Move talk/session/media -> webrtc/pc

talk/session/media/rtcpmuxfilter.cc

-/*
- * libjingle
- * Copyright 2004 Google Inc.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are met:
- *
- *  1. Redistributions of source code must retain the above copyright notice,
- *     this list of conditions and the following disclaimer.
- *  2. Redistributions in binary form must reproduce the above copyright notice,
- *     this list of conditions and the following disclaimer in the documentation
- *     and/or other materials provided with the distribution.
- *  3. The name of the author may not be used to endorse or promote products
- *     derived from this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
- * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
- * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
- * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
- * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
- * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
- * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
- * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
- * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-#include "talk/session/media/rtcpmuxfilter.h"
-
-#include "webrtc/base/logging.h"
-
-namespace cricket {
-
-RtcpMuxFilter::RtcpMuxFilter() : state_(ST_INIT), offer_enable_(false) {
-}
-
-bool RtcpMuxFilter::IsActive() const {
-  return state_ == ST_SENTPRANSWER ||
-         state_ == ST_RECEIVEDPRANSWER ||
-         state_ == ST_ACTIVE;
-}
-
-void RtcpMuxFilter::SetActive() {
-  state_ = ST_ACTIVE;
-}
-
-bool RtcpMuxFilter::SetOffer(bool offer_enable, ContentSource src) {
-  if (state_ == ST_ACTIVE) {
-    // Fail if we try to deactivate and no-op if we try and activate.
-    return offer_enable;
-  }
-
-  if (!ExpectOffer(offer_enable, src)) {
-    LOG(LS_ERROR) << "Invalid state for change of RTCP mux offer";
-    return false;
-  }
-
-  offer_enable_ = offer_enable;
-  state_ = (src == CS_LOCAL) ? ST_SENTOFFER : ST_RECEIVEDOFFER;
-  return true;
-}
-
-bool RtcpMuxFilter::SetProvisionalAnswer(bool answer_enable,
-                                         ContentSource src) {
-  if (state_ == ST_ACTIVE) {
-    // Fail if we try to deactivate and no-op if we try and activate.
-    return answer_enable;
-  }
-
-  if (!ExpectAnswer(src)) {
-    LOG(LS_ERROR) << "Invalid state for RTCP mux provisional answer";
-    return false;
-  }
-
-  if (offer_enable_) {
-    if (answer_enable) {
-      if (src == CS_REMOTE)
-        state_ = ST_RECEIVEDPRANSWER;
-      else  // CS_LOCAL
-        state_ = ST_SENTPRANSWER;
-    } else {
-      // The provisional answer doesn't want to use RTCP mux.
-      // Go back to the original state after the offer was set and wait for next
-      // provisional or final answer.
-      if (src == CS_REMOTE)
-        state_ = ST_SENTOFFER;
-      else  // CS_LOCAL
-        state_ = ST_RECEIVEDOFFER;
-    }
-  } else if (answer_enable) {
-    // If the offer didn't specify RTCP mux, the answer shouldn't either.
-    LOG(LS_WARNING) << "Invalid parameters in RTCP mux provisional answer";
-    return false;
-  }
-
-  return true;
-}
-
-bool RtcpMuxFilter::SetAnswer(bool answer_enable, ContentSource src) {
-  if (state_ == ST_ACTIVE) {
-    // Fail if we try to deactivate and no-op if we try and activate.
-    return answer_enable;
-  }
-
-  if (!ExpectAnswer(src)) {
-    LOG(LS_ERROR) << "Invalid state for RTCP mux answer";
-    return false;
-  }
-
-  if (offer_enable_ && answer_enable) {
-    state_ = ST_ACTIVE;
-  } else if (answer_enable) {
-    // If the offer didn't specify RTCP mux, the answer shouldn't either.
-    LOG(LS_WARNING) << "Invalid parameters in RTCP mux answer";
-    return false;
-  } else {
-    state_ = ST_INIT;
-  }
-  return true;
-}
-
-// Check the RTP payload type.  If 63 < payload type < 96, it's RTCP.
-// For additional details, see http://tools.ietf.org/html/rfc5761.
-bool IsRtcp(const char* data, int len) {
-  if (len < 2) {
-    return false;
-  }
-  char pt = data[1] & 0x7F;
-  return (63 < pt) && (pt < 96);
-}
-
-bool RtcpMuxFilter::DemuxRtcp(const char* data, int len) {
-  // If we're muxing RTP/RTCP, we must inspect each packet delivered
-  // and determine whether it is RTP or RTCP. We do so by looking at
-  // the RTP payload type (see IsRtcp).  Note that if we offer RTCP
-  // mux, we may receive muxed RTCP before we receive the answer, so
-  // we operate in that state too.
-  bool offered_mux = ((state_ == ST_SENTOFFER) && offer_enable_);
-  return (IsActive() || offered_mux) && IsRtcp(data, len);
-}
-
-bool RtcpMuxFilter::ExpectOffer(bool offer_enable, ContentSource source) {
-  return ((state_ == ST_INIT) ||
-          (state_ == ST_ACTIVE && offer_enable == offer_enable_) ||
-          (state_ == ST_SENTOFFER && source == CS_LOCAL) ||
-          (state_ == ST_RECEIVEDOFFER && source == CS_REMOTE));
-}
-
-bool RtcpMuxFilter::ExpectAnswer(ContentSource source) {
-  return ((state_ == ST_SENTOFFER && source == CS_REMOTE) ||
-          (state_ == ST_RECEIVEDOFFER && source == CS_LOCAL) ||
-          (state_ == ST_SENTPRANSWER && source == CS_LOCAL) ||
-          (state_ == ST_RECEIVEDPRANSWER && source == CS_REMOTE));
-}
-
-}  // namespace cricket