objective-c - WebRTC:如何将 RTCVideoEncoderSettings 传递到 RTCVideoEncoder

Question

我正在开发一个 webrtc 屏幕共享应用程序。因此我正在使用objective-c webrtc 框架。

现在我在如何传递 RTCVideoEncoderSettings ( http://cocoadocs.org/docsets/GoogleWebRTC/1.1.20266/Classes/RTCVideoEncoderSettings.html ) 方面遇到问题
到编码器 (VP9)。这是我目前拥有的:

public class CustomVideoEncoderFactory : NSObject, RTCVideoEncoderFactory {

var encoder: RTCVideoEncoder?
var preferredCodec: RTCVideoCodecInfo = RTCVideoCodecInfo(name: "VP9")

public func createEncoder(_ info: RTCVideoCodecInfo) -> RTCVideoEncoder? {

    let vp9Encoder = RTCVideoEncoderVP9.vp9Encoder()!
    // How to pass the RTCVideoEncoderSettings into this encoder???
    return vp9Encoder
}

public func supportedCodecs() -> [RTCVideoCodecInfo] {
    return [RTCVideoCodecInfo(name: "VP9")]
}

}

有一个方法叫做 startEncodeWithSettings ( http://cocoadocs.org/docsets/GoogleWebRTC/1.1.20266/Protocols/RTCVideoEncoder.html )
但我不确定如何将其与我当前的代码集成。我试图子类化 ( public class CustomVideoEncoder: NSObject, RTCVideoEncoder { ... } ) 没有用。

感谢您的帮助!

Answer 1

好的，我找到了解决方案。事实证明，对于 VP9 和 VP8，缺少 Objective-c 包装。 VP9 和 Vp8 直接链接到原生实现!
因此，如果您使用的是 h264，则只能进行子类化。
要更改 VP9 和 VP8 上的设置，需要修改 C++ 代码中的设置!

自定义编码器工厂的示例:

public class CustomVideoEncoderFactory : NSObject, RTCVideoEncoderFactory {

public func createEncoder(_ info: RTCVideoCodecInfo) -> RTCVideoEncoder? {

    let encoder = super.createEncoder(info) // will create the h264 encoder
    let customEncoder = CustomVideoEncoder()
    self.encoder = customEncoder
    return encoder
}

public func supportedCodecs() -> [RTCVideoCodecInfo] {

    return [RTCVideoCodecInfo(name: kRTCVideoCodecH264Name)] }}

自定义编码器示例:

public class CustomVideoEncoder: NSObject, RTCVideoEncoder {

public var encoder: RTCVideoEncoder? // ONLY WORKS WITH h264

public func setCallback(_ callback: @escaping RTCVideoEncoderCallback) {

    return encoder!.setCallback(callback)
}

 public func startEncode(with settings: RTCVideoEncoderSettings, numberOfCores: Int32) -> Int {

     // Change settings here !
    let res = encoder!.startEncode(with: settings, numberOfCores: numberOfCores) 
}

public func release() -> Int {

    return encoder!.release()
}

 public func encode(_ frame: RTCVideoFrame, codecSpecificInfo info: RTCCodecSpecificInfo?, frameTypes: [NSNumber]) -> Int {

     return encoder!.encode(frame, codecSpecificInfo: info, frameTypes: frameTypes)
 }

public func setBitrate(_ bitrateKbit: UInt32, framerate: UInt32) -> Int32 {

    return encoder!.setBitrate(bitrateKbit, framerate: framerate)
}

public func implementationName() -> String {

    return encoder!.implementationName()
}

public func scalingSettings() -> RTCVideoEncoderQpThresholds? {

    return encoder!.scalingSettings()
}}