VLC 1.0.2, wrongly reports broken AVI index

Want to help the VideoLAN project? Designers, testers, translators, please come...
This is NOT about GETTING some help.
Forum rules
Please read the forum's rules carefully before posting. This forum should not be used to post VLC usage related questions.
MSJ
New Cone
New Cone
Posts: 2
Joined: 26 Sep 2009 21:05

VLC 1.0.2, wrongly reports broken AVI index

Postby MSJ » 26 Sep 2009 21:21

AVI file plays perfectly and no problem is reported by other programs like VDUB and GSPOT.

Investigating the problem, it seems that VLC bases its "broken index" check on comparing the video header length and the index-length. Because the first calculation is more unprecise that the second it causes "the broken index" message - a bit misleading - the index is fine.

example:

video 1 (orginal)
--------------------
total frames = 41958
microsecperframe = 33367
length = 1400012586 uS, or 1400,012586 s

stream-index:
total frames = 41958
rate = 30000dec
scale = 000003E9H ()
length = 41958*1000000 * 3E9 / 30000 = 1399998600
in seconds 1399,998600

truncated 1400 in the first case and 1399 in the second case. , VLC player therefore wrongly reports "broken index"

video 2 (last video frame editted out)
---------------------------------------------
hdr:
total frames = 41957
microsecperframe = 33367
length = 1399979219 uS, or 1399,979219 s

stream-index:
total frames = 41957
rate = 30000dec
scale = 000003E9H ()
length = 41957*1000000 * 3E9 / 30000 = 1399965233,3333333333333333333333
in seconds 1399,9652333333333333333333333333

truncated 1399 in both cases

Now VLC accepts the video and its index.

A proper index-check should check whether the index matches the actual frames.

/MSJ

Jean-Baptiste Kempf
Site Administrator
Site Administrator
Posts: 37523
Joined: 22 Jul 2005 15:29
VLC version: 4.0.0-git
Operating System: Linux, Windows, Mac
Location: Cone, France
Contact:

Re: VLC 1.0.2, wrongly reports broken AVI index

Postby Jean-Baptiste Kempf » 27 Sep 2009 17:45

Interesting analysis.
Jean-Baptiste Kempf
http://www.jbkempf.com/ - http://www.jbkempf.com/blog/category/Videolan
VLC media player developer, VideoLAN President and Sites administrator
If you want an answer to your question, just be specific and precise. Don't use Private Messages.

fenrir
Blank Cone
Blank Cone
Posts: 45
Joined: 09 Mar 2004 21:45

Re: VLC 1.0.2, wrongly reports broken AVI index

Postby fenrir » 29 Sep 2009 21:48

Thanks for the analysis, it has been fixed by [a2671feb378ec308e42a0e50ce9bfc41262baf9c] in master.

MSJ
New Cone
New Cone
Posts: 2
Joined: 26 Sep 2009 21:05

Re: VLC 1.0.2, wrongly reports broken AVI index

Postby MSJ » 04 Oct 2009 07:49

great, thanks

:D


Return to “Contribute and help the VideoLAN project”

Who is online

Users browsing this forum: No registered users and 25 guests