1/*
2 * Copyright (C) 2016 Metrological Group B.V.
3 * Copyright (C) 2016, 2017, 2018 Igalia S.L
4 *
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Library General Public
7 * License as published by the Free Software Foundation; either
8 * version 2 of the License, or (at your option) any later version.
9 *
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Library General Public License for more details.
14 *
15 * You should have received a copy of the GNU Library General Public License
16 * aint with this library; see the file COPYING.LIB. If not, write to
17 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
18 * Boston, MA 02110-1301, USA.
19 */
20
21#include "config.h"
22#include "MediaSampleGStreamer.h"
23
24#include "GStreamerCommon.h"
25
26#include <algorithm>
27
28#if ENABLE(VIDEO) && USE(GSTREAMER)
29
30namespace WebCore {
31
32MediaSampleGStreamer::MediaSampleGStreamer(GRefPtr<GstSample>&& sample, const FloatSize& presentationSize, const AtomicString& trackId)
33 : m_pts(MediaTime::zeroTime())
34 , m_dts(MediaTime::zeroTime())
35 , m_duration(MediaTime::zeroTime())
36 , m_trackId(trackId)
37 , m_presentationSize(presentationSize)
38{
39 const GstClockTime minimumDuration = 1000; // 1 us
40 ASSERT(sample);
41 GstBuffer* buffer = gst_sample_get_buffer(sample.get());
42 RELEASE_ASSERT(buffer);
43
44 auto createMediaTime =
45 [](GstClockTime time) -> MediaTime {
46 return MediaTime(GST_TIME_AS_USECONDS(time), G_USEC_PER_SEC);
47 };
48
49 if (GST_BUFFER_PTS_IS_VALID(buffer))
50 m_pts = createMediaTime(GST_BUFFER_PTS(buffer));
51 if (GST_BUFFER_DTS_IS_VALID(buffer) || GST_BUFFER_PTS_IS_VALID(buffer))
52 m_dts = createMediaTime(GST_BUFFER_DTS_OR_PTS(buffer));
53 if (GST_BUFFER_DURATION_IS_VALID(buffer)) {
54 // Sometimes (albeit rarely, so far seen only at the end of a track)
55 // frames have very small durations, so small that may be under the
56 // precision we are working with and be truncated to zero.
57 // SourceBuffer algorithms are not expecting frames with zero-duration,
58 // so let's use something very small instead in those fringe cases.
59 m_duration = createMediaTime(std::max(GST_BUFFER_DURATION(buffer), minimumDuration));
60 } else {
61 // Unfortunately, sometimes samples don't provide a duration. This can never happen in MP4 because of the way
62 // the format is laid out, but it's pretty common in WebM.
63 // The good part is that durations don't matter for playback, just for buffered ranges and coded frame deletion.
64 // We want to pick something small enough to not cause unwanted frame deletion, but big enough to never be
65 // mistaken for a rounding artifact.
66 m_duration = createMediaTime(16666667); // 1/60 seconds
67 }
68
69 m_size = gst_buffer_get_size(buffer);
70 m_sample = sample;
71
72 if (GST_BUFFER_FLAG_IS_SET(buffer, GST_BUFFER_FLAG_DELTA_UNIT))
73 m_flags = MediaSample::None;
74
75 if (GST_BUFFER_FLAG_IS_SET(buffer, GST_BUFFER_FLAG_DECODE_ONLY))
76 m_flags = static_cast<MediaSample::SampleFlags>(m_flags | MediaSample::IsNonDisplaying);
77}
78
79MediaSampleGStreamer::MediaSampleGStreamer(const FloatSize& presentationSize, const AtomicString& trackId)
80 : m_pts(MediaTime::zeroTime())
81 , m_dts(MediaTime::zeroTime())
82 , m_duration(MediaTime::zeroTime())
83 , m_trackId(trackId)
84 , m_presentationSize(presentationSize)
85{
86}
87
88Ref<MediaSampleGStreamer> MediaSampleGStreamer::createFakeSample(GstCaps*, MediaTime pts, MediaTime dts, MediaTime duration, const FloatSize& presentationSize, const AtomicString& trackId)
89{
90 MediaSampleGStreamer* gstreamerMediaSample = new MediaSampleGStreamer(presentationSize, trackId);
91 gstreamerMediaSample->m_pts = pts;
92 gstreamerMediaSample->m_dts = dts;
93 gstreamerMediaSample->m_duration = duration;
94 gstreamerMediaSample->m_flags = MediaSample::IsNonDisplaying;
95 return adoptRef(*gstreamerMediaSample);
96}
97
98void MediaSampleGStreamer::applyPtsOffset(MediaTime timestampOffset)
99{
100 if (m_pts > timestampOffset) {
101 m_duration = m_duration + (m_pts - timestampOffset);
102 m_pts = timestampOffset;
103 }
104}
105
106void MediaSampleGStreamer::offsetTimestampsBy(const MediaTime& timestampOffset)
107{
108 if (!timestampOffset)
109 return;
110 m_pts += timestampOffset;
111 m_dts += timestampOffset;
112 if (auto* buffer = gst_sample_get_buffer(m_sample.get())) {
113 GST_BUFFER_PTS(buffer) = toGstClockTime(m_pts);
114 GST_BUFFER_DTS(buffer) = toGstClockTime(m_dts);
115 }
116}
117
118PlatformSample MediaSampleGStreamer::platformSample()
119{
120 PlatformSample sample = { PlatformSample::GStreamerSampleType, { .gstSample = m_sample.get() } };
121 return sample;
122}
123
124Ref<MediaSample> MediaSampleGStreamer::createNonDisplayingCopy() const
125{
126 if (!m_sample)
127 return createFakeSample(nullptr, m_pts, m_dts, m_duration, m_presentationSize, m_trackId);
128
129 GstBuffer* buffer = gst_sample_get_buffer(m_sample.get());
130 GST_BUFFER_FLAG_SET(buffer, GST_BUFFER_FLAG_DECODE_ONLY);
131
132 GstCaps* caps = gst_sample_get_caps(m_sample.get());
133 GstSegment* segment = gst_sample_get_segment(m_sample.get());
134 const GstStructure* originalInfo = gst_sample_get_info(m_sample.get());
135 GstStructure* info = originalInfo ? gst_structure_copy(originalInfo) : nullptr;
136 GRefPtr<GstSample> sample = adoptGRef(gst_sample_new(buffer, caps, segment, info));
137
138 return adoptRef(*new MediaSampleGStreamer(sample.get(), m_presentationSize, m_trackId));
139}
140
141void MediaSampleGStreamer::dump(PrintStream& out) const
142{
143 out.print("{PTS(", presentationTime(), "), DTS(", decodeTime(), "), duration(", duration(), "), flags(");
144
145 bool anyFlags = false;
146 auto appendFlag = [&out, &anyFlags](const char* flagName) {
147 if (anyFlags)
148 out.print(",");
149 out.print(flagName);
150 anyFlags = true;
151 };
152
153 if (flags() & MediaSample::IsSync)
154 appendFlag("sync");
155 if (flags() & MediaSample::IsNonDisplaying)
156 appendFlag("non-displaying");
157 if (flags() & MediaSample::HasAlpha)
158 appendFlag("has-alpha");
159 if (flags() & ~(MediaSample::IsSync | MediaSample::IsNonDisplaying | MediaSample::HasAlpha))
160 appendFlag("unknown-flag");
161
162 out.print("), trackId(", trackID().string(), "), presentationSize(", presentationSize().width(), "x", presentationSize().height(), ")}");
163}
164
165} // namespace WebCore.
166
167#endif // ENABLE(VIDEO) && USE(GSTREAMER)
168