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feat: MixingPlayer - plays event sounds

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This commit is contained in:
David Madl
2026-03-03 14:19:56 +01:00
parent bc8002fd59
commit 804f83340f
8 changed files with 184 additions and 89 deletions
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38
app/src/main/cpp/PlaybackEngine.cpp
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@@ -6,12 +6,46 @@
#include "PlaybackEngine.h"
#include "logging.h"
#include "mpg123.h"
#include "mp3file.h"
#include <vector>
PlaybackEngine::PlaybackEngine(std::string filesDir): mFilesDir(filesDir) {
static inline int readBuffer2(MP3File* mp3)
{
size_t done = 0;
int err = mpg123_read(mp3->handle, mp3->buffer, mp3->buffer_size, &done);
mp3->leftSamples = done / sizeof(int16_t);
mp3->offset = 0;
return err != MPG123_OK ? 0 : done;
}
static bool read_mp3(std::string filename, std::vector<float>& samples) {
// TODO: assumes 48000 Hz sampling rate of the file
// note: our resource file is mono (1 channel = 1 samples_per_frame)!
MP3File *mFile = mp3file_open(filename.c_str(), 0); // MPG123_ENC_FLOAT_32 (but does not seem to work)
bool ok1 = mFile != nullptr;
bool ok2 = readBuffer2(mFile) != 0; // once is enough (maybe the other one needs to pre-fill other buffers, in oboe etc.)
if(ok1 && ok2) {
// num_frames, num_samples, samples_per_frame
samples.resize(mFile->num_samples);
for(int i = 0; i < mFile->num_samples; i++) {
int16_t *src = ((int16_t *) mFile->buffer) + i;
samples[i] = (*src) / 32768.0f;
}
}
if(mFile)
mp3file_delete(mFile);
return ok1 && ok2;
}
PlaybackEngine::PlaybackEngine(std::string filesDir, int resid): mFilesDir(filesDir) {
LOGI("PlaybackEngine()");
LOGI("NDK LOG_LEVEL=%d", LOG_LEVEL);
// NDK LOG_LEVEL=3 (DEBUG)
mPlayer = new OboeSinePlayer();
std::vector<float> samples;
read_mp3(mFilesDir + "/" + std::to_string(resid) + ".mp3", samples);
mPlayer = new MixingPlayer(samples);
int32_t res = mPlayer->startAudio();
LOGI("startAudio() = %d", res);
}