blob: f3a6e9580a590ce543d123cabe0c8c0c11889367 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
|
// Copyright (c) 2011 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef MEDIA_BASE_PTS_STREAM_H_
#define MEDIA_BASE_PTS_STREAM_H_
// Under some conditions the decoded frames can get invalid or wrong timestamps:
// - compressed frames are often in decode timestamp (dts) order, which
// may not always be in presentation timestamp (pts) order;
// - decoder may report invalid timestamps for the decoded frames;
// - parser may report invalid timestamps for the compressed frames.
//
// To ensure that the decoded frames are displayed in the proper order, the
// PtsStream class assembles the time information from different sources and
// combines it into the "best guess" timestamp and duration for the current
// frame. Data inside the decoded frame (if provided) is trusted the most,
// followed by data from the packet stream. Estimation based on the last known
// PTS and frame rate is reserved as a last-ditch effort.
#include "base/time.h"
#include "media/base/pts_heap.h"
namespace media {
class StreamSample;
class PtsStream {
public:
PtsStream();
~PtsStream();
// Initializes an instance using |frame_duration| as default. In absence of
// other PTS information PtsStream will produce timestamps separated in time
// by this duration.
void Initialize(const base::TimeDelta& frame_duration);
// Sets the |current_pts_| to specified |timestamp| and flushes all enqueued
// timestamps.
void Seek(const base::TimeDelta& timestamp);
// Clears the PTS queue.
void Flush();
// Puts timestamp from the stream packet |sample| into a queue, which is used
// as PTS source if decoded frames don't have a valid timestamp. Only valid
// timestamps are enqueued.
void EnqueuePts(StreamSample* sample);
// Combines data from the decoded |sample|, PTS queue, and PTS estimator
// into the final PTS and duration.
void UpdatePtsAndDuration(StreamSample* sample);
base::TimeDelta current_pts() const { return current_pts_; }
base::TimeDelta current_duration() const { return current_duration_; }
private:
base::TimeDelta default_duration_; // Frame duration based on the frame rate.
PtsHeap pts_heap_; // Heap of presentation timestamps.
base::TimeDelta current_pts_;
base::TimeDelta current_duration_;
DISALLOW_COPY_AND_ASSIGN(PtsStream);
};
} // namespace media
#endif // MEDIA_BASE_PTS_STREAM_H_
|
