I have captured a vhs with this script under Linux
#!/bin/sh
videodevice="/dev/video0"
alsadevice="hw:2,0"
v4l2-ctl -d /dev/video0 --set-ctrl mute=0
v4l2-ctl -d /dev/video0 -i 1
v4l2-ctl -d /dev/video0 --set-standard=PAL
gst-launch-1.0 -q v4l2src device="$videodevice" do-timestamp=true norm="PAL" pixel-aspect-ratio=1 \
! video/x-raw,format=YUY2,framerate=25/1,width=720,height=576 \
! queue max-size-buffers=0 max-size-time=0 max-size-bytes=0 \
! mux. \
alsasrc device="$alsadevice" do-timestamp=true \
! audio/x-raw,format=S16LE,rate=48000,channels=2 \
! queue \
max-size-buffers=0 max-size-time=0 max-size-bytes=0 \
! mux. matroskamux name=mux \
! queue max-size-buffers=0 max-size-time=0 max-size-bytes=0 \
! filesink location=vhs.mkv
The final result is a raw avi, which I had to crop and resize to correct Aspect Ratio. The mediainfo program said is 5:4
mediainfo vhs.mkv |grep -i aspect
Display aspect ratio : 5:4
But as I know the vhs is an old technology and in their times(70-80-90) the standard was 4:3 I ask this because to determine the AR I usually do this
a)make a screenshot with mplayer
b)open with gimp, select rectangle and I read the a/r (1.7777,1.6666,1.3333) in the bottom of program
the screenshot result different and return different a/r if I set with mplayer the a/r
mplayer -vf rectangle,screenshot -aspect 5:4 vhs.mkv
mplayer -vf rectangle,screenshot -aspect 4:3 vhs.mkv
In your opinion I have to use 4/3 or 5/4?