2009-05-30 15:18:21 +00:00
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Gst-LV2 Quickstart
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Dependencies:
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2016-04-01 19:24:34 +00:00
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Lilv 0.6.6 <http://drobilla.net/software/lilv/>
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2009-05-30 15:18:21 +00:00
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2016-05-12 17:52:06 +00:00
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Features:
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The plugin wrapper support the following plugin features:
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http://lv2plug.in/ns/lv2core
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2016-05-16 05:05:43 +00:00
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http://lv2plug.in/ns/ext/event
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2016-05-12 17:52:06 +00:00
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http://lv2plug.in/ns/ext/port-groups
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and these host features:
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2016-05-14 19:35:15 +00:00
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http://lv2plug.in/ns/ext/log
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http://lv2plug.in/ns/ext/urid
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2016-05-12 17:52:06 +00:00
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2009-05-30 15:18:21 +00:00
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Example Pipeline:
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Requires swh-lv2 <http://plugin.org.uk/releases/>
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2016-04-01 19:24:34 +00:00
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gst-launch-1.0 -v filesrc location=/usr/share/sounds/login.wav ! wavparse ! audioconvert ! plugin-org-uk-swh-plugins-djFlanger ! audioconvert ! autoaudiosink
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2009-05-30 15:18:21 +00:00
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(A longer wav will be a better example)
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2010-02-01 20:24:52 +00:00
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2016-05-12 17:52:06 +00:00
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gst-launch-1.0 plugin-org-uk-swh-plugins-analogueOsc num-buffers=100 wave=1 ! wavenc ! filesink location="/tmp/lv2.wav"
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2010-02-01 20:24:52 +00:00
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Requires calf <http://calf.sourceforge.net/>
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2016-04-01 19:24:34 +00:00
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GST_DEBUG="*:2,lv2:5"
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gst-launch-1.0 calf-sourceforge-net-plugins-Monosynth event-in="C-3" ! autoaudiosink
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gst-launch-1.0 calf-sourceforge-net-plugins-Monosynth event-in="C-3" name=ms ! autoaudiosink ms. ! fakesink
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gst-launch-1.0 calf-sourceforge-net-plugins-Organ event-in="C-3" name=s ! interleave name=i ! autoaudiosink s. ! i.
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2010-02-01 20:24:52 +00:00
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2016-05-12 17:52:06 +00:00
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TODO
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2016-06-15 20:22:58 +00:00
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* make filters gap-aware
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2016-07-10 18:43:17 +00:00
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* report latency
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lilv_plugin_has_latency(), lilv_plugin_get_latency_port_index()
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2016-05-12 17:52:06 +00:00
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* support more host features
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2016-05-14 19:35:15 +00:00
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GST_DEBUG="lv2:4" GST_DEBUG_FILE=/tmp/gst.log gst-inspect lv2
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grep -o "needs host feature: .*$" /tmp/gst.log | sort | uniq -c | sort -n
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2016-07-10 18:43:17 +00:00
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* make source elements useful
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Most source elements use Atom port where they accept midi events. Since it is
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full fledged midi, we should only ever use channel-0 and instead use multiple
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instances
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1) We could expose those as "audio/x-midi-event" sink pads, but then those are
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not sources anymore.
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2) We could expose those as properties using a new type like GST_FOURCC. If we
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ignore "System Exclusive" messages, all other midi messages are 1-3 bytes.
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We stuff the bytes right to left. E.g: the lowest byte is the status byte
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3) We could use the GstBtNote enum + the toneconversion classes
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https://www.midi.org/specifications/item/table-1-summary-of-midi-message
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Open questions:
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- with one property, we can't handle polyphony
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- we can't query lv2 plugins for their polyphony :/
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If lv2 gets a polyphony extension it would be a single non-negative integer:
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0: unbound, 1 monophonic, > 1 N-polyphonic
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I've checked a few synths and they all have an upper limit. Still the way
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voices work in trackers is not the same as they work in synths - e.g. in a
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tracker one can play a note twice
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Or we just play them monophonic and try to implement a polychildbin. The bin
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takes a GstElement to be used as a voice. For each new voice it would create a
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new instance and it uses a built-in mixer. Downside is that all properties
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would be per voice.
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2016-05-12 17:52:06 +00:00
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2016-05-16 05:05:43 +00:00
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* example sources:
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2016-05-12 17:52:06 +00:00
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http://svn.drobilla.net/lad/trunk/lilv/utils/lv2info.c
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http://svn.drobilla.net/lad/trunk/jalv/src/jalv.c
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