[SOLVED] Wrong contrast using KDEnlive rendering

For the developers that use FFmpeg in Windows software.
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Bartoloni
Posts: 3
Joined: Sat Aug 19, 2017 5:34 am

[SOLVED] Wrong contrast using KDEnlive rendering

Post by Bartoloni » Sat Aug 19, 2017 5:39 am

i searched the web and finally i found that the "YUVJ to YUV" issue was adressed 6 years ago... ( https://trac.ffmpeg.org/ticket/225 )
i'm experiencing the same issue...
here an output of 2 rendering ( MPEG4 DIVX ... and WMV )

MPG4 --> properties=MPEG-4-ASP qscale=%quality aq=%audioquality'
WMV --> f=asf vcodec=wmv2 acodec=wmav2 qscale=%quality aq=%audioquality

this is the result (UP from DOWN ... ORIGINAL - DIVX - WMV)
http://www.wcn.it/compare.png
Last edited by Bartoloni on Tue Nov 07, 2017 8:58 pm, edited 1 time in total.

Bartoloni
Posts: 3
Joined: Sat Aug 19, 2017 5:34 am

Re: Wrong contrast using KDEnlive

Post by Bartoloni » Sun Nov 05, 2017 10:33 am

this is an updated thread about the issue on YUV videos:

https://forum.kde.org/viewtopic.php?f=272&t=142746

and a new image with latest FFMPEG (but this is a MELT issue or a FFMPEG issue?)
Image

Image

and these are the media informations:
Image

Bartoloni
Posts: 3
Joined: Sat Aug 19, 2017 5:34 am

Re: [SOLVED] Wrong contrast using KDEnlive rendering

Post by Bartoloni » Tue Nov 07, 2017 9:04 pm

i was very sceptical about this issue... some guys are reporting strange contrast errors... others nothing... a lot of time BUG reports are closed by an "UNCONFIRMED" ... or "INVALID"

well .. today i tried to replace the VGA CARD... (very very stupid idea right?) ... i have replaced the GT9500 with a GT610...
reopened the same project on Kdenlive... and now.. (without any YUV parameter passed to MELT) the rendering is ok.

no idea about what's happening on renderings... but the issue are the video drivers (or VGA architecture) ... this can explain why some users have issues on Android... or iOs... and developers can't see the BUG...

i hope this solve (for users) the "YUV ACCIDENT" (finally)...

P.S. now maybe is time to understand what happens on rendering (and YUV) during rendering on different VGA cards.

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