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1 // Copyright 2015 The Chromium Authors. All rights reserved. | |
2 // Use of this source code is governed by a BSD-style license that can be | |
3 // found in the LICENSE file. | |
4 | |
5 #include "media/capture/webm_muxer.h" | |
6 | |
7 #include <limits> | |
8 | |
9 namespace media { | |
10 | |
11 // Template to +1 a non-negative Natural number to make a strictly positive one. | |
12 template <typename NonNegativeNaturalType> | |
13 class PositiveInteger{ | |
14 public: | |
15 explicit PositiveInteger(NonNegativeNaturalType value) | |
16 : value_(value + static_cast<NonNegativeNaturalType>(1)) { | |
17 static_assert(std::numeric_limits<NonNegativeNaturalType>::is_integer && | |
18 !std::numeric_limits<NonNegativeNaturalType>::is_signed, | |
19 "NonNegativeNaturalType must be an unsigned integer type"); | |
20 } | |
21 NonNegativeNaturalType Value() const { return value_; } | |
22 | |
23 private: | |
24 const NonNegativeNaturalType value_; | |
25 | |
26 DISALLOW_IMPLICIT_CONSTRUCTORS(PositiveInteger); | |
27 }; | |
28 | |
29 WebmMuxer::WebmMuxer(const WriteDataCB& write_data_callback) | |
30 : write_data_callback_(write_data_callback), | |
31 position_(0), | |
32 segment_(new mkvmuxer::Segment()) { | |
33 DVLOG(2) << __FUNCTION__; | |
34 DCHECK(thread_checker_.CalledOnValidThread()); | |
35 segment_->Init(this); | |
36 segment_->set_mode(mkvmuxer::Segment::kLive); | |
37 segment_->OutputCues(false); | |
38 | |
39 mkvmuxer::SegmentInfo* const info = segment_->GetSegmentInfo(); | |
40 info->set_writing_app("Chrome"); | |
41 info->set_muxing_app("Chrome"); | |
42 } | |
43 | |
44 WebmMuxer::~WebmMuxer() { | |
45 DCHECK(thread_checker_.CalledOnValidThread()); | |
46 DVLOG(2) << __FUNCTION__; | |
47 segment_->Finalize(); | |
48 } | |
49 | |
50 void WebmMuxer::AddVideoTrack(uint32_t track_number, | |
51 const gfx::Size& frame_size, | |
52 double frame_rate) { | |
53 DCHECK(thread_checker_.CalledOnValidThread()); | |
54 | |
55 // |track_number|, a caller-side identifier, cannot be zero (!), see | |
56 // http://www.matroska.org/technical/specs/index.html#Tracks | |
57 const PositiveInteger<uint32_t> nonzero_track_number(track_number); | |
58 DCHECK(!segment_->GetTrackByNumber(nonzero_track_number.Value())); | |
59 | |
60 segment_->AddVideoTrack(frame_size.width(), | |
61 frame_size.height(), | |
62 nonzero_track_number.Value()); | |
63 mkvmuxer::VideoTrack* const video_track = | |
64 reinterpret_cast<mkvmuxer::VideoTrack*>( | |
65 segment_->GetTrackByNumber(nonzero_track_number.Value())); | |
66 DCHECK(video_track); | |
67 video_track->set_codec_id(mkvmuxer::Tracks::kVp8CodecId); | |
68 DCHECK_EQ(video_track->crop_right(), 0ull); | |
69 DCHECK_EQ(video_track->crop_left(), 0ull); | |
70 DCHECK_EQ(video_track->crop_top(), 0ull); | |
71 DCHECK_EQ(video_track->crop_bottom(), 0ull); | |
72 | |
73 video_track->set_frame_rate(frame_rate); | |
74 video_track->set_default_duration(base::Time::kMicrosecondsPerSecond / | |
75 frame_rate); | |
76 // Change segment's timestamps to microseconds instead of milliseconds: | |
77 // http://matroska.org/technical/specs/index.html#TimecodeScale | |
78 segment_->GetSegmentInfo()->set_timecode_scale( | |
79 base::Time::kNanosecondsPerMicrosecond); | |
80 } | |
81 | |
82 void WebmMuxer::OnEncodedVideo(uint32_t track_number, | |
83 const std::string& encoded_data, | |
84 const base::TimeDelta& timedelta_us, | |
miu
2015/07/18 00:29:39
naming: Remove _us suffix here too, and this shoul
mcasas
2015/07/20 16:25:15
Done.
| |
85 bool keyframe) { | |
86 DVLOG(2) << __FUNCTION__; | |
87 DCHECK(thread_checker_.CalledOnValidThread()); | |
88 | |
89 // |track_number|, a caller-side identifier, cannot be zero (!), see | |
90 // http://www.matroska.org/technical/specs/index.html#Tracks | |
91 const PositiveInteger<uint32_t> nonzero_track_number(track_number); | |
92 DCHECK(segment_->GetTrackByNumber(nonzero_track_number.Value())); | |
93 | |
94 segment_->AddFrame(reinterpret_cast<const uint8_t*>(encoded_data.data()), | |
95 encoded_data.size(), | |
96 nonzero_track_number.Value(), | |
97 timedelta_us.InMicroseconds(), | |
98 keyframe); | |
99 } | |
100 | |
101 mkvmuxer::int32 WebmMuxer::Write(const void* buf, mkvmuxer::uint32 len) { | |
102 DVLOG(3) << __FUNCTION__ << " length=" << len; | |
103 DCHECK(thread_checker_.CalledOnValidThread()); | |
104 write_data_callback_.Run(static_cast<const char*>(buf), len); | |
105 position_ += len; | |
106 return 0; | |
107 } | |
108 | |
109 mkvmuxer::int64 WebmMuxer::Position() const { | |
110 return position_.ValueOrDie(); | |
111 } | |
112 | |
113 mkvmuxer::int32 WebmMuxer::Position(mkvmuxer::int64 position) { | |
114 // The stream is not Seekable() so indicate we cannot set the position. | |
115 return -1; | |
116 } | |
117 | |
118 bool WebmMuxer::Seekable() const { | |
119 return false; | |
120 } | |
121 | |
122 void WebmMuxer::ElementStartNotify(mkvmuxer::uint64 element_id, | |
123 mkvmuxer::int64 position) { | |
124 // This method gets pinged before items are sent to |write_data_callback_|. | |
125 DCHECK_GE(position, position_.ValueOrDefault(0)) | |
126 << "Can't go back in a Live Mkv stream."; | |
127 } | |
128 | |
129 } // namespace media | |
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