}
end
+-- a C memory area.
+-- It needs to be in global scope.
+-- When the variable is set to nil, the allocated memory
+-- is free()ed
+local cmem = nil
+
function dsp_init (rate)
-- global variables (DSP part only)
- samplerate = rate
- bufsiz = 2 * rate
dpy_hz = rate / 25
dpy_wr = 0
-end
-function dsp_configure (ins, outs)
- -- store configuration in global variable
- audio_ins = ins:n_audio ()
- -- allocate shared memory area, ringbuffer between DSP/GUI
- self:shmem ():allocate (4 + bufsiz)
- self:shmem ():clear ()
- self:shmem ():atomic_set_int (0, 0)
- local cfg = self:shmem ():to_int (1):array ()
- cfg[1] = samplerate
- cfg[2] = bufsiz
+ -- create a ringbuffer to hold (float) audio-data
+ rb = PBD.RingBufferF (2 * rate)
+
+ -- allocate memory, local mix buffer
+ cmem = ARDOUR.DSP.DspShm (8192)
+
+ -- create a table of objects to share with the GUI
+ local tbl = {}
+ tbl['rb'] = rb;
+ tbl['samplerate'] = rate
+
+ -- "self" is a special DSP variable referring
+ -- to the plugin instance itself.
+ --
+ -- "table()" is-a http://manual.ardour.org/lua-scripting/class_reference/#ARDOUR.LuaTableRef
+ -- which allows to store/retrieve lua-tables to share them other interpreters
+ self:table ():set (tbl);
end
function dsp_runmap (bufs, in_map, out_map, n_samples, offset)
- local shmem = self:shmem ()
- local write_ptr = shmem:atomic_get_int (0)
+ -- here we sum all audio input channels channels and then copy the data to a ringbuffer
+ -- for the GUI to process later
- -- sum channels, copy to ringbuffer
+ local audio_ins = in_map:count (): n_audio () -- number of audio input buffers
+ local ccnt = 0 -- processed channel count
+ local mem = cmem:to_float(0) -- a "FloatArray", float* for direct C API usage from the previously allocated buffer
for c = 1,audio_ins do
-- Note: lua starts counting at 1, ardour's ChanMapping::get() at 0
local ib = in_map:get (ARDOUR.DataType ("audio"), c - 1) -- get id of mapped input buffer for given cannel
local ob = out_map:get (ARDOUR.DataType ("audio"), c - 1) -- get id of mapped output buffer for given cannel
if (ib ~= ARDOUR.ChanMapping.Invalid) then
- -- check ringbuffer wrap-around
- if (write_ptr + n_samples < bufsiz) then
- if c == 1 then
- ARDOUR.DSP.copy_vector (shmem:to_float (4 + write_ptr), bufs:get_audio (ib):data (offset), n_samples)
- else
- ARDOUR.DSP.mix_buffers_no_gain (shmem:to_float (4 + write_ptr), bufs:get_audio (ib):data (offset), n_samples)
- end
+ if c == 1 then
+ -- first channel, copy as-is
+ ARDOUR.DSP.copy_vector (mem, bufs:get_audio (ib):data (offset), n_samples)
else
- local w0 = bufsiz - write_ptr
- if c == 1 then
- ARDOUR.DSP.copy_vector (shmem:to_float (4 + write_ptr), bufs:get_audio (ib):data (offset), w0)
- ARDOUR.DSP.copy_vector (shmem:to_float (4) , bufs:get_audio (ib):data (offset + w0), n_samples - w0)
- else
- ARDOUR.DSP.mix_buffers_no_gain (shmem:to_float (4 + write_ptr), bufs:get_audio (ib):data (offset), w0)
- ARDOUR.DSP.mix_buffers_no_gain (shmem:to_float (4) , bufs:get_audio (ib):data (offset + w0), n_samples - w0)
- end
+ -- all other channels, add to existing data.
+ ARDOUR.DSP.mix_buffers_no_gain (mem, bufs:get_audio (ib):data (offset), n_samples)
end
+ ccnt = ccnt + 1;
+
-- copy data to output (if not processing in-place)
if (ob ~= ARDOUR.ChanMapping.Invalid and ib ~= ob) then
ARDOUR.DSP.copy_vector (bufs:get_audio (ob):data (offset), bufs:get_audio (ib):data (offset), n_samples)
end
- else
- -- invalid (unconnnected) input
- if (write_ptr + n_samples < bufsiz) then
- ARDOUR.DSP.memset (shmem:to_float (4 + write_ptr), 0, n_samples)
- else
- local w0 = bufsiz - write_ptr
- ARDOUR.DSP.memset (shmem:to_float (4 + write_ptr), 0, w0)
- ARDOUR.DSP.memset (shmem:to_float (4) , 0, n_samples - w0)
- end
- end
- end
-
- -- normalize 1 / channel-count
- if audio_ins > 1 then
- if (write_ptr + n_samples < bufsiz) then
- ARDOUR.DSP.apply_gain_to_buffer (shmem:to_float (4 + write_ptr), n_samples, 1 / audio_ins)
- else
- local w0 = bufsiz - write_ptr
- ARDOUR.DSP.apply_gain_to_buffer (shmem:to_float (4 + write_ptr), w0, 1 / audio_ins)
- ARDOUR.DSP.apply_gain_to_buffer (shmem:to_float (4) , n_samples - w0, 1 / audio_ins)
end
end
- -- clear unconnected inplace buffers
+ -- Clear unconnected output buffers.
+ -- In case we're processing in-place some buffers may be identical,
+ -- so this must be done *after processing*.
for c = 1,audio_ins do
local ib = in_map:get (ARDOUR.DataType ("audio"), c - 1) -- get id of mapped input buffer for given cannel
local ob = out_map:get (ARDOUR.DataType ("audio"), c - 1) -- get id of mapped output buffer for given cannel
end
end
- write_ptr = (write_ptr + n_samples) % bufsiz
- shmem:atomic_set_int (0, write_ptr)
+ -- Normalize gain (1 / channel-count)
+ if ccnt > 1 then
+ ARDOUR.DSP.apply_gain_to_buffer (mem, n_samples, 1 / ccnt)
+ end
+
+ -- if no channels were processed, feed silence.
+ if ccnt == 0 then
+ ARDOUR.DSP.memset (mem, 0, n_samples)
+ end
+
+ -- write data to the ringbuffer
+ rb:write (mem, n_samples)
-- emit QueueDraw every FPS
- -- TODO: call every window-size worth of samples, at most every FPS
+ -- TODO: call every FFT window-size worth of samples, at most every FPS
dpy_wr = dpy_wr + n_samples
if (dpy_wr > dpy_hz) then
dpy_wr = dpy_wr % dpy_hz
function render_inline (ctx, w, max_h)
local ctrl = CtrlPorts:array () -- get control port array (read/write)
- local shmem = self:shmem () -- get shared memory region
- local cfg = shmem:to_int (1):array () -- "cast" into lua-table
- local rate = cfg[1]
- local buf_size = cfg[2]
-
- if buf_size == 0 then
- return
+ local tbl = self:table ():get () -- get shared memory table
+ local rate = tbl['samplerate']
+ if not cmem then
+ cmem = ARDOUR.DSP.DspShm (0)
end
-- get settings
if not fft then
fft = ARDOUR.DSP.FFTSpectrum (fft_size, rate)
+ cmem:allocate (fft_size)
end
if last_log ~= logscale then
local f_b = w / math.log (fft_size / 2) -- inverse log-scale base
local f_l = math.log (fft_size / rate) * f_b -- inverse logscale lower-bound
- -- available samples in ring-buffer
- local write_ptr = shmem:atomic_get_int (0)
- local avail = (write_ptr + buf_size - read_ptr) % buf_size
+ local rb = tbl['rb'];
+ local mem = cmem:to_float (0)
- while (avail >= fft_size) do
+ while (rb:read_space() >= fft_size) do
-- process one line / buffer
- if read_ptr + fft_size < buf_size then
- fft:set_data_hann (shmem:to_float (read_ptr + 4), fft_size, 0)
- else
- local r0 = buf_size - read_ptr
- fft:set_data_hann (shmem:to_float (read_ptr + 4), r0, 0)
- fft:set_data_hann (shmem:to_float (4), fft_size - r0, r0)
- end
-
+ rb:read (mem, fft_size)
+ fft:set_data_hann (mem, fft_size, 0)
fft:execute ()
- read_ptr = (read_ptr + fft_size) % buf_size
- avail = (write_ptr + buf_size - read_ptr ) % buf_size
-
-- draw spectrum
assert (bpx >= 1)
projects / ardour.git / commitdiff