Segment

This helper structure holds the relevant values for tracking the region of interest in a media file, called a segment.

The structure can be used for two purposes:

* performing seeks (handling seek events) * tracking playback regions (handling newsegment events)

The segment is usually configured by the application with a seek event which is propagated upstream and eventually handled by an element that performs the seek.

The configured segment is then propagated back downstream with a newsegment event. This information is then used to clip media to the segment boundaries.

A segment structure is initialized with Segment.init, which takes a GstFormat that will be used as the format of the segment values. The segment will be configured with a start value of 0 and a stop/duration of -1, which is undefined. The default rate and applied_rate is 1.0.

The public duration field contains the duration of the segment. When using the segment for seeking, the start and time members should normally be left to their default 0 value. The stop position is left to -1 unless explicitly configured to a different value after a seek event.

The current position in the segment should be set by changing the position member in the structure.

For elements that perform seeks, the current segment should be updated with the Segment.doSeek and the values from the seek event. This method will update all the segment fields. The position field will contain the new playback position. If the start_type was different from GST_SEEK_TYPE_NONE, playback continues from the position position, possibly with updated flags or rate.

For elements that want to use gstreamer.Segment to track the playback region, update the segment fields with the information from the newsegment event. The Segment.clip method can be used to check and clip the media data to the segment boundaries.

For elements that want to synchronize to the pipeline clock, Segment.toRunningTime can be used to convert a timestamp to a value that can be used to synchronize to the clock. This function takes into account the base as well as any rate or applied_rate conversions.

For elements that need to perform operations on media data in stream_time, Segment.toStreamTime can be used to convert a timestamp and the segment info to stream time (which is always between 0 and the duration of the stream).

Constructors

this
this(GstSegment* gstSegment, bool ownedRef = false)

Sets our main struct and passes it to the parent class.

this
this()

Allocate a new gstreamer.Segment structure and initialize it using Segment.init.

Destructor

A destructor is present on this object, but not explicitly documented in the source.

Members

Functions

clip
bool clip(GstFormat format, ulong start, ulong stop, out ulong clipStart, out ulong clipStop)

Clip the given start and stop values to the segment boundaries given in segment. start and stop are compared and clipped to segment start and stop values.

copy
Segment copy()

Create a copy of given segment.

copyInto
void copyInto(Segment dest)

Copy the contents of src into dest.

doSeek
bool doSeek(double rate, GstFormat format, GstSeekFlags flags, GstSeekType startType, ulong start, GstSeekType stopType, ulong stop, ref bool update)

Update the segment structure with the field values of a seek event (see Event.newSeek).

free
void free()

Free the allocated segment segment.

getSegmentStruct
GstSegment* getSegmentStruct(bool transferOwnership = false)

Get the main Gtk struct

getStruct
void* getStruct()

the main Gtk struct as a void*

init
void init(GstFormat format)

The start/position fields are set to 0 and the stop/duration fields are set to -1 (unknown). The default rate of 1.0 and no flags are set.

isEqual
bool isEqual(Segment s1)

Checks for two segments being equal. Equality here is defined as perfect equality, including floating point values.

offsetRunningTime
bool offsetRunningTime(GstFormat format, long offset)

Adjust the values in segment so that offset is applied to all future running-time calculations.

positionFromRunningTime
ulong positionFromRunningTime(GstFormat format, ulong runningTime)

Convert running_time into a position in the segment so that Segment.toRunningTime with that position returns running_time.

positionFromRunningTimeFull
int positionFromRunningTimeFull(GstFormat format, ulong runningTime, out ulong position)

Translate running_time to the segment position using the currently configured segment. Compared to Segment.positionFromRunningTime this function can return negative segment position.

positionFromStreamTime
ulong positionFromStreamTime(GstFormat format, ulong streamTime)

Convert stream_time into a position in the segment so that Segment.toStreamTime with that position returns stream_time.

positionFromStreamTimeFull
int positionFromStreamTimeFull(GstFormat format, ulong streamTime, out ulong position)

Translate stream_time to the segment position using the currently configured segment. Compared to Segment.positionFromStreamTime this function can return negative segment position.

setRunningTime
bool setRunningTime(GstFormat format, ulong runningTime)

Adjust the start/stop and base values of segment such that the next valid buffer will be one with running_time.

toPosition
ulong toPosition(GstFormat format, ulong runningTime)

Convert running_time into a position in the segment so that Segment.toRunningTime with that position returns running_time.

toRunningTime
ulong toRunningTime(GstFormat format, ulong position)

Translate position to the total running time using the currently configured segment. Position is a value between segment start and stop time.

toRunningTimeFull
int toRunningTimeFull(GstFormat format, ulong position, out ulong runningTime)

Translate position to the total running time using the currently configured segment. Compared to Segment.toRunningTime this function can return negative running-time.

toStreamTime
ulong toStreamTime(GstFormat format, ulong position)

Translate position to stream time using the currently configured segment. The position value must be between segment start and stop value.

toStreamTimeFull
int toStreamTimeFull(GstFormat format, ulong position, out ulong streamTime)

Translate position to the total stream time using the currently configured segment. Compared to Segment.toStreamTime this function can return negative stream-time.

Static functions

getType
GType getType()

Variables

gstSegment
GstSegment* gstSegment;

the main Gtk struct

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