SDLAudio::AudioOutOutput: protect against invalid handle, support NULL input (wait only), replace fixed 65536 with an amount based on settable latency target (20ms for now)

This commit is contained in:
j 2024-08-21 19:01:58 +10:00
parent 8a42c207df
commit fc6a2590f6
1 changed files with 24 additions and 11 deletions

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@ -84,7 +84,7 @@ int SDLAudio::AudioOutOpen(int type, u32 samples_num, u32 freq,
port.stream =
SDL_OpenAudioDeviceStream(SDL_AUDIO_DEVICE_DEFAULT_PLAYBACK, &fmt, NULL, NULL);
SDL_ResumeAudioDevice(SDL_GetAudioStreamDevice(port.stream));
return id + 1;
return id + 1; // Handle range 1..n keeps 0 reserved
}
}
@ -93,22 +93,35 @@ int SDLAudio::AudioOutOpen(int type, u32 samples_num, u32 freq,
s32 SDLAudio::AudioOutOutput(s32 handle, const void* ptr) {
std::shared_lock lock{m_mutex};
if (handle < 1 || handle > portsOut.size()) {
// Handle is outside range 1..n
return ORBIS_AUDIO_OUT_ERROR_INVALID_PORT;
}
auto& port = portsOut[handle - 1];
if (!port.isOpen) {
return ORBIS_AUDIO_OUT_ERROR_INVALID_PORT;
}
if (ptr == nullptr) {
return 0;
}
// Allow call with null - this acts as "wait for buffer ready"
if (ptr != nullptr) {
// TODO mixing channels
int result = SDL_PutAudioStreamData(port.stream, ptr,
port.samples_num * port.sample_size * port.channels_num);
// TODO find a correct value 8192 is estimated
while (SDL_GetAudioStreamAvailable(port.stream) > 65536) {
SDL_Delay(0);
int result = SDL_PutAudioStreamData(
port.stream, ptr, port.samples_num * port.sample_size * port.channels_num);
if (result != 0) {
// There's various possible failures, just assume some buffer is full
return ORBIS_AUDIO_OUT_ERROR_PORT_FULL;
}
}
return result;
auto bytesPerSecond = 48000 * port.sample_size * port.channels_num;
const int TARGET_LATENCY_MS = 20; // Arbitrary, but slightly more than one 60fps frame
auto sizeTarget = (bytesPerSecond * TARGET_LATENCY_MS) / 1000;
while (SDL_GetAudioStreamAvailable(port.stream) > sizeTarget) {
SDL_Delay(1); // Sleep behaviour is platform-dependent; 1ms may be up to 17ms
}
return ORBIS_OK;
}
bool SDLAudio::AudioOutSetVolume(s32 handle, s32 bitflag, s32* volume) {