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Diffstat (limited to 'third_party/libwebrtc/api/audio_codecs/opus/audio_decoder_multi_channel_opus_config.h')
-rw-r--r-- | third_party/libwebrtc/api/audio_codecs/opus/audio_decoder_multi_channel_opus_config.h | 66 |
1 files changed, 66 insertions, 0 deletions
diff --git a/third_party/libwebrtc/api/audio_codecs/opus/audio_decoder_multi_channel_opus_config.h b/third_party/libwebrtc/api/audio_codecs/opus/audio_decoder_multi_channel_opus_config.h new file mode 100644 index 0000000000..f97c5c3193 --- /dev/null +++ b/third_party/libwebrtc/api/audio_codecs/opus/audio_decoder_multi_channel_opus_config.h @@ -0,0 +1,66 @@ +/* + * Copyright (c) 2019 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. + */ + +#ifndef API_AUDIO_CODECS_OPUS_AUDIO_DECODER_MULTI_CHANNEL_OPUS_CONFIG_H_ +#define API_AUDIO_CODECS_OPUS_AUDIO_DECODER_MULTI_CHANNEL_OPUS_CONFIG_H_ + +#include <vector> + +#include "api/audio_codecs/audio_decoder.h" + +namespace webrtc { +struct AudioDecoderMultiChannelOpusConfig { + // The number of channels that the decoder will output. + int num_channels; + + // Number of mono or stereo encoded Opus streams. + int num_streams; + + // Number of channel pairs coupled together, see RFC 7845 section + // 5.1.1. Has to be less than the number of streams. + int coupled_streams; + + // Channel mapping table, defines the mapping from encoded streams to output + // channels. See RFC 7845 section 5.1.1. + std::vector<unsigned char> channel_mapping; + + bool IsOk() const { + if (num_channels < 1 || num_channels > AudioDecoder::kMaxNumberOfChannels || + num_streams < 0 || coupled_streams < 0) { + return false; + } + if (num_streams < coupled_streams) { + return false; + } + if (channel_mapping.size() != static_cast<size_t>(num_channels)) { + return false; + } + + // Every mono stream codes one channel, every coupled stream codes two. This + // is the total coded channel count: + const int max_coded_channel = num_streams + coupled_streams; + for (const auto& x : channel_mapping) { + // Coded channels >= max_coded_channel don't exist. Except for 255, which + // tells Opus to put silence in output channel x. + if (x >= max_coded_channel && x != 255) { + return false; + } + } + + if (num_channels > 255 || max_coded_channel >= 255) { + return false; + } + return true; + } +}; + +} // namespace webrtc + +#endif // API_AUDIO_CODECS_OPUS_AUDIO_DECODER_MULTI_CHANNEL_OPUS_CONFIG_H_ |