codec.h revision 822bdf978435b8eba9343ea96e9a9bc54b9c7df0 
1/*
2 * libjingle
3 * Copyright 2004 Google Inc.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are met:
7 *
8 *  1. Redistributions of source code must retain the above copyright notice,
9 *     this list of conditions and the following disclaimer.
10 *  2. Redistributions in binary form must reproduce the above copyright notice,
11 *     this list of conditions and the following disclaimer in the documentation
12 *     and/or other materials provided with the distribution.
13 *  3. The name of the author may not be used to endorse or promote products
14 *     derived from this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
17 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
18 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
19 * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
20 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
21 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
22 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
23 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
24 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
25 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
27
28#ifndef TALK_MEDIA_BASE_CODEC_H_
29#define TALK_MEDIA_BASE_CODEC_H_
30
31#include <map>
32#include <set>
33#include <string>
34#include <vector>
35
36#include "talk/media/base/constants.h"
37
38namespace cricket {
39
40typedef std::map<std::string, std::string> CodecParameterMap;
41
42extern const int kMaxPayloadId;
43
44class FeedbackParam {
45 public:
46  FeedbackParam(const std::string& id, const std::string& param)
47      : id_(id),
48        param_(param) {
49  }
50  explicit FeedbackParam(const std::string& id)
51      : id_(id),
52        param_(kParamValueEmpty) {
53  }
54  bool operator==(const FeedbackParam& other) const;
55
56  const std::string& id() const { return id_; }
57  const std::string& param() const { return param_; }
58
59 private:
60  std::string id_;  // e.g. "nack", "ccm"
61  std::string param_;  // e.g. "", "rpsi", "fir"
62};
63
64class FeedbackParams {
65 public:
66  bool operator==(const FeedbackParams& other) const;
67
68  bool Has(const FeedbackParam& param) const;
69  void Add(const FeedbackParam& param);
70
71  void Intersect(const FeedbackParams& from);
72
73  const std::vector<FeedbackParam>& params() const { return params_; }
74 private:
75  bool HasDuplicateEntries() const;
76
77  std::vector<FeedbackParam> params_;
78};
79
80struct Codec {
81  int id;
82  std::string name;
83  int clockrate;
84  int preference;
85  CodecParameterMap params;
86  FeedbackParams feedback_params;
87
88  // Creates a codec with the given parameters.
89  Codec(int id, const std::string& name, int clockrate, int preference);
90  // Creates an empty codec.
91  Codec();
92  Codec(const Codec& c);
93  ~Codec();
94
95  // Indicates if this codec is compatible with the specified codec.
96  bool Matches(const Codec& codec) const;
97
98  // Find the parameter for |name| and write the value to |out|.
99  bool GetParam(const std::string& name, std::string* out) const;
100  bool GetParam(const std::string& name, int* out) const;
101
102  void SetParam(const std::string& name, const std::string& value);
103  void SetParam(const std::string& name, int value);
104
105  // It is safe to input a non-existent parameter.
106  // Returns true if the parameter existed, false if it did not exist.
107  bool RemoveParam(const std::string& name);
108
109  bool HasFeedbackParam(const FeedbackParam& param) const;
110  void AddFeedbackParam(const FeedbackParam& param);
111
112  static bool Preferable(const Codec& first, const Codec& other) {
113    return first.preference > other.preference;
114  }
115
116  // Filter |this| feedbacks params such that only those shared by both |this|
117  // and |other| are kept.
118  void IntersectFeedbackParams(const Codec& other);
119
120  Codec& operator=(const Codec& c);
121
122  bool operator==(const Codec& c) const;
123
124  bool operator!=(const Codec& c) const {
125    return !(*this == c);
126  }
127};
128
129struct AudioCodec : public Codec {
130  int bitrate;
131  int channels;
132
133  // Creates a codec with the given parameters.
134  AudioCodec(int pt, const std::string& nm, int cr, int br, int cs, int pr);
135  // Creates an empty codec.
136  AudioCodec();
137  AudioCodec(const AudioCodec& c);
138  ~AudioCodec() = default;
139
140  // Indicates if this codec is compatible with the specified codec.
141  bool Matches(const AudioCodec& codec) const;
142
143  static bool Preferable(const AudioCodec& first, const AudioCodec& other) {
144    return first.preference > other.preference;
145  }
146
147  std::string ToString() const;
148
149  AudioCodec& operator=(const AudioCodec& c);
150
151  bool operator==(const AudioCodec& c) const;
152
153  bool operator!=(const AudioCodec& c) const {
154    return !(*this == c);
155  }
156};
157
158struct VideoCodec : public Codec {
159  int width;
160  int height;
161  int framerate;
162
163  // Creates a codec with the given parameters.
164  VideoCodec(int pt, const std::string& nm, int w, int h, int fr, int pr);
165  VideoCodec(int pt, const std::string& nm);
166  // Creates an empty codec.
167  VideoCodec();
168  VideoCodec(const VideoCodec& c);
169  ~VideoCodec() = default;
170
171  static bool Preferable(const VideoCodec& first, const VideoCodec& other) {
172    return first.preference > other.preference;
173  }
174
175  std::string ToString() const;
176
177  VideoCodec& operator=(const VideoCodec& c);
178
179  bool operator==(const VideoCodec& c) const;
180
181  bool operator!=(const VideoCodec& c) const {
182    return !(*this == c);
183  }
184
185  static VideoCodec CreateRtxCodec(int rtx_payload_type,
186                                   int associated_payload_type);
187
188  enum CodecType {
189    CODEC_VIDEO,
190    CODEC_RED,
191    CODEC_ULPFEC,
192    CODEC_RTX,
193  };
194
195  CodecType GetCodecType() const;
196  // Validates a VideoCodec's payload type, dimensions and bitrates etc. If they
197  // don't make sense (such as max < min bitrate), and error is logged and
198  // ValidateCodecFormat returns false.
199  bool ValidateCodecFormat() const;
200};
201
202struct DataCodec : public Codec {
203  DataCodec(int id, const std::string& name, int preference);
204  DataCodec();
205  DataCodec(const DataCodec& c);
206
207  DataCodec& operator=(const DataCodec& c);
208
209  std::string ToString() const;
210};
211
212// Get the codec setting associated with |payload_type|. If there
213// is no codec associated with that payload type it returns false.
214template <class Codec>
215bool FindCodecById(const std::vector<Codec>& codecs,
216                   int payload_type,
217                   Codec* codec_out) {
218  for (const auto& codec : codecs) {
219    if (codec.id == payload_type) {
220      *codec_out = codec;
221      return true;
222    }
223  }
224  return false;
225}
226
227bool CodecNamesEq(const std::string& name1, const std::string& name2);
228bool HasNack(const VideoCodec& codec);
229bool HasRemb(const VideoCodec& codec);
230bool HasTransportCc(const VideoCodec& codec);
231
232}  // namespace cricket
233
234#endif  // TALK_MEDIA_BASE_CODEC_H_
235