ardour/libs/audiographer/audiographer/general/silence_trimmer.h

284 lines
7.9 KiB
C++

#ifndef AUDIOGRAPHER_SILENCE_TRIMMER_H
#define AUDIOGRAPHER_SILENCE_TRIMMER_H
#include "audiographer/debug_utils.h"
#include "audiographer/flag_debuggable.h"
#include "audiographer/sink.h"
#include "audiographer/exception.h"
#include "audiographer/utils/listed_source.h"
#include <cstring>
namespace AudioGrapher {
/// Removes and adds silent frames to beginning and/or end of stream
template<typename T = DefaultSampleType>
class SilenceTrimmer
: public ListedSource<T>
, public Sink<T>
, public FlagDebuggable<>
, public Throwing<>
{
public:
/// Constructor, \see reset() \n Not RT safe
SilenceTrimmer(nframes_t silence_buffer_size_ = 1024)
: silence_buffer_size (0)
, silence_buffer (0)
{
reset (silence_buffer_size_);
add_supported_flag (ProcessContext<T>::EndOfInput);
}
~SilenceTrimmer()
{
delete [] silence_buffer;
}
/** Reset state \n Not RT safe
* Allocates a buffer the size of \a silence_buffer_size_
* This also defines the maximum length of output process context
* which can be output during long intermediate silence.
*/
void reset (nframes_t silence_buffer_size_ = 1024)
{
if (throw_level (ThrowObject) && silence_buffer_size_ == 0) {
throw Exception (*this,
"Silence trimmer constructor and reset() must be called with a non-zero parameter!");
}
if (silence_buffer_size != silence_buffer_size_) {
silence_buffer_size = silence_buffer_size_;
delete [] silence_buffer;
silence_buffer = new T[silence_buffer_size];
TypeUtils<T>::zero_fill (silence_buffer, silence_buffer_size);
}
in_beginning = true;
in_end = false;
trim_beginning = false;
trim_end = false;
silence_frames = 0;
max_output_frames = 0;
add_to_beginning = 0;
add_to_end = 0;
}
/** Tells that \a frames_per_channel frames of silence per channel should be added to beginning
* Needs to be called before starting processing.
* \n RT safe
*/
void add_silence_to_beginning (nframes_t frames_per_channel)
{
if (throw_level (ThrowObject) && !in_beginning) {
throw Exception(*this, "Tried to add silence to beginning after already outputting data");
}
add_to_beginning = frames_per_channel;
}
/** Tells that \a frames_per_channel frames of silence per channel should be added to end
* Needs to be called before end is reached.
* \n RT safe
*/
void add_silence_to_end (nframes_t frames_per_channel)
{
if (throw_level (ThrowObject) && in_end) {
throw Exception(*this, "Tried to add silence to end after already reaching end");
}
add_to_end = frames_per_channel;
}
/** Tells whether ot nor silence should be trimmed from the beginning
* Has to be called before starting processing.
* \n RT safe
*/
void set_trim_beginning (bool yn)
{
if (throw_level (ThrowObject) && !in_beginning) {
throw Exception(*this, "Tried to set beginning trim after already outputting data");
}
trim_beginning = yn;
}
/** Tells whether ot nor silence should be trimmed from the end
* Has to be called before the is reached.
* \n RT safe
*/
void set_trim_end (bool yn)
{
if (throw_level (ThrowObject) && in_end) {
throw Exception(*this, "Tried to set end trim after already reaching end");
}
trim_end = yn;
}
/** Process stream according to current settings.
* Note that some calls will not produce any output,
* while others may produce many. \see reset()
* \n RT safe
*/
void process (ProcessContext<T> const & c)
{
if (debug_level (DebugVerbose)) {
debug_stream () << DebugUtils::demangled_name (*this) <<
"::process()" << std::endl;
}
check_flags (*this, c);
if (throw_level (ThrowStrict) && in_end) {
throw Exception(*this, "process() after reacing end of input");
}
in_end = c.has_flag (ProcessContext<T>::EndOfInput);
nframes_t frame_index = 0;
if (in_beginning) {
bool has_data = true;
// only check silence if doing either of these
// This will set both has_data and frame_index
if (add_to_beginning || trim_beginning) {
has_data = find_first_non_zero_sample (c, frame_index);
}
// Added silence if there is silence to add
if (add_to_beginning) {
if (debug_level (DebugVerbose)) {
debug_stream () << DebugUtils::demangled_name (*this) <<
" adding to beginning" << std::endl;
}
ConstProcessContext<T> c_copy (c);
if (has_data) { // There will be more output, so remove flag
c_copy().remove_flag (ProcessContext<T>::EndOfInput);
}
add_to_beginning *= c.channels();
output_silence_frames (c_copy, add_to_beginning);
}
// If we are not trimming the beginning, output everything
// Then has_data = true and frame_index = 0
// Otherwise these reflect the silence state
if (has_data) {
if (debug_level (DebugVerbose)) {
debug_stream () << DebugUtils::demangled_name (*this) <<
" outputting whole frame to beginning" << std::endl;
}
in_beginning = false;
ConstProcessContext<T> c_out (c, &c.data()[frame_index], c.frames() - frame_index);
ListedSource<T>::output (c_out);
}
} else if (trim_end) { // Only check zero samples if trimming end
if (find_first_non_zero_sample (c, frame_index)) {
if (debug_level (DebugVerbose)) {
debug_stream () << DebugUtils::demangled_name (*this) <<
" flushing intermediate silence and outputting frame" << std::endl;
}
// context contains non-zero data
output_silence_frames (c, silence_frames); // flush intermediate silence
ListedSource<T>::output (c); // output rest of data
} else { // whole context is zero
if (debug_level (DebugVerbose)) {
debug_stream () << DebugUtils::demangled_name (*this) <<
" no, output, adding frames to silence count" << std::endl;
}
silence_frames += c.frames();
}
} else { // no need to do anything special
if (debug_level (DebugVerbose)) {
debug_stream () << DebugUtils::demangled_name (*this) <<
" outputting whole frame in middle" << std::endl;
}
ListedSource<T>::output (c);
}
// Finally, if in end, add silence to end
if (in_end && add_to_end) {
if (debug_level (DebugVerbose)) {
debug_stream () << DebugUtils::demangled_name (*this) <<
" adding to end" << std::endl;
}
add_to_end *= c.channels();
output_silence_frames (c, add_to_end, true);
}
}
using Sink<T>::process;
private:
bool find_first_non_zero_sample (ProcessContext<T> const & c, nframes_t & result_frame)
{
for (nframes_t i = 0; i < c.frames(); ++i) {
if (c.data()[i] != static_cast<T>(0.0)) {
result_frame = i;
// Round down to nearest interleaved "frame" beginning
result_frame -= result_frame % c.channels();
return true;
}
}
return false;
}
void output_silence_frames (ProcessContext<T> const & c, nframes_t & total_frames, bool adding_to_end = false)
{
bool end_of_input = c.has_flag (ProcessContext<T>::EndOfInput);
c.remove_flag (ProcessContext<T>::EndOfInput);
while (total_frames > 0) {
nframes_t frames = std::min (silence_buffer_size, total_frames);
if (max_output_frames) {
frames = std::min (frames, max_output_frames);
}
frames -= frames % c.channels();
total_frames -= frames;
ConstProcessContext<T> c_out (c, silence_buffer, frames);
// boolean commentation :)
bool const no_more_silence_will_be_added = adding_to_end || (add_to_end == 0);
bool const is_last_frame_output_in_this_function = (total_frames == 0);
if (end_of_input && no_more_silence_will_be_added && is_last_frame_output_in_this_function) {
c_out().set_flag (ProcessContext<T>::EndOfInput);
}
ListedSource<T>::output (c_out);
}
}
bool in_beginning;
bool in_end;
bool trim_beginning;
bool trim_end;
nframes_t silence_frames;
nframes_t max_output_frames;
nframes_t add_to_beginning;
nframes_t add_to_end;
nframes_t silence_buffer_size;
T * silence_buffer;
};
} // namespace
#endif // AUDIOGRAPHER_SILENCE_TRIMMER_H