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/*
Copyright (C) 2012 Paul Davis
Author: Sakari Bergen
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., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include "audiographer/general/sr_converter.h"
#include "audiographer/exception.h"
#include "audiographer/type_utils.h"
#include <cmath>
#include <boost/format.hpp>
namespace AudioGrapher
{
using boost::format;
using boost::str;
SampleRateConverter::SampleRateConverter (uint32_t channels)
: active (false)
, channels (channels)
, max_samples_in(0)
, leftover_data (0)
, leftover_samples (0)
, max_leftover_samples (0)
, data_out (0)
, data_out_size (0)
, src_state (0)
{
add_supported_flag (ProcessContext<>::EndOfInput);
}
void
SampleRateConverter::init (samplecnt_t in_rate, samplecnt_t out_rate, int quality)
{
reset();
if (in_rate == out_rate) {
src_data.src_ratio = 1;
return;
}
active = true;
int err;
src_state = src_new (quality, channels, &err);
if (throw_level (ThrowObject) && !src_state) {
throw Exception (*this, str (format
("Cannot initialize sample rate converter: %1%")
% src_strerror (err)));
}
src_data.src_ratio = (double) out_rate / (double) in_rate;
}
SampleRateConverter::~SampleRateConverter ()
{
reset();
}
samplecnt_t
SampleRateConverter::allocate_buffers (samplecnt_t max_samples)
{
if (!active) { return max_samples; }
samplecnt_t max_samples_out = (samplecnt_t) ceil (max_samples * src_data.src_ratio);
max_samples_out -= max_samples_out % channels;
if (data_out_size < max_samples_out) {
delete[] data_out;
data_out = new float[max_samples_out];
src_data.data_out = data_out;
max_leftover_samples = 4 * max_samples;
leftover_data = (float *) realloc (leftover_data, max_leftover_samples * sizeof (float));
if (throw_level (ThrowObject) && !leftover_data) {
throw Exception (*this, "A memory allocation error occurred");
}
max_samples_in = max_samples;
data_out_size = max_samples_out;
}
return max_samples_out;
}
void
SampleRateConverter::process (ProcessContext<float> const & c)
{
check_flags (*this, c);
if (!active) {
output (c);
return;
}
samplecnt_t samples = c.samples();
float * in = const_cast<float *> (c.data()); // TODO check if this is safe!
if (throw_level (ThrowProcess) && samples > max_samples_in) {
throw Exception (*this, str (format (
"process() called with too many samples, %1% instead of %2%")
% samples % max_samples_in));
}
int err;
bool first_time = true;
do {
src_data.output_frames = data_out_size / channels;
src_data.data_out = data_out;
if (leftover_samples > 0) {
/* input data will be in leftover_data rather than data_in */
src_data.data_in = leftover_data;
if (first_time) {
/* first time, append new data from data_in into the leftover_data buffer */
TypeUtils<float>::copy (in, &leftover_data [leftover_samples * channels], samples);
src_data.input_frames = samples / channels + leftover_samples;
} else {
/* otherwise, just use whatever is still left in leftover_data; the contents
were adjusted using memmove() right after the last SRC call (see
below)
*/
src_data.input_frames = leftover_samples;
}
} else {
src_data.data_in = in;
src_data.input_frames = samples / channels;
}
first_time = false;
if (debug_level (DebugVerbose)) {
debug_stream() << "data_in: " << src_data.data_in <<
", input_frames: " << src_data.input_frames <<
", data_out: " << src_data.data_out <<
", output_frames: " << src_data.output_frames << std::endl;
}
err = src_process (src_state, &src_data);
if (throw_level (ThrowProcess) && err) {
throw Exception (*this, str (format
("An error occurred during sample rate conversion: %1%")
% src_strerror (err)));
}
leftover_samples = src_data.input_frames - src_data.input_frames_used;
if (leftover_samples > 0) {
if (throw_level (ThrowProcess) && leftover_samples > max_leftover_samples) {
throw Exception(*this, "leftover samples overflowed");
}
TypeUtils<float>::move (&src_data.data_in[src_data.input_frames_used * channels],
leftover_data, leftover_samples * channels);
}
ProcessContext<float> c_out (c, data_out, src_data.output_frames_gen * channels);
if (!src_data.end_of_input || leftover_samples) {
c_out.remove_flag (ProcessContext<float>::EndOfInput);
}
output (c_out);
if (debug_level (DebugProcess)) {
debug_stream() <<
"src_data.output_frames_gen: " << src_data.output_frames_gen <<
", leftover_samples: " << leftover_samples << std::endl;
}
if (throw_level (ThrowProcess) && src_data.output_frames_gen == 0 && leftover_samples) {
throw Exception (*this, boost::str (boost::format
("No output samples generated with %1% leftover samples")
% leftover_samples));
}
} while (leftover_samples > samples);
// src_data.end_of_input has to be checked to prevent infinite recursion
if (!src_data.end_of_input && c.has_flag(ProcessContext<float>::EndOfInput)) {
set_end_of_input (c);
}
}
void SampleRateConverter::set_end_of_input (ProcessContext<float> const & c)
{
src_data.end_of_input = true;
float f;
ProcessContext<float> const dummy (c, &f, 0, channels);
/* No idea why this has to be done twice for all data to be written,
* but that just seems to be the way it is...
*/
dummy.remove_flag (ProcessContext<float>::EndOfInput);
process (dummy);
dummy.set_flag (ProcessContext<float>::EndOfInput);
process (dummy);
}
void SampleRateConverter::reset ()
{
active = false;
max_samples_in = 0;
src_data.end_of_input = false;
if (src_state) {
src_delete (src_state);
}
leftover_samples = 0;
max_leftover_samples = 0;
if (leftover_data) {
free (leftover_data);
}
data_out_size = 0;
delete [] data_out;
data_out = 0;
}
} // namespace
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