Output from webcodecs.html isn't playable

[19521178]

I've just tried to running webcodecs.html in /test folder. I found that the video element cannot run. After adding some console line, the output of encoder (Uint8Array and URL created from Array) as below:

• Uint8Array(140) [0, 0, 0, 24, 102, 116, 121, 112, 109, 112, 52, 50, 0, 0, 0, 0, 109, 112, 52, 50, 105, 115, 111, 109, 0, 0, 0, 116, 109, 111, 111, 118, 0, 0, 0, 108, 109, 118, 104, 100, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 232, 0, 0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, …]
• blob:null/87cdcb30-f33b-49dd-ac5c-880a91b8ca16

I really don't understand reason why information of a 300-frame video is so short. Is there anybody show me the way to get a playable video's URL from encoder of webcodecs.html.

I run html file on Edge Browser Version 108.0.1462.54. I've changed some code in webcodecs.html to fix bugs occupied in encoding time such as:

• In h264_write function, argument chunk doesn't have "data" attribute, so I replaced "chunk.data" by only "chunk".
• In add function of createEncoder returns, frame.destroy() is not longer a function, so I replaced "frame.destroy()" by "frame.close()".