Oh hi!
See,
https://github.com/dholroyd/gst-audiodescriptionI have some WAV files containing 'WHP 198' audio description data [1].
The Internet doesn't seem know of any tools that could help me use these
files, so I created the above plugin providing a couple of elements,
* whp198dec - decodes and checksums the Manchester Encoded audio
waveform per WHP 198 to produce buffers of 'AD_descriptor' structures
* adcontrol - consumes 'AD_descriptor' structures and uses these to
apply a 'fade' to the volume of some other audio stream
Combining these with other existing elements ('deinterleave',
'audiomix', gaffer tape, string etc.) will eventually allow construction
of pipelines which can combine one of these WAV files with the file for
the video being described, and usefully render the described audio.
Code is just a proof of concept at the moment, but I would be very
interested to hear if,
a) anyone else uses data in these formats themselves (collaborators
welcome!)
b) there are any problems with the code (I'm new to gstreamer!)
c) I missed something out there that *does* already support WHP 198
etc. (which I've just not been smart enough to find!)
ta,
dave
[1] If you're not quite interested enough to google the spec, there is
effectively mono description audio in the left channel, and some
manchester-encoded metadata in the right channel. This metadata signals
temporary reductions in the volume of the main audio track in the
related video content (i.e. in another file), so as to make the
description audio clearer.
--
http://david.holroyd.me.uk/_______________________________________________
gstreamer-devel mailing list
[hidden email]
https://lists.freedesktop.org/mailman/listinfo/gstreamer-devel
Locked
