source: mainline/uspace/lib/trackmod/trackmod.c@ fd1b1ce

/*
 * Copyright (c) 2014 Jiri Svoboda
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/** @addtogroup trackmod
 * @{
 */
/**
 * @file Tracker module handling library.
 */

#include <assert.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>

#include "macros.h"
#include "trackmod.h"

/** Tunables */
enum {
        amp_factor = 16
};

/** Standard definitions set in stone */
enum {
        /** Base sample clock */
        base_clock = 8363 * 428,
        /** Maximum sample volume */
        vol_max = 63,
        /** Default TPR */
        def_tpr = 6,
        /** Default BPM */
        def_bpm = 125
};

static size_t trackmod_get_next_ord_idx(trackmod_modplay_t *);

/** Destroy sample.
 *
 * @param sample Sample
 */
static void trackmod_sample_destroy(trackmod_sample_t *sample)
{
        free(sample->data);
}

/** Destroy pattern.
 *
 * @param pattern Pattern
 */
static void trackmod_pattern_destroy(trackmod_pattern_t *pattern)
{
        free(pattern->data);
}

/** Create new empty module structure.
 *
 * @return New module
 */
trackmod_module_t *trackmod_module_new(void)
{
        return calloc(1, sizeof(trackmod_module_t));
}

/** Destroy module.
 *
 * @param module Module
 */
void trackmod_module_destroy(trackmod_module_t *module)
{
        size_t i;

        /* Destroy samples */
        if (module->sample != NULL) {
                for (i = 0; i < module->samples; i++)
                        trackmod_sample_destroy(&module->sample[i]);
                free(module->sample);
        }

        /* Destroy patterns */
        if (module->pattern != NULL) {
                for (i = 0; i < module->patterns; i++)
                        trackmod_pattern_destroy(&module->pattern[i]);
                free(module->pattern);
        }

        free(module->ord_list);
        free(module);
}

/** Return current pattern.
 *
 * @param modplay Module playback
 * @return        Pattern
 */
static trackmod_pattern_t *trackmod_cur_pattern(trackmod_modplay_t *modplay)
{
        unsigned pat_idx;

        pat_idx = modplay->module->ord_list[modplay->ord_idx];
        return &modplay->module->pattern[pat_idx];
}

/** Decode pattern cell.
 *
 * @param pattern Pattern
 * @param row     Row number
 * @param channel Channel number
 * @param cell    Place to store decoded cell
 */
static void trackmod_pattern_get_cell(trackmod_pattern_t *pattern,
    size_t row, size_t channel, trackmod_cell_t *cell)
{
        uint32_t code;

        code = pattern->data[row * pattern->channels + channel];
        cell->period = (code >> (4 * 4)) & 0xfff;
        cell->sample = (((code >> (7 * 4)) & 0xf) << 4) |
            ((code >> (3 * 4)) & 0xf);
        cell->effect = code & 0xfff;
}

/** Process note (period, sample index)
 *
 * @param modplay Module playback
 * @param i       Channel number
 * @param cell    Cell
 */
static void trackmod_process_note(trackmod_modplay_t *modplay, size_t i,
    trackmod_cell_t *cell)
{
        trackmod_chan_t *chan = &modplay->chan[i];
        size_t smpidx;

        smpidx = (cell->sample - 1) % modplay->module->samples;
        chan->sample = &modplay->module->sample[smpidx];
        chan->smp_pos = 0;
        chan->lsmp = 0;
        chan->period = cell->period;
        chan->volume = modplay->chan[i].sample->def_vol;
}

/** Process Set volume effect.
 *
 * @param modplay Module playback
 * @param chan    Channel number
 * @param param   Effect parameter
 */
static void trackmod_effect_set_volume(trackmod_modplay_t *modplay, size_t chan,
    uint8_t param)
{
        modplay->chan[chan].volume = param & vol_max;
}

/** Process Pattern break effect.
 *
 * @param modplay Module playback
 * @param chan    Channel number
 * @param param   Effect parameter
 */
static void trackmod_effect_pattern_break(trackmod_modplay_t *modplay,
    size_t chan, uint8_t param)
{
        size_t next_idx;
        trackmod_pattern_t *next_pat;

        next_idx = trackmod_get_next_ord_idx(modplay);
        next_pat = &modplay->module->pattern[next_idx]; 

        modplay->pat_break = true;
        modplay->pat_break_row = param % next_pat->rows;
}

/** Process Set speed effect.
 *
 * @param modplay Module playback
 * @param chan    Channel number
 * @param param   Effect parameter
 */
static void trackmod_effect_set_speed(trackmod_modplay_t *modplay, size_t chan,
    uint8_t param)
{
        if (param > 0 && param < 32)
                modplay->tpr = param;
        else if (param > 0)
                modplay->bpm = param;
}

/** Process effect.
 *
 * @param modplay Module playback
 * @param chan    Channel number
 * @param cell    Cell
 */
static void trackmod_process_effect(trackmod_modplay_t *modplay, size_t chan,
    trackmod_cell_t *cell)
{
        uint8_t param8;

        param8 = cell->effect & 0xff;

        switch (cell->effect & 0xf00) {
        case 0xc00:
                trackmod_effect_set_volume(modplay, chan, param8);
                break;
        case 0xd00:
                trackmod_effect_pattern_break(modplay, chan, param8);
                break;
        case 0xf00:
                trackmod_effect_set_speed(modplay, chan, param8);
                break;
        default:
                break;
        }
}

/** Process pattern cell.
 *
 * @param modplay Module playback
 * @param chan    Channel number
 * @param cell    Cell
 */
static void trackmod_process_cell(trackmod_modplay_t *modplay, size_t chan,
    trackmod_cell_t *cell)
{
        if (cell->period != 0 && cell->sample != 0)
                trackmod_process_note(modplay, chan, cell);

        trackmod_process_effect(modplay, chan, cell);
}

/** Process pattern row.
 *
 * @param modplay Module playback
 */
static void trackmod_process_row(trackmod_modplay_t *modplay)
{
        trackmod_pattern_t *pattern;
        trackmod_cell_t cell;
        size_t i;

        pattern = trackmod_cur_pattern(modplay);

        for (i = 0; i < modplay->module->channels; i++) {
                trackmod_pattern_get_cell(pattern, modplay->row, i, &cell);
                if (modplay->debug)
                        printf("%4d %02x %03x |", cell.period, cell.sample, cell.effect);
                trackmod_process_cell(modplay, i, &cell);
        }

        if (modplay->debug)
                printf("\n");
}

/** Get next order list index.
 *
 * @param modplay Module playback
 * @return        Next order list index
 */
static size_t trackmod_get_next_ord_idx(trackmod_modplay_t *modplay)
{
        size_t ord_idx;

        ord_idx = modplay->ord_idx + 1;
        if (ord_idx >= modplay->module->ord_list_len)
                ord_idx = 0; /* XXX */

        return ord_idx;
}

/** Advance to next pattern.
 *
 * @param modplay Module playback
 */
static void trackmod_next_pattern(trackmod_modplay_t *modplay)
{
        if (modplay->debug)
                printf("Next pattern\n");

        modplay->row = 0;
        modplay->ord_idx = trackmod_get_next_ord_idx(modplay);

        /* If we are doing a pattern break */
        if (modplay->pat_break) {
                modplay->row = modplay->pat_break_row;
                modplay->pat_break = false;
        }
}

/** Advance to next row.
 *
 * @param modplay Module playback
 */
static void trackmod_next_row(trackmod_modplay_t *modplay)
{
        trackmod_pattern_t *pattern;

        pattern = trackmod_cur_pattern(modplay);

        modplay->tick = 0;
        ++modplay->row;
        if (modplay->row >= pattern->rows || modplay->pat_break)
                trackmod_next_pattern(modplay);

        trackmod_process_row(modplay);
}

/** Advance to next tick.
 *
 * @param modplay Module playback
 */
static void trackmod_next_tick(trackmod_modplay_t *modplay)
{
        modplay->smp = 0;
        ++modplay->tick;
        if (modplay->tick >= modplay->tpr)
                trackmod_next_row(modplay);
}

/** Create module playback object.
 *
 * @param module   Module
 * @param smp_freq Sampling frequency
 * @param rmodplay Place to store pointer to module playback object
 */
int trackmod_modplay_create(trackmod_module_t *module,
    unsigned smp_freq, trackmod_modplay_t **rmodplay)
{
        trackmod_modplay_t *modplay = NULL;

        modplay = calloc(1, sizeof(trackmod_modplay_t));
        if (modplay == NULL)
                goto error;

        modplay->module = module;
        modplay->smp_freq = smp_freq;
        modplay->frame_size = sizeof(int16_t);
        modplay->ord_idx = 0;
        modplay->row = 0;
        modplay->tick = 0;
        modplay->smp = 0;

        modplay->tpr = def_tpr;
        modplay->bpm = def_bpm;

        modplay->chan = calloc(module->channels,
            sizeof(trackmod_chan_t));
        if (modplay->chan == NULL)
                goto error;

        trackmod_process_row(modplay);

        *rmodplay = modplay;
        return EOK;
error:
        if (modplay != NULL)
                free(modplay->chan);
        free(modplay);
        return ENOMEM;
}

/** Destroy module playback object.
 *
 * @param modplay Module playback
 */
void trackmod_modplay_destroy(trackmod_modplay_t *modplay)
{
        free(modplay->chan);
        free(modplay);
}

/** Get number of samples per tick.
 *
 * @param modplay Module playback
 * @return        Number of samples per tick
 */
static size_t samples_per_tick(trackmod_modplay_t *modplay)
{
        return modplay->smp_freq * 10 / 4 / modplay->bpm;
}

/** Get number of samples remaining in current tick.
 *
 * @param modplay Module playback
 * @return        Number of remaining samples in tick
 */
static size_t samples_remain_tick(trackmod_modplay_t *modplay)
{
        /* XXX Integer samples per tick is a simplification */
        return samples_per_tick(modplay) - modplay->smp;
}

/** Advance sample position to next frame.
 *
 * @param chan Channel playback
 */
static void chan_smp_next_frame(trackmod_chan_t *chan)
{
        chan->lsmp = chan->sample->data[chan->smp_pos];
        ++chan->smp_pos;

        if (chan->sample->loop_len == 0) {
                /* No looping */
                if (chan->smp_pos >= chan->sample->length) {
                        chan->sample = NULL;
                        chan->smp_pos = 0;
                }
        } else {
                /** Looping */
                if (chan->smp_pos >= chan->sample->loop_start +
                    chan->sample->loop_len) {
                        chan->smp_pos = chan->sample->loop_start;
                }
        }
}

/** Render next sample on channel.
 *
 * @param modplay Module playback
 * @param cidx    Channel number
 * @return        Sample value
 */
static int trackmod_chan_next_sample(trackmod_modplay_t *modplay,
    size_t cidx)
{
        int sl, sn;
        int period, clk;
        int s;

        trackmod_chan_t *chan = &modplay->chan[cidx];

        if (chan->sample == NULL)
                return 0;

        /*
         * Linear interpolation. Note this is slightly simplified:
         * We ignore the half-sample offset and the boundary condition
         * at the end of the sample (we should extend with zero).
         */
        sl = (int)chan->lsmp * amp_factor * chan->volume / vol_max;
        sn = (int)chan->sample->data[chan->smp_pos] * amp_factor *
            chan->volume / vol_max;

        period = (int)chan->period;
        clk = (int)chan->smp_clk;

        s = (sl * (period - clk) + sn * clk) / period;

        chan->smp_clk += base_clock / modplay->smp_freq;
        while (chan->sample != NULL && chan->smp_clk >= chan->period) {
                chan->smp_clk -= chan->period;
                chan_smp_next_frame(chan);
        }

        return s;
}

/** Render a segment of samples contained entirely within a tick.
 *
 * @param modplay Module playback
 * @param buffer  Buffer for storing audio data
 * @param bufsize Size of @a buffer in bytes
 */
static void get_samples_within_tick(trackmod_modplay_t *modplay,
    void *buffer, size_t bufsize)
{
        size_t nsamples;
        size_t smpidx;
        size_t chan;
        int s;

        nsamples = bufsize / modplay->frame_size;

        for (smpidx = 0; smpidx < nsamples; smpidx++) {
                s = 0;
                for (chan = 0; chan < modplay->module->channels; chan++) {
                        s += trackmod_chan_next_sample(modplay, chan);
                }

                ((int16_t *)buffer)[smpidx] = s;
        }

        modplay->smp += nsamples;
}

/** Render a segment of samples.
 *
 * @param modplay Module playback
 * @param buffer  Buffer for storing audio data
 * @param bufsize Size of @a buffer in bytes
 */
void trackmod_modplay_get_samples(trackmod_modplay_t *modplay,
    void *buffer, size_t bufsize)
{
        size_t nsamples;
        size_t rsmp;
        size_t now;

        nsamples = bufsize / modplay->frame_size;
        while (nsamples > 0) {
                rsmp = samples_remain_tick(modplay);
                if (rsmp == 0)
                        trackmod_next_tick(modplay);

                rsmp = samples_remain_tick(modplay);
                now = min(rsmp, nsamples);

                get_samples_within_tick(modplay, buffer,
                    now * modplay->frame_size);
                nsamples -= now;
                buffer += now * modplay->frame_size;
        }
}

/** @}
 */