[quake2] Choppy sound with default (non-SDL) client
danfe at nsu.ru
Sun Apr 28 00:07:50 EDT 2013
On Sat, Apr 27, 2013 at 01:24:18PM +0300, Ozkan Sezer wrote:
> On 4/27/13, Alexey Dokuchaev <danfe at nsu.ru> wrote:
> > I've heard several reports over quite some time that default (non-SDL)
> > client executable gives choppy sound on FreeBSD (that is, OSS).
> It is because the SNDCTL_DSP_GETOSPACE ioctl is issued before setting
> other important parameters: if it is move to the place just below the
> mmaping it is fixed. See the patch I just cooked up (which contains a
> few additional bits)
I confirm that moving SNDCTL_DSP_GETOSPACE ioctl() call lower does fix the
problem for me here on FreeBSD 8.3, thanks!
May I ask a few questions on the remaining bits of the patch?
> @@ -76,7 +74,7 @@
> - audio_fd = open(snddevice->string, O_RDWR);
> + audio_fd = open(snddevice->string, O_RDWR|O_NONBLOCK);
What happens when opening file in blocking mode? I did not observe any
problems... Although I've seen this change in some other quake engine
> - if (fmt & AFMT_S16_LE) dma.samplebits = 16;
> + if (fmt & AFMT_S16_NE) dma.samplebits = 16;
> else if (fmt & AFMT_U8) dma.samplebits = 8;
> if (dma.samplebits == 16)
> - rc = AFMT_S16_LE;
> + rc = AFMT_S16_NE;
Do I understand correctly that using AFMT_S16_LE would break on big-endian
machines? I.e., AFMT_S16_NE makes code CPU (endian) agnostic, ergo correct?
> + mmaplen = info.fragstotal * info.fragsize;
> + sz = sysconf (_SC_PAGESIZE);
> + mmaplen += sz - 1;
> + mmaplen &= ~(sz - 1);
What benefits forcing page size aligned mmaplen brings us here?
> + munmap (dma.buffer, mmaplen);
> + dma.buffer=NULL;
Fixing resource leaks are clear.
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