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1 /*
2  *  Copyright (c) 2013 The WebRTC project authors. All Rights Reserved.
3  *
4  *  Use of this source code is governed by a BSD-style license
5  *  that can be found in the LICENSE file in the root of the source
6  *  tree. An additional intellectual property rights grant can be found
7  *  in the file PATENTS.  All contributing project authors may
8  *  be found in the AUTHORS file in the root of the source tree.
9  */
10 
11 #ifndef WEBRTC_VIDEO_SEND_STREAM_H_
12 #define WEBRTC_VIDEO_SEND_STREAM_H_
13 
14 #include <map>
15 #include <string>
16 
17 #include "webrtc/common_types.h"
18 #include "webrtc/config.h"
19 #include "webrtc/frame_callback.h"
20 #include "webrtc/video_renderer.h"
21 
22 namespace webrtc {
23 
24 class VideoEncoder;
25 
26 // Class to deliver captured frame to the video send stream.
27 class VideoSendStreamInput {
28  public:
29   // These methods do not lock internally and must be called sequentially.
30   // If your application switches input sources synchronization must be done
31   // externally to make sure that any old frames are not delivered concurrently.
32   virtual void SwapFrame(I420VideoFrame* video_frame) = 0;
33 
34  protected:
~VideoSendStreamInput()35   virtual ~VideoSendStreamInput() {}
36 };
37 
38 class VideoSendStream {
39  public:
40   struct Stats {
StatsStats41     Stats()
42         : input_frame_rate(0),
43           encode_frame_rate(0),
44           suspended(false) {}
45     int input_frame_rate;
46     int encode_frame_rate;
47     bool suspended;
48     std::map<uint32_t, StreamStats> substreams;
49   };
50 
51   struct Config {
ConfigConfig52     Config()
53         : pre_encode_callback(NULL),
54           post_encode_callback(NULL),
55           local_renderer(NULL),
56           render_delay_ms(0),
57           target_delay_ms(0),
58           suspend_below_min_bitrate(false) {}
59     std::string ToString() const;
60 
61     struct EncoderSettings {
EncoderSettingsConfig::EncoderSettings62       EncoderSettings() : payload_type(-1), encoder(NULL) {}
63       std::string ToString() const;
64 
65       std::string payload_name;
66       int payload_type;
67 
68       // Uninitialized VideoEncoder instance to be used for encoding. Will be
69       // initialized from inside the VideoSendStream.
70       webrtc::VideoEncoder* encoder;
71     } encoder_settings;
72 
73     static const size_t kDefaultMaxPacketSize = 1500 - 40;  // TCP over IPv4.
74     struct Rtp {
RtpConfig::Rtp75       Rtp()
76           : max_packet_size(kDefaultMaxPacketSize),
77             min_transmit_bitrate_bps(0) {}
78       std::string ToString() const;
79 
80       std::vector<uint32_t> ssrcs;
81 
82       // Max RTP packet size delivered to send transport from VideoEngine.
83       size_t max_packet_size;
84 
85       // Padding will be used up to this bitrate regardless of the bitrate
86       // produced by the encoder. Padding above what's actually produced by the
87       // encoder helps maintaining a higher bitrate estimate.
88       int min_transmit_bitrate_bps;
89 
90       // RTP header extensions to use for this send stream.
91       std::vector<RtpExtension> extensions;
92 
93       // See NackConfig for description.
94       NackConfig nack;
95 
96       // See FecConfig for description.
97       FecConfig fec;
98 
99       // Settings for RTP retransmission payload format, see RFC 4588 for
100       // details.
101       struct Rtx {
RtxConfig::Rtp::Rtx102         Rtx() : payload_type(-1), pad_with_redundant_payloads(false) {}
103         std::string ToString() const;
104         // SSRCs to use for the RTX streams.
105         std::vector<uint32_t> ssrcs;
106 
107         // Payload type to use for the RTX stream.
108         int payload_type;
109         // Use redundant payloads to pad the bitrate. Instead of padding with
110         // randomized packets, we will preemptively retransmit media packets on
111         // the RTX stream.
112         bool pad_with_redundant_payloads;
113       } rtx;
114 
115       // RTCP CNAME, see RFC 3550.
116       std::string c_name;
117     } rtp;
118 
119     // Called for each I420 frame before encoding the frame. Can be used for
120     // effects, snapshots etc. 'NULL' disables the callback.
121     I420FrameCallback* pre_encode_callback;
122 
123     // Called for each encoded frame, e.g. used for file storage. 'NULL'
124     // disables the callback.
125     EncodedFrameObserver* post_encode_callback;
126 
127     // Renderer for local preview. The local renderer will be called even if
128     // sending hasn't started. 'NULL' disables local rendering.
129     VideoRenderer* local_renderer;
130 
131     // Expected delay needed by the renderer, i.e. the frame will be delivered
132     // this many milliseconds, if possible, earlier than expected render time.
133     // Only valid if |local_renderer| is set.
134     int render_delay_ms;
135 
136     // Target delay in milliseconds. A positive value indicates this stream is
137     // used for streaming instead of a real-time call.
138     int target_delay_ms;
139 
140     // True if the stream should be suspended when the available bitrate fall
141     // below the minimum configured bitrate. If this variable is false, the
142     // stream may send at a rate higher than the estimated available bitrate.
143     bool suspend_below_min_bitrate;
144   };
145 
146   // Gets interface used to insert captured frames. Valid as long as the
147   // VideoSendStream is valid.
148   virtual VideoSendStreamInput* Input() = 0;
149 
150   virtual void Start() = 0;
151   virtual void Stop() = 0;
152 
153   // Set which streams to send. Must have at least as many SSRCs as configured
154   // in the config. Encoder settings are passed on to the encoder instance along
155   // with the VideoStream settings.
156   virtual bool ReconfigureVideoEncoder(const VideoEncoderConfig& config) = 0;
157 
158   virtual Stats GetStats() const = 0;
159 
160  protected:
~VideoSendStream()161   virtual ~VideoSendStream() {}
162 };
163 
164 }  // namespace webrtc
165 
166 #endif  // WEBRTC_VIDEO_SEND_STREAM_H_
167