RTCCVPixelBuffer doesn't work with 420YpCbCr8PlanarFullRange for VP8

[na...@cape.com]

Hi,

I'm developing an iPad app and having a problem using VP8 for three-plane YCbCr stream.

Basically, what I'm doing is to generate CVPixelBuffer and feed it via the module below.

class MyVideoCapturer: RTCVideoCapturer {

    func feed(pixelBuffer: CVPixelBuffer) {

        let rtcPixelBuffer = RTCCVPixelBuffer(pixelBuffer: pixelBuffer)

        let ts = llround(CACurrentMediaTime() * Double(NSEC_PER_SEC))

        let videoFrame = RTCVideoFrame(buffer: rtcPixelBuffer, rotation: ._0, timeStampNs: ts)

        delegate?.capturer(self, didCapture: videoFrame)

    }

}

This works perfectly without any problem if I use "H264" codec, but if I use "VP8", this doesn't seem to work

(Chrome - 66.0.3359.170 (Official Build) (64-bit) shows solid grey box) when the format of pixelBuffer is

kCVPixelFormatType_420YpCbCr8PlanarFullRange.

Interestingly, when it's kCVPixelFormatType_420YpCbCr8BiPlanarFullRange, it works like a charm.

chrome://webrtc-internals/ doesn't show anything strange.

Is this a known issue or am I missing something?

P.S. I'm terribly sorry if I happened to post this twice. My first post seems lost forever, but maybe just taking time?