- Add a patch to schismtracker that restores sound for

sound chips that lack hardware mixing capabilities.

OBS-URL: https://build.opensuse.org/package/show/multimedia:apps/schismtracker?expand=0&rev=4

schism-alsa.diff

@@ -0,0 +1,61 @@
+From: Jan Engelhardt <jengelh@medozas.de>
+
+schism/audio: do not force "hw" ALSA device
+
+Forcing direct hardware access using the "hw" device is incorrect
+IMHO, especially so with sound chips that lack hardware mixing on any
+of the three levels: (1) concurrent access to the hw device, (2) lack
+of volume control, (3) lack of rate conversion.
+
+"default" is the sane choice to have schism output to the converters
+that handle any or all of these three points.
+
+Developer Storlek claims problems with fake devices. Upon furhter
+investigation, fake devices such as the ALSA plugins have a reason to
+ignore it, or at least tinker with it. Consider my case with a
+Realtek ALC259 (driven by snd-hda-intel) that fails (1) and (3):
+
+By default, schismtracker asks for 1024 fragments and 44.1 kHz. If
+the sound chip however does not support hardware mixing and can only
+do, for example, 48 kHz, ALSA will automatically add converters into
+the audio chain such that the program can still operate at 44100 Hz
+without distorted sound.
+
+1024 fragments of 128 bytes each are requested and thusly allocated,
+that is, the sound buffer will be 128 kilobytes in total. This value
+is taken at face - but for 48 kHz. The 44.1 kHz ALSA user thus only
+gets a 44100/48000*131072 = 120422 byte buffer, or 940 fragments. The
+rate conversion will then automatically interpolate the signal to
+1024 fragments. (No distortions or lag ensues from this for me.)
+
+So 940 is correct and the comment seemingly bogus.
+
+Storlek still does not like changing "hw" :-(
+
+A workaround is to call schismtracker with the "-a alsa:default"
+option.
+---
+ schism/audio_playback.c |    7 +------
+ 1 file changed, 1 insertion(+), 6 deletions(-)
+
+Index: schismtracker/schism/audio_playback.c
+===================================================================
+--- schismtracker.orig/schism/audio_playback.c
++++ schismtracker/schism/audio_playback.c
+@@ -1274,15 +1274,10 @@ static int _audio_open(const char *drive
+         if (SDL_InitSubSystem(SDL_INIT_AUDIO) < 0)
+                 return 0;
+ 
+-        /* This is needed in order to coax alsa into actually respecting the buffer size, since it's evidently
+-        ignored entirely for "fake" devices such as "default" -- which SDL happens to use if no device name
+-        is set. (see SDL_alsa_audio.c: http://tinyurl.com/ybf398f)
+-        If hw doesn't exist, so be it -- let this fail, we'll fall back to the dummy device, and the
+-        user can pick a more reasonable device later. */
+         if (SDL_AudioDriverName(driver_name, sizeof(driver_name)) != NULL && !strcmp(driver_name, "alsa")) {
+                 char *dev = getenv("AUDIODEV");
+                 if (!dev || !*dev)
+-                        put_env_var("AUDIODEV", "hw");
++                        put_env_var("AUDIODEV", "default");
+         }
+ 
+         /* ... THIS is needed because, if the buffer size isn't a power of two, the dsp driver will punt since

schismtracker.changes

@@ -1,3 +1,9 @@
+-------------------------------------------------------------------
+Mon Aug 30 23:41:58 UTC 2010 - jengelh@medozas.de
+
+- Add a patch to schismtracker that restores sound for
+  sound chips that lack hardware mixing capabilities.
+
 -------------------------------------------------------------------
 Wed Feb 24 12:22:56 UTC 2010 - prusnak@suse.cz
 

schismtracker.spec

@@ -8,6 +8,7 @@ Summary:        Music editor that aims to match the look and feel of Impulse Tra
 #Hg-Clone:      http://schismtracker.org/hg/
 Source:         %{name}-%{version}.tar.bz2
 Source1:        %{name}.desktop
+Patch1:		schism-alsa.diff
 BuildRoot:      %{_tmppath}/%{name}-%{version}-build
 BuildRequires:  SDL-devel >= 1.2.10
 BuildRequires:  xorg-x11-devel