[rtp-to-webrtc v4 example] - use H264 instead of VP8

[Ryan-ZL-Lin]

Hi, I'm following this doc to test out the example, and I could use gstreamer with VP8 to see the video on fiddle web page successfully.

Now, I want to switch to H264 instead of VP8.
I'm using
ffmpeg -re -f lavfi -i testsrc=size=640x480:rate=30 -pix_fmt yuv420p -c:v libx264 -g 10 -preset ultrafast -tune zerolatency -f rtp 'rtp://127.0.0.1:5004?pkt_size=1200'as the test video source.

I changed this line since it's the only occurrence that I can find in https://github.com/pion/webrtc/blob/master/examples/rtp-to-webrtc/main.go

// Create a video track
	videoTrack, err := webrtc.NewTrackLocalStaticRTP(
		webrtc.RTPCodecCapability{MimeType: webrtc.MimeTypeVP8}, "video", "pion",
	)

to

// Create a video track
	videoTrack, err := webrtc.NewTrackLocalStaticRTP(
		webrtc.RTPCodecCapability{MimeType: webrtc.MimeTypeH264}, "video", "pion",
	)

However, I cannot see the video stream on fiddle web site anymore and the vide player keeps loading, although I can see log Connection State has changed connected printed out.

Is there anything I missed out here?