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Diffstat (limited to 'src/masher.c')
| -rw-r--r-- | src/masher.c | 244 |
1 files changed, 244 insertions, 0 deletions
diff --git a/src/masher.c b/src/masher.c new file mode 100644 index 0000000..0a9eeda --- /dev/null +++ b/src/masher.c @@ -0,0 +1,244 @@ +/* Masher + * Copyright 2001 David Griffiths <dave@pawfal.org> + * LV2fication 2005 David Robillard <drobilla@connect.carelton.ca> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. + */ + +/* NOTE: This is a very dirty hack full of arbitrary limits and assumptions. + * It needs fixing/completion */ + +#define _XOPEN_SOURCE 600 /* posix_memalign */ +#include <stdlib.h> +#include <math.h> +#include <string.h> +#include <stdbool.h> + +#include <lv2/lv2plug.in/ns/lv2core/lv2.h> + +#define MASHER_BASE_ID 4310 + +#define MASHER_NUM_PORTS 4 + +/* Port Numbers */ +#define MASHER_INPUT 0 +#define MASHER_GRAINPITCH 1 +#define MASHER_DENSITY 2 +#define MASHER_OUTPUT 3 + +#define GRAINSTORE_SIZE 1000 +#define OVERLAPS_SIZE 1000 +#define MAX_GRAIN_SIZE 2048 + +typedef struct { + float* data; + size_t length; +} Sample; + +typedef struct { + int pos; + int grain; +} GrainDesc; + +/* All state information for plugin */ +typedef struct { + /* Ports */ + float *input; + float *grain_pitch; + float *density; + float *output; + + Sample grain_store[GRAINSTORE_SIZE]; + GrainDesc overlaps[OVERLAPS_SIZE]; + size_t overlaps_size; + + size_t write_grain; +} Masher; + +/* Construct a new plugin instance */ +static LV2_Handle +instantiate(const LV2_Descriptor* descriptor, + double sample_rate, + const char* bundle_path, + const LV2_Feature* const* features) +{ + return (LV2_Handle)malloc(sizeof(Masher)); +} + +/** Activate an instance */ +static void +activate(LV2_Handle instance) +{ + Masher *plugin = (Masher*)instance; + int i = 0; + + plugin->overlaps_size = 0; + plugin->write_grain = 0; + + for (i=0; i < GRAINSTORE_SIZE; ++i) { +#ifdef HAVE_POSIX_MEMALIGN + posix_memalign((void**)&plugin->grain_store[i].data, 16, MAX_GRAIN_SIZE * sizeof(float)); +#else + plugin->grain_store[i].data = (float*)calloc(MAX_GRAIN_SIZE, sizeof(float)); +#endif + plugin->grain_store[i].length = 0; + } +} + +/* Connect a port to a data location */ +static void +connect_port(LV2_Handle instance, + uint32_t port, + void * data) +{ + Masher *plugin = (Masher *) instance; + + switch (port) { + case MASHER_INPUT: + plugin->input = (float*)data; + break; + case MASHER_GRAINPITCH: + plugin->grain_pitch = (float*)data; + break; + case MASHER_DENSITY: + plugin->density = (float*)data; + break; + case MASHER_OUTPUT: + plugin->output = (float*)data; + break; + } +} + +static void +mix_pitch(Sample* src, Sample* dst, size_t pos, float pitch) +{ + float n = 0; + size_t p = pos; + + while (n < src->length && p < dst->length) { + dst->data[p] = dst->data[p] + src->data[(size_t)n]; + n += pitch; + p++; + } +} + +static void +run(LV2_Handle instance, uint32_t nframes) +{ + Masher* plugin = (Masher*)instance; + + static const int randomness = 1.0; // FIXME: make a control port + int read_grain = 0; // FIXME: what is this? + int grain_store_size = 100; // FIXME: what is this? (max 1000) + + const float grain_pitch = *plugin->grain_pitch; + const float density = *plugin->density; + + const float* const in = plugin->input; + float* const out = plugin->output; + + Sample out_sample = { out, nframes }; + + size_t n = 0; + float s = in[0]; + int last = 0; + bool first = true; + size_t grain_index = 0; + size_t next_grain = 0; + + // Zero output buffer + for (n = 0; n < nframes; ++n) + out[n] = 0.0f; + + // Paste any overlapping grains to the start of the buffer. + for (n = 0; n < plugin->overlaps_size; ++n) { + mix_pitch(&plugin->grain_store[plugin->overlaps[n].grain], &out_sample, + plugin->overlaps[n].pos - nframes, grain_pitch); + } + plugin->overlaps_size = 0; + + // Chop up the buffer and put the grains in the grainstore + for (n = 0; n < nframes; n++) { + if ((s < 0 && in[n] > 0) || (s > 0 && in[n] < 0)) { + // Chop the bits between zero crossings + if (!first) { + if (n - last <= MAX_GRAIN_SIZE) { + grain_index = plugin->write_grain % grain_store_size; + memcpy(plugin->grain_store[grain_index].data, in, nframes); + plugin->grain_store[grain_index].length = n - last; + } + plugin->write_grain++; // FIXME: overflow? + } else { + first = false; + } + + last = n; + s = in[n]; + } + } + + for (n = 0; n < nframes; n++) { + if (n >= next_grain || rand() % 1000 < density) { + size_t grain_num = read_grain % grain_store_size; + mix_pitch(&plugin->grain_store[grain_num], &out_sample, n, grain_pitch); + size_t grain_length = (plugin->grain_store[grain_num].length * grain_pitch); + + next_grain = n + plugin->grain_store[grain_num].length; + + // If this grain overlaps the buffer + if (n + grain_length > nframes) { + if (plugin->overlaps_size < OVERLAPS_SIZE) { + GrainDesc new_grain; + + new_grain.pos = n; + new_grain.grain = grain_num; + plugin->overlaps[plugin->overlaps_size++] = new_grain; + } + } + + if (randomness) + read_grain += 1 + rand() % randomness; + else + read_grain++; + } + } +} + +static void +cleanup(LV2_Handle instance) +{ + free(instance); +} + + +static const LV2_Descriptor descriptor = { + "http://drobilla.net/plugins/omins/masher", + instantiate, + connect_port, + activate, + run, + NULL, + cleanup, + NULL, +}; + +LV2_SYMBOL_EXPORT const LV2_Descriptor* +lv2_descriptor(uint32_t index) +{ + switch (index) { + case 0: return &descriptor; + default: return NULL; + } +} |