On 22.07.2010 22:57, Dan Dennedy wrote: > On Thu, Jul 22, 2010 at 12:09 PM, Simon Eugster<simon...@gmail.com> wrote: >> 2010/7/21 Dan Dennedy<d...@dennedy.org>: >>> On Wed, Jul 21, 2010 at 12:16 PM, Simon Eugster<simon...@gmail.com> wrote: >>>> 2010/7/21 Dan Dennedy<d...@dennedy.org>: >>>>> On Wed, Jul 21, 2010 at 10:51 AM, Simon Eugster<simon...@gmail.com> >>>>> wrote: >>>>>> Dear friends, >>>>>> >>>>>> I've just added an RGB parade to kdenlive. While testing I found >>>>>> something interesting: Although I'm painting on a rect with height 256 >>>>>> (as atm we're dealing with 8 bits per channel only) and scaling the >>>>>> parade afterwards to the target height, I got kind of scanlines. >>>>>> Compare these two images: >>>>>> http://granjow.net/uploads/kdenlive/kdenlive-mlt-rgbparade-noeffect.png >>>>>> http://granjow.net/uploads/kdenlive/kdenlive-mlt-rgbparade-witheffect.png >>>>>> With the MLT effect there are scanlines, without it there are none. >>>>>> >>>>>> This is quite interesting, as this visualizes how color information >>>>>> gets lost when converting between different color spaces (according to >>>>>> [1], MLT is using YUV422, the input image is RGB). >>>>> >>>>> It does not operate exclusively in YUV422. The color/image-format >>>>> conversion implementation depends on your build and your version of >>>>> libswscale (>= 0.7.2) whether MLT uses libswscale or inbuilt routines. >>>>> Maybe the problem is in the composite transition. >>>> >>>> libswscale is at 0..6 here in debian sid. >>> >>> I do not believe that is correct. Maybe you are looking at a package >>> version. What does 'ffmpeg -version' show as the libswscale version? >> >> Something different. >> libswscale 0.11. 0 / 0.11. 0 >> > > So your MLT should be using libswscale for colorspace and image format > conversion as well as scaling. This is generally a good thing.
By the way, what happens when rendering to a file? If the input is in RGB, and no filters/effects operating in YUV only are put on top of it, will it remain RGB until being written to the output file? Simon ------------------------------------------------------------------------------ The Palm PDK Hot Apps Program offers developers who use the Plug-In Development Kit to bring their C/C++ apps to Palm for a share of $1 Million in cash or HP Products. Visit us here for more details: http://p.sf.net/sfu/dev2dev-palm _______________________________________________ Kdenlive-devel mailing list Kdenlive-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/kdenlive-devel
