82 lines
2.5 KiB
C++
82 lines
2.5 KiB
C++
|
/*
|
||
|
|
* Copyright (c) 2017 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 "api/audio_codecs/ilbc/audio_encoder_ilbc.h"
|
||
|
|
|
||
|
|
#include <memory>
|
||
|
|
#include <vector>
|
||
|
|
|
||
|
|
#include "absl/strings/match.h"
|
||
|
|
#include "modules/audio_coding/codecs/ilbc/audio_encoder_ilbc.h"
|
||
|
|
#include "rtc_base/numerics/safe_conversions.h"
|
||
|
|
#include "rtc_base/numerics/safe_minmax.h"
|
||
|
|
#include "rtc_base/string_to_number.h"
|
||
|
|
|
||
|
|
namespace webrtc {
|
||
|
|
namespace {
|
||
|
|
int GetIlbcBitrate(int ptime) {
|
||
|
|
switch (ptime) {
|
||
|
|
case 20:
|
||
|
|
case 40:
|
||
|
|
// 38 bytes per frame of 20 ms => 15200 bits/s.
|
||
|
|
return 15200;
|
||
|
|
case 30:
|
||
|
|
case 60:
|
||
|
|
// 50 bytes per frame of 30 ms => (approx) 13333 bits/s.
|
||
|
|
return 13333;
|
||
|
|
default:
|
||
|
|
FATAL();
|
||
|
|
}
|
||
|
|
}
|
||
|
|
} // namespace
|
||
|
|
|
||
|
|
absl::optional<AudioEncoderIlbcConfig> AudioEncoderIlbc::SdpToConfig(
|
||
|
|
const SdpAudioFormat& format) {
|
||
|
|
if (!absl::EqualsIgnoreCase(format.name.c_str(), "ILBC") ||
|
||
|
|
format.clockrate_hz != 8000 || format.num_channels != 1) {
|
||
|
|
return absl::nullopt;
|
||
|
|
}
|
||
|
|
|
||
|
|
AudioEncoderIlbcConfig config;
|
||
|
|
auto ptime_iter = format.parameters.find("ptime");
|
||
|
|
if (ptime_iter != format.parameters.end()) {
|
||
|
|
auto ptime = rtc::StringToNumber<int>(ptime_iter->second);
|
||
|
|
if (ptime && *ptime > 0) {
|
||
|
|
const int whole_packets = *ptime / 10;
|
||
|
|
config.frame_size_ms = rtc::SafeClamp<int>(whole_packets * 10, 20, 60);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
return config.IsOk() ? absl::optional<AudioEncoderIlbcConfig>(config)
|
||
|
|
: absl::nullopt;
|
||
|
|
}
|
||
|
|
|
||
|
|
void AudioEncoderIlbc::AppendSupportedEncoders(
|
||
|
|
std::vector<AudioCodecSpec>* specs) {
|
||
|
|
const SdpAudioFormat fmt = {"ILBC", 8000, 1};
|
||
|
|
const AudioCodecInfo info = QueryAudioEncoder(*SdpToConfig(fmt));
|
||
|
|
specs->push_back({fmt, info});
|
||
|
|
}
|
||
|
|
|
||
|
|
AudioCodecInfo AudioEncoderIlbc::QueryAudioEncoder(
|
||
|
|
const AudioEncoderIlbcConfig& config) {
|
||
|
|
RTC_DCHECK(config.IsOk());
|
||
|
|
return {8000, 1, GetIlbcBitrate(config.frame_size_ms)};
|
||
|
|
}
|
||
|
|
|
||
|
|
std::unique_ptr<AudioEncoder> AudioEncoderIlbc::MakeAudioEncoder(
|
||
|
|
const AudioEncoderIlbcConfig& config,
|
||
|
|
int payload_type,
|
||
|
|
absl::optional<AudioCodecPairId> /*codec_pair_id*/) {
|
||
|
|
RTC_DCHECK(config.IsOk());
|
||
|
|
return std::make_unique<AudioEncoderIlbcImpl>(config, payload_type);
|
||
|
|
}
|
||
|
|
|
||
|
|
} // namespace webrtc
|