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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 leftover_buffer_.reset( | |
41 new int16[speex_frame_size_ * AudioPacket::CHANNELS_STEREO]); | |
42 if (result < 0) { | |
43 LOG(FATAL) << "Failed to get the frame size for the Speex encoder"; | |
44 return; | |
45 } | |
46 } | |
47 | |
48 AudioEncoderSpeex::~AudioEncoderSpeex() { | |
49 speex_encoder_destroy(speex_state_); | |
50 speex_bits_destroy(speex_bits_.get()); | |
51 } | |
52 | |
53 scoped_ptr<AudioPacket> AudioEncoderSpeex::Encode( | |
54 scoped_ptr<AudioPacket> packet) { | |
55 DCHECK_EQ(AudioPacket::ENCODING_RAW, packet->encoding()); | |
56 DCHECK_EQ(1, packet->data_size()); | |
57 DCHECK_EQ(AudioPacket::BYTES_PER_SAMPLE_2, packet->bytes_per_sample()); | |
58 DCHECK_NE(AudioPacket::SAMPLING_RATE_INVALID, packet->sampling_rate()); | |
59 DCHECK_EQ(AudioPacket::CHANNELS_STEREO, packet->channels()); | |
60 | |
61 int frames_left = packet->data(0).size() / packet->bytes_per_sample() | |
62 / packet->channels(); | |
Sergey Ulanov
2012/08/21 17:32:23
nit: / goes to the previous line.
kxing
2012/08/21 18:10:20
Done.
| |
63 const int16* next_sample = | |
64 reinterpret_cast<const int16*>(packet->data(0).data()); | |
65 | |
66 // Create a new packet of encoded data. | |
67 scoped_ptr<AudioPacket> encoded_packet(new AudioPacket()); | |
68 encoded_packet->set_encoding(AudioPacket::ENCODING_SPEEX); | |
69 encoded_packet->set_sampling_rate(packet->sampling_rate()); | |
70 encoded_packet->set_bytes_per_sample(packet->bytes_per_sample()); | |
71 encoded_packet->set_channels(packet->channels()); | |
72 | |
73 while (leftover_frames_ + frames_left >= speex_frame_size_) { | |
74 int16* unencoded_buffer = NULL; | |
75 int frames_consumed = 0; | |
76 | |
77 if (leftover_frames_ > 0) { | |
78 unencoded_buffer = leftover_buffer_.get(); | |
79 frames_consumed = speex_frame_size_ - leftover_frames_; | |
80 | |
81 memcpy(leftover_buffer_.get() + leftover_frames_ * packet->channels(), | |
82 next_sample, | |
83 frames_consumed * packet->bytes_per_sample() * packet->channels()); | |
84 | |
85 leftover_frames_ = 0; | |
86 } else { | |
87 unencoded_buffer = const_cast<int16*>(next_sample); | |
88 frames_consumed = speex_frame_size_; | |
89 } | |
90 | |
91 // Transform stereo to mono. | |
92 speex_encode_stereo_int(unencoded_buffer, | |
93 speex_frame_size_, | |
94 speex_bits_.get()); | |
95 | |
96 // Encode the frame, treating all samples as integers. | |
97 speex_encode_int(speex_state_, | |
98 unencoded_buffer, | |
99 speex_bits_.get()); | |
100 | |
101 next_sample += frames_consumed * packet->channels(); | |
102 frames_left -= frames_consumed; | |
103 | |
104 std::string* new_data = encoded_packet->add_data(); | |
105 new_data->resize(speex_bits_nbytes(speex_bits_.get())); | |
106 | |
107 // Copy the encoded data from the bits structure into the buffer. | |
108 int bytes_written = speex_bits_write(speex_bits_.get(), | |
109 string_as_array(new_data), | |
110 new_data->size()); | |
111 | |
112 // Expect that the bytes are all written. | |
113 DCHECK_EQ(bytes_written, static_cast<int>(new_data->size())); | |
114 | |
115 // Reset the bits structure for this frame. | |
116 speex_bits_reset(speex_bits_.get()); | |
117 } | |
118 | |
119 // Store the leftover samples. | |
120 if (frames_left > 0) { | |
121 CHECK_LE(leftover_frames_ + frames_left, speex_frame_size_); | |
122 memcpy(leftover_buffer_.get() + leftover_frames_ * packet->channels(), | |
123 next_sample, | |
124 frames_left * packet->bytes_per_sample() * packet->channels()); | |
125 leftover_frames_ += frames_left; | |
126 } | |
127 | |
128 // Return NULL if there's nothing in the packet. | |
129 if (encoded_packet->data_size() == 0) | |
130 return scoped_ptr<AudioPacket>(); | |
131 | |
132 return encoded_packet.Pass(); | |
133 } | |
134 | |
135 } // namespace remoting | |
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