Add ALSA hardware mixing

2003-10-22 02:34:44 +00:00
parent b101cba858
commit 0d2671bb01
9 changed files with 508 additions and 116 deletions
@@ -0,0 +1,165 @@
+#include "global.h"
+#include "RageSoundDriver_ALSA9_Software.h"
+
+#include "RageLog.h"
+#include "RageSound.h"
+#include "RageSoundManager.h"
+#include "RageUtil.h"
+
+const int channels = 2;
+const int samplerate = 44100;
+
+const int samples_per_frame = channels;
+const int bytes_per_frame = sizeof(Sint16) * samples_per_frame;
+
+const unsigned max_writeahead = 1024*8;
+
+int RageSound_ALSA9_Software::MixerThread_start(void *p)
+{
+	((RageSound_ALSA9_Software *) p)->MixerThread();
+	return 0;
+}
+
+void RageSound_ALSA9_Software::MixerThread()
+{
+	/* SOUNDMAN will be set once RageSoundManager's ctor returns and
+	 * assigns it; we might get here before that happens, though. */
+	while(!SOUNDMAN && !shutdown) SDL_Delay(10);
+
+	while(!shutdown)
+	{
+		GetData();
+		const float delay_ms = 1000 * float(max_writeahead) / samplerate;
+		SDL_Delay( int(delay_ms) / 2);
+	}
+}
+
+/* Returns the number of frames processed */
+void RageSound_ALSA9_Software::GetData()
+{
+	const int frames_to_fill = pcm->GetNumFramesToFill( max_writeahead );
+	if( frames_to_fill <= 0 )
+		return;
+
+	/* Sint16 represents a single sample
+	 * each frame contains one sample per channel
+	 */
+    static Sint16 *buf = NULL;
+	if (!buf)
+		buf = new Sint16[max_writeahead*samples_per_frame*4];
+
+    static SoundMixBuffer mix;
+	mix.SetVolume( SOUNDMAN->GetMixVolume() );
+
+	LockMutex L(SOUNDMAN->lock);
+	for(unsigned i = 0; i < sounds.size(); ++i)
+	{
+		if(sounds[i]->stopping)
+			continue;
+
+		/* Call the callback.
+		 * Get the units straight,
+		 * <bytes> = GetPCM(<bytes*>, <bytes>, <frames>)
+		 */
+		unsigned got = sounds[i]->snd->GetPCM( (char *) buf, frames_to_fill*bytes_per_frame, pcm->GetPlayPos() ) / sizeof(Sint16);
+		mix.write((Sint16 *) buf, got);
+
+		if( int(got) < frames_to_fill )
+		{
+			/* This sound is finishing. */
+			sounds[i]->stopping = true;
+		}
+    }
+	L.Unlock();
+
+    memset( buf, 0, sizeof(Sint16) * frames_to_fill * samples_per_frame );
+	mix.read( buf );
+
+	pcm->Write( buf, frames_to_fill );
+}
+
+
+void RageSound_ALSA9_Software::StartMixing(RageSound *snd)
+{
+	sound *s = new sound;
+	s->snd = snd;
+
+	LockMutex L(SOUNDMAN->lock);
+	sounds.push_back(s);
+}
+
+void RageSound_ALSA9_Software::Update(float delta)
+{
+	LockMutex L(SOUNDMAN->lock);
+
+	/* SoundStopped might erase sounds out from under us, so make a copy
+	 * of the sound list. */
+	vector<sound *> snds = sounds;
+	for(unsigned i = 0; i < snds.size(); ++i)
+	{
+		if(!sounds[i]->stopping) continue;
+
+		if(GetPosition(snds[i]->snd) < sounds[i]->flush_pos)
+			continue; /* stopping but still flushing */
+
+		/* This sound is done. */
+		snds[i]->snd->StopPlaying();
+	}
+}
+
+void RageSound_ALSA9_Software::StopMixing(RageSound *snd)
+{
+	LockMutex L(SOUNDMAN->lock);
+
+	/* Find the sound. */
+	unsigned i;
+	for(i = 0; i < sounds.size(); ++i)
+		if(sounds[i]->snd == snd) break;
+	if(i == sounds.size())
+	{
+		LOG->Trace("not stopping a sound because it's not playing");
+		return;
+	}
+
+	delete sounds[i];
+	sounds.erase(sounds.begin()+i, sounds.begin()+i+1);
+}
+
+
+int RageSound_ALSA9_Software::GetPosition(const RageSound *snd) const
+{
+	return pcm->GetPosition();
+}       
+
+
+RageSound_ALSA9_Software::RageSound_ALSA9_Software()
+{
+	shutdown = false;
+
+	pcm = new Alsa9Buf( Alsa9Buf::HW_DONT_CARE, channels, samplerate );
+	
+	MixingThread.SetName( "RageSound_ALSA9_Software" );
+	MixingThread.Create( MixerThread_start, this );
+}
+
+RageSound_ALSA9_Software::~RageSound_ALSA9_Software()
+{
+	/* Signal the mixing thread to quit. */
+	shutdown = true;
+	LOG->Trace("Shutting down mixer thread ...");
+	MixingThread.Wait();
+	LOG->Trace("Mixer thread shut down.");
+ 
+	delete pcm;
+}
+
+float RageSound_ALSA9_Software::GetPlayLatency() const
+{
+	return float(max_writeahead)/samplerate;
+}
+
+/*
+ * Copyright (c) 2002 by the person(s) listed below.  All rights reserved.
+ *
+ * Glenn Maynard (RageSoundDriver_WaveOut)
+ */