2 * Copyright (C) 2005 Wim Taymans <wim@fluendo.com>
4 * gstsegment.h: Header for GstSegment subsystem
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Library General Public
8 * License as published by the Free Software Foundation; either
9 * version 2 of the License, or (at your option) any later version.
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Library General Public License for more details.
16 * You should have received a copy of the GNU Library General Public
17 * License along with this library; if not, write to the
18 * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
19 * Boston, MA 02110-1301, USA.
23 #ifndef __GST_SEGMENT_H__
24 #define __GST_SEGMENT_H__
26 #include <gst/gstformat.h>
30 #define GST_TYPE_SEGMENT (gst_segment_get_type())
32 typedef struct _GstSegment GstSegment;
36 * @GST_SEEK_TYPE_NONE: no change in position is required
37 * @GST_SEEK_TYPE_SET: absolute position is requested
38 * @GST_SEEK_TYPE_END: relative position to duration is requested
40 * The different types of seek events. When constructing a seek event with
41 * gst_event_new_seek() or when doing gst_segment_do_seek ().
45 GST_SEEK_TYPE_NONE = 0,
46 GST_SEEK_TYPE_SET = 1,
52 * @GST_SEEK_FLAG_NONE: no flag
53 * @GST_SEEK_FLAG_FLUSH: flush pipeline
54 * @GST_SEEK_FLAG_ACCURATE: accurate position is requested, this might
55 * be considerably slower for some formats.
56 * @GST_SEEK_FLAG_KEY_UNIT: seek to the nearest keyframe. This might be
57 * faster but less accurate.
58 * @GST_SEEK_FLAG_SEGMENT: perform a segment seek.
59 * @GST_SEEK_FLAG_TRICKMODE: when doing fast forward or fast reverse playback, allow
60 * elements to skip frames instead of generating all
61 * frames. (Since: 1.6)
62 * @GST_SEEK_FLAG_SNAP_BEFORE: go to a location before the requested position,
63 * if KEY_UNIT this means the keyframe at or before the
64 * requested position the one at or before the seek target.
65 * @GST_SEEK_FLAG_SNAP_AFTER: go to a location after the requested position,
66 * if KEY_UNIT this means the keyframe at of after the
68 * @GST_SEEK_FLAG_SNAP_NEAREST: go to a position near the requested position,
69 * if KEY_UNIT this means the keyframe closest to the
70 * requested position, if both keyframes are at an equal
71 * distance, behaves like SNAP_BEFORE.
72 * @GST_SEEK_FLAG_TRICKMODE_KEY_UNITS: when doing fast forward or fast reverse
73 * playback, request that elements only decode keyframes
74 * and skip all other content, for formats that have
75 * keyframes. (Since: 1.6)
76 * @GST_SEEK_FLAG_TRICKMODE_NO_AUDIO: when doing fast forward or fast reverse
77 * playback, request that audio decoder elements skip
78 * decoding and output only gap events or silence. (Since: 1.6)
79 * @GST_SEEK_FLAG_SKIP: Deprecated backward compatibility flag, replaced
80 * by @GST_SEEK_FLAG_TRICKMODE
82 * Flags to be used with gst_element_seek() or gst_event_new_seek(). All flags
83 * can be used together.
85 * A non flushing seek might take some time to perform as the currently
86 * playing data in the pipeline will not be cleared.
88 * An accurate seek might be slower for formats that don't have any indexes
89 * or timestamp markers in the stream. Specifying this flag might require a
90 * complete scan of the file in those cases.
92 * When performing a segment seek: after the playback of the segment completes,
93 * no EOS will be emitted by the element that performed the seek, but a
94 * #GST_MESSAGE_SEGMENT_DONE message will be posted on the bus by the element.
95 * When this message is posted, it is possible to send a new seek event to
96 * continue playback. With this seek method it is possible to perform seamless
97 * looping or simple linear editing.
99 * When doing fast forward (rate > 1.0) or fast reverse (rate < -1.0) trickmode
100 * playback, the @GST_SEEK_FLAG_TRICKMODE flag can be used to instruct decoders
101 * and demuxers to adjust the playback rate by skipping frames. This can improve
102 * performance and decrease CPU usage because not all frames need to be decoded.
104 * Beyond that, the @GST_SEEK_FLAG_TRICKMODE_KEY_UNITS flag can be used to
105 * request that decoders skip all frames except key units, and
106 * @GST_SEEK_FLAG_TRICKMODE_NO_AUDIO flags can be used to request that audio
107 * decoders do no decoding at all, and simple output silence.
109 * The @GST_SEEK_FLAG_SNAP_BEFORE flag can be used to snap to the previous
110 * relevant location, and the @GST_SEEK_FLAG_SNAP_AFTER flag can be used to
111 * select the next relevant location. If KEY_UNIT is specified, the relevant
112 * location is a keyframe. If both flags are specified, the nearest of these
113 * locations will be selected. If none are specified, the implementation is
114 * free to select whichever it wants.
115 * The before and after here are in running time, so when playing backwards,
116 * the next location refers to the one that will played in next, and not the
117 * one that is located after in the actual source stream.
119 * Also see part-seeking.txt in the GStreamer design documentation for more
120 * details on the meaning of these flags and the behaviour expected of
121 * elements that handle them.
124 GST_SEEK_FLAG_NONE = 0,
125 GST_SEEK_FLAG_FLUSH = (1 << 0),
126 GST_SEEK_FLAG_ACCURATE = (1 << 1),
127 GST_SEEK_FLAG_KEY_UNIT = (1 << 2),
128 GST_SEEK_FLAG_SEGMENT = (1 << 3),
129 GST_SEEK_FLAG_TRICKMODE = (1 << 4),
130 /* FIXME 2.0: Remove _SKIP flag,
131 * which was kept for backward compat when _TRICKMODE was added */
132 GST_SEEK_FLAG_SKIP = (1 << 4),
133 GST_SEEK_FLAG_SNAP_BEFORE = (1 << 5),
134 GST_SEEK_FLAG_SNAP_AFTER = (1 << 6),
135 GST_SEEK_FLAG_SNAP_NEAREST = GST_SEEK_FLAG_SNAP_BEFORE | GST_SEEK_FLAG_SNAP_AFTER,
136 /* Careful to restart next flag with 1<<7 here */
137 GST_SEEK_FLAG_TRICKMODE_KEY_UNITS = (1 << 7),
138 GST_SEEK_FLAG_TRICKMODE_NO_AUDIO = (1 << 8),
143 * @GST_SEGMENT_FLAG_NONE: no flags
144 * @GST_SEGMENT_FLAG_RESET: reset the pipeline running_time to the segment
146 * @GST_SEGMENT_FLAG_TRICKMODE: perform skip playback (Since: 1.6)
147 * @GST_SEGMENT_FLAG_SEGMENT: send SEGMENT_DONE instead of EOS
148 * @GST_SEGMENT_FLAG_TRICKMODE_KEY_UNITS: Decode only keyframes, where
149 * possible (Since: 1.6)
150 * @GST_SEGMENT_FLAG_TRICKMODE_NO_AUDIO: Do not decode any audio, where
151 * possible (Since: 1.6)
152 * @GST_SEGMENT_FLAG_SKIP: Deprecated backward compatibility flag, replaced
153 * by @GST_SEGMENT_FLAG_TRICKMODE
155 * Flags for the GstSegment structure. Currently mapped to the corresponding
156 * values of the seek flags.
158 /* Note: update gst_segment_do_seek() when adding new flags here */
159 typedef enum { /*< flags >*/
160 GST_SEGMENT_FLAG_NONE = GST_SEEK_FLAG_NONE,
161 GST_SEGMENT_FLAG_RESET = GST_SEEK_FLAG_FLUSH,
162 GST_SEGMENT_FLAG_TRICKMODE = GST_SEEK_FLAG_TRICKMODE,
163 /* FIXME 2.0: Remove _SKIP flag,
164 * which was kept for backward compat when _TRICKMODE was added */
165 GST_SEGMENT_FLAG_SKIP = GST_SEEK_FLAG_TRICKMODE,
166 GST_SEGMENT_FLAG_SEGMENT = GST_SEEK_FLAG_SEGMENT,
167 GST_SEGMENT_FLAG_TRICKMODE_KEY_UNITS = GST_SEEK_FLAG_TRICKMODE_KEY_UNITS,
168 GST_SEGMENT_FLAG_TRICKMODE_NO_AUDIO = GST_SEEK_FLAG_TRICKMODE_NO_AUDIO
173 * @flags: flags for this segment
174 * @rate: the rate of the segment
175 * @applied_rate: the already applied rate to the segment
176 * @format: the format of the segment values
177 * @base: the base of the segment
178 * @offset: the offset to apply to @start or @stop
179 * @start: the start of the segment
180 * @stop: the stop of the segment
181 * @time: the stream time of the segment
182 * @position: the position in the segment
183 * @duration: the duration of the segment
185 * A helper structure that holds the configured region of
186 * interest in a media file.
190 GstSegmentFlags flags;
193 gdouble applied_rate;
206 gpointer _gst_reserved[GST_PADDING];
209 GType gst_segment_get_type (void);
211 GstSegment * gst_segment_new (void) G_GNUC_MALLOC;
212 GstSegment * gst_segment_copy (const GstSegment *segment) G_GNUC_MALLOC;
213 void gst_segment_copy_into (const GstSegment *src, GstSegment *dest);
214 void gst_segment_free (GstSegment *segment);
216 void gst_segment_init (GstSegment *segment, GstFormat format);
218 guint64 gst_segment_to_stream_time (const GstSegment *segment, GstFormat format, guint64 position);
219 guint64 gst_segment_to_running_time (const GstSegment *segment, GstFormat format, guint64 position);
221 gint gst_segment_to_running_time_full (const GstSegment *segment, GstFormat format, guint64 position,
222 guint64 * running_time);
223 guint64 gst_segment_to_position (const GstSegment *segment, GstFormat format, guint64 running_time);
225 gboolean gst_segment_set_running_time (GstSegment *segment, GstFormat format, guint64 running_time);
227 gboolean gst_segment_offset_running_time (GstSegment *segment, GstFormat format, gint64 offset);
229 gboolean gst_segment_clip (const GstSegment *segment, GstFormat format, guint64 start,
230 guint64 stop, guint64 *clip_start, guint64 *clip_stop);
233 gboolean gst_segment_do_seek (GstSegment * segment, gdouble rate,
234 GstFormat format, GstSeekFlags flags,
235 GstSeekType start_type, guint64 start,
236 GstSeekType stop_type, guint64 stop, gboolean * update);
237 gboolean gst_segment_is_equal (const GstSegment * s0, const GstSegment * s1);
241 #endif /* __GST_SEGMENT_H__ */