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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 // Types and classes used in media session descriptions.
29 
30 #ifndef TALK_SESSION_MEDIA_MEDIASESSION_H_
31 #define TALK_SESSION_MEDIA_MEDIASESSION_H_
32 
33 #include <algorithm>
34 #include <string>
35 #include <vector>
36 
37 #include "talk/media/base/codec.h"
38 #include "talk/media/base/constants.h"
39 #include "talk/media/base/cryptoparams.h"
40 #include "talk/media/base/mediachannel.h"
41 #include "talk/media/base/mediaengine.h"  // For DataChannelType
42 #include "talk/media/base/streamparams.h"
43 #include "talk/p2p/base/sessiondescription.h"
44 #include "talk/p2p/base/transport.h"
45 #include "talk/p2p/base/transportdescriptionfactory.h"
46 #include "webrtc/base/scoped_ptr.h"
47 
48 namespace cricket {
49 
50 class ChannelManager;
51 typedef std::vector<AudioCodec> AudioCodecs;
52 typedef std::vector<VideoCodec> VideoCodecs;
53 typedef std::vector<DataCodec> DataCodecs;
54 typedef std::vector<CryptoParams> CryptoParamsVec;
55 typedef std::vector<RtpHeaderExtension> RtpHeaderExtensions;
56 
57 enum MediaType {
58   MEDIA_TYPE_AUDIO,
59   MEDIA_TYPE_VIDEO,
60   MEDIA_TYPE_DATA
61 };
62 
63 std::string MediaTypeToString(MediaType type);
64 
65 enum MediaContentDirection {
66   MD_INACTIVE,
67   MD_SENDONLY,
68   MD_RECVONLY,
69   MD_SENDRECV
70 };
71 
72 enum CryptoType {
73   CT_NONE,
74   CT_SDES,
75   CT_DTLS
76 };
77 
78 // RTC4585 RTP/AVPF
79 extern const char kMediaProtocolAvpf[];
80 // RFC5124 RTP/SAVPF
81 extern const char kMediaProtocolSavpf[];
82 
83 extern const char kMediaProtocolDtlsSavpf[];
84 
85 extern const char kMediaProtocolRtpPrefix[];
86 
87 extern const char kMediaProtocolSctp[];
88 extern const char kMediaProtocolDtlsSctp[];
89 
90 // Options to control how session descriptions are generated.
91 const int kAutoBandwidth = -1;
92 const int kBufferedModeDisabled = 0;
93 
94 struct MediaSessionOptions {
MediaSessionOptionsMediaSessionOptions95   MediaSessionOptions() :
96       has_audio(true),  // Audio enabled by default.
97       has_video(false),
98       data_channel_type(DCT_NONE),
99       is_muc(false),
100       vad_enabled(true),  // When disabled, removes all CN codecs from SDP.
101       rtcp_mux_enabled(true),
102       bundle_enabled(false),
103       video_bandwidth(kAutoBandwidth),
104       data_bandwidth(kDataMaxBandwidth) {
105   }
106 
has_dataMediaSessionOptions107   bool has_data() const { return data_channel_type != DCT_NONE; }
108 
109   // Add a stream with MediaType type and id.
110   // All streams with the same sync_label will get the same CNAME.
111   // All ids must be unique.
112   void AddStream(MediaType type,
113                  const std::string& id,
114                  const std::string& sync_label);
115   void AddVideoStream(const std::string& id,
116                       const std::string& sync_label,
117                       int num_sim_layers);
118   void RemoveStream(MediaType type, const std::string& id);
119 
120 
121   // Helper function.
122   void AddStreamInternal(MediaType type,
123                          const std::string& id,
124                          const std::string& sync_label,
125                          int num_sim_layers);
126 
127   bool has_audio;
128   bool has_video;
129   DataChannelType data_channel_type;
130   bool is_muc;
131   bool vad_enabled;
132   bool rtcp_mux_enabled;
133   bool bundle_enabled;
134   // bps. -1 == auto.
135   int video_bandwidth;
136   int data_bandwidth;
137   TransportOptions transport_options;
138 
139   struct Stream {
StreamMediaSessionOptions::Stream140     Stream(MediaType type,
141            const std::string& id,
142            const std::string& sync_label,
143            int num_sim_layers)
144         : type(type), id(id), sync_label(sync_label),
145           num_sim_layers(num_sim_layers) {
146     }
147     MediaType type;
148     std::string id;
149     std::string sync_label;
150     int num_sim_layers;
151   };
152 
153   typedef std::vector<Stream> Streams;
154   Streams streams;
155 };
156 
157 // "content" (as used in XEP-0166) descriptions for voice and video.
158 class MediaContentDescription : public ContentDescription {
159  public:
MediaContentDescription()160   MediaContentDescription()
161       : rtcp_mux_(false),
162         bandwidth_(kAutoBandwidth),
163         crypto_required_(CT_NONE),
164         rtp_header_extensions_set_(false),
165         multistream_(false),
166         conference_mode_(false),
167         partial_(false),
168         buffered_mode_latency_(kBufferedModeDisabled),
169         direction_(MD_SENDRECV) {
170   }
171 
172   virtual MediaType type() const = 0;
173   virtual bool has_codecs() const = 0;
174 
175   // |protocol| is the expected media transport protocol, such as RTP/AVPF,
176   // RTP/SAVPF or SCTP/DTLS.
protocol()177   std::string protocol() const { return protocol_; }
set_protocol(const std::string & protocol)178   void set_protocol(const std::string& protocol) { protocol_ = protocol; }
179 
direction()180   MediaContentDirection direction() const { return direction_; }
set_direction(MediaContentDirection direction)181   void set_direction(MediaContentDirection direction) {
182     direction_ = direction;
183   }
184 
rtcp_mux()185   bool rtcp_mux() const { return rtcp_mux_; }
set_rtcp_mux(bool mux)186   void set_rtcp_mux(bool mux) { rtcp_mux_ = mux; }
187 
bandwidth()188   int bandwidth() const { return bandwidth_; }
set_bandwidth(int bandwidth)189   void set_bandwidth(int bandwidth) { bandwidth_ = bandwidth; }
190 
cryptos()191   const std::vector<CryptoParams>& cryptos() const { return cryptos_; }
AddCrypto(const CryptoParams & params)192   void AddCrypto(const CryptoParams& params) {
193     cryptos_.push_back(params);
194   }
set_cryptos(const std::vector<CryptoParams> & cryptos)195   void set_cryptos(const std::vector<CryptoParams>& cryptos) {
196     cryptos_ = cryptos;
197   }
198 
crypto_required()199   CryptoType crypto_required() const { return crypto_required_; }
set_crypto_required(CryptoType type)200   void set_crypto_required(CryptoType type) {
201     crypto_required_ = type;
202   }
203 
rtp_header_extensions()204   const RtpHeaderExtensions& rtp_header_extensions() const {
205     return rtp_header_extensions_;
206   }
set_rtp_header_extensions(const RtpHeaderExtensions & extensions)207   void set_rtp_header_extensions(const RtpHeaderExtensions& extensions) {
208     rtp_header_extensions_ = extensions;
209     rtp_header_extensions_set_ = true;
210   }
AddRtpHeaderExtension(const RtpHeaderExtension & ext)211   void AddRtpHeaderExtension(const RtpHeaderExtension& ext) {
212     rtp_header_extensions_.push_back(ext);
213     rtp_header_extensions_set_ = true;
214   }
ClearRtpHeaderExtensions()215   void ClearRtpHeaderExtensions() {
216     rtp_header_extensions_.clear();
217     rtp_header_extensions_set_ = true;
218   }
219   // We can't always tell if an empty list of header extensions is
220   // because the other side doesn't support them, or just isn't hooked up to
221   // signal them. For now we assume an empty list means no signaling, but
222   // provide the ClearRtpHeaderExtensions method to allow "no support" to be
223   // clearly indicated (i.e. when derived from other information).
rtp_header_extensions_set()224   bool rtp_header_extensions_set() const {
225     return rtp_header_extensions_set_;
226   }
227   // True iff the client supports multiple streams.
set_multistream(bool multistream)228   void set_multistream(bool multistream) { multistream_ = multistream; }
multistream()229   bool multistream() const { return multistream_; }
streams()230   const StreamParamsVec& streams() const {
231     return streams_;
232   }
233   // TODO(pthatcher): Remove this by giving mediamessage.cc access
234   // to MediaContentDescription
mutable_streams()235   StreamParamsVec& mutable_streams() {
236     return streams_;
237   }
AddStream(const StreamParams & stream)238   void AddStream(const StreamParams& stream) {
239     streams_.push_back(stream);
240   }
241   // Legacy streams have an ssrc, but nothing else.
AddLegacyStream(uint32 ssrc)242   void AddLegacyStream(uint32 ssrc) {
243     streams_.push_back(StreamParams::CreateLegacy(ssrc));
244   }
AddLegacyStream(uint32 ssrc,uint32 fid_ssrc)245   void AddLegacyStream(uint32 ssrc, uint32 fid_ssrc) {
246     StreamParams sp = StreamParams::CreateLegacy(ssrc);
247     sp.AddFidSsrc(ssrc, fid_ssrc);
248     streams_.push_back(sp);
249   }
250   // Sets the CNAME of all StreamParams if it have not been set.
251   // This can be used to set the CNAME of legacy streams.
SetCnameIfEmpty(const std::string & cname)252   void SetCnameIfEmpty(const std::string& cname) {
253     for (cricket::StreamParamsVec::iterator it = streams_.begin();
254          it != streams_.end(); ++it) {
255       if (it->cname.empty())
256         it->cname = cname;
257     }
258   }
first_ssrc()259   uint32 first_ssrc() const {
260     if (streams_.empty()) {
261       return 0;
262     }
263     return streams_[0].first_ssrc();
264   }
has_ssrcs()265   bool has_ssrcs() const {
266     if (streams_.empty()) {
267       return false;
268     }
269     return streams_[0].has_ssrcs();
270   }
271 
set_conference_mode(bool enable)272   void set_conference_mode(bool enable) { conference_mode_ = enable; }
conference_mode()273   bool conference_mode() const { return conference_mode_; }
274 
set_partial(bool partial)275   void set_partial(bool partial) { partial_ = partial; }
partial()276   bool partial() const { return partial_;  }
277 
set_buffered_mode_latency(int latency)278   void set_buffered_mode_latency(int latency) {
279     buffered_mode_latency_ = latency;
280   }
buffered_mode_latency()281   int buffered_mode_latency() const { return buffered_mode_latency_; }
282 
283  protected:
284   bool rtcp_mux_;
285   int bandwidth_;
286   std::string protocol_;
287   std::vector<CryptoParams> cryptos_;
288   CryptoType crypto_required_;
289   std::vector<RtpHeaderExtension> rtp_header_extensions_;
290   bool rtp_header_extensions_set_;
291   bool multistream_;
292   StreamParamsVec streams_;
293   bool conference_mode_;
294   bool partial_;
295   int buffered_mode_latency_;
296   MediaContentDirection direction_;
297 };
298 
299 template <class C>
300 class MediaContentDescriptionImpl : public MediaContentDescription {
301  public:
302   struct PreferenceSort {
operatorPreferenceSort303     bool operator()(C a, C b) { return a.preference > b.preference; }
304   };
305 
codecs()306   const std::vector<C>& codecs() const { return codecs_; }
set_codecs(const std::vector<C> & codecs)307   void set_codecs(const std::vector<C>& codecs) { codecs_ = codecs; }
has_codecs()308   virtual bool has_codecs() const { return !codecs_.empty(); }
HasCodec(int id)309   bool HasCodec(int id) {
310     bool found = false;
311     for (typename std::vector<C>::iterator iter = codecs_.begin();
312          iter != codecs_.end(); ++iter) {
313       if (iter->id == id) {
314         found = true;
315         break;
316       }
317     }
318     return found;
319   }
AddCodec(const C & codec)320   void AddCodec(const C& codec) {
321     codecs_.push_back(codec);
322   }
AddOrReplaceCodec(const C & codec)323   void AddOrReplaceCodec(const C& codec) {
324     for (typename std::vector<C>::iterator iter = codecs_.begin();
325          iter != codecs_.end(); ++iter) {
326       if (iter->id == codec.id) {
327         *iter = codec;
328         return;
329       }
330     }
331     AddCodec(codec);
332   }
AddCodecs(const std::vector<C> & codecs)333   void AddCodecs(const std::vector<C>& codecs) {
334     typename std::vector<C>::const_iterator codec;
335     for (codec = codecs.begin(); codec != codecs.end(); ++codec) {
336       AddCodec(*codec);
337     }
338   }
SortCodecs()339   void SortCodecs() {
340     std::sort(codecs_.begin(), codecs_.end(), PreferenceSort());
341   }
342 
343  private:
344   std::vector<C> codecs_;
345 };
346 
347 class AudioContentDescription : public MediaContentDescriptionImpl<AudioCodec> {
348  public:
AudioContentDescription()349   AudioContentDescription() :
350       agc_minus_10db_(false) {}
351 
Copy()352   virtual ContentDescription* Copy() const {
353     return new AudioContentDescription(*this);
354   }
type()355   virtual MediaType type() const { return MEDIA_TYPE_AUDIO; }
356 
lang()357   const std::string &lang() const { return lang_; }
set_lang(const std::string & lang)358   void set_lang(const std::string &lang) { lang_ = lang; }
359 
agc_minus_10db()360   bool agc_minus_10db() const { return agc_minus_10db_; }
set_agc_minus_10db(bool enable)361   void set_agc_minus_10db(bool enable) {
362     agc_minus_10db_ = enable;
363   }
364 
365  private:
366   bool agc_minus_10db_;
367 
368  private:
369   std::string lang_;
370 };
371 
372 class VideoContentDescription : public MediaContentDescriptionImpl<VideoCodec> {
373  public:
Copy()374   virtual ContentDescription* Copy() const {
375     return new VideoContentDescription(*this);
376   }
type()377   virtual MediaType type() const { return MEDIA_TYPE_VIDEO; }
378 };
379 
380 class DataContentDescription : public MediaContentDescriptionImpl<DataCodec> {
381  public:
Copy()382   virtual ContentDescription* Copy() const {
383     return new DataContentDescription(*this);
384   }
type()385   virtual MediaType type() const { return MEDIA_TYPE_DATA; }
386 };
387 
388 // Creates media session descriptions according to the supplied codecs and
389 // other fields, as well as the supplied per-call options.
390 // When creating answers, performs the appropriate negotiation
391 // of the various fields to determine the proper result.
392 class MediaSessionDescriptionFactory {
393  public:
394   // Default ctor; use methods below to set configuration.
395   // The TransportDescriptionFactory is not owned by MediaSessionDescFactory,
396   // so it must be kept alive by the user of this class.
397   explicit MediaSessionDescriptionFactory(
398       const TransportDescriptionFactory* factory);
399   // This helper automatically sets up the factory to get its configuration
400   // from the specified ChannelManager.
401   MediaSessionDescriptionFactory(ChannelManager* cmanager,
402                                  const TransportDescriptionFactory* factory);
403 
audio_codecs()404   const AudioCodecs& audio_codecs() const { return audio_codecs_; }
set_audio_codecs(const AudioCodecs & codecs)405   void set_audio_codecs(const AudioCodecs& codecs) { audio_codecs_ = codecs; }
set_audio_rtp_header_extensions(const RtpHeaderExtensions & extensions)406   void set_audio_rtp_header_extensions(const RtpHeaderExtensions& extensions) {
407     audio_rtp_extensions_ = extensions;
408   }
audio_rtp_header_extensions()409   const RtpHeaderExtensions& audio_rtp_header_extensions() const {
410     return audio_rtp_extensions_;
411   }
video_codecs()412   const VideoCodecs& video_codecs() const { return video_codecs_; }
set_video_codecs(const VideoCodecs & codecs)413   void set_video_codecs(const VideoCodecs& codecs) { video_codecs_ = codecs; }
set_video_rtp_header_extensions(const RtpHeaderExtensions & extensions)414   void set_video_rtp_header_extensions(const RtpHeaderExtensions& extensions) {
415     video_rtp_extensions_ = extensions;
416   }
video_rtp_header_extensions()417   const RtpHeaderExtensions& video_rtp_header_extensions() const {
418     return video_rtp_extensions_;
419   }
data_codecs()420   const DataCodecs& data_codecs() const { return data_codecs_; }
set_data_codecs(const DataCodecs & codecs)421   void set_data_codecs(const DataCodecs& codecs) { data_codecs_ = codecs; }
secure()422   SecurePolicy secure() const { return secure_; }
set_secure(SecurePolicy s)423   void set_secure(SecurePolicy s) { secure_ = s; }
424   // Decides if a StreamParams shall be added to the audio and video media
425   // content in SessionDescription when CreateOffer and CreateAnswer is called
426   // even if |options| don't include a Stream. This is needed to support legacy
427   // applications. |add_legacy_| is true per default.
set_add_legacy_streams(bool add_legacy)428   void set_add_legacy_streams(bool add_legacy) { add_legacy_ = add_legacy; }
429 
430   SessionDescription* CreateOffer(
431       const MediaSessionOptions& options,
432       const SessionDescription* current_description) const;
433   SessionDescription* CreateAnswer(
434         const SessionDescription* offer,
435         const MediaSessionOptions& options,
436         const SessionDescription* current_description) const;
437 
438  private:
439   void GetCodecsToOffer(const SessionDescription* current_description,
440                         AudioCodecs* audio_codecs,
441                         VideoCodecs* video_codecs,
442                         DataCodecs* data_codecs) const;
443   void GetRtpHdrExtsToOffer(const SessionDescription* current_description,
444                             RtpHeaderExtensions* audio_extensions,
445                             RtpHeaderExtensions* video_extensions) const;
446   bool AddTransportOffer(
447       const std::string& content_name,
448       const TransportOptions& transport_options,
449       const SessionDescription* current_desc,
450       SessionDescription* offer) const;
451 
452   TransportDescription* CreateTransportAnswer(
453       const std::string& content_name,
454       const SessionDescription* offer_desc,
455       const TransportOptions& transport_options,
456       const SessionDescription* current_desc) const;
457 
458   bool AddTransportAnswer(
459       const std::string& content_name,
460       const TransportDescription& transport_desc,
461       SessionDescription* answer_desc) const;
462 
463   // Helpers for adding media contents to the SessionDescription. Returns true
464   // it succeeds or the media content is not needed, or false if there is any
465   // error.
466 
467   bool AddAudioContentForOffer(
468       const MediaSessionOptions& options,
469       const SessionDescription* current_description,
470       const RtpHeaderExtensions& audio_rtp_extensions,
471       const AudioCodecs& audio_codecs,
472       StreamParamsVec* current_streams,
473       SessionDescription* desc) const;
474 
475   bool AddVideoContentForOffer(
476       const MediaSessionOptions& options,
477       const SessionDescription* current_description,
478       const RtpHeaderExtensions& video_rtp_extensions,
479       const VideoCodecs& video_codecs,
480       StreamParamsVec* current_streams,
481       SessionDescription* desc) const;
482 
483   bool AddDataContentForOffer(
484       const MediaSessionOptions& options,
485       const SessionDescription* current_description,
486       DataCodecs* data_codecs,
487       StreamParamsVec* current_streams,
488       SessionDescription* desc) const;
489 
490   bool AddAudioContentForAnswer(
491       const SessionDescription* offer,
492       const MediaSessionOptions& options,
493       const SessionDescription* current_description,
494       StreamParamsVec* current_streams,
495       SessionDescription* answer) const;
496 
497   bool AddVideoContentForAnswer(
498       const SessionDescription* offer,
499       const MediaSessionOptions& options,
500       const SessionDescription* current_description,
501       StreamParamsVec* current_streams,
502       SessionDescription* answer) const;
503 
504   bool AddDataContentForAnswer(
505       const SessionDescription* offer,
506       const MediaSessionOptions& options,
507       const SessionDescription* current_description,
508       StreamParamsVec* current_streams,
509       SessionDescription* answer) const;
510 
511   AudioCodecs audio_codecs_;
512   RtpHeaderExtensions audio_rtp_extensions_;
513   VideoCodecs video_codecs_;
514   RtpHeaderExtensions video_rtp_extensions_;
515   DataCodecs data_codecs_;
516   SecurePolicy secure_;
517   bool add_legacy_;
518   std::string lang_;
519   const TransportDescriptionFactory* transport_desc_factory_;
520 };
521 
522 // Convenience functions.
523 bool IsMediaContent(const ContentInfo* content);
524 bool IsAudioContent(const ContentInfo* content);
525 bool IsVideoContent(const ContentInfo* content);
526 bool IsDataContent(const ContentInfo* content);
527 const ContentInfo* GetFirstAudioContent(const ContentInfos& contents);
528 const ContentInfo* GetFirstVideoContent(const ContentInfos& contents);
529 const ContentInfo* GetFirstDataContent(const ContentInfos& contents);
530 const ContentInfo* GetFirstAudioContent(const SessionDescription* sdesc);
531 const ContentInfo* GetFirstVideoContent(const SessionDescription* sdesc);
532 const ContentInfo* GetFirstDataContent(const SessionDescription* sdesc);
533 const AudioContentDescription* GetFirstAudioContentDescription(
534     const SessionDescription* sdesc);
535 const VideoContentDescription* GetFirstVideoContentDescription(
536     const SessionDescription* sdesc);
537 const DataContentDescription* GetFirstDataContentDescription(
538     const SessionDescription* sdesc);
539 bool GetStreamBySsrc(
540     const SessionDescription* sdesc, MediaType media_type,
541     uint32 ssrc, StreamParams* stream_out);
542 bool GetStreamByIds(
543     const SessionDescription* sdesc, MediaType media_type,
544     const std::string& groupid, const std::string& id,
545     StreamParams* stream_out);
546 
547 // Functions for translating media candidate names.
548 
549 // For converting between media ICE component and G-ICE channel
550 // names.  For example:
551 // "rtp" <=> 1
552 // "rtcp" <=> 2
553 // "video_rtp" <=> 1
554 // "video_rtcp" <=> 2
555 // Will not convert in the general case of arbitrary channel names,
556 // but is useful for cases where we have candidates for media
557 // channels.
558 // returns false if there is no mapping.
559 bool GetMediaChannelNameFromComponent(
560     int component, cricket::MediaType media_type, std::string* channel_name);
561 bool GetMediaComponentFromChannelName(
562     const std::string& channel_name, int* component);
563 bool GetMediaTypeFromChannelName(
564     const std::string& channel_name, cricket::MediaType* media_type);
565 
566 void GetSupportedAudioCryptoSuites(std::vector<std::string>* crypto_suites);
567 void GetSupportedVideoCryptoSuites(std::vector<std::string>* crypto_suites);
568 void GetSupportedDataCryptoSuites(std::vector<std::string>* crypto_suites);
569 void GetSupportedDefaultCryptoSuites(std::vector<std::string>* crypto_suites);
570 }  // namespace cricket
571 
572 #endif  // TALK_SESSION_MEDIA_MEDIASESSION_H_
573