Hello.
Investigating Kdenlive bug http://kdenlive.org/mantis/view.php?id=2468, I
discovered that several filters break the playlist position when attached to a
track. For example, when trying to play frames 50 to 100:
melt broken.mlt in=50 out=100
It will play the first frame (50), then rewind to the first frame and play
frames 0-49.
This can be reproduced with melt. For my example, I used the pango producer
but the bug can be reproduced using any producer on the track.
1 - Working case:
melt -track -attach sepia -producer pango text="Broken" in=0 out=50 pango
text="OK" in=0 out=50 -consumer xml:test.mlt
This will create a test.mlt playlist with text "Broken" in the first 50 frames
and "Ok" in the frames 50-100.
Now try:
melt test.mlt in=60 out=70
It will display frames 60-70 (showing "Ok"), good.
2 - Same playlist with the dust effect reveals the bug:
melt -track -attach dust -producer pango text="Broken" in=0 out=50 pango
text="OK" in=0 out=50 -consumer xml:test2.mlt
melt test2.mlt in=60 out=70
It will display "Ok" for the first frame, then "Broken", because the playlist
position was somehow reset to 0 by the filter!
This bug can be reproduced with effects dust, lines, watermark and volume and
maybe others.
Looking at the dust filter (in oldfilm/filter_dust.c), I noticed that the bug
can be solved by commenting out lines 143 to 145 that are:
mlt_properties_set_data ( properties , savename , savepic , sizeof(uint8_t*) ,
mlt_pool_release, NULL );
mlt_properties_set_data (
properties , savename1 , savealpha ,
sizeof(uint8_t*) , mlt_pool_release, NULL );
mlt_properties_set_int (
properties , cachedy , luma_height );
Uncommenting any of them makes the bug re-appear. So my guess is that somehow,
when a filter is attached to a track, trying to change one of its property
corrupts the track...
Hope it helps solving the problem
regards
jb
------------------------------------------------------------------------------
Ridiculously easy VDI. With Citrix VDI-in-a-Box, you don't need a complex
infrastructure or vast IT resources to deliver seamless, secure access to
virtual desktops. With this all-in-one solution, easily deploy virtual
desktops for less than the cost of PCs and save 60% on VDI infrastructure
costs. Try it free! http://p.sf.net/sfu/Citrix-VDIinabox
_______________________________________________
Mlt-devel mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/mlt-devel
