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gstsegment.c
1254 lines (1138 loc) · 37.3 KB
/
gstsegment.c
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/* GStreamer
* Copyright (C) 2005 Wim Taymans <wim@fluendo.com>
*
* gstsegment.c: GstSegment subsystem
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
#include "gst_private.h"
#include <math.h>
#include "gstutils.h"
#include "gstsegment.h"
/**
* SECTION:gstsegment
* @title: GstSegment
* @short_description: Structure describing the configured region of interest
* in a media file.
* @see_also: #GstEvent
*
* 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 gst_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
* gst_segment_do_seek() 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 #GstSegment to track the playback region,
* update the segment fields with the information from the newsegment event.
* The gst_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, gst_segment_to_running_time()
* 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,
* gst_segment_to_stream_time() 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).
*/
/* FIXME 2.0: remove unused format parameter.
* Most of the methods in gstsegment.c take and extra GstFormat format, just to
* verify segment->format == format.
* See https://bugzilla.gnome.org/show_bug.cgi?id=788979
*/
/**
* gst_segment_copy:
* @segment: (transfer none): a #GstSegment
*
* Create a copy of given @segment.
*
* Free-function: gst_segment_free
*
* Returns: (transfer full): a new #GstSegment, free with gst_segment_free().
*/
GstSegment *
gst_segment_copy (const GstSegment * segment)
{
GstSegment *result = NULL;
if (segment) {
result = (GstSegment *) g_slice_copy (sizeof (GstSegment), segment);
}
return result;
}
/**
* gst_segment_copy_into:
* @src: (transfer none): a #GstSegment
* @dest: (transfer none): a #GstSegment
*
* Copy the contents of @src into @dest.
*/
void
gst_segment_copy_into (const GstSegment * src, GstSegment * dest)
{
memcpy (dest, src, sizeof (GstSegment));
}
G_DEFINE_BOXED_TYPE (GstSegment, gst_segment,
(GBoxedCopyFunc) gst_segment_copy, (GBoxedFreeFunc) gst_segment_free);
/**
* gst_segment_new:
*
* Allocate a new #GstSegment structure and initialize it using
* gst_segment_init().
*
* Free-function: gst_segment_free
*
* Returns: (transfer full): a new #GstSegment, free with gst_segment_free().
*/
GstSegment *
gst_segment_new (void)
{
GstSegment *result;
result = g_slice_new0 (GstSegment);
gst_segment_init (result, GST_FORMAT_UNDEFINED);
return result;
}
/**
* gst_segment_free:
* @segment: (in) (transfer full): a #GstSegment
*
* Free the allocated segment @segment.
*/
void
gst_segment_free (GstSegment * segment)
{
g_slice_free (GstSegment, segment);
}
/**
* gst_segment_init:
* @segment: a #GstSegment structure.
* @format: the format of the segment.
*
* 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.
*
* Initialize @segment to its default values.
*/
void
gst_segment_init (GstSegment * segment, GstFormat format)
{
g_return_if_fail (segment != NULL);
segment->flags = GST_SEGMENT_FLAG_NONE;
segment->rate = 1.0;
segment->applied_rate = 1.0;
segment->format = format;
segment->base = 0;
segment->offset = 0;
segment->start = 0;
segment->stop = -1;
segment->time = 0;
segment->position = 0;
segment->duration = -1;
}
/**
* gst_segment_do_seek:
* @segment: a #GstSegment structure.
* @rate: the rate of the segment.
* @format: the format of the segment.
* @flags: the segment flags for the segment
* @start_type: the seek method
* @start: the seek start value
* @stop_type: the seek method
* @stop: the seek stop value
* @update: (out) (allow-none): boolean holding whether position was updated.
*
* Update the segment structure with the field values of a seek event (see
* gst_event_new_seek()).
*
* After calling this method, the segment field position and time will
* contain the requested new position in the segment. The new requested
* position in the segment depends on @rate and @start_type and @stop_type.
*
* For positive @rate, the new position in the segment is the new @segment
* start field when it was updated with a @start_type different from
* #GST_SEEK_TYPE_NONE. If no update was performed on @segment start position
* (#GST_SEEK_TYPE_NONE), @start is ignored and @segment position is
* unmodified.
*
* For negative @rate, the new position in the segment is the new @segment
* stop field when it was updated with a @stop_type different from
* #GST_SEEK_TYPE_NONE. If no stop was previously configured in the segment, the
* duration of the segment will be used to update the stop position.
* If no update was performed on @segment stop position (#GST_SEEK_TYPE_NONE),
* @stop is ignored and @segment position is unmodified.
*
* The applied rate of the segment will be set to 1.0 by default.
* If the caller can apply a rate change, it should update @segment
* rate and applied_rate after calling this function.
*
* @update will be set to %TRUE if a seek should be performed to the segment
* position field. This field can be %FALSE if, for example, only the @rate
* has been changed but not the playback position.
*
* Returns: %TRUE if the seek could be performed.
*/
gboolean
gst_segment_do_seek (GstSegment * segment, gdouble rate,
GstFormat format, GstSeekFlags flags,
GstSeekType start_type, guint64 start,
GstSeekType stop_type, guint64 stop, gboolean * update)
{
gboolean update_stop, update_start;
guint64 position, base;
g_return_val_if_fail (rate != 0.0, FALSE);
g_return_val_if_fail (segment != NULL, FALSE);
g_return_val_if_fail (segment->format == format, FALSE);
/* Elements should not pass instant-rate seeks to gst_segment_do_seek().
* This helps catch elements that have not been updated yet */
if (flags & GST_SEEK_FLAG_INSTANT_RATE_CHANGE)
return FALSE;
update_start = update_stop = TRUE;
position = segment->position;
/* segment->start is never invalid */
switch (start_type) {
case GST_SEEK_TYPE_NONE:
/* no update to segment, take previous start */
start = segment->start;
update_start = FALSE;
break;
case GST_SEEK_TYPE_SET:
/* start holds desired position, map -1 to the start */
if (start == -1)
start = 0;
break;
case GST_SEEK_TYPE_END:
if (segment->duration != -1) {
/* add start to total length */
start = segment->duration + start;
} else {
/* no update if duration unknown */
start = segment->start;
update_start = FALSE;
}
break;
}
/* bring in sane range */
if (segment->duration != -1)
start = MIN (start, segment->duration);
else
start = MAX ((gint64) start, 0);
/* stop can be -1 if we have not configured a stop. */
switch (stop_type) {
case GST_SEEK_TYPE_NONE:
stop = segment->stop;
update_stop = FALSE;
break;
case GST_SEEK_TYPE_SET:
/* stop holds required value */
break;
case GST_SEEK_TYPE_END:
if (segment->duration != -1) {
stop = segment->duration + stop;
} else {
stop = segment->stop;
update_stop = FALSE;
}
break;
}
/* if we have a valid stop time, make sure it is clipped */
if (stop != -1) {
if (segment->duration != -1)
stop = CLAMP ((gint64) stop, 0, (gint64) segment->duration);
else
stop = MAX ((gint64) stop, 0);
}
/* we can't have stop before start */
if (stop != -1) {
if (start > stop) {
GST_WARNING ("segment update failed: start(%" G_GUINT64_FORMAT
") > stop(%" G_GUINT64_FORMAT ")", start, stop);
g_return_val_if_fail (start <= stop, FALSE);
return FALSE;
}
}
if (flags & GST_SEEK_FLAG_FLUSH) {
/* flush resets the running_time */
base = 0;
} else {
/* make sure the position is inside the segment start/stop */
position = CLAMP (position, segment->start, segment->stop);
/* remember the elapsed time */
base = gst_segment_to_running_time (segment, format, position);
GST_DEBUG ("updated segment.base: %" G_GUINT64_FORMAT, base);
}
if (update_start && rate > 0.0) {
position = start;
}
if (update_stop && rate < 0.0) {
if (stop != -1)
position = stop;
else {
if (segment->duration != -1)
position = segment->duration;
else
position = 0;
}
}
/* set update arg to reflect update of position */
if (update)
*update = position != segment->position;
/* update new values */
/* be explicit about our GstSeekFlag -> GstSegmentFlag conversion */
segment->flags = GST_SEGMENT_FLAG_NONE;
if ((flags & GST_SEEK_FLAG_FLUSH) != 0)
segment->flags |= GST_SEGMENT_FLAG_RESET;
if ((flags & GST_SEEK_FLAG_TRICKMODE) != 0)
segment->flags |= GST_SEGMENT_FLAG_TRICKMODE;
if ((flags & GST_SEEK_FLAG_SEGMENT) != 0)
segment->flags |= GST_SEGMENT_FLAG_SEGMENT;
if ((flags & GST_SEEK_FLAG_TRICKMODE_KEY_UNITS) != 0)
segment->flags |= GST_SEGMENT_FLAG_TRICKMODE_KEY_UNITS;
if ((flags & GST_SEEK_FLAG_TRICKMODE_NO_AUDIO) != 0)
segment->flags |= GST_SEGMENT_FLAG_TRICKMODE_NO_AUDIO;
if ((flags & GST_SEEK_FLAG_TRICKMODE_FORWARD_PREDICTED) != 0)
segment->flags |= GST_SEGMENT_FLAG_TRICKMODE_FORWARD_PREDICTED;
segment->rate = rate;
segment->applied_rate = 1.0;
segment->base = base;
if (rate > 0.0)
segment->offset = position - start;
else {
if (stop != -1)
segment->offset = stop - position;
else if (segment->duration != -1)
segment->offset = segment->duration - position;
else
segment->offset = 0;
}
segment->start = start;
segment->stop = stop;
segment->time = start;
segment->position = position;
GST_INFO ("segment updated: %" GST_SEGMENT_FORMAT, segment);
return TRUE;
}
/**
* gst_segment_to_stream_time_full:
* @segment: a #GstSegment structure.
* @format: the format of the segment.
* @position: the position in the segment
* @stream_time: (out): result stream-time
*
* Translate @position to the total stream time using the currently configured
* segment. Compared to gst_segment_to_stream_time() this function can return
* negative stream-time.
*
* This function is typically used by elements that need to synchronize buffers
* against the clock or each other.
*
* @position can be any value and the result of this function for values outside
* of the segment is extrapolated.
*
* When 1 is returned, @position resulted in a positive stream-time returned
* in @stream_time.
*
* When this function returns -1, the returned @stream_time should be negated
* to get the real negative stream time.
*
* Returns: a 1 or -1 on success, 0 on failure.
*
* Since: 1.8
*/
gint
gst_segment_to_stream_time_full (const GstSegment * segment, GstFormat format,
guint64 position, guint64 * stream_time)
{
guint64 start, stop, time;
gdouble abs_applied_rate;
gint res;
/* format does not matter for -1 */
if (G_UNLIKELY (position == -1)) {
*stream_time = -1;
return 0;
}
g_return_val_if_fail (segment != NULL, 0);
g_return_val_if_fail (segment->format == format, 0);
stop = segment->stop;
start = segment->start;
time = segment->time;
/* time must be known */
if (G_UNLIKELY (time == -1))
return 0;
abs_applied_rate = ABS (segment->applied_rate);
/* add or subtract from segment time based on applied rate */
if (G_LIKELY (segment->applied_rate > 0.0)) {
if (G_LIKELY (position > start)) {
/* bring to uncorrected position in segment */
*stream_time = position - start;
/* correct for applied rate if needed */
if (G_UNLIKELY (abs_applied_rate != 1.0))
*stream_time *= abs_applied_rate;
/* correct for segment time */
*stream_time += time;
res = 1;
} else {
*stream_time = start - position;
if (G_UNLIKELY (abs_applied_rate != 1.0))
*stream_time *= abs_applied_rate;
if (*stream_time > time) {
*stream_time -= time;
res = -1;
} else {
*stream_time = time - *stream_time;
res = 1;
}
}
} else {
/* correct for segment time. Streams with a negative applied_rate
* have timestamps between start and stop, as usual, but have the
* time member starting high and going backwards. */
/* cannot continue without a known segment stop */
if (G_UNLIKELY (stop == -1))
return 0;
if (G_UNLIKELY (position > stop)) {
*stream_time = position - stop;
if (G_UNLIKELY (abs_applied_rate != 1.0))
*stream_time *= abs_applied_rate;
if (*stream_time > time) {
*stream_time -= time;
res = -1;
} else {
*stream_time = time - *stream_time;
res = 1;
}
} else {
*stream_time = stop - position;
if (G_UNLIKELY (abs_applied_rate != 1.0))
*stream_time *= abs_applied_rate;
*stream_time += time;
res = 1;
}
}
return res;
}
/**
* gst_segment_to_stream_time:
* @segment: a #GstSegment structure.
* @format: the format of the segment.
* @position: the position in the segment
*
* Translate @position to stream time using the currently configured
* segment. The @position value must be between @segment start and
* stop value.
*
* This function is typically used by elements that need to operate on
* the stream time of the buffers it receives, such as effect plugins.
* In those use cases, @position is typically the buffer timestamp or
* clock time that one wants to convert to the stream time.
* The stream time is always between 0 and the total duration of the
* media stream.
*
* Returns: the position in stream_time or -1 when an invalid position
* was given.
*
* Since: 1.8
*/
guint64
gst_segment_to_stream_time (const GstSegment * segment, GstFormat format,
guint64 position)
{
guint64 result;
g_return_val_if_fail (segment != NULL, -1);
g_return_val_if_fail (segment->format == format, -1);
/* before the segment boundary */
if (G_UNLIKELY (position < segment->start)) {
GST_DEBUG ("position(%" G_GUINT64_FORMAT ") < start(%" G_GUINT64_FORMAT
")", position, segment->start);
return -1;
}
/* after the segment boundary */
if (G_UNLIKELY (segment->stop != -1 && position > segment->stop)) {
GST_DEBUG ("position(%" G_GUINT64_FORMAT ") > stop(%" G_GUINT64_FORMAT
")", position, segment->stop);
return -1;
}
if (gst_segment_to_stream_time_full (segment, format, position, &result) == 1)
return result;
return -1;
}
/**
* gst_segment_position_from_stream_time_full:
* @segment: a #GstSegment structure.
* @format: the format of the segment.
* @stream_time: the stream-time
* @position: (out): the resulting position in the segment
*
* Translate @stream_time to the segment position using the currently configured
* segment. Compared to gst_segment_position_from_stream_time() this function can
* return negative segment position.
*
* This function is typically used by elements that need to synchronize buffers
* against the clock or each other.
*
* @stream_time can be any value and the result of this function for values outside
* of the segment is extrapolated.
*
* When 1 is returned, @stream_time resulted in a positive position returned
* in @position.
*
* When this function returns -1, the returned @position should be negated
* to get the real negative segment position.
*
* Returns: a 1 or -1 on success, 0 on failure.
*
* Since: 1.8
*/
gint
gst_segment_position_from_stream_time_full (const GstSegment * segment,
GstFormat format, guint64 stream_time, guint64 * position)
{
guint64 start, time;
gdouble abs_applied_rate;
gint res;
/* format does not matter for -1 */
if (G_UNLIKELY (stream_time == -1)) {
*position = -1;
return 0;
}
g_return_val_if_fail (segment != NULL, -1);
g_return_val_if_fail (segment->format == format, -1);
start = segment->start;
time = segment->time;
/* time must be known */
if (G_UNLIKELY (time == -1))
return 0;
abs_applied_rate = ABS (segment->applied_rate);
if (G_LIKELY (segment->applied_rate > 0.0)) {
if (G_LIKELY (stream_time > time)) {
res = 1;
*position = stream_time - time;
} else {
res = -1;
*position = time - stream_time;
}
/* correct for applied rate if needed */
if (G_UNLIKELY (abs_applied_rate != 1.0))
*position /= abs_applied_rate;
if (G_UNLIKELY (res == -1)) {
if (*position > start) {
*position -= start;
} else {
*position = start - *position;
res = 1;
}
} else {
*position += start;
}
} else {
GstClockTime stop = segment->stop;
/* cannot continue without a known segment stop */
if (G_UNLIKELY (stop == -1))
return 0;
if (G_UNLIKELY (time > stream_time)) {
res = -1;
*position = time - stream_time;
} else {
res = 1;
*position = stream_time - time;
}
if (G_UNLIKELY (abs_applied_rate != 1.0))
*position /= abs_applied_rate;
if (G_UNLIKELY (stop < *position)) {
if (G_LIKELY (res == 1)) {
*position -= stop;
res = -1;
} else {
*position += stop;
res = 1;
}
} else {
if (G_LIKELY (res == 1)) {
*position = stop - *position;
res = 1;
} else {
*position += stop;
res = 1;
}
}
}
return res;
}
/**
* gst_segment_position_from_stream_time:
* @segment: a #GstSegment structure.
* @format: the format of the segment.
* @stream_time: the stream_time in the segment
*
* Convert @stream_time into a position in the segment so that
* gst_segment_to_stream_time() with that position returns @stream_time.
*
* Returns: the position in the segment for @stream_time. This function returns
* -1 when @stream_time is -1 or when it is not inside @segment.
*
* Since: 1.8
*/
guint64
gst_segment_position_from_stream_time (const GstSegment * segment,
GstFormat format, guint64 stream_time)
{
guint64 position;
gint res;
g_return_val_if_fail (segment != NULL, -1);
g_return_val_if_fail (segment->format == format, -1);
res =
gst_segment_position_from_stream_time_full (segment, format, stream_time,
&position);
/* before the segment boundary */
if (G_UNLIKELY (position < segment->start)) {
GST_DEBUG ("position(%" G_GUINT64_FORMAT ") < start(%" G_GUINT64_FORMAT
")", position, segment->start);
return -1;
}
/* after the segment boundary */
if (G_UNLIKELY (segment->stop != -1 && position > segment->stop)) {
GST_DEBUG ("position(%" G_GUINT64_FORMAT ") > stop(%" G_GUINT64_FORMAT
")", position, segment->stop);
return -1;
}
if (res == 1)
return position;
return -1;
}
/**
* gst_segment_to_running_time_full:
* @segment: a #GstSegment structure.
* @format: the format of the segment.
* @position: the position in the segment
* @running_time: (out) (allow-none): result running-time
*
* Translate @position to the total running time using the currently configured
* segment. Compared to gst_segment_to_running_time() this function can return
* negative running-time.
*
* This function is typically used by elements that need to synchronize buffers
* against the clock or each other.
*
* @position can be any value and the result of this function for values outside
* of the segment is extrapolated.
*
* When 1 is returned, @position resulted in a positive running-time returned
* in @running_time.
*
* When this function returns -1, the returned @running_time should be negated
* to get the real negative running time.
*
* Returns: a 1 or -1 on success, 0 on failure.
*
* Since: 1.6
*/
gint
gst_segment_to_running_time_full (const GstSegment * segment, GstFormat format,
guint64 position, guint64 * running_time)
{
gint res = 0;
guint64 result;
guint64 start, stop, offset;
gdouble abs_rate;
if (G_UNLIKELY (position == -1)) {
GST_DEBUG ("invalid position (-1)");
goto done;
}
g_return_val_if_fail (segment != NULL, 0);
g_return_val_if_fail (segment->format == format, 0);
offset = segment->offset;
if (G_LIKELY (segment->rate > 0.0)) {
start = segment->start + offset;
/* bring to uncorrected position in segment */
if (position < start) {
/* negative value */
result = start - position;
res = -1;
} else {
result = position - start;
res = 1;
}
} else {
stop = segment->stop;
if (stop == -1 && segment->duration != -1)
stop = segment->start + segment->duration;
/* cannot continue if no stop position set or invalid offset */
g_return_val_if_fail (stop != -1, 0);
g_return_val_if_fail (stop >= offset, 0);
stop -= offset;
/* bring to uncorrected position in segment */
if (position > stop) {
/* negative value */
result = position - stop;
res = -1;
} else {
result = stop - position;
res = 1;
}
}
if (running_time) {
/* scale based on the rate, avoid division by and conversion to
* float when not needed */
abs_rate = ABS (segment->rate);
if (G_UNLIKELY (abs_rate != 1.0))
result /= abs_rate;
/* correct for base of the segment */
if (res == 1)
/* positive, add base */
*running_time = result + segment->base;
else if (segment->base >= result) {
/* negative and base is bigger, subtract from base and we have a
* positive value again */
*running_time = segment->base - result;
res = 1;
} else {
/* negative and base is smaller, subtract base and remainder is
* negative */
*running_time = result - segment->base;
}
}
return res;
done:
{
if (running_time)
*running_time = -1;
return 0;
}
}
/**
* gst_segment_to_running_time:
* @segment: a #GstSegment structure.
* @format: the format of the segment.
* @position: the position in the segment
*
* Translate @position to the total running time using the currently configured
* segment. Position is a value between @segment start and stop time.
*
* This function is typically used by elements that need to synchronize to the
* global clock in a pipeline. The running time is a constantly increasing value
* starting from 0. When gst_segment_init() is called, this value will reset to
* 0.
*
* This function returns -1 if the position is outside of @segment start and stop.
*
* Returns: the position as the total running time or -1 when an invalid position
* was given.
*/
guint64
gst_segment_to_running_time (const GstSegment * segment, GstFormat format,
guint64 position)
{
guint64 result;
g_return_val_if_fail (segment != NULL, -1);
g_return_val_if_fail (segment->format == format, -1);
/* before the segment boundary */
if (G_UNLIKELY (position < segment->start)) {
GST_DEBUG ("position(%" G_GUINT64_FORMAT ") < start(%" G_GUINT64_FORMAT
")", position, segment->start);
return -1;
}
/* after the segment boundary */
if (G_UNLIKELY (segment->stop != -1 && position > segment->stop)) {
GST_DEBUG ("position(%" G_GUINT64_FORMAT ") > stop(%" G_GUINT64_FORMAT
")", position, segment->stop);
return -1;
}
if (gst_segment_to_running_time_full (segment, format, position,
&result) == 1)
return result;
return -1;
}
/**
* gst_segment_clip:
* @segment: a #GstSegment structure.
* @format: the format of the segment.
* @start: the start position in the segment
* @stop: the stop position in the segment
* @clip_start: (out) (allow-none): the clipped start position in the segment
* @clip_stop: (out) (allow-none): the clipped stop position in the segment
*
* 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.
*
* If the function returns %FALSE, @start and @stop are known to fall
* outside of @segment and @clip_start and @clip_stop are not updated.
*
* When the function returns %TRUE, @clip_start and @clip_stop will be
* updated. If @clip_start or @clip_stop are different from @start or @stop
* respectively, the region fell partially in the segment.
*
* Note that when @stop is -1, @clip_stop will be set to the end of the
* segment. Depending on the use case, this may or may not be what you want.
*
* Returns: %TRUE if the given @start and @stop times fall partially or
* completely in @segment, %FALSE if the values are completely outside
* of the segment.
*/
gboolean
gst_segment_clip (const GstSegment * segment, GstFormat format, guint64 start,
guint64 stop, guint64 * clip_start, guint64 * clip_stop)
{
g_return_val_if_fail (segment != NULL, FALSE);
g_return_val_if_fail (segment->format == format, FALSE);
/* if we have a stop position and a valid start and start is bigger,
* we're outside of the segment. (Special case) segment start and
* segment stop can be identical. In this case, if start is also identical,
* it's inside of segment */
if (G_UNLIKELY (segment->stop != -1 && start != -1 && (start > segment->stop
|| (segment->start != segment->stop && start == segment->stop))))
return FALSE;
/* if a stop position is given and is before the segment start,
* we're outside of the segment. Special case is were start
* and stop are equal to the segment start. In that case we
* are inside the segment. */
if (G_UNLIKELY (stop != -1 && (stop < segment->start || (start != stop
&& stop == segment->start))))
return FALSE;
if (clip_start) {
if (start == -1)
*clip_start = -1;
else
*clip_start = MAX (start, segment->start);
}
if (clip_stop) {
if (stop == -1)
*clip_stop = segment->stop;
else if (segment->stop == -1)
*clip_stop = stop;
else
*clip_stop = MIN (stop, segment->stop);
}
return TRUE;
}
/**
* gst_segment_position_from_running_time:
* @segment: a #GstSegment structure.
* @format: the format of the segment.
* @running_time: the running_time in the segment
*
* Convert @running_time into a position in the segment so that
* gst_segment_to_running_time() with that position returns @running_time.
*
* Returns: the position in the segment for @running_time. This function returns
* -1 when @running_time is -1 or when it is not inside @segment.
*
* Since: 1.8
*/
guint64
gst_segment_position_from_running_time (const GstSegment * segment,
GstFormat format, guint64 running_time)
{
guint64 position;
gint res;
g_return_val_if_fail (segment != NULL, -1);
g_return_val_if_fail (segment->format == format, -1);
res =
gst_segment_position_from_running_time_full (segment, format,
running_time, &position);
if (res != 1)
return -1;
/* before the segment boundary */
if (G_UNLIKELY (position < segment->start)) {
GST_DEBUG ("position(%" G_GUINT64_FORMAT ") < start(%" G_GUINT64_FORMAT
")", position, segment->start);
return -1;
}
/* after the segment boundary */
if (G_UNLIKELY (segment->stop != -1 && position > segment->stop)) {
GST_DEBUG ("position(%" G_GUINT64_FORMAT ") > stop(%" G_GUINT64_FORMAT
")", position, segment->stop);
return -1;
}
return position;
}
/**
* gst_segment_position_from_running_time_full:
* @segment: a #GstSegment structure.
* @format: the format of the segment.
* @running_time: the running-time
* @position: (out): the resulting position in the segment
*
* Translate @running_time to the segment position using the currently configured
* segment. Compared to gst_segment_position_from_running_time() this function can
* return negative segment position.
*
* This function is typically used by elements that need to synchronize buffers
* against the clock or each other.
*
* @running_time can be any value and the result of this function for values
* outside of the segment is extrapolated.