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/*
* Copyright (c) 2004 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 MEDIA_BASE_CODEC_H_
#define MEDIA_BASE_CODEC_H_
#include <map>
#include <set>
#include <string>
#include <vector>
#include "absl/container/inlined_vector.h"
#include "absl/strings/string_view.h"
#include "absl/types/optional.h"
#include "api/field_trials_view.h"
#include "api/rtp_parameters.h"
#include "api/video_codecs/sdp_video_format.h"
#include "media/base/media_constants.h"
#include "rtc_base/system/rtc_export.h"
namespace cricket {
typedef std::map<std::string, std::string> CodecParameterMap;
class FeedbackParam {
public:
FeedbackParam() = default;
FeedbackParam(absl::string_view id, const std::string& param)
: id_(id), param_(param) {}
explicit FeedbackParam(absl::string_view id)
: id_(id), param_(kParamValueEmpty) {}
bool operator==(const FeedbackParam& other) const;
const std::string& id() const { return id_; }
const std::string& param() const { return param_; }
private:
std::string id_; // e.g. "nack", "ccm"
std::string param_; // e.g. "", "rpsi", "fir"
};
class FeedbackParams {
public:
FeedbackParams();
~FeedbackParams();
bool operator==(const FeedbackParams& other) const;
bool Has(const FeedbackParam& param) const;
void Add(const FeedbackParam& param);
void Intersect(const FeedbackParams& from);
const std::vector<FeedbackParam>& params() const { return params_; }
private:
bool HasDuplicateEntries() const;
std::vector<FeedbackParam> params_;
};
struct RTC_EXPORT Codec {
int id;
std::string name;
int clockrate;
// Non key-value parameters such as the telephone-event "0‐15" are
// represented using an empty string as key, i.e. {"": "0-15"}.
CodecParameterMap params;
FeedbackParams feedback_params;
virtual ~Codec();
// Indicates if this codec is compatible with the specified codec.
bool Matches(const Codec& codec,
const webrtc::FieldTrialsView* field_trials = nullptr) const;
bool MatchesCapability(const webrtc::RtpCodecCapability& capability) const;
// Find the parameter for `name` and write the value to `out`.
bool GetParam(const std::string& name, std::string* out) const;
bool GetParam(const std::string& name, int* out) const;
void SetParam(const std::string& name, const std::string& value);
void SetParam(const std::string& name, int value);
// It is safe to input a non-existent parameter.
// Returns true if the parameter existed, false if it did not exist.
bool RemoveParam(const std::string& name);
bool HasFeedbackParam(const FeedbackParam& param) const;
void AddFeedbackParam(const FeedbackParam& param);
// Filter `this` feedbacks params such that only those shared by both `this`
// and `other` are kept.
void IntersectFeedbackParams(const Codec& other);
virtual webrtc::RtpCodecParameters ToCodecParameters() const;
Codec& operator=(const Codec& c);
Codec& operator=(Codec&& c);
bool operator==(const Codec& c) const;
bool operator!=(const Codec& c) const { return !(*this == c); }
protected:
// A Codec can't be created without a subclass.
// Creates a codec with the given parameters.
Codec(int id, const std::string& name, int clockrate);
// Creates an empty codec.
Codec();
Codec(const Codec& c);
Codec(Codec&& c);
};
struct AudioCodec : public Codec {
int bitrate;
size_t channels;
// Creates a codec with the given parameters.
AudioCodec(int id,
const std::string& name,
int clockrate,
int bitrate,
size_t channels);
// Creates an empty codec.
AudioCodec();
AudioCodec(const AudioCodec& c);
AudioCodec(AudioCodec&& c);
~AudioCodec() override = default;
// Indicates if this codec is compatible with the specified codec.
bool Matches(const AudioCodec& codec,
const webrtc::FieldTrialsView* field_trials = nullptr) const;
std::string ToString() const;
webrtc::RtpCodecParameters ToCodecParameters() const override;
AudioCodec& operator=(const AudioCodec& c);
AudioCodec& operator=(AudioCodec&& c);
bool operator==(const AudioCodec& c) const;
bool operator!=(const AudioCodec& c) const { return !(*this == c); }
};
struct RTC_EXPORT VideoCodec : public Codec {
absl::optional<std::string> packetization;
absl::InlinedVector<webrtc::ScalabilityMode, webrtc::kScalabilityModeCount>
scalability_modes;
// Creates a codec with the given parameters.
VideoCodec(int id, const std::string& name);
// Creates a codec with the given name and empty id.
explicit VideoCodec(const std::string& name);
// Creates an empty codec.
VideoCodec();
VideoCodec(const VideoCodec& c);
explicit VideoCodec(const webrtc::SdpVideoFormat& c);
VideoCodec(VideoCodec&& c);
~VideoCodec() override = default;
// Indicates if this video codec is the same as the other video codec, e.g. if
// they are both VP8 or VP9, or if they are both H264 with the same H264
// profile. H264 levels however are not compared.
bool Matches(const VideoCodec& codec,
const webrtc::FieldTrialsView* field_trials = nullptr) const;
std::string ToString() const;
webrtc::RtpCodecParameters ToCodecParameters() const override;
VideoCodec& operator=(const VideoCodec& c);
VideoCodec& operator=(VideoCodec&& c);
bool operator==(const VideoCodec& c) const;
bool operator!=(const VideoCodec& c) const { return !(*this == c); }
// Return packetization which both `local_codec` and `remote_codec` support.
static absl::optional<std::string> IntersectPacketization(
const VideoCodec& local_codec,
const VideoCodec& remote_codec);
static VideoCodec CreateRtxCodec(int rtx_payload_type,
int associated_payload_type);
enum CodecType {
CODEC_VIDEO,
CODEC_RED,
CODEC_ULPFEC,
CODEC_FLEXFEC,
CODEC_RTX,
};
CodecType GetCodecType() const;
// Validates a VideoCodec's payload type, dimensions and bitrates etc. If they
// don't make sense (such as max < min bitrate), and error is logged and
// ValidateCodecFormat returns false.
bool ValidateCodecFormat() const;
private:
void SetDefaultParameters();
};
// Get the codec setting associated with `payload_type`. If there
// is no codec associated with that payload type it returns nullptr.
template <class Codec>
const Codec* FindCodecById(const std::vector<Codec>& codecs, int payload_type) {
for (const auto& codec : codecs) {
if (codec.id == payload_type)
return &codec;
}
return nullptr;
}
bool HasLntf(const Codec& codec);
bool HasNack(const Codec& codec);
bool HasRemb(const Codec& codec);
bool HasRrtr(const Codec& codec);
bool HasTransportCc(const Codec& codec);
// Returns the first codec in `supported_codecs` that matches `codec`, or
// nullptr if no codec matches.
const VideoCodec* FindMatchingCodec(
const std::vector<VideoCodec>& supported_codecs,
const VideoCodec& codec);
RTC_EXPORT void AddH264ConstrainedBaselineProfileToSupportedFormats(
std::vector<webrtc::SdpVideoFormat>* supported_formats);
} // namespace cricket
#endif // MEDIA_BASE_CODEC_H_
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