<p>I have tested a 4:3 vhs, and using 5:4 a/r making screenshot report bad final a/r(1:22)</p>
<pre><code>mplayer -aspect 5:4 -vf screenshot
</code></pre>
<p>using 4:3 a/r report in screenshot the correct ar(1:31:1)</p>
<pre><code>mplayer -aspect 4:3 -vf screenshot
</code></pre>
<p>So I think the correct answer is 4:3.</p>

CC BY-SA 4.0
2021-02-26T07:35:28.323Z
PAL and NTSC both use non-square pixels, so the physical image width / physical image height ≠ number of pixels wide/ number of pixels high.  https://en.wikipedia.org/wiki/Pixel_aspect_ratio
Jason Conrad
CC BY-SA 4.0
2021-02-26T02:42:09.900Z
2021-02-26T02:42:09.900Z
elbarna
<p>I have captured a vhs with this script under Linux</p>
<pre><code>#!/bin/sh

videodevice=&quot;/dev/video0&quot;
alsadevice=&quot;hw:2,0&quot;

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=&quot;$videodevice&quot; do-timestamp=true norm=&quot;PAL&quot; pixel-aspect-ratio=1 \
    ! video/x-raw,format=YUY2,framerate=25/1,width=720,height=576 \
    ! queue max-size-buffers=0 max-size-time=0 max-size-bytes=0 \
    ! mux. \
  alsasrc device=&quot;$alsadevice&quot; 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
</code></pre>
<p>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</p>
<pre><code>mediainfo vhs.mkv |grep -i aspect
Display aspect ratio                     : 5:4
</code></pre>
<p>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</p>
<pre><code>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
</code></pre>
<p>the screenshot result different and return different a/r if I set with mplayer the a/r</p>
<pre><code>mplayer -vf rectangle,screenshot -aspect 5:4 vhs.mkv
mplayer -vf rectangle,screenshot -aspect 4:3 vhs.mkv
</code></pre>
<p>In your opinion I have to use 4/3 or 5/4?</p>

<vhs>
VHS and capture: what is the real aspect ratio?
elbarna
# VHS and capture: what is the real aspect ratio?

(Asked by: username_0 on 2021-02-25)

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?

**Tags:** vhs


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## 1 answers

### Answer by username_0 on 2021-02-26. Score: 0 | Accepted answer

I have tested a 4:3 vhs, and using 5:4 a/r making screenshot report bad final a/r(1:22)
mplayer -aspect 5:4 -vf screenshot

using 4:3 a/r report in screenshot the correct ar(1:31:1)
mplayer -aspect 4:3 -vf screenshot

So I think the correct answer is 4:3.

> **Comments:**
> **username_1**: PAL and NTSC both use non-square pixels, so the physical image width / physical image height ≠ number of pixels wide/ number of pixels high.  https://en.wikipedia.org/wiki/Pixel_aspect_ratio  

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