From 21915e956c410a51db9f67b92896a891e6eb6f3f Mon Sep 17 00:00:00 2001
From: Ozkan Sezer <sezeroz@gmail.com>
Date: Fri, 20 Sep 2019 18:40:00 +0000
Subject: [PATCH] snd_sdl.c:  pass NULL as the 'obtained' spec to
 SDL_OpenAudio():

this way, SDL will convert to hardware format for us if needed.
most of the times we do get what we want. however, for example,
the WASAPI backend of SDL2 returns AUDIO_F32LSB as the obtained
format (which is not an SDL thing but a WASAPI thing) and we do
not support that. the SDL2.dll we ship with has WASAPI disabled,
but if the user replaces our dll with a one with WASAPI enabled
(official libsdl.org build or his own build) then we refuse the
obtained AUDIO_F32LSB format and run without sound.  after this
patch, such a thing is transparent to us.

git-svn-id: svn://svn.code.sf.net/p/quakespasm/code/trunk/quakespasm@1639 af15c1b1-3010-417e-b628-4374ebc0bcbd
---
 Quake/snd_sdl.c | 38 ++++++++++++--------------------------
 1 file changed, 12 insertions(+), 26 deletions(-)

diff --git a/Quake/snd_sdl.c b/Quake/snd_sdl.c
index 2dd2f8c6..6e0791b2 100644
--- a/Quake/snd_sdl.c
+++ b/Quake/snd_sdl.c
@@ -80,7 +80,7 @@ static void SDLCALL paint_audio (void *unused, Uint8 *stream, int len)
 
 qboolean SNDDMA_Init (dma_t *dma)
 {
-	SDL_AudioSpec desired, obtained;
+	SDL_AudioSpec desired;
 	int		tmp, val;
 	char	drivername[128];
 
@@ -91,7 +91,7 @@ qboolean SNDDMA_Init (dma_t *dma)
 	}
 
 	/* Set up the desired format */
-	desired.freq = tmp = snd_mixspeed.value;
+	desired.freq = snd_mixspeed.value;
 	desired.format = (loadas8bit.value) ? AUDIO_U8 : AUDIO_S16SYS;
 	desired.channels = 2; /* = desired_channels; */
 	if (desired.freq <= 11025)
@@ -108,39 +108,25 @@ qboolean SNDDMA_Init (dma_t *dma)
 	desired.userdata = NULL;
 
 	/* Open the audio device */
-	if (SDL_OpenAudio(&desired, &obtained) == -1)
+	if (SDL_OpenAudio(&desired, NULL) == -1)
 	{
 		Con_Printf("Couldn't open SDL audio: %s\n", SDL_GetError());
 		SDL_QuitSubSystem(SDL_INIT_AUDIO);
 		return false;
 	}
 
-	/* Make sure we can support the audio format */
-	switch (obtained.format)
-	{
-	case AUDIO_S8:		/* maybe needed by AHI */
-	case AUDIO_U8:
-	case AUDIO_S16SYS:
-		/* Supported */
-		break;
-	default:
-		Con_Printf ("Unsupported audio format received (%u)\n", obtained.format);
-		SDL_CloseAudio();
-		SDL_QuitSubSystem(SDL_INIT_AUDIO);
-		return false;
-	}
-
 	memset ((void *) dma, 0, sizeof(dma_t));
 	shm = dma;
 
 	/* Fill the audio DMA information block */
-	shm->samplebits = (obtained.format & 0xFF); /* first byte of format is bits */
-	shm->signed8 = (obtained.format == AUDIO_S8);
-	if (obtained.freq != tmp)
-		Con_Printf ("Warning: Rate set (%d) didn't match requested rate (%d)!\n", obtained.freq, tmp);
-	shm->speed = obtained.freq;
-	shm->channels = obtained.channels;
-	tmp = (obtained.samples * obtained.channels) * 10;
+	/* Since we passed NULL as the 'obtained' spec to SDL_OpenAudio(),
+	 * SDL will convert to hardware format for us if needed, hence we
+	 * directly use the desired values here. */
+	shm->samplebits = (desired.format & 0xFF); /* first byte of format is bits */
+	shm->signed8 = (desired.format == AUDIO_S8);
+	shm->speed = desired.freq;
+	shm->channels = desired.channels;
+	tmp = (desired.samples * desired.channels) * 10;
 	if (tmp & (tmp - 1))
 	{	/* make it a power of two */
 		val = 1;
@@ -154,7 +140,7 @@ qboolean SNDDMA_Init (dma_t *dma)
 	shm->submission_chunk = 1;
 
 	Con_Printf ("SDL audio spec  : %d Hz, %d samples, %d channels\n",
-			obtained.freq, obtained.samples, obtained.channels);
+			desired.freq, desired.samples, desired.channels);
 #if defined(USE_SDL2)
 	{
 		const char *driver = SDL_GetCurrentAudioDriver();