OLD | NEW |
(Empty) | |
| 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/speex.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 |
OLD | NEW |