Preview fail with youtube video.

[mac1202]

Hi when you enable the choose quality option for youtube video and select separate video and audio track like this preview doesn't work and i got this error in log :

(E)[mpv/preview/cache] Cache keeps not responding.

I got no problem when choosing video+audio muxed together like this.

[bylee20]

I don't think this is relavant with DASH format(audio/video separated ones) itself.
In fact, I don't have any problem to display preview with DASH.
Does this problem occur always all DASH formats?

Well, there's still a possibility your log says the whole point.
Normal format requires one connection(+one for preview) but DASH format requires two connections(+one for preview), so maybe your network is stuck.
Just in case, can you let me know the URL you tested?

[mac1202]

I use this video for testing https://youtube.com/watch?v=Y9b1gBTztCI but i got the same result with other video. After more testing i found that the problem occurs with DASH video in mp4 format. If i select the webm one (same resolution and fps) the preview work properly.

[bylee20]

That makes my guess that your network stuck more plausible because generally, webm/vp is better for streaming than mp4/h264, unless your internet connection is good enough.

I tested your URL and I can see preview in any format including mp4 DASH container.

[bylee20]

I have an idea.
The preview does not require high resolution, so it would be better to choose low quality source for preview.
Before applying that, I want to know which factor impacts more for performance between container and resolution.
I know webm is better than mp4 when the resolution is high from your comment.
Now I want to know this is still true for low resolution.
Can you check if the preview work for you when you select low resolution (240p or 360p) with mp4 and webm respectively?

[mac1202]

I do more testing, in fact the preview work but it take more than 10sec for the window preview appear for the first time in mp4 format and with any resolution (from 1920x1080 to 256x144). After that the preview work properly. With webm the preview window appear instantly with any resolution.

[bylee20]

Fixed.

FYI, the dialog to ask video quality removed.
Now you can configure default video quality in preference and you can change format through 'Play > Streaming Format' menu while playing.