*
* 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., 59 Temple Place - Suite 330,
- * Boston, MA 02111-1307, USA.
+ * 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"
* This helper structure holds the relevant values for tracking the region of
* interest in a media file, called a segment.
*
- * Last reviewed on 2005-20-09 (0.9.5)
+ * The structure can be used for two purposes:
+ * <itemizedlist>
+ * <listitem><para>performing seeks (handling seek events)</para></listitem>
+ * <listitem><para>tracking playback regions (handling newsegment events)</para></listitem>
+ * </itemizedlist>
+ *
+ * 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).
*/
/**
- * gst_segment_init:
- * @segment: a #GstSegment structure.
- * @format: the format of the segment.
+ * gst_segment_copy:
+ * @segment: (transfer none): a #GstSegment
*
- * Initialize @segment to its default values, which is a rate of 1.0, a
- * start time of 0.
+ * Create a copy of given @segment.
+ *
+ * Free-function: gst_segment_free
+ *
+ * Returns: (transfer full): a new #GstSegment, free with gst_segment_free().
*/
-void
-gst_segment_init (GstSegment * segment, GstFormat format)
+GstSegment *
+gst_segment_copy (const GstSegment * segment)
{
- g_return_if_fail (segment != NULL);
+ GstSegment *result = NULL;
- segment->rate = 1.0;
- segment->abs_rate = 1.0;
- segment->format = format;
- segment->flags = 0;
- segment->start = 0;
- segment->stop = -1;
- segment->time = 0;
- segment->accum = 0;
- segment->last_stop = -1;
- segment->duration = -1;
+ if (segment) {
+ result = (GstSegment *) g_slice_copy (sizeof (GstSegment), segment);
+ }
+ return result;
}
/**
- * gst_segment_set_duration:
- * @segment: a #GstSegment structure.
- * @format: the format of the segment.
- * @duration: the duration of the segment info.
+ * gst_segment_copy_into:
+ * @src: (transfer none): a #GstSegment
+ * @dest: (transfer none): a #GstSegment
*
- * Set the duration of the segment to @duration. This function is mainly
- * used by elements that perform seeking and know the total duration of the
- * segment.
+ * Copy the contents of @src into @dest.
*/
void
-gst_segment_set_duration (GstSegment * segment, GstFormat format,
- gint64 duration)
+gst_segment_copy_into (const GstSegment * src, GstSegment * dest)
{
- g_return_if_fail (segment != NULL);
- g_return_if_fail (segment->format == format);
+ 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;
- segment->duration = duration;
+ result = g_slice_new0 (GstSegment);
+ gst_segment_init (result, GST_FORMAT_UNDEFINED);
+
+ return result;
}
/**
- * gst_segment_set_last_stop:
+ * 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.
- * @position: the position
*
- * Set the last observed stop position in the segment to @position.
+ * 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_set_last_stop (GstSegment * segment, GstFormat format,
- gint64 position)
+gst_segment_init (GstSegment * segment, GstFormat format)
{
g_return_if_fail (segment != NULL);
- g_return_if_fail (segment->format == format);
- segment->last_stop = position;
+ 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_set_seek:
+ * gst_segment_do_seek:
* @segment: a #GstSegment structure.
* @rate: the rate of the segment.
* @format: the format of the segment.
- * @flags: the seek flags for the segment
- * @cur_type: the seek method
- * @cur: the seek start value
+ * @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: 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 the segment structure with the field values of a seek event.
+ * @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.
*/
-void
-gst_segment_set_seek (GstSegment * segment, gdouble rate,
+gboolean
+gst_segment_do_seek (GstSegment * segment, gdouble rate,
GstFormat format, GstSeekFlags flags,
- GstSeekType cur_type, gint64 cur, GstSeekType stop_type, gint64 stop)
+ GstSeekType start_type, guint64 start,
+ GstSeekType stop_type, guint64 stop, gboolean * update)
{
gboolean update_stop, update_start;
+ guint64 position, base;
- g_return_if_fail (rate != 0.0);
- g_return_if_fail (segment != NULL);
- g_return_if_fail (segment->format == format);
+ 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);
+
+ update_start = update_stop = TRUE;
- update_stop = update_start = TRUE;
+ position = segment->position;
- /* start is never invalid */
- switch (cur_type) {
+ /* segment->start is never invalid */
+ switch (start_type) {
case GST_SEEK_TYPE_NONE:
- /* no update to segment */
- cur = segment->start;
+ /* no update to segment, take previous start */
+ start = segment->start;
update_start = FALSE;
break;
case GST_SEEK_TYPE_SET:
- /* cur holds desired position */
- break;
- case GST_SEEK_TYPE_CUR:
- /* add cur to currently configure segment */
- cur = segment->start + cur;
+ /* 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 cur to total length */
- cur = segment->duration + cur;
+ /* add start to total length */
+ start = segment->duration + start;
} else {
/* no update if duration unknown */
- cur = segment->start;
+ start = segment->start;
update_start = FALSE;
}
break;
}
/* bring in sane range */
if (segment->duration != -1)
- cur = CLAMP (cur, 0, segment->duration);
+ start = MIN (start, segment->duration);
else
- cur = MAX (cur, 0);
+ start = MAX ((gint64) start, 0);
/* stop can be -1 if we have not configured a stop. */
switch (stop_type) {
update_stop = FALSE;
break;
case GST_SEEK_TYPE_SET:
- /* stop folds required value */
- break;
- case GST_SEEK_TYPE_CUR:
- if (segment->stop != -1)
- stop = segment->stop + stop;
- else
- stop = -1;
+ /* stop holds required value */
break;
case GST_SEEK_TYPE_END:
- if (segment->duration != -1)
+ if (segment->duration != -1) {
stop = segment->duration + stop;
- else {
+ } else {
stop = segment->stop;
update_stop = FALSE;
}
/* if we have a valid stop time, make sure it is clipped */
if (stop != -1) {
if (segment->duration != -1)
- stop = CLAMP (stop, 0, segment->duration);
+ stop = CLAMP ((gint64) stop, 0, (gint64) segment->duration);
else
- stop = MAX (stop, 0);
+ stop = MAX ((gint64) stop, 0);
}
/* we can't have stop before start */
- if (stop != -1)
- g_return_if_fail (cur <= stop);
-
- segment->rate = rate;
- segment->abs_rate = ABS (rate);
- segment->flags = flags;
- segment->start = cur;
- segment->stop = stop;
-}
-
-/**
- * gst_segment_set_newsegment:
- * @segment: a #GstSegment structure.
- * @update: flag indicating a new segment is started or updated
- * @rate: the rate of the segment.
- * @format: the format of the segment.
- * @start: the new start value
- * @stop: the new stop value
- * @time: the new stream time
- *
- * Update the segment structure with the field values of a new segment event.
- */
-void
-gst_segment_set_newsegment (GstSegment * segment, gboolean update, gdouble rate,
- GstFormat format, gint64 start, gint64 stop, gint64 time)
-{
- gint64 duration;
+ 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;
+ }
+ }
- g_return_if_fail (rate != 0.0);
- g_return_if_fail (segment != NULL);
+ 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);
- /* any other format with 0 also gives time 0, the other values are
- * invalid in the format though. */
- if (format != segment->format && start == 0) {
- format = segment->format;
- if (stop != 0)
- stop = -1;
- if (time != 0)
- time = -1;
+ /* remember the elapsed time */
+ base = gst_segment_to_running_time (segment, format, position);
+ GST_DEBUG ("updated segment.base: %" G_GUINT64_FORMAT, base);
}
- g_return_if_fail (segment->format == format);
-
- if (update) {
- /* an update to the current segment is done, elapsed time is
- * difference between the old start and new start. */
- duration = start - segment->start;
- } else {
- /* the new segment has to be aligned with the old segment.
- * We first update the accumulated time of the previous
- * segment. the accumulated time is used when syncing to the
- * clock.
- */
- if (GST_CLOCK_TIME_IS_VALID (segment->stop)) {
- duration = segment->stop - segment->start;
- } else if (GST_CLOCK_TIME_IS_VALID (segment->last_stop)) {
- /* else use last seen timestamp as segment stop */
- duration = segment->last_stop - segment->start;
- } else {
- /* else we don't know */
- duration = 0;
+ 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;
}
}
- /* use previous rate to calculate duration */
- segment->accum += gst_gdouble_to_guint64 (
- (gst_guint64_to_gdouble (duration) / segment->abs_rate));
- /* then update the current segment */
+
+ /* 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_SKIP) != 0)
+ segment->flags |= GST_SEGMENT_FLAG_SKIP;
+ if ((flags & GST_SEEK_FLAG_SEGMENT) != 0)
+ segment->flags |= GST_SEGMENT_FLAG_SEGMENT;
+
segment->rate = rate;
- segment->abs_rate = ABS (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 = time;
+ segment->time = start;
+ segment->position = position;
+
+ GST_INFO ("segment updated: %" GST_SEGMENT_FORMAT, segment);
+
+ return TRUE;
}
/**
* @format: the format of the segment.
* @position: the position in the segment
*
- * Translate @position to stream time using the currently configured
- * 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.
+ * Returns: the position in stream_time or -1 when an invalid position
+ * was given.
*/
-gint64
-gst_segment_to_stream_time (GstSegment * segment, GstFormat format,
- gint64 position)
+guint64
+gst_segment_to_stream_time (const GstSegment * segment, GstFormat format,
+ guint64 position)
{
- gint64 result;
+ guint64 result, start, stop, time;
+ gdouble abs_applied_rate;
- g_return_val_if_fail (segment != NULL, FALSE);
- g_return_val_if_fail (segment->format == format, FALSE);
+ /* format does not matter for -1 */
+ if (G_UNLIKELY (position == -1))
+ return -1;
+
+ g_return_val_if_fail (segment != NULL, -1);
+ g_return_val_if_fail (segment->format == format, -1);
+
+ stop = segment->stop;
+
+ /* outside of the segment boundary stop */
+ if (G_UNLIKELY (stop != -1 && position > stop))
+ return -1;
+
+ start = segment->start;
+
+ /* before the segment boundary */
+ if (G_UNLIKELY (position < start))
+ return -1;
+
+ time = segment->time;
- result = ((position - segment->start) / segment->abs_rate) + segment->time;
+ /* time must be known */
+ if (G_UNLIKELY (time == -1))
+ return -1;
+
+ /* bring to uncorrected position in segment */
+ result = position - start;
+
+ abs_applied_rate = ABS (segment->applied_rate);
+
+ /* correct for applied rate if needed */
+ if (G_UNLIKELY (abs_applied_rate != 1.0))
+ result *= abs_applied_rate;
+
+ /* add or subtract from segment time based on applied rate */
+ if (G_LIKELY (segment->applied_rate > 0.0)) {
+ /* correct for segment time */
+ result += time;
+ } else {
+ /* correct for segment time, clamp at 0. Streams with a negative
+ * applied_rate have timestamps between start and stop, as usual, but have
+ * the time member starting high and going backwards. */
+ if (G_LIKELY (time > result))
+ result = time - result;
+ else
+ result = 0;
+ }
return result;
}
* @format: the format of the segment.
* @position: the position in the segment
*
- * Translate @position to the total running time using the currently configured
- * 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.
+ * 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.
*
- * Returns: the position as the total running time.
+ * 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.
*/
-gint64
-gst_segment_to_running_time (GstSegment * segment, GstFormat format,
- gint64 position)
+guint64
+gst_segment_to_running_time (const GstSegment * segment, GstFormat format,
+ guint64 position)
{
- gint64 result;
+ guint64 result;
+ guint64 start, stop;
+ gdouble abs_rate;
- g_return_val_if_fail (segment != NULL, FALSE);
- g_return_val_if_fail (segment->format == format, FALSE);
+ if (G_UNLIKELY (position == -1)) {
+ GST_DEBUG ("invalid position (-1)");
+ return -1;
+ }
+
+ g_return_val_if_fail (segment != NULL, -1);
+ g_return_val_if_fail (segment->format == format, -1);
+
+ start = segment->start;
+
+ if (segment->rate > 0.0)
+ start += segment->offset;
- result = ((position - segment->start) / segment->abs_rate) + segment->accum;
+ /* before the segment boundary */
+ if (G_UNLIKELY (position < start)) {
+ GST_DEBUG ("position(%" G_GUINT64_FORMAT ") < start(%" G_GUINT64_FORMAT
+ ")", position, start);
+ return -1;
+ }
+
+ stop = segment->stop;
+
+ if (G_LIKELY (segment->rate > 0.0)) {
+ /* after of the segment boundary */
+ if (G_UNLIKELY (stop != -1 && position > stop)) {
+ GST_DEBUG ("position(%" G_GUINT64_FORMAT ") > stop(%" G_GUINT64_FORMAT
+ ")", position, stop);
+ return -1;
+ }
+
+ /* bring to uncorrected position in segment */
+ result = position - start;
+ } else {
+ /* cannot continue if no stop position set or outside of
+ * the segment. */
+ if (G_UNLIKELY (stop == -1)) {
+ GST_DEBUG ("invalid stop (-1)");
+ return -1;
+ }
+
+ stop -= segment->offset;
+ if (G_UNLIKELY (position > stop)) {
+ GST_DEBUG ("position(%" G_GUINT64_FORMAT ") > stop(%" G_GUINT64_FORMAT
+ ")", position, stop);
+ return -1;
+ }
+
+ /* bring to uncorrected position in segment */
+ result = stop - position;
+ }
+
+ /* 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 */
+ result += segment->base;
return result;
}
* @format: the format of the segment.
* @start: the start position in the segment
* @stop: the stop position in the segment
- * @clip_start: the clipped start position in the segment
- * @clip_stop: the clipped 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.
+ * 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.
*
- * Returns: TRUE if the given @start and @stop times fall partially in
- * @segment, FALSE if the values are completely outside of the segment.
+ * 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 (GstSegment * segment, GstFormat format, gint64 start,
- gint64 stop, gint64 * clip_start, gint64 * clip_stop)
+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);
- /* we need a valid start position */
- if (start == -1)
- return FALSE;
-
- /* if we have a stop position and start is bigger, we're
- * outside of the segment */
- if (segment->stop != -1 && start >= segment->stop)
+ /* if we have a stop position and a valid start and start is bigger,
+ * we're outside of the segment */
+ if (G_UNLIKELY (segment->stop != -1 && start != -1 && start >= segment->stop))
return FALSE;
/* if a stop position is given and is before the segment start,
- * we're outside of the segment */
- if (stop != -1 && stop <= 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)
- *clip_start = MAX (start, segment->start);
+ 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 = MAX (-1, stop);
+ *clip_stop = stop;
else
*clip_stop = MIN (stop, segment->stop);
+ }
- if (segment->duration != -1)
- *clip_stop = MIN (*clip_stop, segment->duration);
+ return TRUE;
+}
+
+/**
+ * gst_segment_to_position:
+ * @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.
+ */
+guint64
+gst_segment_to_position (const GstSegment * segment, GstFormat format,
+ guint64 running_time)
+{
+ guint64 result;
+ guint64 start, stop, base;
+ gdouble abs_rate;
+
+ if (G_UNLIKELY (running_time == -1))
+ return -1;
+
+ g_return_val_if_fail (segment != NULL, -1);
+ g_return_val_if_fail (segment->format == format, FALSE);
+
+ base = segment->base;
+
+ /* this running_time was for a previous segment */
+ if (running_time < base)
+ return -1;
+
+ /* start by subtracting the base time */
+ result = running_time - base;
+
+ /* move into the segment at the right rate */
+ abs_rate = ABS (segment->rate);
+ if (G_UNLIKELY (abs_rate != 1.0))
+ result = ceil (result * abs_rate);
+
+ start = segment->start;
+ stop = segment->stop;
+
+ if (G_LIKELY (segment->rate > 0.0)) {
+ /* bring to corrected position in segment */
+ result += start + segment->offset;
+
+ /* outside of the segment boundary stop */
+ if (G_UNLIKELY (stop != -1 && result > stop))
+ return -1;
+ } else {
+ /* cannot continue if no stop position set or outside of
+ * the segment. */
+ if (G_UNLIKELY (stop == -1 || result + start > stop))
+ return -1;
+
+ /* bring to corrected position in segment */
+ result = stop - result - segment->offset;
+ }
+ return result;
+}
+
+/**
+ * gst_segment_set_running_time:
+ * @segment: a #GstSegment structure.
+ * @format: the format of the segment.
+ * @running_time: the running_time in the segment
+ *
+ * Adjust the start/stop and base values of @segment such that the next valid
+ * buffer will be one with @running_time.
+ *
+ * Returns: %TRUE if the segment could be updated successfully. If %FALSE is
+ * returned, @running_time is -1 or not in @segment.
+ */
+gboolean
+gst_segment_set_running_time (GstSegment * segment, GstFormat format,
+ guint64 running_time)
+{
+ guint64 position;
+ guint64 start, stop;
+
+ /* start by bringing the running_time into the segment position */
+ position = gst_segment_to_position (segment, format, running_time);
+
+ /* we must have a valid position now */
+ if (G_UNLIKELY (position == -1))
+ return FALSE;
+
+ start = segment->start;
+ stop = segment->stop;
+
+ if (G_LIKELY (segment->rate > 0.0)) {
+ /* update the start and time values */
+ start = position;
+ } else {
+ /* reverse, update stop */
+ stop = position;
}
+ /* and base time is exactly the running time */
+ segment->time = gst_segment_to_stream_time (segment, format, start);
+ segment->start = start;
+ segment->stop = stop;
+ segment->base = running_time;
+
+ return TRUE;
+}
+/**
+ * gst_segment_offset_running_time:
+ * @segment: a #GstSegment structure.
+ * @format: the format of the segment.
+ * @offset: the offset to apply in the segment
+ *
+ * Adjust the values in @segment so that @offset is applied to all
+ * future running-time calculations.
+ *
+ * Since: 1.2.3
+ *
+ * Returns: %TRUE if the segment could be updated successfully. If %FALSE is
+ * returned, @offset is not in @segment.
+ */
+gboolean
+gst_segment_offset_running_time (GstSegment * segment, GstFormat format,
+ gint64 offset)
+{
+ g_return_val_if_fail (segment != NULL, FALSE);
+ g_return_val_if_fail (segment->format == format, FALSE);
+
+ if (offset == 0)
+ return TRUE;
+
+ if (offset > 0) {
+ /* positive offset, we can simply apply to the base time */
+ segment->base += offset;
+ } else {
+ offset = -offset;
+ /* negative offset, first try to subtract from base */
+ if (segment->base > offset) {
+ segment->base -= offset;
+ } else {
+ guint64 position;
+
+ /* subtract all from segment.base, remainder in offset */
+ offset -= segment->base;
+ segment->base = 0;
+ position = gst_segment_to_position (segment, format, offset);
+ if (position == -1)
+ return FALSE;
+
+ segment->offset = position;
+ }
+ }
return TRUE;
}
projects / platform / upstream / gstreamer.git / blobdiff