Arch Linux

Modeler

Member

From: United Kingdom

Registered: 2011-07-28

Posts: 70

Video4Linux / FFMPEG Simultaneous Play / Record?

Hi,

I'm using FFMPEG to capture from my WebCam on /dev/video0 and it works great, but the problem is I can't monitor what's being recorded. ffplay can't attach to /dev/video0 because it's in use, so just wondered if anyone knew an easy way around this?

I know VLC can stream and capture from V4L devices at the same time, but there is a noticeable lag. Ideally I'd like to record a piece to camera for a YouTube video.

Thanks.

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Wirth's law: "Software is getting slower more rapidly than hardware becomes faster"

x33a

Forum Fellow

Registered: 2009-08-15

Posts: 4,587

Re: Video4Linux / FFMPEG Simultaneous Play / Record?

Can't you simply play the file that the recording is being saved on? I guess, it won't be realtime, but it should be doable with mpv or such.

DrZaius

Member

Registered: 2008-01-02

Posts: 193

Re: Video4Linux / FFMPEG Simultaneous Play / Record?

Use the tee muxer:

ffmpeg -f v4l2 -i /dev/video0 -map 0 -c:v libx264 -f tee "output.mkv|[f=nut]pipe:" | ffplay pipe:

Last edited by DrZaius (2017-04-27 21:33:13)