[Ffmpeg-devel] wrong aspect ratio

[Stefan Lucke]

On Donnerstag, 29. September 2005 16:02, Reinhard Amersberger wrote:
> hi,
> 
> I notice that some of my files are playes back with wrong aspect ratio.
> originally the problem has attract attention when I played back a file
> in jahshaka (mlt) which in turn use ffmpeg functionallity.
> 
> So I used ffplay directly from the command line which shows the same
> behaviour.
> 
> since ffplay_acl is also installed on my machine, I noticed that playing
> back using ffplay_acl works fine!!!
> 
> here you can take a look:
> www.groovision.de/mlt/correct aspect ratio using ffplay_acl.png
> 
> on the left side you can see ffplay_acl output and the blua area on the
> right side is the output from ffplay (video height is too low).
> 
> the file I used is located here:
> www.groovision.de/mlt/mjpeg.avi
> 
> 
> please tell me if you need more info on that topic.

I got a similar report from a vdr-softdevice user. In my case it is an
DVB recording which shows a wrong aspect ratio when played from
beginning. Seems to be detected as :

Oct  1 10:01:19 jarada vdr[2374]: thread started (pid=2374, tid=245770)
Oct  1 10:01:19 jarada vdr[2374]: [VideoOut]: aspect changed (0 -> 0 ; 1,333333 -> 5,113636)
Oct  1 10:01:19 jarada vdr[2374]: [VideoOut]: PAN/SCAN info present ([0] 5632 - 17280, 45 11)
Oct  1 10:01:19 jarada vdr[2374]: [VideoOut]: PAN/SCAN  position  0 (0 0)
Oct  1 10:01:19 jarada vdr[2374]: [VideoOut]: PAN/SCAN  position  1 (0 0)
Oct  1 10:01:19 jarada vdr[2374]: [VideoOut]: PAN/SCAN  position  2 (0 0)
Oct  1 10:01:19 jarada vdr[2374]: [VideoOut]: 720x576 [0,0 720x576] -> 1024x576 [0,188 1024x200]
Oct  1 10:01:19 jarada vdr[2372]: setting audio track to 1 (0)
Oct  1 10:01:19 jarada vdr[2375]: thread started (pid=2375, tid=262155)
Oct  1 10:01:19 jarada vdr[2374]: [VideoOut]: resolution changed: W(720 -> 704); H(576 ->576)
Oct  1 10:01:19 jarada vdr[2374]: [VideoOut]: aspect changed (0 -> 8 ; 5,113636 -> 5,000000)
Oct  1 10:01:19 jarada vdr[2374]: [VideoOut]: PAN/SCAN info present ([0] 5632 - 17280, 45 11)
Oct  1 10:01:19 jarada vdr[2374]: [VideoOut]: PAN/SCAN  position  0 (0 0)
Oct  1 10:01:19 jarada vdr[2374]: [VideoOut]: PAN/SCAN  position  1 (0 0)
Oct  1 10:01:19 jarada vdr[2374]: [VideoOut]: PAN/SCAN  position  2 (0 0)
Oct  1 10:01:19 jarada vdr[2374]: [VideoOut]: 704x576 [0,0 704x576] -> 1024x576 [0,185 1024x205]

Interestingly when moving cut marks inside that short clip, correct
A/Rs are reported (starts in 4:3 and continues in 16:9 later).
The first I-frame in my example seems to be at time mark 00:00:00.06.
When moving cut marks, a new decoder is started.

Oct  1 10:07:28 jarada vdr[2377]: [VideoOut]: aspect changed (8 -> 8 ; 5,000000 -> 1,333333)
Oct  1 10:07:28 jarada vdr[2377]: [VideoOut]: 704x576 [0,0 704x576] -> 1024x576 [128,0 768x576]

-- 
Stefan Lucke