1 files changed, 243 insertions, 0 deletions
diff --git a/third_party/libwebrtc/pc/dtmf_sender.cc b/third_party/libwebrtc/pc/dtmf_sender.cc
new file mode 100644
index 0000000000..45a4a58abb
--- /dev/null
+++ b/third_party/libwebrtc/pc/dtmf_sender.cc
@@ -0,0 +1,243 @@
+/*
+ *  Copyright 2012 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "pc/dtmf_sender.h"
+
+#include <ctype.h>
+#include <string.h>
+
+#include "api/task_queue/pending_task_safety_flag.h"
+#include "api/task_queue/task_queue_base.h"
+#include "api/units/time_delta.h"
+#include "rtc_base/checks.h"
+#include "rtc_base/logging.h"
+
+namespace webrtc {
+
+// RFC4733
+//  +-------+--------+------+---------+
+//  | Event | Code   | Type | Volume? |
+//  +-------+--------+------+---------+
+//  | 0--9  | 0--9   | tone | yes     |
+//  | *     | 10     | tone | yes     |
+//  | #     | 11     | tone | yes     |
+//  | A--D  | 12--15 | tone | yes     |
+//  +-------+--------+------+---------+
+// The "," is a special event defined by the WebRTC spec. It means to delay for
+// 2 seconds before processing the next tone. We use -1 as its code.
+static const int kDtmfCommaDelay = -1;
+static const char kDtmfValidTones[] = ",0123456789*#ABCDabcd";
+static const char kDtmfTonesTable[] = ",0123456789*#ABCD";
+// The duration cannot be more than 6000ms or less than 40ms. The gap between
+// tones must be at least 50 ms.
+// Source for values: W3C WEBRTC specification.
+// https://w3c.github.io/webrtc-pc/#dom-rtcdtmfsender-insertdtmf
+static const int kDtmfDefaultDurationMs = 100;
+static const int kDtmfMinDurationMs = 40;
+static const int kDtmfMaxDurationMs = 6000;
+static const int kDtmfDefaultGapMs = 50;
+static const int kDtmfMinGapMs = 30;
+
+// Get DTMF code from the DTMF event character.
+bool GetDtmfCode(char tone, int* code) {
+  // Convert a-d to A-D.
+  char event = toupper(tone);
+  const char* p = strchr(kDtmfTonesTable, event);
+  if (!p) {
+    return false;
+  }
+  *code = p - kDtmfTonesTable - 1;
+  return true;
+}
+
+rtc::scoped_refptr<DtmfSender> DtmfSender::Create(
+    TaskQueueBase* signaling_thread,
+    DtmfProviderInterface* provider) {
+  if (!signaling_thread) {
+    return nullptr;
+  }
+  return rtc::make_ref_counted<DtmfSender>(signaling_thread, provider);
+}
+
+DtmfSender::DtmfSender(TaskQueueBase* signaling_thread,
+                       DtmfProviderInterface* provider)
+    : observer_(nullptr),
+      signaling_thread_(signaling_thread),
+      provider_(provider),
+      duration_(kDtmfDefaultDurationMs),
+      inter_tone_gap_(kDtmfDefaultGapMs),
+      comma_delay_(kDtmfDefaultCommaDelayMs) {
+  RTC_DCHECK(signaling_thread_);
+  RTC_DCHECK(provider_);
+}
+
+void DtmfSender::OnDtmfProviderDestroyed() {
+  RTC_DCHECK_RUN_ON(signaling_thread_);
+  RTC_DLOG(LS_INFO) << "The Dtmf provider is deleted. Clear the sending queue.";
+  StopSending();
+  provider_ = nullptr;
+}
+
+DtmfSender::~DtmfSender() {
+  RTC_DCHECK_RUN_ON(signaling_thread_);
+  StopSending();
+}
+
+void DtmfSender::RegisterObserver(DtmfSenderObserverInterface* observer) {
+  RTC_DCHECK_RUN_ON(signaling_thread_);
+  observer_ = observer;
+}
+
+void DtmfSender::UnregisterObserver() {
+  RTC_DCHECK_RUN_ON(signaling_thread_);
+  observer_ = nullptr;
+}
+
+bool DtmfSender::CanInsertDtmf() {
+  RTC_DCHECK_RUN_ON(signaling_thread_);
+  if (!provider_) {
+    return false;
+  }
+  return provider_->CanInsertDtmf();
+}
+
+bool DtmfSender::InsertDtmf(const std::string& tones,
+                            int duration,
+                            int inter_tone_gap,
+                            int comma_delay) {
+  RTC_DCHECK_RUN_ON(signaling_thread_);
+
+  if (duration > kDtmfMaxDurationMs || duration < kDtmfMinDurationMs ||
+      inter_tone_gap < kDtmfMinGapMs || comma_delay < kDtmfMinGapMs) {
+    RTC_LOG(LS_ERROR)
+        << "InsertDtmf is called with invalid duration or tones gap. "
+           "The duration cannot be more than "
+        << kDtmfMaxDurationMs << "ms or less than " << kDtmfMinDurationMs
+        << "ms. The gap between tones must be at least " << kDtmfMinGapMs
+        << "ms.";
+    return false;
+  }
+
+  if (!CanInsertDtmf()) {
+    RTC_LOG(LS_ERROR)
+        << "InsertDtmf is called on DtmfSender that can't send DTMF.";
+    return false;
+  }
+
+  tones_ = tones;
+  duration_ = duration;
+  inter_tone_gap_ = inter_tone_gap;
+  comma_delay_ = comma_delay;
+
+  // Cancel any remaining tasks for previous tones.
+  if (safety_flag_) {
+    safety_flag_->SetNotAlive();
+  }
+  safety_flag_ = PendingTaskSafetyFlag::Create();
+  // Kick off a new DTMF task.
+  QueueInsertDtmf(1 /*ms*/);
+  return true;
+}
+
+std::string DtmfSender::tones() const {
+  RTC_DCHECK_RUN_ON(signaling_thread_);
+  return tones_;
+}
+
+int DtmfSender::duration() const {
+  RTC_DCHECK_RUN_ON(signaling_thread_);
+  return duration_;
+}
+
+int DtmfSender::inter_tone_gap() const {
+  RTC_DCHECK_RUN_ON(signaling_thread_);
+  return inter_tone_gap_;
+}
+
+int DtmfSender::comma_delay() const {
+  RTC_DCHECK_RUN_ON(signaling_thread_);
+  return comma_delay_;
+}
+
+void DtmfSender::QueueInsertDtmf(uint32_t delay_ms) {
+  signaling_thread_->PostDelayedHighPrecisionTask(
+      SafeTask(safety_flag_,
+               [this] {
+                 RTC_DCHECK_RUN_ON(signaling_thread_);
+                 DoInsertDtmf();
+               }),
+      TimeDelta::Millis(delay_ms));
+}
+
+void DtmfSender::DoInsertDtmf() {
+  // Get the first DTMF tone from the tone buffer. Unrecognized characters will
+  // be ignored and skipped.
+  size_t first_tone_pos = tones_.find_first_of(kDtmfValidTones);
+  int code = 0;
+  if (first_tone_pos == std::string::npos) {
+    tones_.clear();
+    // Fire a “OnToneChange” event with an empty string and stop.
+    if (observer_) {
+      observer_->OnToneChange(std::string(), tones_);
+      observer_->OnToneChange(std::string());
+    }
+    return;
+  } else {
+    char tone = tones_[first_tone_pos];
+    if (!GetDtmfCode(tone, &code)) {
+      // The find_first_of(kDtmfValidTones) should have guarantee `tone` is
+      // a valid DTMF tone.
+      RTC_DCHECK_NOTREACHED();
+    }
+  }
+
+  int tone_gap = inter_tone_gap_;
+  if (code == kDtmfCommaDelay) {
+    // Special case defined by WebRTC - By default, the character ',' indicates
+    // a delay of 2 seconds before processing the next character in the tones
+    // parameter. The comma delay can be set to a non default value via
+    // InsertDtmf to comply with legacy WebRTC clients.
+    tone_gap = comma_delay_;
+  } else {
+    if (!provider_) {
+      RTC_LOG(LS_ERROR) << "The DtmfProvider has been destroyed.";
+      return;
+    }
+    // The provider starts playout of the given tone on the
+    // associated RTP media stream, using the appropriate codec.
+    if (!provider_->InsertDtmf(code, duration_)) {
+      RTC_LOG(LS_ERROR) << "The DtmfProvider can no longer send DTMF.";
+      return;
+    }
+    // Wait for the number of milliseconds specified by `duration_`.
+    tone_gap += duration_;
+  }
+
+  // Fire a “OnToneChange” event with the tone that's just processed.
+  if (observer_) {
+    observer_->OnToneChange(tones_.substr(first_tone_pos, 1),
+                            tones_.substr(first_tone_pos + 1));
+    observer_->OnToneChange(tones_.substr(first_tone_pos, 1));
+  }
+
+  // Erase the unrecognized characters plus the tone that's just processed.
+  tones_.erase(0, first_tone_pos + 1);
+
+  // Continue with the next tone.
+  QueueInsertDtmf(tone_gap);
+}
+
+void DtmfSender::StopSending() {
+  if (safety_flag_) {
+    safety_flag_->SetNotAlive();
+  }
+}
+
+}  // namespace webrtc