Dan, >> Now that I'm forced to move away from Kino, I went searching to see if >> anyone has put any work into this feature for other NLEs. I didn't find >> anyone working on it, but I found some requests: >> The plan I have in mind is as follows: >> 1) Implement a dynamic title feature in MLT that provides access to metadata >> that is available from the file attributes that don't require understanding >> the codecs within the file (filename, modification date, etc). > >Mlt already has dynamic titles. See the FAQ item about burning in timecode. > >> 2) Implement the feature in Kdenlive and Openshot >> 3) Extend libav to extract timecode and date/time metadata from applicable >> codecs and make it available in the API. > >This is the hard part. A way to handle DV only is to attach the raw DV >packets to the mlt frames and make a libdv filter that reads the >timecode and date/time and applies them to the mlt frame as metadata >properties. > >> 4) Extend MLT to support the new timecode and date/time metadata provided by >> libav for dynamic titles. > >done. The data_feed and data_show combo is extensible to any meta >attributes. Also, mlt already supports the FFmpeg AVMetadata API, but >that API is currently stream-oriented and not temporal in nature. If >you look at the discussion forum on mltframework.org, I just had a >discussion with another guy about the inability to support QuickTime >timecode tracks. > >> After these steps, Kdenlive and Openshot would match the current dynamic >> title functionality of Kino. >> >> I started to examine the MLT source to get an idea of what it would take to >> implement this feature. I see that titles are typically generated using the >> Gtk2 Pixbuf producer. So it stands to reason that we can simply extend the >> implementation to support dynamic text which can be replaced in an SVG file, > >The component that handles dynamic titles is core/filter_data_show.c. >It reads a mlt properties file. If you still feel the need to use >SVG, you could make make a new data_show that is a generic text >template processor ala web server app technologies.
Nice work. It looks like you knew I'd be asking for this. I've spent some time playing with data_show. It looks promising. A couple of questions: 1) Is there any way to apply the meta.attr.* properties to the playlist, or the entire timeline? The only way I can make it work is to add the meta properties to every producer. If someone wants the timecode to apply to the entire output, it is a bit cumbersome to apply the properties to each producer. 2) Can you show an example of how to use the data_feed filter? I can't seem to get it to do anything. 3) It appears that MLT has properties for the file name - which I think would be useful as an overlay. How would I go about overlaying the file name for all files in the track? 4) Ultimately, I want to overlay the file creation date. That information is not currently a property that is available within MLT. The application (or user) would have to add the creation date to the producer for each file. This isn't too difficult for an application, but it is cumbersome to do by hand. Do you have any interest in having MLT get the file creation date and make it available within the framework? Or is that a task best left to the application? Thanks in advance, ~Brian ------------------------------------------------------------------------------ WhatsUp Gold - Download Free Network Management Software The most intuitive, comprehensive, and cost-effective network management toolset available today. Delivers lowest initial acquisition cost and overall TCO of any competing solution. http://p.sf.net/sfu/whatsupgold-sd _______________________________________________ Mlt-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/mlt-devel
