The Tor Browser: content/media/webspeech/recognition/endpointer.h@44a2da4a2ab2 (annotated)

content/media/webspeech/recognition/endpointer.h@44a2da4a2ab2 (annotated)

content/media/webspeech/recognition/endpointer.h

Fri, 16 Jan 2015 04:50:19 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Fri, 16 Jan 2015 04:50:19 +0100
branch: TOR_BUG_9701
changeset 13: 44a2da4a2ab2
permissions: -rw-r--r--

Replace accessor implementation with direct member state manipulation, by
request https://trac.torproject.org/projects/tor/ticket/9701#comment:32

 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //    * Redistributions of source code must retain the above copyright
 // notice, this list of conditions and the following disclaimer.
 //    * 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.
 //    * Neither the name of Google Inc. nor the names of its
 // contributors may be used to endorse or promote products derived from
 // this software without specific prior written permission.
 //
 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 // "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 COPYRIGHT
 // OWNER OR CONTRIBUTORS 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.
 #ifndef CONTENT_BROWSER_SPEECH_ENDPOINTER_ENDPOINTER_H_
 #define CONTENT_BROWSER_SPEECH_ENDPOINTER_ENDPOINTER_H_
 #include "energy_endpointer.h"
 namespace mozilla {
 struct AudioChunk;
 // A simple interface to the underlying energy-endpointer implementation, this
 // class lets callers provide audio as being recorded and let them poll to find
 // when the user has stopped speaking.
 //
 // There are two events that may trigger the end of speech:
 //
 // speechInputPossiblyComplete event:
 //
 // Signals that silence/noise has  been detected for a *short* amount of
 // time after some speech has been detected. It can be used for low latency
 // UI feedback. To disable it, set it to a large amount.
 //
 // speechInputComplete event:
 //
 // This event is intended to signal end of input and to stop recording.
 // The amount of time to wait after speech is set by
 // speech_input_complete_silence_length_ and optionally two other
 // parameters (see below).
 // This time can be held constant, or can change as more speech is detected.
 // In the latter case, the time changes after a set amount of time from the
 // *beginning* of speech.  This is motivated by the expectation that there
 // will be two distinct types of inputs: short search queries and longer
 // dictation style input.
 //
 // Three parameters are used to define the piecewise constant timeout function.
 // The timeout length is speech_input_complete_silence_length until
 // long_speech_length, when it changes to
 // long_speech_input_complete_silence_length.
 class Endpointer {
  public:
   explicit Endpointer(int sample_rate);
   // Start the endpointer. This should be called at the beginning of a session.
   void StartSession();
   // Stop the endpointer.
   void EndSession();
   // Start environment estimation. Audio will be used for environment estimation
   // i.e. noise level estimation.
   void SetEnvironmentEstimationMode();
   // Start user input. This should be called when the user indicates start of
   // input, e.g. by pressing a button.
   void SetUserInputMode();
   // Process a segment of audio, which may be more than one frame.
   // The status of the last frame will be returned.
   EpStatus ProcessAudio(const AudioChunk& raw_audio, float* rms_out);
   // Get the status of the endpointer.
   EpStatus Status(int64_t *time_us);
   // Get the expected frame size for audio chunks. Audio chunks are expected
   // to contain a number of samples that is a multiple of this number, and extra
   // samples will be dropped.
   int32_t FrameSize() const {
     return frame_size_;
   }
   // Returns true if the endpointer detected reasonable audio levels above
   // background noise which could be user speech, false if not.
   bool DidStartReceivingSpeech() const {
     return speech_previously_detected_;
   }
   bool IsEstimatingEnvironment() const {
     return energy_endpointer_.estimating_environment();
   }
   void set_speech_input_complete_silence_length(int64_t time_us) {
     speech_input_complete_silence_length_us_ = time_us;
   }
   void set_long_speech_input_complete_silence_length(int64_t time_us) {
     long_speech_input_complete_silence_length_us_ = time_us;
   }
   void set_speech_input_possibly_complete_silence_length(int64_t time_us) {
     speech_input_possibly_complete_silence_length_us_ = time_us;
   }
   void set_long_speech_length(int64_t time_us) {
     long_speech_length_us_ = time_us;
   }
   bool speech_input_complete() const {
     return speech_input_complete_;
   }
   // RMS background noise level in dB.
   float NoiseLevelDb() const { return energy_endpointer_.GetNoiseLevelDb(); }
  private:
   // Reset internal states. Helper method common to initial input utterance
   // and following input utternaces.
   void Reset();
   // Minimum allowable length of speech input.
   int64_t speech_input_minimum_length_us_;
   // The speechInputPossiblyComplete event signals that silence/noise has been
   // detected for a *short* amount of time after some speech has been detected.
   // This proporty specifies the time period.
   int64_t speech_input_possibly_complete_silence_length_us_;
   // The speechInputComplete event signals that silence/noise has been
   // detected for a *long* amount of time after some speech has been detected.
   // This property specifies the time period.
   int64_t speech_input_complete_silence_length_us_;
   // Same as above, this specifies the required silence period after speech
   // detection. This period is used instead of
   // speech_input_complete_silence_length_ when the utterance is longer than
   // long_speech_length_. This parameter is optional.
   int64_t long_speech_input_complete_silence_length_us_;
   // The period of time after which the endpointer should consider
   // long_speech_input_complete_silence_length_ as a valid silence period
   // instead of speech_input_complete_silence_length_. This parameter is
   // optional.
   int64_t long_speech_length_us_;
   // First speech onset time, used in determination of speech complete timeout.
   int64_t speech_start_time_us_;
   // Most recent end time, used in determination of speech complete timeout.
   int64_t speech_end_time_us_;
   int64_t audio_frame_time_us_;
   EpStatus old_ep_status_;
   bool waiting_for_speech_possibly_complete_timeout_;
   bool waiting_for_speech_complete_timeout_;
   bool speech_previously_detected_;
   bool speech_input_complete_;
   EnergyEndpointer energy_endpointer_;
   int sample_rate_;
   int32_t frame_size_;
 };
 }  // namespace mozilla
 #endif  // CONTENT_BROWSER_SPEECH_ENDPOINTER_ENDPOINTER_H_

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content/media/webspeech/recognition/endpointer.h@44a2da4a2ab2 (annotated)

content/media/webspeech/recognition/endpointer.h