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cog/Frameworks/vgmstream/vgmstream/src/mixing.c

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#include "vgmstream.h"
#include "mixing.h"
#include "plugins.h"
#include <math.h>
#include <limits.h>
/**
* Mixing lets vgmstream modify the resulting sample buffer before final output.
* This can be implemented in a number of ways but it's done like it is considering
* overall simplicity in coding, usage and performance (main complexity is allowing
* down/upmixing). Code is mostly independent with some hooks in the main vgmstream
* code.
*
* It works using two buffers:
* - outbuf: plugin's pcm16 buffer, at least input_channels*sample_count
* - mixbuf: internal's pcmfloat buffer, at least mixing_channels*sample_count
* outbuf starts with decoded samples of vgmstream->channel size. This unsures that
* if no mixing is done (most common case) we can skip copying samples between buffers.
* Resulting outbuf after mixing has samples for ->output_channels (plus garbage).
* - output_channels is the resulting total channels (that may be less/more/equal)
* - input_channels is normally ->channels or ->output_channels when it's higher
*
* First, a meta (ex. TXTP) or plugin may add mixing commands through the API,
* validated so non-sensical mixes are ignored (to ensure mixing code doesn't
* have to recheck every time). Then, before starting to decode mixing must be
* manually activated, because plugins need to be ready for possibly different
* input/output channels. API could be improved but this way we can avoid having
* to update all plugins, while allowing internal setup and layer/segment mixing
* (may change in the future for simpler usage).
*
* Then after decoding normally, vgmstream applies mixing internally:
* - detect if mixing is active and needs to be done at this point (some effects
* like fades only apply after certain time) and skip otherwise.
* - copy outbuf to mixbuf, as using a float buffer to increase accuracy (most ops
* apply float volumes) and slightly improve performance (avoids doing
* int16-to-float casts per mix, as it's not free)
* - apply all mixes on mixbuf
* - copy mixbuf to outbuf
* segmented/layered layouts handle mixing on their own.
*
* Mixing is tuned for most common case (no mix except fade-out at the end) and is
* fast enough but not super-optimized yet, there is some penalty the more effects
* are applied. Maybe could add extra sub-ops to avoid ifs and dumb values (volume=0.0
* could simply use a clear op), only use mixbuf if necessary (swap can be done without
* mixbuf if it goes first) or add function pointer indexes but isn't too important.
* Operations are applied once per "step" with 1 sample from all channels to simplify code
* (and maybe improve memory cache?), though maybe it should call one function per operation.
*/
#define VGMSTREAM_MAX_MIXING 512
#define MIXING_PI 3.14159265358979323846f
/* mixing info */
typedef enum {
MIX_SWAP,
MIX_ADD,
MIX_VOLUME,
MIX_LIMIT,
MIX_UPMIX,
MIX_DOWNMIX,
MIX_KILLMIX,
MIX_FADE
} mix_command_t;
typedef struct {
mix_command_t command;
/* common */
int ch_dst;
int ch_src;
float vol;
/* fade envelope */
float vol_start; /* volume from pre to start */
float vol_end; /* volume from end to post */
char shape; /* curve type */
int32_t time_pre; /* position before time_start where vol_start applies (-1 = beginning) */
int32_t time_start; /* fade start position where vol changes from vol_start to vol_end */
int32_t time_end; /* fade end position where vol changes from vol_start to vol_end */
int32_t time_post; /* position after time_end where vol_end applies (-1 = end) */
} mix_command_data;
typedef struct {
int mixing_channels; /* max channels needed to mix */
int output_channels; /* resulting channels after mixing */
int mixing_on; /* mixing allowed */
int mixing_count; /* mixing number */
size_t mixing_size; /* mixing max */
mix_command_data mixing_chain[VGMSTREAM_MAX_MIXING]; /* effects to apply (could be alloc'ed but to simplify...) */
float* mixbuf; /* internal mixing buffer */
} mixing_data;
/* ******************************************************************* */
static int is_active(mixing_data *data, int32_t current_start, int32_t current_end) {
int i;
int32_t fade_start, fade_end;
for (i = 0; i < data->mixing_count; i++) {
mix_command_data *mix = &data->mixing_chain[i];
if (mix->command != MIX_FADE)
return 1; /* has non-fades = active */
/* check is current range falls within a fade
* (assuming fades were already optimized on add) */
fade_start = mix->time_pre < 0 ? 0 : mix->time_pre;
fade_end = mix->time_post < 0 ? INT_MAX : mix->time_post;
if (current_start < fade_end && current_end > fade_start)
return 1;
}
return 0;
}
static int32_t get_current_pos(VGMSTREAM* vgmstream, int32_t sample_count) {
int32_t current_pos;
if (vgmstream->loop_flag && vgmstream->loop_count > 0) {
int loop_pre = vgmstream->loop_start_sample; /* samples before looping */
int loop_into = (vgmstream->current_sample - vgmstream->loop_start_sample); /* samples after loop */
int loop_samples = (vgmstream->loop_end_sample - vgmstream->loop_start_sample); /* looped section */
current_pos = loop_pre + (loop_samples * vgmstream->loop_count) + loop_into - sample_count;
}
else {
current_pos = (vgmstream->current_sample - sample_count);
}
return current_pos;
}
static float get_fade_gain_curve(char shape, float index) {
float gain;
/* don't bother doing calcs near 0.0/1.0 */
if (index <= 0.0001f || index >= 0.9999f) {
return index;
}
//todo optimizations: interleave calcs, maybe use cosf, powf, etc? (with extra defines)
/* (curve math mostly from SoX/FFmpeg) */
switch(shape) {
/* 2.5f in L/E 'pow' is the attenuation factor, where 5.0 (100db) is common but a bit fast
* (alt calculations with 'exp' from FFmpeg use (factor)*ln(0.1) = -NN.N... */
case 'E': /* exponential (for fade-outs, closer to natural decay of sound) */
//gain = pow(0.1f, (1.0f - index) * 2.5f);
gain = exp(-5.75646273248511f * (1.0f - index));
break;
case 'L': /* logarithmic (inverse of the above, maybe for crossfades) */
//gain = 1 - pow(0.1f, (index) * 2.5f);
gain = 1 - exp(-5.75646273248511f * (index));
break;
case 'H': /* raised sine wave or cosine wave (for more musical crossfades) */
gain = (1.0f - cos(index * MIXING_PI)) / 2.0f;
break;
case 'Q': /* quarter of sine wave (for musical fades) */
gain = sin(index * MIXING_PI / 2.0f);
break;
case 'p': /* parabola (maybe for crossfades) */
gain = 1.0f - sqrt(1.0f - index);
break;
case 'P': /* inverted parabola (maybe for fades) */
gain = (1.0f - (1.0f - index) * (1.0f - index));
break;
case 'T': /* triangular/linear (simpler/sharper fades) */
default:
gain = index;
break;
}
return gain;
}
static int get_fade_gain(mix_command_data *mix, float *out_cur_vol, int32_t current_subpos) {
float cur_vol = 0.0f;
if ((current_subpos >= mix->time_pre || mix->time_pre < 0) && current_subpos < mix->time_start) {
cur_vol = mix->vol_start; /* before */
}
else if (current_subpos >= mix->time_end && (current_subpos < mix->time_post || mix->time_post < 0)) {
cur_vol = mix->vol_end; /* after */
}
else if (current_subpos >= mix->time_start && current_subpos < mix->time_end) {
/* in between */
float range_vol, range_dur, range_idx, index, gain;
if (mix->vol_start < mix->vol_end) { /* fade in */
range_vol = mix->vol_end - mix->vol_start;
range_dur = mix->time_end - mix->time_start;
range_idx = current_subpos - mix->time_start;
index = range_idx / range_dur;
} else { /* fade out */
range_vol = mix->vol_end - mix->vol_start;
range_dur = mix->time_end - mix->time_start;
range_idx = mix->time_end - current_subpos;
index = range_idx / range_dur;
}
/* Fading is done like this:
* - find current position within fade duration
* - get linear % (or rather, index from 0.0 .. 1.0) of duration
* - apply shape to % (from linear fade to curved fade)
* - get final volume for that point
*
* Roughly speaking some curve shapes are better for fades (decay rate is more natural
* sounding in that highest to mid/low happens faster but low to lowest takes more time,
* kinda like a gunshot or bell), and others for crossfades (decay of fade-in + fade-out
* is adjusted so that added volume level stays constant-ish).
*
* As curves can fade in two ways ('normal' and curving 'the other way'), they are adjusted
* to get 'normal' shape on both fades (by reversing index and making 1 - gain), thus some
* curves are complementary (exponential fade-in ~= logarithmic fade-out); the following
* are described taking fade-in = normal.
*/
gain = get_fade_gain_curve(mix->shape, index);
if (mix->vol_start < mix->vol_end) { /* fade in */
cur_vol = mix->vol_start + range_vol * gain;
} else { /* fade out */
cur_vol = mix->vol_end - range_vol * gain; //mix->vol_start - range_vol * (1 - gain);
}
}
else {
/* fade is outside reach */
goto fail;
}
*out_cur_vol = cur_vol;
return 1;
fail:
return 0;
}
void mix_vgmstream(sample_t *outbuf, int32_t sample_count, VGMSTREAM* vgmstream) {
mixing_data *data = vgmstream->mixing_data;
int ch, s, m, ok;
int32_t current_pos, current_subpos;
float temp_f, temp_min, temp_max, cur_vol = 0.0f;
float *temp_mixbuf;
sample_t *temp_outbuf;
const float limiter_max = 32767.0f;
const float limiter_min = -32768.0f;
/* no support or not need to apply */
if (!data || !data->mixing_on || data->mixing_count == 0)
return;
/* try to skip if no ops apply (for example if fade set but does nothing yet) */
current_pos = get_current_pos(vgmstream, sample_count);
if (!is_active(data, current_pos, current_pos + sample_count))
return;
/* use advancing buffer pointers to simplify logic */
temp_mixbuf = data->mixbuf;
temp_outbuf = outbuf;
current_subpos = current_pos;
/* apply mixes in order per channel */
for (s = 0; s < sample_count; s++) {
/* reset after new sample 'step'*/
float *stpbuf = temp_mixbuf;
int step_channels = vgmstream->channels;
for (ch = 0; ch < step_channels; ch++) {
stpbuf[ch] = temp_outbuf[ch]; /* copy current 'lane' */
}
for (m = 0; m < data->mixing_count; m++) {
mix_command_data *mix = &data->mixing_chain[m];
/* mixing ops are designed to apply in order, all channels per 1 sample 'step'. Since some ops change
* total channels, channel number meaning varies as ops move them around, ex:
* - 4ch w/ "1-2,2+3" = ch1<>ch3, ch2(old ch1)+ch3 = 4ch: ch2 ch1+ch3 ch3 ch4
* - 4ch w/ "2+3,1-2" = ch2+ch3, ch1<>ch2(modified) = 4ch: ch2+ch3 ch1 ch3 ch4
* - 2ch w/ "1+2,1u" = ch1+ch2, ch1(add and push rest) = 3ch: ch1' ch1+ch2 ch2
* - 2ch w/ "1u,1+2" = ch1(add and push rest) = 3ch: ch1'+ch1 ch1 ch2
* - 2ch w/ "1-2,1d" = ch1<>ch2, ch1(drop and move ch2(old ch1) to ch1) = ch1
* - 2ch w/ "1d,1-2" = ch1(drop and pull rest), ch1(do nothing, ch2 doesn't exist now) = ch2
*/
switch(mix->command) {
case MIX_SWAP:
temp_f = stpbuf[mix->ch_dst];
stpbuf[mix->ch_dst] = stpbuf[mix->ch_src];
stpbuf[mix->ch_src] = temp_f;
break;
case MIX_ADD:
stpbuf[mix->ch_dst] = stpbuf[mix->ch_dst] + stpbuf[mix->ch_src] * mix->vol;
break;
case MIX_VOLUME:
if (mix->ch_dst < 0) {
for (ch = 0; ch < step_channels; ch++) {
stpbuf[ch] = stpbuf[ch] * mix->vol;
}
}
else {
stpbuf[mix->ch_dst] = stpbuf[mix->ch_dst] * mix->vol;
}
break;
case MIX_LIMIT:
temp_max = limiter_max * mix->vol;
temp_min = limiter_min * mix->vol;
if (mix->ch_dst < 0) {
for (ch = 0; ch < step_channels; ch++) {
if (stpbuf[ch] > temp_max)
stpbuf[ch] = temp_max;
else if (stpbuf[ch] < temp_min)
stpbuf[ch] = temp_min;
}
}
else {
if (stpbuf[mix->ch_dst] > temp_max)
stpbuf[mix->ch_dst] = temp_max;
else if (stpbuf[mix->ch_dst] < temp_min)
stpbuf[mix->ch_dst] = temp_min;
}
break;
case MIX_UPMIX:
step_channels += 1;
for (ch = step_channels - 1; ch > mix->ch_dst; ch--) {
stpbuf[ch] = stpbuf[ch-1]; /* 'push' channels forward (or pull backwards) */
}
stpbuf[mix->ch_dst] = 0; /* inserted as silent */
break;
case MIX_DOWNMIX:
step_channels -= 1;
for (ch = mix->ch_dst; ch < step_channels; ch++) {
stpbuf[ch] = stpbuf[ch+1]; /* 'pull' channels back */
}
break;
case MIX_KILLMIX:
step_channels = mix->ch_dst; /* clamp channels */
break;
case MIX_FADE:
ok = get_fade_gain(mix, &cur_vol, current_subpos);
if (!ok) {
break; /* fade doesn't apply right now */
}
if (mix->ch_dst < 0) {
for (ch = 0; ch < step_channels; ch++) {
stpbuf[ch] = stpbuf[ch] * cur_vol;
}
}
else {
stpbuf[mix->ch_dst] = stpbuf[mix->ch_dst] * cur_vol;
}
break;
default:
break;
}
}
current_subpos++;
temp_mixbuf += step_channels;
temp_outbuf += vgmstream->channels;
}
/* copy resulting mix to output */
for (s = 0; s < sample_count * data->output_channels; s++) {
/* when casting float to int, value is simply truncated:
* - (int)1.7 = 1, (int)-1.7 = -1
* alts for more accurate rounding could be:
* - (int)floor(f)
* - (int)(f < 0 ? f - 0.5f : f + 0.5f)
* - (((int) (f1 + 32768.5)) - 32768)
* - etc
* but since +-1 isn't really audible we'll just cast as it's the fastest
*/
outbuf[s] = clamp16( (int32_t)data->mixbuf[s] );
}
}
/* ******************************************************************* */
void mixing_init(VGMSTREAM* vgmstream) {
mixing_data *data = calloc(1, sizeof(mixing_data));
if (!data) goto fail;
data->mixing_size = VGMSTREAM_MAX_MIXING; /* fixed array for now */
data->mixing_channels = vgmstream->channels;
data->output_channels = vgmstream->channels;
vgmstream->mixing_data = data;
return;
fail:
free(data);
return;
}
void mixing_close(VGMSTREAM* vgmstream) {
mixing_data *data = NULL;
if (!vgmstream) return;
data = vgmstream->mixing_data;
if (!data) return;
free(data->mixbuf);
free(data);
}
void mixing_update_channel(VGMSTREAM* vgmstream) {
mixing_data *data = vgmstream->mixing_data;
if (!data) return;
/* lame hack for dual stereo, but dual stereo is pretty hack-ish to begin with */
data->mixing_channels++;
data->output_channels++;
}
/* ******************************************************************* */
static int add_mixing(VGMSTREAM* vgmstream, mix_command_data *mix) {
mixing_data *data = vgmstream->mixing_data;
if (!data) return 0;
if (data->mixing_on) {
VGM_LOG("MIX: ignoring new mixes when mixing active\n");
return 0; /* to avoid down/upmixing after activation */
}
if (data->mixing_count + 1 > data->mixing_size) {
VGM_LOG("MIX: too many mixes\n");
return 0;
}
data->mixing_chain[data->mixing_count] = *mix; /* memcpy */
data->mixing_count++;
//;VGM_LOG("MIX: total %i\n", data->mixing_count);
return 1;
}
void mixing_push_swap(VGMSTREAM* vgmstream, int ch_dst, int ch_src) {
mixing_data *data = vgmstream->mixing_data;
mix_command_data mix = {0};
if (ch_dst < 0 || ch_src < 0 || ch_dst == ch_src) return;
if (!data || ch_dst >= data->output_channels || ch_src >= data->output_channels) return;
mix.command = MIX_SWAP;
mix.ch_dst = ch_dst;
mix.ch_src = ch_src;
add_mixing(vgmstream, &mix);
}
void mixing_push_add(VGMSTREAM* vgmstream, int ch_dst, int ch_src, double volume) {
mixing_data *data = vgmstream->mixing_data;
mix_command_data mix = {0};
if (!data) return;
//if (volume < 0.0) return; /* negative volume inverts the waveform */
if (volume == 0.0) return; /* ch_src becomes silent and nothing is added */
if (ch_dst < 0 || ch_src < 0) return;
if (!data || ch_dst >= data->output_channels || ch_src >= data->output_channels) return;
mix.command = MIX_ADD; //if (volume == 1.0) MIX_ADD_COPY /* could simplify */
mix.ch_dst = ch_dst;
mix.ch_src = ch_src;
mix.vol = volume;
//;VGM_LOG("MIX: add %i+%i*%f\n", ch_dst,ch_src,volume);
add_mixing(vgmstream, &mix);
}
void mixing_push_volume(VGMSTREAM* vgmstream, int ch_dst, double volume) {
mixing_data *data = vgmstream->mixing_data;
mix_command_data mix = {0};
//if (ch_dst < 0) return; /* means all channels */
//if (volume < 0.0) return; /* negative volume inverts the waveform */
if (volume == 1.0) return; /* no change */
if (!data || ch_dst >= data->output_channels) return;
mix.command = MIX_VOLUME; //if (volume == 0.0) MIX_VOLUME0 /* could simplify */
mix.ch_dst = ch_dst;
mix.vol = volume;
//;VGM_LOG("MIX: volume %i*%f\n", ch_dst,volume);
add_mixing(vgmstream, &mix);
}
void mixing_push_limit(VGMSTREAM* vgmstream, int ch_dst, double volume) {
mixing_data *data = vgmstream->mixing_data;
mix_command_data mix = {0};
//if (ch_dst < 0) return; /* means all channels */
if (volume < 0.0) return;
if (volume == 1.0) return; /* no actual difference */
if (!data || ch_dst >= data->output_channels) return;
//if (volume == 0.0) return; /* dumb but whatevs */
mix.command = MIX_LIMIT;
mix.ch_dst = ch_dst;
mix.vol = volume;
add_mixing(vgmstream, &mix);
}
void mixing_push_upmix(VGMSTREAM* vgmstream, int ch_dst) {
mixing_data *data = vgmstream->mixing_data;
mix_command_data mix = {0};
int ok;
if (ch_dst < 0) return;
if (!data || ch_dst > data->output_channels || data->output_channels +1 > VGMSTREAM_MAX_CHANNELS) return;
/* dst can be == output_channels here, since we are inserting */
mix.command = MIX_UPMIX;
mix.ch_dst = ch_dst;
ok = add_mixing(vgmstream, &mix);
if (ok) {
data->output_channels += 1;
if (data->mixing_channels < data->output_channels)
data->mixing_channels = data->output_channels;
}
}
void mixing_push_downmix(VGMSTREAM* vgmstream, int ch_dst) {
mixing_data *data = vgmstream->mixing_data;
mix_command_data mix = {0};
int ok;
if (ch_dst < 0) return;
if (!data || ch_dst >= data->output_channels || data->output_channels - 1 < 1) return;
mix.command = MIX_DOWNMIX;
mix.ch_dst = ch_dst;
ok = add_mixing(vgmstream, &mix);
if (ok) {
data->output_channels -= 1;
}
}
void mixing_push_killmix(VGMSTREAM* vgmstream, int ch_dst) {
mixing_data *data = vgmstream->mixing_data;
mix_command_data mix = {0};
int ok;
if (ch_dst <= 0) return; /* can't kill from first channel */
if (!data || ch_dst >= data->output_channels) return;
mix.command = MIX_KILLMIX;
mix.ch_dst = ch_dst;
//;VGM_LOG("MIX: killmix %i\n", ch_dst);
ok = add_mixing(vgmstream, &mix);
if (ok) {
data->output_channels = ch_dst; /* clamp channels */
}
}
static mix_command_data* get_last_fade(mixing_data *data, int target_channel) {
int i;
for (i = data->mixing_count; i > 0; i--) {
mix_command_data *mix = &data->mixing_chain[i-1];
if (mix->command != MIX_FADE)
continue;
if (mix->ch_dst == target_channel)
return mix;
}
return NULL;
}
void mixing_push_fade(VGMSTREAM* vgmstream, int ch_dst, double vol_start, double vol_end, char shape,
int32_t time_pre, int32_t time_start, int32_t time_end, int32_t time_post) {
mixing_data *data = vgmstream->mixing_data;
mix_command_data mix = {0};
mix_command_data *mix_prev;
//if (ch_dst < 0) return; /* means all channels */
if (!data || ch_dst >= data->output_channels) return;
if (time_pre > time_start || time_start > time_end || (time_post >= 0 && time_end > time_post)) return;
if (time_start < 0 || time_end < 0) return;
//if (time_pre < 0 || time_post < 0) return; /* special meaning of file start/end */
//if (vol_start == vol_end) /* weird but let in case of being used to cancel others fades... maybe? */
if (shape == '{' || shape == '}')
shape = 'E';
if (shape == '(' || shape == ')')
shape = 'H';
mix.command = MIX_FADE;
mix.ch_dst = ch_dst;
mix.vol_start = vol_start;
mix.vol_end = vol_end;
mix.shape = shape;
mix.time_pre = time_pre;
mix.time_start = time_start;
mix.time_end = time_end;
mix.time_post = time_post;
/* cancel fades and optimize a bit when using negative pre/post:
* - fades work like this:
* <----------|----------|---------->
* pre1 start1 end1 post1
* - when pre and post are set nothing is done (fade is exact and multiple fades may overlap)
* - when previous fade's post or current fade's pre are negative (meaning file end/start)
* they should cancel each other (to allow chaning fade-in + fade-out + fade-in + etc):
* <----------|----------|----------| |----------|----------|---------->
* pre1 start1 end1 post1 pre2 start2 end2 post2
* - other cases (previous fade is actually after/in-between current fade) are ignored
* as they're uncommon and hard to optimize
* fades cancel fades of the same channel, and 'all channel' (-1) fades also cancel 'all channels'
*/
mix_prev = get_last_fade(data, mix.ch_dst);
if (mix_prev == NULL) {
if (vol_start == 1.0 && time_pre < 0)
time_pre = time_start; /* fade-out helds default volume before fade start can be clamped */
if (vol_end == 1.0 && time_post < 0)
time_post = time_end; /* fade-in helds default volume after fade end can be clamped */
}
else if (mix_prev->time_post < 0 || mix.time_pre < 0) {
int is_prev = 1;
if ((mix_prev->time_end > mix.time_start) ||
(mix_prev->time_post >= 0 && mix_prev->time_post > mix.time_start) ||
(mix.time_pre >= 0 && mix.time_pre < mix_prev->time_end))
is_prev = 0;
if (is_prev) {
/* change negative values to actual points */
if (mix_prev->time_post < 0 && mix_prev->time_post < 0) {
mix_prev->time_post = mix_prev->time_end;
mix.time_pre = mix_prev->time_post;
}
if (mix_prev->time_post >= 0 && mix.time_pre < 0) {
mix.time_pre = mix_prev->time_post;
}
else if (mix_prev->time_post < 0 && mix.time_pre >= 0) {
mix_prev->time_post = mix.time_pre;
}
/* else: both define start/ends, do nothing */
}
/* should only modify prev if add_mixing but meh */
}
//;VGM_LOG("MIX: fade %i^%f~%f=%c@%i~%i~%i~%i\n", ch_dst, vol_start, vol_end, shape, time_pre, time_start, time_end, time_post);
add_mixing(vgmstream, &mix);
}
/* ******************************************************************* */
void mixing_macro_volume(VGMSTREAM* vgmstream, double volume, uint32_t mask) {
mixing_data *data = vgmstream->mixing_data;
int ch;
if (!data)
return;
if (mask == 0) {
mixing_push_volume(vgmstream, -1, volume);
return;
}
for (ch = 0; ch < data->output_channels; ch++) {
if (!((mask >> ch) & 1))
continue;
mixing_push_volume(vgmstream, ch, volume);
}
}
void mixing_macro_track(VGMSTREAM* vgmstream, uint32_t mask) {
mixing_data *data = vgmstream->mixing_data;
int ch;
if (!data)
return;
if (mask == 0) {
return;
}
/* reverse remove all channels (easier this way as when removing channels numbers change) */
for (ch = data->output_channels - 1; ch >= 0; ch--) {
if ((mask >> ch) & 1)
continue;
mixing_push_downmix(vgmstream, ch);
}
}
void mixing_macro_layer(VGMSTREAM* vgmstream, int max, uint32_t mask, char mode) {
mixing_data *data = vgmstream->mixing_data;
int current, ch, output_channels, selected_channels;
if (!data)
return;
if (max <= 0 || data->output_channels <= max)
return;
/* set all channels (non-existant channels will be ignored) */
if (mask == 0) {
mask = ~mask;
}
/* save before adding fake channels */
output_channels = data->output_channels;
/* count possibly set channels */
selected_channels = 0;
for (ch = 0; ch < output_channels; ch++) {
selected_channels += (mask >> ch) & 1;
}
/* make N fake channels at the beginning for easier calcs */
for (ch = 0; ch < max; ch++) {
mixing_push_upmix(vgmstream, 0);
}
/* add all layers in this order: ch0: 0, 0+N, 0+N*2 ... / ch1: 1, 1+N ... */
current = 0;
for (ch = 0; ch < output_channels; ch++) {
double volume = 1.0;
if (!((mask >> ch) & 1))
continue;
/* mode 'v': same volume for all layers (for layered vocals) */
/* mode 'b': volume adjusted depending on layers (for layered bgm) */
/* mode 'e': volume adjusted equally for all layers (for generic downmixing) */
if (mode == 'b' && ch < max) {
/* reduce a bit main channels (see below) */
int channel_mixes = selected_channels / max;
if (current < selected_channels % (channel_mixes * max)) /* may be simplified? */
channel_mixes += 1;
channel_mixes -= 1; /* better formula? */
if (channel_mixes <= 0) /* ??? */
channel_mixes = 1;
volume = 1 / sqrt(channel_mixes);
}
if ((mode == 'b' && ch >= max) || (mode == 'e')) {
/* find how many will be mixed in current channel (earlier channels receive more
* mixes than later ones, ex: selected 8ch + max 3ch: ch0=0+3+6, ch1=1+4+7, ch2=2+5) */
int channel_mixes = selected_channels / max;
if (channel_mixes <= 0) /* ??? */
channel_mixes = 1;
if (current < selected_channels % (channel_mixes * max)) /* may be simplified? */
channel_mixes += 1;
volume = 1 / sqrt(channel_mixes); /* "power" add */
}
//;VGM_LOG("MIX: layer ch=%i, cur=%i, v=%f\n", ch, current, volume);
mixing_push_add(vgmstream, current, max + ch, volume); /* ch adjusted considering upmixed channels */
current++;
if (current >= max)
current = 0;
}
/* remove all mixed channels */
mixing_push_killmix(vgmstream, max);
}
void mixing_macro_crosstrack(VGMSTREAM* vgmstream, int max) {
mixing_data *data = vgmstream->mixing_data;
int current, ch, track, track_ch, track_num, output_channels;
int32_t change_pos, change_next, change_time;
if (!data)
return;
if (max <= 0 || data->output_channels <= max)
return;
if (!vgmstream->loop_flag) /* maybe force loop? */
return;
/* this probably only makes sense for even channels so upmix before if needed) */
output_channels = data->output_channels;
if (output_channels % 2) {
mixing_push_upmix(vgmstream, output_channels);
output_channels += 1;
}
/* set loops to hear all track changes */
track_num = output_channels / max;
if (vgmstream->config.loop_count < track_num)
vgmstream->config.loop_count = track_num;
ch = 0;
for (track = 0; track < track_num; track++) {
double volume = 1.0; /* won't play at the same time, no volume change needed */
int loop_pre = vgmstream->loop_start_sample;
int loop_samples = vgmstream->loop_end_sample - vgmstream->loop_start_sample;
change_pos = loop_pre + loop_samples * track;
change_next = loop_pre + loop_samples * (track + 1);
change_time = 15.0 * vgmstream->sample_rate; /* in secs */
for (track_ch = 0; track_ch < max; track_ch++) {
if (track > 0) { /* fade-in when prev track fades-out */
mixing_push_fade(vgmstream, ch + track_ch, 0.0, volume, '(', -1, change_pos, change_pos + change_time, -1);
}
if (track + 1 < track_num) { /* fade-out when next track fades-in */
mixing_push_fade(vgmstream, ch + track_ch, volume, 0.0, ')', -1, change_next, change_next + change_time, -1);
}
}
ch += max;
}
/* mix all tracks into first */
current = 0;
for (ch = max; ch < output_channels; ch++) {
mixing_push_add(vgmstream, current, ch, 1.0); /* won't play at the same time, no volume change needed */
current++;
if (current >= max)
current = 0;
}
/* remove unneeded channels */
mixing_push_killmix(vgmstream, max);
}
void mixing_macro_crosslayer(VGMSTREAM* vgmstream, int max, char mode) {
mixing_data *data = vgmstream->mixing_data;
int current, ch, layer, layer_ch, layer_num, loop, output_channels;
int32_t change_pos, change_time;
if (!data)
return;
if (max <= 0 || data->output_channels <= max)
return;
if (!vgmstream->loop_flag) /* maybe force loop? */
return;
/* this probably only makes sense for even channels so upmix before if needed) */
output_channels = data->output_channels;
if (output_channels % 2) {
mixing_push_upmix(vgmstream, output_channels);
output_channels += 1;
}
/* set loops to hear all track changes */
layer_num = output_channels / max;
if (vgmstream->config.loop_count < layer_num)
vgmstream->config.loop_count = layer_num;
/* mode 'v': constant volume
* mode 'e': sets fades to successively lower/equalize volume per loop for each layer
* (to keep final volume constant-ish), ex. 3 layers/loops, 2 max:
* - layer0 (ch0+1): loop0 --[1.0]--, loop1 )=1.0..0.7, loop2 )=0.7..0.5, loop3 --[0.5/end]--
* - layer1 (ch2+3): loop0 --[0.0]--, loop1 (=0.0..0.7, loop2 )=0.7..0.5, loop3 --[0.5/end]--
* - layer2 (ch4+5): loop0 --[0.0]--, loop1 ---[0.0]--, loop2 (=0.0..0.5, loop3 --[0.5/end]--
* mode 'b': similar but 1st layer (main) has higher/delayed volume:
* - layer0 (ch0+1): loop0 --[1.0]--, loop1 )=1.0..1.0, loop2 )=1.0..0.7, loop3 --[0.7/end]--
*/
for (loop = 1; loop < layer_num; loop++) {
double volume1 = 1.0;
double volume2 = 1.0;
int loop_pre = vgmstream->loop_start_sample;
int loop_samples = vgmstream->loop_end_sample - vgmstream->loop_start_sample;
change_pos = loop_pre + loop_samples * loop;
change_time = 10.0 * vgmstream->sample_rate; /* in secs */
if (mode == 'e') {
volume1 = 1 / sqrt(loop + 0);
volume2 = 1 / sqrt(loop + 1);
}
ch = 0;
for (layer = 0; layer < layer_num; layer++) {
char type;
if (mode == 'b') {
if (layer == 0) {
volume1 = 1 / sqrt(loop - 1 <= 0 ? 1 : loop - 1);
volume2 = 1 / sqrt(loop + 0);
}
else {
volume1 = 1 / sqrt(loop + 0);
volume2 = 1 / sqrt(loop + 1);
}
}
if (layer > loop) { /* not playing yet (volume is implicitly 0.0 from first fade in) */
continue;
} else if (layer == loop) { /* fades in for the first time */
volume1 = 0.0;
type = '(';
} else { /* otherwise fades out to match other layers's volume */
type = ')';
}
//;VGM_LOG("MIX: loop=%i, layer %i, vol1=%f, vol2=%f\n", loop, layer, volume1, volume2);
for (layer_ch = 0; layer_ch < max; layer_ch++) {
mixing_push_fade(vgmstream, ch + layer_ch, volume1, volume2, type, -1, change_pos, change_pos + change_time, -1);
}
ch += max;
}
}
/* mix all tracks into first */
current = 0;
for (ch = max; ch < output_channels; ch++) {
mixing_push_add(vgmstream, current, ch, 1.0);
current++;
if (current >= max)
current = 0;
}
/* remove unneeded channels */
mixing_push_killmix(vgmstream, max);
}
typedef enum {
pos_FL = 0,
pos_FR = 1,
pos_FC = 2,
pos_LFE = 3,
pos_BL = 4,
pos_BR = 5,
pos_FLC = 6,
pos_FRC = 7,
pos_BC = 8,
pos_SL = 9,
pos_SR = 10,
} mixing_position_t;
void mixing_macro_downmix(VGMSTREAM* vgmstream, int max /*, mapping_t output_mapping*/) {
mixing_data *data = vgmstream->mixing_data;
int ch, output_channels, mp_in, mp_out, ch_in, ch_out;
mapping_t input_mapping, output_mapping;
const double vol_max = 1.0;
const double vol_sqrt = 1 / sqrt(2);
const double vol_half = 1 / 2;
double matrix[16][16] = {{0}};
if (!data)
return;
if (max <= 1 || data->output_channels <= max || max >= 8)
return;
/* assume WAV defaults if not set */
input_mapping = vgmstream->channel_layout;
if (input_mapping == 0) {
switch(data->output_channels) {
case 1: input_mapping = mapping_MONO; break;
case 2: input_mapping = mapping_STEREO; break;
case 3: input_mapping = mapping_2POINT1; break;
case 4: input_mapping = mapping_QUAD; break;
case 5: input_mapping = mapping_5POINT0; break;
case 6: input_mapping = mapping_5POINT1; break;
case 7: input_mapping = mapping_7POINT0; break;
case 8: input_mapping = mapping_7POINT1; break;
default: return;
}
}
/* build mapping matrix[input channel][output channel] = volume,
* using standard WAV/AC3 downmix formulas
* - https://www.audiokinetic.com/library/edge/?source=Help&id=downmix_tables
* - https://www.audiokinetic.com/library/edge/?source=Help&id=standard_configurations
*/
switch(max) {
case 1:
output_mapping = mapping_MONO;
matrix[pos_FL][pos_FC] = vol_sqrt;
matrix[pos_FR][pos_FC] = vol_sqrt;
matrix[pos_FC][pos_FC] = vol_max;
matrix[pos_SL][pos_FC] = vol_half;
matrix[pos_SR][pos_FC] = vol_half;
matrix[pos_BL][pos_FC] = vol_half;
matrix[pos_BR][pos_FC] = vol_half;
break;
case 2:
output_mapping = mapping_STEREO;
matrix[pos_FL][pos_FL] = vol_max;
matrix[pos_FR][pos_FR] = vol_max;
matrix[pos_FC][pos_FL] = vol_sqrt;
matrix[pos_FC][pos_FR] = vol_sqrt;
matrix[pos_SL][pos_FL] = vol_sqrt;
matrix[pos_SR][pos_FR] = vol_sqrt;
matrix[pos_BL][pos_FL] = vol_sqrt;
matrix[pos_BR][pos_FR] = vol_sqrt;
break;
default:
/* not sure if +3ch would use FC/LFE, SL/BR and whatnot without passing extra config, so ignore for now */
return;
}
/* save and make N fake channels at the beginning for easier calcs */
output_channels = data->output_channels;
for (ch = 0; ch < max; ch++) {
mixing_push_upmix(vgmstream, 0);
}
/* downmix */
ch_in = 0;
for (mp_in = 0; mp_in < 16; mp_in++) {
/* read input mapping (ex. 5.1) and find channel */
if (!(input_mapping & (1<<mp_in)))
continue;
ch_out = 0;
for (mp_out = 0; mp_out < 16; mp_out++) {
/* read output mapping (ex. 2.0) and find channel */
if (!(output_mapping & (1<<mp_out)))
continue;
mixing_push_add(vgmstream, ch_out, max + ch_in, matrix[mp_in][mp_out]);
ch_out++;
if (ch_out > max)
break;
}
ch_in++;
if (ch_in >= output_channels)
break;
}
/* remove unneeded channels */
mixing_push_killmix(vgmstream, max);
}
/* ******************************************************************* */
void mixing_setup(VGMSTREAM * vgmstream, int32_t max_sample_count) {
mixing_data *data = vgmstream->mixing_data;
float *mixbuf_re = NULL;
if (!data) goto fail;
/* a bit wonky but eh... */
if (vgmstream->channel_layout && vgmstream->channels != data->output_channels) {
vgmstream->channel_layout = 0;
((VGMSTREAM*)vgmstream->start_vgmstream)->channel_layout = 0;
}
/* special value to not actually enable anything (used to query values) */
if (max_sample_count <= 0)
goto fail;
/* create or alter internal buffer */
mixbuf_re = realloc(data->mixbuf, max_sample_count*data->mixing_channels*sizeof(float));
if (!mixbuf_re) goto fail;
data->mixbuf = mixbuf_re;
data->mixing_on = 1;
/* since data exists on its own memory and pointer is already set
* there is no need to propagate to start_vgmstream */
/* segments/layers are independant from external buffers and may always mix */
return;
fail:
return;
}
void mixing_info(VGMSTREAM * vgmstream, int *out_input_channels, int *out_output_channels) {
mixing_data *data = vgmstream->mixing_data;
int input_channels, output_channels;
if (!data) goto fail;
output_channels = data->output_channels;
if (data->output_channels > vgmstream->channels)
input_channels = data->output_channels;
else
input_channels = vgmstream->channels;
if (out_input_channels) *out_input_channels = input_channels;
if (out_output_channels) *out_output_channels = output_channels;
//;VGM_LOG("MIX: channels %i, in=%i, out=%i, mix=%i\n", vgmstream->channels, input_channels, output_channels, data->mixing_channels);
return;
fail:
return;
}
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