 1.0


gtk_media_stream_set_volume ()

void
gtk_media_stream_set_volume (GtkMediaStream *self,
                             double volume);

Sets the volume of the audio stream. This function call will work even if the stream is muted.

The given volume should range from 0.0 for silence to 1.0 for as loud as possible. Values outside of this range will be clamped to the nearest value.

If the stream has no audio or is muted, calling this function will still work but it will not have an immediate audible effect. When the stream is unmuted, the new volume setting will take effect.

Parameters

self

a GtkMediaStream

 

volume

New volume of the stream from 0.0 to 1.0

 

gtk_media_stream_realize ()

void
gtk_media_stream_realize (GtkMediaStream *self,
                          GdkSurface *surface);

Called by users to attach the media stream to a GdkSurface they manage. The stream can then access the resources of surface for its rendering purposes. In particular, media streams might want to create GdkGLContexts or sync to the GdkFrameClock.

Whoever calls this function is responsible for calling gtk_media_stream_unrealize() before either the stream or surface get destroyed.

Multiple calls to this function may happen from different users of the video, even with the same surface . Each of these calls must be followed by its own call to gtk_media_stream_unrealize().

It is not required to call this function to make a media stream work.

Parameters

self

a GtkMediaStream

 

surface

a GdkSurface

 

gtk_media_stream_unrealize ()

void
gtk_media_stream_unrealize (GtkMediaStream *self,
                            GdkSurface *surface);

Undoes a previous call to gtk_media_stream_realize() and causes the stream to release all resources it had allocated from surface .

Parameters

self

a GtkMediaStream previously realized

 

surface

the GdkSurface the stream was realized with

 

gtk_media_stream_prepared ()

void
gtk_media_stream_prepared (GtkMediaStream *self,
                           gboolean has_audio,
                           gboolean has_video,
                           gboolean seekable,
                           gint64 duration);

Called by GtkMediaStream implementations to advertise the stream being ready to play and providing details about the stream.

Note that the arguments are hints. If the stream implementation cannot determine the correct values, it is better to err on the side of caution and return TRUE. User interfaces will use those values to determine what controls to show.

This function may not be called again until the stream has been reset via gtk_media_stream_unprepared().

Parameters

self

a GtkMediaStream

 

has_audio

TRUE if the stream should advertise audio support

 

has_video

TRUE if the stream should advertise video support

 

seekable

TRUE if the stream should advertise seekability

 

duration

The duration of the stream or 0 if unknown

 

gtk_media_stream_unprepared ()

void
gtk_media_stream_unprepared (GtkMediaStream *self);

Resets a given media stream implementation. gtk_media_stream_prepared() can now be called again.

This function will also reset any error state the stream was in.

Parameters

self

a GtkMediaStream

 

gtk_media_stream_update ()

void
gtk_media_stream_update (GtkMediaStream *self,
                         gint64 timestamp);

Media stream implementations should regularly call this function to update the timestamp reported by the stream. It is up to implementations to call this at the frequency they deem appropriate.

Parameters

self

a GtkMediaStream

 

timestamp

the new timestamp

 

gtk_media_stream_ended ()

void
gtk_media_stream_ended (GtkMediaStream *self);

Pauses the media stream and marks it as ended. This is a hint only, calls to GtkMediaStream.play() may still happen.

Parameters

self

a GtkMediaStream

 

gtk_media_stream_seek_success ()

void
gtk_media_stream_seek_success (GtkMediaStream *self);

Ends a seek operation started via GtkMediaStream.seek() successfully. This function will unset the GtkMediaStream:ended property if it was set.

See gtk_media_stream_seek_failed() for the other way of ending a seek.

Parameters

self

a GtkMediaStream

 

gtk_media_stream_seek_failed ()

void
gtk_media_stream_seek_failed (GtkMediaStream *self);

Ends a seek operation started via GtkMediaStream.seek() as a failure. This will not cause an error on the stream and will assume that playback continues as if no seek had happened.

See gtk_media_stream_seek_success() for the other way of ending a seek.

Parameters

self

a GtkMediaStream

 

gtk_media_stream_gerror ()

void
gtk_media_stream_gerror (GtkMediaStream *self,
                         GError *error);

Sets self into an error state. This will pause the stream (you can check for an error via gtk_media_stream_get_error() in your GtkMediaStream.pause() implementation), abort pending seeks and mark the stream as prepared.

if the stream is already in an error state, this call will be ignored and the existing error will be retained. FIXME: Or do we want to set the new error?

To unset an error, the stream must be reset via a call to gtk_media_stream_unprepared().

Parameters

self

a GtkMediaStream

 

error

the GError to set.

[transfer full]

gtk_media_stream_error ()

void
gtk_media_stream_error (GtkMediaStream *self,
                        GQuark domain,
                        gint code,
                        const gchar *format,
                        ...);

Sets self into an error state using a printf()-style format string.

This is a utility function that calls gtk_media_stream_gerror(). See that function for details.

Parameters

self

a GtkMediaStream

 

domain

error domain

 

code

error code

 

format

printf()-style format for error message

 

...

parameters for message format

 

gtk_media_stream_error_valist ()

void
gtk_media_stream_error_valist (GtkMediaStream *self,
                               GQuark domain,
                               gint code,
                               const gchar *format,
                               va_list args);

Sets self into an error state using a printf()-style format string.

This is a utility function that calls gtk_media_stream_gerror(). See that function for details.

Parameters

self

a GtkMediaStream

 

domain

error domain

 

code

error code

 

format

printf()-style format for error message

 

args

va_list of parameters for the message format

 

Types and Values

GtkMediaStream

typedef struct _GtkMediaStream GtkMediaStream;

struct GtkMediaStreamClass

struct GtkMediaStreamClass {
  GObjectClass parent_class;

  gboolean              (* play)                                (GtkMediaStream *self);
  void                  (* pause)                               (GtkMediaStream *self);
  void                  (* seek)                                (GtkMediaStream *self,
                                                                 gint64          timestamp);
  void                  (* update_audio)                        (GtkMediaStream *self,
                                                                 gboolean        muted,
                                                                 double          volume);
  void                  (* realize)                             (GtkMediaStream *self,
                                                                 GdkSurface      *surface);
  void                  (* unrealize)                           (GtkMediaStream *self,
                                                                 GdkSurface      *surface);

  /* Padding for future expansion */
  void (*_gtk_reserved1) (void);
  void (*_gtk_reserved2) (void);
  void (*_gtk_reserved3) (void);
  void (*_gtk_reserved4) (void);
  void (*_gtk_reserved5) (void);
  void (*_gtk_reserved6) (void);
  void (*_gtk_reserved7) (void);
  void (*_gtk_reserved8) (void);
};

Property Details

The “duration” property

  “duration”                 gint64

The stream's duration in microseconds or 0 if unknown.

Owner: GtkMediaStream

Flags: Read

Allowed values: >= 0

Default value: 0


The “ended” property

  “ended”                    gboolean

Set when playback has finished.

Owner: GtkMediaStream

Flags: Read

Default value: FALSE


The “error” property

  “error”                    GError *

NULL for a properly working stream or the GError that the stream is in.

Owner: GtkMediaStream

Flags: Read


The “has-audio” property

  “has-audio”                gboolean

Whether the stream contains audio

Owner: GtkMediaStream

Flags: Read

Default value: FALSE


The “has-video” property

  “has-video”                gboolean

Whether the stream contains video

Owner: GtkMediaStream

Flags: Read

Default value: FALSE


The “loop” property

  “loop”                     gboolean

Try to restart the media from the beginning once it ended.

Owner: GtkMediaStream

Flags: Read / Write

Default value: FALSE


The “muted” property

  “muted”                    gboolean

Whether the audio stream should be muted.

Owner: GtkMediaStream

Flags: Read / Write

Default value: FALSE


The “playing” property

  “playing”                  gboolean

Whether the stream is currently playing.

Owner: GtkMediaStream

Flags: Read / Write

Default value: FALSE


The “prepared” property

  “prepared”                 gboolean

Whether the stream has finished initializing and existence of audio and video is known.

Owner: GtkMediaStream

Flags: Read / Write

Default value: FALSE


The “seekable” property

  “seekable”                 gboolean

Set unless the stream is known to not support seeking.

Owner: GtkMediaStream

Flags: Read

Default value: TRUE


The “seeking” property

  “seeking”                  gboolean

Set while a seek is in progress.

Owner: GtkMediaStream

Flags: Read

Default value: FALSE


The “timestamp” property

  “timestamp”                gint64

The current presentation timestamp in microseconds.

Owner: GtkMediaStream

Flags: Read

Allowed values: >= 0

Default value: 0


The “volume” property

  “volume”                   gdouble

Volume of the audio stream.

Owner: GtkMediaStream

Flags: Read / Write

Allowed values: [0,1]

Default value: 1

See Also

GdkPaintable