Re: [Mlt-devel] what renders svg?

[Carl K. <ca...@pe...>]

On Wed, Sep 23, 2009 at 12:08 PM, Dan Dennedy <da...@de...> wrote:
> On Wed, Sep 23, 2009 at 9:44 AM, Carl Karsten <ca...@pe...> wrote:
>> I am adding a title slide svg made with inkscape.  it has a few .png
>> images, they are in the same dir as the .svg.
>>
>> 1. When I render it in melt, it seems that I need to cd into the
>> directory with the svg/images, otherwise the images don't show up.
>
> The images references in your document are relative, and they appear
> to not resolve properly. They should be relative to the SVG document.
> Did you move any of the svg or png files? If they are properly
> relative to the SVG document, then there might be some oddness with
> the SVG processor based on the current working directory of the host
> application. You could edit the SVG XML to add paths and make them
> absolute.

flow problem/solution makes this a non issue, so just fyi:

Doing my inkscape work on my desktop, all files in
/home/carl/dev/py/vid/djcon/  then move all of them to another box:
juser@dhcp232:~/vid for that has mlt trunk.

insscape stores both:

    <image       id="image2842"
       y="374.63049"        x="330.67047"
       height="41.901447"        width="53.049335"
       sodipodi:absref="/home/carl/dev/py/vid/djcon/pscLogo.png"
       xlink:href="pscLogo.png"
       transform="matrix(0.9999165,-1.2920749e-2,7.1658324e-3,0.9999743,0,0)" />

This doesn't find the images:
juser@dhcp232:~/a$ rsvg ~/vid/djc09b.svg x.png

I'll file a bug report against librsvg.

>
>> 2. I am using  some text flow elements, which also show up as black
>> boxes, not my text; in #inkscape: "Isn't text flow SVG 1.2?"   so I am
>> guessing whatever mlt is using doesn't support it.
>
> MLT first tries to use gdk-pixbuf, which uses a loader provided by
> librsvg, and then tries Qt QImage if gdk-pixbuf fails. 'melt some.svg
> -consumer xml' will tell you which is being used. You can test
> gdk-pixbuf using the 'eog' tool.

No 'flowRoot' in
http://git.gnome.org/cgit/librsvg/tree/rsvg-base.c
so no chance of this working.

This works:
inkscape djc09b.svg --export-png x.png

>
>> 3. It is changing the aspect ratio.
>> carl@gw42:~/a$ identify djc09b.svg
>> djc09b.svg SVG 720x480 720x480+0+0 16-bit DirectClass 3.51kb 1.000u 0:02
>> + melt -verbose -profile dv_ntsc /home/juser/vga2usb/mlt/x.mlt
>> -consumer avformat:/home/juser/a/x.ogg acodec=libvorbis ab=128k
>> ar=44100 vcodec=libtheora minrate=0 b=600k
>
> No, you are using an incorrect display aspect ratio in your SVG. MLT
> profile dv_ntsc is 4:3. SVG is square pixels. 720x480 with square
> pixels is not 4:3; however, 640x480 is. Same concept goes for all
> still images - they are assumed to be square pixels. (There is a way
> to override this, but that is an advanced feature to be used only when
> you understand sample aspect ratio.)

Ah right.  I might have thought of this if the pal/ntsc thing hadn't
distracted me.  but probably not.

> Please try to do a bit more homework.

pfft...  I was up to 2:30 learning how to hack xml.  I gotta sleep
sometime ya know :)


-- 
Carl K