diff options
Diffstat (limited to 'webrtc/modules/audio_coding/codecs/g722/audio_encoder_g722.cc')
-rw-r--r-- | webrtc/modules/audio_coding/codecs/g722/audio_encoder_g722.cc | 164 |
1 files changed, 164 insertions, 0 deletions
diff --git a/webrtc/modules/audio_coding/codecs/g722/audio_encoder_g722.cc b/webrtc/modules/audio_coding/codecs/g722/audio_encoder_g722.cc new file mode 100644 index 0000000000..43b097fa0e --- /dev/null +++ b/webrtc/modules/audio_coding/codecs/g722/audio_encoder_g722.cc @@ -0,0 +1,164 @@ +/* + * Copyright (c) 2014 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 "webrtc/modules/audio_coding/codecs/g722/include/audio_encoder_g722.h" + +#include <limits> +#include "webrtc/base/checks.h" +#include "webrtc/common_types.h" +#include "webrtc/modules/audio_coding/codecs/g722/include/g722_interface.h" + +namespace webrtc { + +namespace { + +const size_t kSampleRateHz = 16000; + +AudioEncoderG722::Config CreateConfig(const CodecInst& codec_inst) { + AudioEncoderG722::Config config; + config.num_channels = codec_inst.channels; + config.frame_size_ms = codec_inst.pacsize / 16; + config.payload_type = codec_inst.pltype; + return config; +} + +} // namespace + +bool AudioEncoderG722::Config::IsOk() const { + return (frame_size_ms > 0) && (frame_size_ms % 10 == 0) && + (num_channels >= 1); +} + +AudioEncoderG722::AudioEncoderG722(const Config& config) + : num_channels_(config.num_channels), + payload_type_(config.payload_type), + num_10ms_frames_per_packet_( + static_cast<size_t>(config.frame_size_ms / 10)), + num_10ms_frames_buffered_(0), + first_timestamp_in_buffer_(0), + encoders_(new EncoderState[num_channels_]), + interleave_buffer_(2 * num_channels_) { + RTC_CHECK(config.IsOk()); + const size_t samples_per_channel = + kSampleRateHz / 100 * num_10ms_frames_per_packet_; + for (int i = 0; i < num_channels_; ++i) { + encoders_[i].speech_buffer.reset(new int16_t[samples_per_channel]); + encoders_[i].encoded_buffer.SetSize(samples_per_channel / 2); + } + Reset(); +} + +AudioEncoderG722::AudioEncoderG722(const CodecInst& codec_inst) + : AudioEncoderG722(CreateConfig(codec_inst)) {} + +AudioEncoderG722::~AudioEncoderG722() = default; + +size_t AudioEncoderG722::MaxEncodedBytes() const { + return SamplesPerChannel() / 2 * num_channels_; +} + +int AudioEncoderG722::SampleRateHz() const { + return kSampleRateHz; +} + +int AudioEncoderG722::NumChannels() const { + return num_channels_; +} + +int AudioEncoderG722::RtpTimestampRateHz() const { + // The RTP timestamp rate for G.722 is 8000 Hz, even though it is a 16 kHz + // codec. + return kSampleRateHz / 2; +} + +size_t AudioEncoderG722::Num10MsFramesInNextPacket() const { + return num_10ms_frames_per_packet_; +} + +size_t AudioEncoderG722::Max10MsFramesInAPacket() const { + return num_10ms_frames_per_packet_; +} + +int AudioEncoderG722::GetTargetBitrate() const { + // 4 bits/sample, 16000 samples/s/channel. + return 64000 * NumChannels(); +} + +AudioEncoder::EncodedInfo AudioEncoderG722::EncodeInternal( + uint32_t rtp_timestamp, + const int16_t* audio, + size_t max_encoded_bytes, + uint8_t* encoded) { + RTC_CHECK_GE(max_encoded_bytes, MaxEncodedBytes()); + + if (num_10ms_frames_buffered_ == 0) + first_timestamp_in_buffer_ = rtp_timestamp; + + // Deinterleave samples and save them in each channel's buffer. + const size_t start = kSampleRateHz / 100 * num_10ms_frames_buffered_; + for (size_t i = 0; i < kSampleRateHz / 100; ++i) + for (int j = 0; j < num_channels_; ++j) + encoders_[j].speech_buffer[start + i] = audio[i * num_channels_ + j]; + + // If we don't yet have enough samples for a packet, we're done for now. + if (++num_10ms_frames_buffered_ < num_10ms_frames_per_packet_) { + return EncodedInfo(); + } + + // Encode each channel separately. + RTC_CHECK_EQ(num_10ms_frames_buffered_, num_10ms_frames_per_packet_); + num_10ms_frames_buffered_ = 0; + const size_t samples_per_channel = SamplesPerChannel(); + for (int i = 0; i < num_channels_; ++i) { + const size_t encoded = WebRtcG722_Encode( + encoders_[i].encoder, encoders_[i].speech_buffer.get(), + samples_per_channel, encoders_[i].encoded_buffer.data()); + RTC_CHECK_EQ(encoded, samples_per_channel / 2); + } + + // Interleave the encoded bytes of the different channels. Each separate + // channel and the interleaved stream encodes two samples per byte, most + // significant half first. + for (size_t i = 0; i < samples_per_channel / 2; ++i) { + for (int j = 0; j < num_channels_; ++j) { + uint8_t two_samples = encoders_[j].encoded_buffer.data()[i]; + interleave_buffer_.data()[j] = two_samples >> 4; + interleave_buffer_.data()[num_channels_ + j] = two_samples & 0xf; + } + for (int j = 0; j < num_channels_; ++j) + encoded[i * num_channels_ + j] = interleave_buffer_.data()[2 * j] << 4 | + interleave_buffer_.data()[2 * j + 1]; + } + EncodedInfo info; + info.encoded_bytes = samples_per_channel / 2 * num_channels_; + info.encoded_timestamp = first_timestamp_in_buffer_; + info.payload_type = payload_type_; + return info; +} + +void AudioEncoderG722::Reset() { + num_10ms_frames_buffered_ = 0; + for (int i = 0; i < num_channels_; ++i) + RTC_CHECK_EQ(0, WebRtcG722_EncoderInit(encoders_[i].encoder)); +} + +AudioEncoderG722::EncoderState::EncoderState() { + RTC_CHECK_EQ(0, WebRtcG722_CreateEncoder(&encoder)); +} + +AudioEncoderG722::EncoderState::~EncoderState() { + RTC_CHECK_EQ(0, WebRtcG722_FreeEncoder(encoder)); +} + +size_t AudioEncoderG722::SamplesPerChannel() const { + return kSampleRateHz / 100 * num_10ms_frames_per_packet_; +} + +} // namespace webrtc |