Manually generated XML to apply chroma key and composite filters.

[ekiim]

I'm trying to articulate a script that automates some PDF slides to video overlaying a video on top of the slide. (I assume it's not that complicated) the setup is one video per slide.

Right now it works perfectly without "green screen videos" filtering, but when I try to do a chroma key filter, It seems that it's not getting it.

I've looked through the documentation, and haven't found a concert answer, my suspicion is that I might be consuming incorrectly the filters, but I've tried several combinations of orderings and where applying them, with no result. Either the chrome key is not being applied or the video is not being or I get wildly different (than expected result)

In the following code snippet, I show how I'm producing the video for a given slide.

I have an image and a video (with known duration in frames), I take a chroma key filter and a composite filter.

Am I doing something wrong here?

      <producer id="slide-0006_image">    
          <property name="resource">intermediate/slide-0006.png</property>    
          <property name="mlt_service">pixbuf</property>    
      </producer>  

      <producer id="slide-0006_overlay">    
          <property name="resource">media/chromakey.mkv</property>    
          <property name="mlt_service">avformat</property>    
          <property name="video_index">0</property>    
          <property name="audio_index">1</property>    
      </producer>  

      <filter id="slide-0006_chroma">    
          <property name="mlt_service">chroma</property>    
          <property name="key_color">#13d900</property>    
          <property name="threshold">0.4</property>    
          <property name="tolerance">0.2</property>    
          <property name="operation">or</property>    
      </filter>  

      <playlist id="slide-0006_playlist">    
          <entry producer="slide-0006_image" in="0" out="168"/>    
      </playlist>  

      <playlist id="slide-0006_overlay_playlist">    
          <entry producer="slide-0006_overlay" in="0" out="168">      
                <filter>slide-0006_chroma</filter>      
          </entry>    
      </playlist>  

      <tractor id="slide-0006">    
          <track producer="slide-0006_playlist"/>    
          <track producer="slide-0006_overlay_playlist"/>    
          <transition>      
              <property name="a_track">0</property>      
              <property name="b_track">1</property>      
              <property name="mlt_service">composite</property>      
              <property name="geometry">68.8%/70%:30%x30%:100</property>      
              <property name="progressive">1</property>      
              <property name="distort">0</property>      
          </transition>    
      </tractor>  

This XML bit is generated by I script I'm writing, but I've manually tried the modifications, for purposes of this discussion, the generating script is irrelevant.

Any help or guidance would be greatly appreciated.

[ddennedy]

Shotcut and Kdenlive save to MLT XML. You should use those to learn and prototype.

<filter>slide-0006_chroma</filter> does nothing.

[ekiim]

Ended up doing that and found a solution, I guess I was trying to mix (in my attempts) the parameters from Chroma key Basic and Advance

      <producer id="slide-0006_image">    
          <property name="resource">intermediate/slide-0006.png</property>    
          <property name="mlt_service">pixbuf</property>    
      </producer>  

      <producer id="slide-0006_overlay">    
          <property name="resource">media/chromakey.mkv</property>    
          <property name="mlt_service">avformat</property>    
          <property name="video_index">0</property>    
          <property name="audio_index">1</property>    
      </producer>  

      <playlist id="slide-0006_playlist">    
          <entry producer="slide-0006_image" in="0" out="168"/>    
      </playlist>  

      <playlist id="slide-0006_overlay_playlist">    
          <entry producer="slide-0006_overlay" in="0" out="168">      
          
              <filter id="slide-0006_chroma">        
                  <property name="mlt_service">chroma</property>        
                  <property name="key">0x13d900ff</property>        
                  <property name="variance">0.15</property>        
                  <property name="operation">or</property>        
              </filter>      
        
          </entry>    
      </playlist>  

      <tractor id="slide-0006">    
          <track producer="slide-0006_playlist"/>    
          <track producer="slide-0006_overlay_playlist"/>    
          <transition>      
              <property name="a_track">0</property>      
              <property name="b_track">1</property>      
              <property name="mlt_service">composite</property>      
              <property name="geometry">68.8%/70%:30%x30%:100</property>      
              <property name="progressive">1</property>      
              <property name="distort">0</property>      
          </transition>    
      </tractor>