1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #include "remoting/codec/audio_encoder_speex.h" 6 7 #include <string> 8 #include <sstream> 9 10 #include "base/basictypes.h" 11 #include "base/logging.h" 12 #include "base/stl_util.h" 13 #include "remoting/proto/audio.pb.h" 14 #include "third_party/speex/include/speex/speex_callbacks.h" 15 #include "third_party/speex/include/speex/speex_stereo.h" 16 17 namespace { 18 // A quality of 8 in wide band mode corresponds to 27,800 bits per second. 19 const int kSpeexHighQuality = 8; 20 const int kEncodedDataBufferSize = 0xFF; 21 } // namespace 22 23 namespace remoting { 24 25 AudioEncoderSpeex::AudioEncoderSpeex() 26 : leftover_frames_(0) { 27 // Create and initialize the Speex structures. 28 speex_bits_.reset(new SpeexBits()); 29 speex_bits_init(speex_bits_.get()); 30 speex_state_ = speex_encoder_init(&speex_wb_mode); 31 32 // Set the encoding quality. 33 int quality = kSpeexHighQuality; 34 speex_encoder_ctl(speex_state_, SPEEX_SET_QUALITY, &quality); 35 36 // Get the frame size and construct the input buffer accordingly. 37 int result = speex_encoder_ctl(speex_state_, 38 SPEEX_GET_FRAME_SIZE, 39 &speex_frame_size_); 40 CHECK_EQ(result, 0); 41 42 leftover_buffer_.reset( 43 new int16[speex_frame_size_ * AudioPacket::CHANNELS_STEREO]); 44 } 45 46 AudioEncoderSpeex::~AudioEncoderSpeex() { 47 speex_encoder_destroy(speex_state_); 48 speex_bits_destroy(speex_bits_.get()); 49 } 50 51 scoped_ptr<AudioPacket> AudioEncoderSpeex::Encode( 52 scoped_ptr<AudioPacket> packet) { 53 DCHECK_EQ(AudioPacket::ENCODING_RAW, packet->encoding()); 54 DCHECK_EQ(1, packet->data_size()); 55 DCHECK_EQ(AudioPacket::BYTES_PER_SAMPLE_2, packet->bytes_per_sample()); 56 DCHECK_NE(AudioPacket::SAMPLING_RATE_INVALID, packet->sampling_rate()); 57 DCHECK_EQ(AudioPacket::CHANNELS_STEREO, packet->channels()); 58 59 int frames_left = 60 packet->data(0).size() / packet->bytes_per_sample() / packet->channels(); 61 const int16* next_sample = 62 reinterpret_cast<const int16*>(packet->data(0).data()); 63 64 // Create a new packet of encoded data. 65 scoped_ptr<AudioPacket> encoded_packet(new AudioPacket()); 66 encoded_packet->set_encoding(AudioPacket::ENCODING_SPEEX); 67 encoded_packet->set_sampling_rate(packet->sampling_rate()); 68 encoded_packet->set_bytes_per_sample(packet->bytes_per_sample()); 69 encoded_packet->set_channels(packet->channels()); 70 71 while (leftover_frames_ + frames_left >= speex_frame_size_) { 72 int16* unencoded_buffer = NULL; 73 int frames_consumed = 0; 74 75 if (leftover_frames_ > 0) { 76 unencoded_buffer = leftover_buffer_.get(); 77 frames_consumed = speex_frame_size_ - leftover_frames_; 78 79 memcpy(leftover_buffer_.get() + leftover_frames_ * packet->channels(), 80 next_sample, 81 frames_consumed * packet->bytes_per_sample() * packet->channels()); 82 83 leftover_frames_ = 0; 84 } else { 85 unencoded_buffer = const_cast<int16*>(next_sample); 86 frames_consumed = speex_frame_size_; 87 } 88 89 // Transform stereo to mono. 90 speex_encode_stereo_int(unencoded_buffer, 91 speex_frame_size_, 92 speex_bits_.get()); 93 94 // Encode the frame, treating all samples as integers. 95 speex_encode_int(speex_state_, 96 unencoded_buffer, 97 speex_bits_.get()); 98 99 next_sample += frames_consumed * packet->channels(); 100 frames_left -= frames_consumed; 101 102 std::string* new_data = encoded_packet->add_data(); 103 new_data->resize(speex_bits_nbytes(speex_bits_.get())); 104 105 // Copy the encoded data from the bits structure into the buffer. 106 int bytes_written = speex_bits_write(speex_bits_.get(), 107 string_as_array(new_data), 108 new_data->size()); 109 110 // Expect that the bytes are all written. 111 DCHECK_EQ(bytes_written, static_cast<int>(new_data->size())); 112 113 // Reset the bits structure for this frame. 114 speex_bits_reset(speex_bits_.get()); 115 } 116 117 // Store the leftover samples. 118 if (frames_left > 0) { 119 CHECK_LE(leftover_frames_ + frames_left, speex_frame_size_); 120 memcpy(leftover_buffer_.get() + leftover_frames_ * packet->channels(), 121 next_sample, 122 frames_left * packet->bytes_per_sample() * packet->channels()); 123 leftover_frames_ += frames_left; 124 } 125 126 // Return NULL if there's nothing in the packet. 127 if (encoded_packet->data_size() == 0) 128 return scoped_ptr<AudioPacket>(); 129 130 return encoded_packet.Pass(); 131 } 132 133 } // namespace remoting 134