void resample_start (int * channels, int * rate)
{
if (state)
{
src_delete (state);
state = NULL;
}
int new_rate = 0;
if (aud_get_bool ("resample", "use-mappings"))
{
char rate_s[16];
str_itoa (* rate, rate_s, sizeof rate_s);
new_rate = aud_get_int ("resample", rate_s);
}
if (! new_rate)
new_rate = aud_get_int ("resample", "default-rate");
new_rate = CLAMP (new_rate, MIN_RATE, MAX_RATE);
if (new_rate == * rate)
return;
int method = aud_get_int ("resample", "method");
int error;
if ((state = src_new (method, * channels, & error)) == NULL)
{
RESAMPLE_ERROR (error);
return;
}
stored_channels = * channels;
ratio = (double) new_rate / * rate;
* rate = new_rate;
}
void
resample_scale_ref (ResampleState * r)
{
if (r->need_reinit) {
RESAMPLE_DEBUG ("sample size %d", r->sample_size);
if (r->buffer)
free (r->buffer);
r->buffer_len = r->sample_size * r->filter_length;
r->buffer = malloc (r->buffer_len);
memset (r->buffer, 0, r->buffer_len);
r->buffer_filled = 0;
r->i_inc = r->o_rate / r->i_rate;
r->o_inc = r->i_rate / r->o_rate;
RESAMPLE_DEBUG ("i_inc %g o_inc %g", r->i_inc, r->o_inc);
r->i_start = -r->i_inc * r->filter_length;
r->need_reinit = 0;
#if 0
if (r->i_inc < 1.0) {
r->sinc_scale = r->i_inc;
if (r->sinc_scale == 0.5) {
/* strange things happen at integer multiples */
r->sinc_scale = 1.0;
}
} else {
r->sinc_scale = 1.0;
}
#else
r->sinc_scale = 1.0;
#endif
}
RESAMPLE_DEBUG ("asked to resample %d bytes", r->o_size);
RESAMPLE_DEBUG ("%d bytes in queue",
audioresample_buffer_queue_get_depth (r->queue));
while (r->o_size >= r->sample_size) {
double midpoint;
int i;
int j;
midpoint = r->i_start + (r->filter_length - 1) * 0.5 * r->i_inc;
RESAMPLE_DEBUG
("still need to output %d bytes, %d input left, i_start %g, midpoint %f",
r->o_size, audioresample_buffer_queue_get_depth (r->queue), r->i_start,
midpoint);
if (midpoint > 0.5 * r->i_inc) {
RESAMPLE_ERROR ("inconsistent state");
}
while (midpoint < -0.5 * r->i_inc) {
AudioresampleBuffer *buffer;
RESAMPLE_DEBUG ("midpoint %f < %f, r->i_inc %f", midpoint,
-0.5 * r->i_inc, r->i_inc);
buffer = audioresample_buffer_queue_pull (r->queue, r->sample_size);
if (buffer == NULL) {
/* FIXME: for the first buffer, this isn't necessarily an error,
* since because of the filter length we'll output less buffers.
* deal with that so we don't print to console */
RESAMPLE_ERROR ("buffer_queue_pull returned NULL");
return;
}
r->i_start += r->i_inc;
RESAMPLE_DEBUG ("pulling (i_start = %g)", r->i_start);
midpoint += r->i_inc;
memmove (r->buffer, r->buffer + r->sample_size,
r->buffer_len - r->sample_size);
memcpy (r->buffer + r->buffer_len - r->sample_size, buffer->data,
r->sample_size);
r->buffer_filled = MIN (r->buffer_filled + r->sample_size, r->buffer_len);
audioresample_buffer_unref (buffer);
}
switch (r->format) {
case RESAMPLE_FORMAT_S16:
for (i = 0; i < r->n_channels; i++) {
double acc = 0;
double offset;
double x;
for (j = 0; j < r->filter_length; j++) {
offset = (r->i_start + j * r->i_inc) * r->o_inc;
x = *(int16_t *) (r->buffer + i * sizeof (int16_t) +
j * r->sample_size);
acc +=
resample_sinc_window (offset, r->filter_length * 0.5,
r->sinc_scale) * x;
}
if (acc < -32768.0)
acc = -32768.0;
if (acc > 32767.0)
acc = 32767.0;
*(int16_t *) (r->o_buf + i * sizeof (int16_t)) = rint (acc);
}
break;
case RESAMPLE_FORMAT_S32:
for (i = 0; i < r->n_channels; i++) {
double acc = 0;
double offset;
double x;
for (j = 0; j < r->filter_length; j++) {
offset = (r->i_start + j * r->i_inc) * r->o_inc;
x = *(int32_t *) (r->buffer + i * sizeof (int32_t) +
j * r->sample_size);
acc +=
resample_sinc_window (offset, r->filter_length * 0.5,
r->sinc_scale) * x;
}
if (acc < -2147483648.0)
acc = -2147483648.0;
if (acc > 2147483647.0)
acc = 2147483647.0;
*(int32_t *) (r->o_buf + i * sizeof (int32_t)) = rint (acc);
}
break;
case RESAMPLE_FORMAT_F32:
for (i = 0; i < r->n_channels; i++) {
double acc = 0;
double offset;
double x;
for (j = 0; j < r->filter_length; j++) {
offset = (r->i_start + j * r->i_inc) * r->o_inc;
x = *(float *) (r->buffer + i * sizeof (float) +
j * r->sample_size);
acc +=
resample_sinc_window (offset, r->filter_length * 0.5,
r->sinc_scale) * x;
}
*(float *) (r->o_buf + i * sizeof (float)) = acc;
}
break;
case RESAMPLE_FORMAT_F64:
for (i = 0; i < r->n_channels; i++) {
double acc = 0;
double offset;
double x;
for (j = 0; j < r->filter_length; j++) {
offset = (r->i_start + j * r->i_inc) * r->o_inc;
x = *(double *) (r->buffer + i * sizeof (double) +
j * r->sample_size);
acc +=
resample_sinc_window (offset, r->filter_length * 0.5,
r->sinc_scale) * x;
}
*(double *) (r->o_buf + i * sizeof (double)) = acc;
}
break;
}
r->i_start -= 1.0;
r->o_buf += r->sample_size;
r->o_size -= r->sample_size;
}
}