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stella
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fixed WAV echo problem and enabled on-the-fly resampling

This commit is contained in:
Thomas Jentzsch 2022-09-15 18:34:37 +02:00
parent 5e09f486af
commit fbcf4670b9
2 changed files with 12 additions and 33 deletions
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39
src/common/SoundSDL2.cxx
View File

@ -175,7 +175,7 @@ void SoundSDL2::open(shared_ptr<AudioQueue> audioQueue,
openDevice();
myEmulationTiming = emulationTiming;
#ifdef RESAMPLE_WAV_CB
#ifdef RESAMPLE_WAV
myWavSpeed = 262 * 60 * 2. / myEmulationTiming->audioSampleRate();
#endif
@ -446,26 +446,7 @@ bool SoundSDL2::playWav(const string& fileName, const uInt32 position,
myWavLen = length
? std::min(length, myWavLength - position)
: myWavLength;
#ifndef RESAMPLE_WAV
myWavPos = myWavBuffer + position;
#else
SDL_free(myCvt.buf);
//const double speed = BSPF::clamp(262 * 60 * 2. / myEmulationTiming->audioSampleRate(), 0.5, 2.0);
const double speed = 262 * 60 * 2. / myEmulationTiming->audioSampleRate();
SDL_BuildAudioCVT(&myCvt, myWavSpec.format, myWavSpec.channels, myWavSpec.freq,
myWavSpec.format, myWavSpec.channels, myWavSpec.freq * speed);
SDL_assert(myCvt.needed); // Obviously, this one is always needed.
myCvt.len = myWavLen * myWavSpec.channels; // Mono 8 bit sample frames
myCvt.buf = static_cast<uInt8*>(SDL_malloc(myCvt.len * myCvt.len_mult * 2)); // Double buffer size to avoid memory access exception
// Read original data into conversion buffer
SDL_memcpy(myCvt.buf, myWavBuffer + position, myCvt.len);
SDL_ConvertAudio(&myCvt);
myWavPos = myCvt.buf;
myWavLen = myCvt.len_cvt;
#endif
// Open audio device
if(!myWavDevice)
@ -507,21 +488,23 @@ void SoundSDL2::wavCallback(void* udata, uInt8* stream, int len)
SDL_memset(stream, myWavSpec.silence, len);
if(myWavLen)
{
#ifdef RESAMPLE_WAV_CB
#ifdef RESAMPLE_WAV
if(myWavSpeed != 1.0)
{
int newLen = std::round(len / myWavSpeed);
const int newFreq = std::round(static_cast<double>(myWavSpec.freq) * len / newLen);
const int origLen = len;
if(static_cast<uInt32>(newLen) > myWavLen)
newLen = myWavLen;
len = std::round(len / myWavSpeed);
const int newFreq = std::round(static_cast<double>(myWavSpec.freq) * origLen / len);
if(static_cast<uInt32>(len) > myWavLen)
len = myWavLen;
SDL_AudioCVT cvt;
SDL_BuildAudioCVT(&cvt, myWavSpec.format, myWavSpec.channels, myWavSpec.freq,
myWavSpec.format, myWavSpec.channels, newFreq);
SDL_assert(cvt.needed); // Obviously, this one is always needed.
cvt.len = newLen * myWavSpec.channels; // Mono 8 bit sample frames
cvt.buf = static_cast<uInt8*>(SDL_malloc(cvt.len * cvt.len_mult * 2)); // Double buffer size to avoid memory access exception
cvt.len = len * myWavSpec.channels; // Mono 8 bit sample frames
cvt.buf = static_cast<uInt8*>(SDL_malloc(cvt.len * cvt.len_mult));
// Read original data into conversion buffer
SDL_memcpy(cvt.buf, myWavPos, cvt.len);
SDL_ConvertAudio(&cvt);
@ -552,7 +535,7 @@ float SoundSDL2::myWavVolumeFactor = 0xffff;
SDL_AudioSpec SoundSDL2::myWavSpec; // audio output format
uInt8* SoundSDL2::myWavPos = nullptr; // pointer to the audio buffer to be played
uInt32 SoundSDL2::myWavLen = 0; // remaining length of the sample we have to play
#ifdef RESAMPLE_WAV_CB
#ifdef RESAMPLE_WAV
double SoundSDL2::myWavSpeed = 1.0;
#endif

6
src/common/SoundSDL2.hxx
View File

@ -20,8 +20,7 @@
#ifndef SOUND_SDL2_HXX
#define SOUND_SDL2_HXX
//#define RESAMPLE_WAV // does not adjust to speed immediately
//#define RESAMPLE_WAV_CB // causes echo in in-the-fly resampling
#define RESAMPLE_WAV
class OSystem;
class AudioQueue;
@ -196,9 +195,6 @@ class SoundSDL2 : public Sound
SDL_AudioDeviceID myWavDevice{0};
uInt8* myWavBuffer{nullptr};
#ifdef RESAMPLE_WAV
SDL_AudioCVT myCvt{0};
#endif
#ifdef RESAMPLE_WAV_CB
static double myWavSpeed;
#endif