SINT ReadAheadManager::getNextSamples(double dRate, CSAMPLE* pOutput,
SINT requested_samples) {
// TODO(XXX): Remove implicit assumption of 2 channels
if (!even(requested_samples)) {
qDebug() << "ERROR: Non-even requested_samples to ReadAheadManager::getNextSamples";
requested_samples--;
}
bool in_reverse = dRate < 0;
//qDebug() << "start" << start_sample << requested_samples;
// A loop will only limit the amount we can read in one shot.
const double loop_trigger = m_pLoopingControl->nextTrigger(
dRate, m_currentPosition, 0, 0);
bool loop_active = loop_trigger != kNoTrigger;
SINT preloop_samples = 0;
double samplesToLoopTrigger = 0.0;
SINT samples_from_reader = requested_samples;
if (loop_active) {
samplesToLoopTrigger = in_reverse ?
m_currentPosition - loop_trigger :
loop_trigger - m_currentPosition;
if (samplesToLoopTrigger < 0) {
// We have already passed the loop trigger
samples_from_reader = 0;
} else {
// We can only read whole frames from the reader.
// Use ceil here, to be sure to reach the loop trigger.
preloop_samples = SampleUtil::ceilPlayPosToFrameStart(samplesToLoopTrigger,
kNumChannels);
// clamp requested samples from the caller to the loop trigger point
samples_from_reader = math_clamp(requested_samples,
static_cast<SINT>(0), preloop_samples);
}
}
// Sanity checks.
if (samples_from_reader < 0) {
qDebug() << "Need negative samples in ReadAheadManager::getNextSamples. Ignoring read";
return 0;
}
SINT start_sample = SampleUtil::roundPlayPosToFrameStart(
m_currentPosition, kNumChannels);
SINT samples_read = m_pReader->read(
start_sample, samples_from_reader, in_reverse, pOutput);
if (samples_read != samples_from_reader) {
qDebug() << "didn't get what we wanted" << samples_read << samples_from_reader;
}
// Increment or decrement current read-ahead position
// Mixing int and double here is desired, because the fractional frame should
// be resist
if (in_reverse) {
addReadLogEntry(m_currentPosition, m_currentPosition - samples_read);
m_currentPosition -= samples_read;
} else {
addReadLogEntry(m_currentPosition, m_currentPosition + samples_read);
m_currentPosition += samples_read;
}
// Activate on this trigger if necessary
if (loop_active) {
// LoopingControl makes the decision about whether we should loop or
// not.
const double loop_target = m_pLoopingControl->process(
dRate, m_currentPosition, 0, 0);
if (loop_target != kNoTrigger) {
m_currentPosition = loop_target;
if (preloop_samples > 0) {
// we are up to one frame ahead of the loop trigger
double overshoot = preloop_samples - samplesToLoopTrigger;
// start the loop later accordingly to be sure the loop length is as desired
// e.g. exactly one bar.
m_currentPosition += overshoot;
// Example in frames;
// loop start 1.1 loop end 3.3 loop length 2.2
// m_currentPosition samplesToLoopTrigger preloop_samples
// 2.0 1.3 2
// 1.8 1.5 2
// 1.6 1.7 2
// 1.4 1.9 2
// 1.2 2.1 3
// Average preloop_samples = 2.2
}
// start reading before the loop start point, to crossfade these samples
// with the samples we need to the loop end
int loop_read_position = SampleUtil::roundPlayPosToFrameStart(
m_currentPosition + (in_reverse ? preloop_samples : -preloop_samples), kNumChannels);
int looping_samples_read = m_pReader->read(
loop_read_position, samples_read, in_reverse, m_pCrossFadeBuffer);
if (looping_samples_read != samples_read) {
qDebug() << "ERROR: Couldn't get all needed samples for crossfade.";
}
// do crossfade from the current buffer into the new loop beginning
if (samples_read != 0) { // avoid division by zero
SampleUtil::linearCrossfadeBuffers(pOutput, pOutput, m_pCrossFadeBuffer, samples_read);
}
}
}
//qDebug() << "read" << m_currentPosition << samples_read;
return samples_read;
}
int ReadAheadManager::getNextSamples(double dRate, CSAMPLE* buffer,
int requested_samples) {
if (!even(requested_samples)) {
qDebug() << "ERROR: Non-even requested_samples to ReadAheadManager::getNextSamples";
requested_samples--;
}
bool in_reverse = dRate < 0;
int start_sample = m_iCurrentPosition;
//qDebug() << "start" << start_sample << requested_samples;
int samples_needed = requested_samples;
CSAMPLE* base_buffer = buffer;
// A loop will only limit the amount we can read in one shot.
const double loop_trigger = m_sEngineControls[0]->nextTrigger(
dRate, m_iCurrentPosition, 0, 0);
bool loop_active = loop_trigger != kNoTrigger;
int preloop_samples = 0;
if (loop_active) {
int samples_available = in_reverse ?
m_iCurrentPosition - loop_trigger :
loop_trigger - m_iCurrentPosition;
preloop_samples = samples_available;
samples_needed = math_max(0, math_min(samples_needed,
samples_available));
}
if (in_reverse) {
start_sample = m_iCurrentPosition - samples_needed;
}
// Sanity checks.
if (samples_needed < 0) {
qDebug() << "Need negative samples in ReadAheadManager::getNextSamples. Ignoring read";
return 0;
}
int samples_read = m_pReader->read(start_sample, samples_needed,
base_buffer);
if (samples_read != samples_needed) {
qDebug() << "didn't get what we wanted" << samples_read << samples_needed;
}
// Increment or decrement current read-ahead position
if (in_reverse) {
addReadLogEntry(m_iCurrentPosition, m_iCurrentPosition - samples_read);
m_iCurrentPosition -= samples_read;
} else {
addReadLogEntry(m_iCurrentPosition, m_iCurrentPosition + samples_read);
m_iCurrentPosition += samples_read;
}
// Activate on this trigger if necessary
if (loop_active) {
// LoopingControl makes the decision about whether we should loop or
// not.
const double loop_target = m_sEngineControls[0]->
process(dRate, m_iCurrentPosition, 0, 0);
if (loop_target != kNoTrigger) {
m_iCurrentPosition = loop_target;
int loop_read_position = m_iCurrentPosition +
(in_reverse ? preloop_samples : -preloop_samples);
int looping_samples_read = m_pReader->read(
loop_read_position, samples_read, m_pCrossFadeBuffer);
if (looping_samples_read != samples_read) {
qDebug() << "ERROR: Couldn't get all needed samples for crossfade.";
}
// do crossfade from the current buffer into the new loop beginning
double mix_amount = 0.0;
double mix_inc = 2.0 / static_cast<double>(samples_read);
for (int i = 0; i < samples_read; i += 2) {
base_buffer[i] = base_buffer[i] * (1.0 - mix_amount) + m_pCrossFadeBuffer[i] * mix_amount;
base_buffer[i+1] = base_buffer[i+1] * (1.0 - mix_amount) + m_pCrossFadeBuffer[i+1] * mix_amount;
mix_amount += mix_inc;
}
}
}
// Reverse the samples in-place
if (in_reverse) {
// TODO(rryan) pull this into MixxxUtil or something
CSAMPLE temp1, temp2;
for (int j = 0; j < samples_read/2; j += 2) {
const int endpos = samples_read-1-j-1;
temp1 = base_buffer[j];
temp2 = base_buffer[j+1];
base_buffer[j] = base_buffer[endpos];
base_buffer[j+1] = base_buffer[endpos+1];
base_buffer[endpos] = temp1;
base_buffer[endpos+1] = temp2;
}
}
//qDebug() << "read" << m_iCurrentPosition << samples_read;
return samples_read;
}
int ReadAheadManager::getNextSamples(double dRate, CSAMPLE* buffer,
int requested_samples) {
if (!even(requested_samples)) {
qDebug() << "ERROR: Non-even requested_samples to ReadAheadManager::getNextSamples";
requested_samples--;
}
bool in_reverse = dRate < 0;
int start_sample = m_iCurrentPosition;
//qDebug() << "start" << start_sample << requested_samples;
int samples_needed = requested_samples;
CSAMPLE* base_buffer = buffer;
// A loop will only limit the amount we can read in one shot.
const double loop_trigger = m_pLoopingControl->nextTrigger(
dRate, m_iCurrentPosition, 0, 0);
bool loop_active = loop_trigger != kNoTrigger;
int preloop_samples = 0;
if (loop_active) {
int samples_available = in_reverse ?
m_iCurrentPosition - loop_trigger :
loop_trigger - m_iCurrentPosition;
if (samples_available < 0) {
samples_needed = 0;
} else {
preloop_samples = samples_available;
samples_needed = math_clamp(samples_needed, 0, samples_available);
}
}
if (in_reverse) {
start_sample = m_iCurrentPosition - samples_needed;
}
// Sanity checks.
if (samples_needed < 0) {
qDebug() << "Need negative samples in ReadAheadManager::getNextSamples. Ignoring read";
return 0;
}
int samples_read = m_pReader->read(start_sample, in_reverse, samples_needed,
base_buffer);
if (samples_read != samples_needed) {
qDebug() << "didn't get what we wanted" << samples_read << samples_needed;
}
// Increment or decrement current read-ahead position
if (in_reverse) {
addReadLogEntry(m_iCurrentPosition, m_iCurrentPosition - samples_read);
m_iCurrentPosition -= samples_read;
} else {
addReadLogEntry(m_iCurrentPosition, m_iCurrentPosition + samples_read);
m_iCurrentPosition += samples_read;
}
// Activate on this trigger if necessary
if (loop_active) {
// LoopingControl makes the decision about whether we should loop or
// not.
const double loop_target = m_pLoopingControl->
process(dRate, m_iCurrentPosition, 0, 0);
if (loop_target != kNoTrigger) {
m_iCurrentPosition = loop_target;
int loop_read_position = m_iCurrentPosition +
(in_reverse ? preloop_samples : -preloop_samples);
int looping_samples_read = m_pReader->read(
loop_read_position, in_reverse, samples_read, m_pCrossFadeBuffer);
if (looping_samples_read != samples_read) {
qDebug() << "ERROR: Couldn't get all needed samples for crossfade.";
}
// do crossfade from the current buffer into the new loop beginning
if (samples_read != 0) { // avoid division by zero
SampleUtil::linearCrossfadeBuffers(base_buffer, base_buffer, m_pCrossFadeBuffer, samples_read);
}
}
}
//qDebug() << "read" << m_iCurrentPosition << samples_read;
return samples_read;
}
