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Diffstat (limited to 'examples/7-sqlite-resynth.csd')
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diff --git a/examples/7-sqlite-resynth.csd b/examples/7-sqlite-resynth.csd new file mode 100644 index 0000000..cabc753 --- /dev/null +++ b/examples/7-sqlite-resynth.csd @@ -0,0 +1,172 @@ +<CsoundSynthesizer> +<CsOptions> +-odac +</CsOptions> +<CsInstruments> +/* + EXAMPLE 7 + + A rudimentary pitch tracking concatenative resynthesizer as such + + This creates a sqlite database in memory, and then uses the opcode getpitches to scan through a + sound file in non-realtime, storing detected pitches and the relevant offset time of the pitch in + the database. The example file is a descending violin glissando. + + When done, the instrument "playmatches" is scheduled twice which plays an oscillator varying in pitch, + which is pitch tracked and the nearest frequency is found in the database, prompting the "segment" + instrument to be scheduled with the relevant offset. + + + 1. for 20s in which nearest matches are played only if the detected pitch has changed outside of a threshold + 2. as above but with matches played continuously + + The result is that the violin segments picked should moreorless match what the oscillator is doing. + +*/ + +sr = 44100 +kr = 4410 +nchnls = 2 +0dbfs = 1 + + +; create an in-memory sqlite database and create a table +gidb dbconnect "sqlite", ":memory:" +dbexec gidb, "CREATE TABLE pitches (time REAL, cps REAL)" + +; file of ascending piano pitches +gSfile = "sounds/violin.wav" +gifn ftgen 0, 0, 0, 1, gSfile, 0, 0, 0 + +; detect pitches and insert time/cps to database given a filename, in non-realtime +opcode getpitches, 0, S + Sfile xin + ktimek timeinstk + ktime timeinsts + klast init -1 + kcount init 0 + + ; run in the first single k-rate cycle + if (ktimek == 0) then + + ; get file length in k-cycles + ilen filelen Sfile + kcycles = ilen * kr +loop: + ; read file and track pitch + ain diskin2 Sfile, 1 + ;ain butterbp ain, 500, 250 + koct, kamp pitch ain, 0.01, 6, 12, 6, 12, 60 + + ; only take action if pitch has changed + kchanged changed2 koct + if (kchanged == 1) then + + ; only store if cps is reasonably different from the last value + kcps = cpsoct(koct) + + if (1==1) then + + ; insert to database: the dbexec_kb opcode is k-rate but blocking/synchronous. + ; simpler to use for the non-realtime operation as regular _k opcodes are threaded/asynchronous + ktime = kcount / kr + Squery sprintfk "INSERT INTO pitches (time, cps) VALUES (%f, %f)", ktime, kcps + dbexec_kb gidb, Squery + klast = kcps + endif + endif + loop_lt kcount, 1, kcycles, loop + + endif +endop + + + +; begin the example: find pitches and then schedule the next step +instr start_example + getpitches gSfile + schedkwhen 1, 0, 0, "playmatches", 0, 20, 0 + schedkwhen 1, 0, 0, "playmatches", 20, 20, 1 + turnoff + +endin + + + +; pitch follow a descending oscillator and attempt to find a similar cps in the database, then schedule segment accordingly +instr playmatches + kdone init 0 ; for when the select query is done + klast init 0 ; last pitch played, in order to avoid repeats + + + ; oscillator + k1 linseg 400, p3, 200 + ktime linseg 0.001, p3, 2 + k2 oscil k1, ktime + ain oscil 1, abs(k2)+550, 1 + + ; track it + koct, kamp pitch ain, 0.01, 5, 10, 6, 12 + + ; only take action when the tracked pitch has changed + kchanged changed2 koct + if (kchanged == 1) then + + ; (very roughly) get a near frequency match from the database + kcps = cpsoct(koct) + + ; fairly nasty looking query for obtaining the nearest value + SquerySource = {{ + SELECT time FROM ( + SELECT time, cps FROM ( + SELECT time, cps FROM pitches WHERE cps >= %f ORDER BY cps ASC LIMIT 1 + ) + UNION SELECT time, cps FROM ( + SELECT time, cps FROM pitches WHERE cps < %f ORDER BY cps DESC LIMIT 1 + ) + ) x ORDER BY ABS(cps - %f) ASC LIMIT 1 + }} + + Squery sprintfk SquerySource, kcps, kcps, kcps + kdone, kpos dbscalar_k gidb, Squery, kchanged + + ;schedule the notes + if (p4 == 1) then + schedkwhen kdone, 0, 0, "segment", 0, 0.2, kpos + else + if (kpos < klast*0.8 || kpos > klast*1.2) then + schedkwhen kdone, 0, 0, "segment", 0, 0.2, kpos + klast = kpos + endif + endif + endif + + + ; uncomment to hear the oscillator as well as pitch matched output + ;outs ain*0.01, ain*0.01 +endin + + + +; play part of the sound file given a skip time with a basic envelope +instr segment + il = ftlen(gifn) + isec = il/sr + ist = sr*p4 + icps = 1/isec + aphs phasor icps + andx = aphs * il + aout tablei andx+ist, gifn + kamp linseg 0, p3*0.3, 1, p3*0.4, 1, p3*0.3, 0 + outs aout*0.1*kamp, aout*0.1*kamp +endin + + +</CsInstruments> +<CsScore> +f1 0 16384 10 1 0 0.3 0 0.2 0 0.14 0 .111 ; square wave + +i"start_example" 0 1 + +</CsScore> +</CsoundSynthesizer>
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