audio_decoder_factory.h (2119B)
1 /* 2 * Copyright (c) 2016 The WebRTC project authors. All Rights Reserved. 3 * 4 * Use of this source code is governed by a BSD-style license 5 * that can be found in the LICENSE file in the root of the source 6 * tree. An additional intellectual property rights grant can be found 7 * in the file PATENTS. All contributing project authors may 8 * be found in the AUTHORS file in the root of the source tree. 9 */ 10 11 #ifndef API_AUDIO_CODECS_AUDIO_DECODER_FACTORY_H_ 12 #define API_AUDIO_CODECS_AUDIO_DECODER_FACTORY_H_ 13 14 #include <memory> 15 #include <optional> 16 #include <vector> 17 18 #include "absl/base/nullability.h" 19 #include "api/audio_codecs/audio_codec_pair_id.h" 20 #include "api/audio_codecs/audio_decoder.h" 21 #include "api/audio_codecs/audio_format.h" 22 #include "api/environment/environment.h" 23 #include "api/ref_count.h" 24 25 namespace webrtc { 26 27 // A factory that creates AudioDecoders. 28 class AudioDecoderFactory : public RefCountInterface { 29 public: 30 virtual std::vector<AudioCodecSpec> GetSupportedDecoders() = 0; 31 32 virtual bool IsSupportedDecoder(const SdpAudioFormat& format) = 0; 33 34 // Create a new decoder instance. The `codec_pair_id` argument is used to link 35 // encoders and decoders that talk to the same remote entity: if a 36 // AudioEncoderFactory::Create() and a AudioDecoderFactory::Create() call 37 // receive non-null IDs that compare equal, the factory implementations may 38 // assume that the encoder and decoder form a pair. (The intended use case for 39 // this is to set up communication between the AudioEncoder and AudioDecoder 40 // instances, which is needed for some codecs with built-in bandwidth 41 // adaptation.) 42 // 43 // Returns null if the format isn't supported. 44 // 45 // Note: Implementations need to be robust against combinations other than 46 // one encoder, one decoder getting the same ID; such decoders must still 47 // work. 48 virtual absl_nullable std::unique_ptr<AudioDecoder> Create( 49 const Environment& env, 50 const SdpAudioFormat& format, 51 std::optional<AudioCodecPairId> codec_pair_id) = 0; 52 }; 53 54 } // namespace webrtc 55 56 #endif // API_AUDIO_CODECS_AUDIO_DECODER_FACTORY_H_