flycast/core/audio/audiobackend_null.cpp

55 lines
1.2 KiB
C++

#include "audiostream.h"
#include <chrono>
#include <thread>
class NullAudioBackend : public AudioBackend
{
using the_clock = std::chrono::high_resolution_clock;
public:
NullAudioBackend()
: AudioBackend("null", "No Audio") {}
bool init() override
{
last_time = the_clock::time_point();
return true;
}
u32 push(const void* frame, u32 samples, bool wait) override
{
if (wait && last_time.time_since_epoch() != the_clock::duration::zero())
{
auto fduration = std::chrono::nanoseconds(1'000'000'000LL * samples / 44100);
auto duration = fduration - (the_clock::now() - last_time);
if (duration > std::chrono::nanoseconds::zero())
std::this_thread::sleep_for(duration);
if (duration < -std::chrono::milliseconds(67))
// if ~4 frames ahead, reset time (fast forward detection)
last_time = the_clock::now();
else
last_time += fduration;
}
else {
last_time = the_clock::now();
}
return 1;
}
bool initRecord(u32 sampling_freq) override
{
return true;
}
u32 record(void *buffer, u32 samples) override
{
memset(buffer, 0, samples * 2);
return samples;
}
private:
the_clock::time_point last_time;
};
static NullAudioBackend nullBackend;