From 26500425f6cf97ebec21b6cf0929c2e4c08f46d6 Mon Sep 17 00:00:00 2001
From: wm4 <wm4@nowhere>
Date: Fri, 22 Aug 2014 16:10:34 +0200
Subject: [PATCH] ao_dsound: raise default buffer size to 200ms, make it
 configurable

---
 DOCS/man/ao.rst       | 3 +++
 audio/out/ao_dsound.c | 8 +++++---
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/DOCS/man/ao.rst b/DOCS/man/ao.rst
index 5bd82cd9f4..f82906d062 100644
--- a/DOCS/man/ao.rst
+++ b/DOCS/man/ao.rst
@@ -181,6 +181,9 @@ Available audio output drivers are:
         Sets the device number to use. Playing a file with ``-v`` will show a
         list of available devices.
 
+    ``buffersize=<ms>``
+        DirectSound buffer size in milliseconds (default: 200).
+
 ``sdl``
     SDL 1.2+ audio output driver. Should work on any platform supported by SDL
     1.2, but may require the ``SDL_AUDIODRIVER`` environment variable to be set
diff --git a/audio/out/ao_dsound.c b/audio/out/ao_dsound.c
index e313c7d440..e03db481c8 100644
--- a/audio/out/ao_dsound.c
+++ b/audio/out/ao_dsound.c
@@ -98,6 +98,7 @@ struct priv {
     int outburst;                   ///play in multiple of chunks of this size
 
     int cfg_device;
+    int cfg_buffersize;
 };
 
 static float get_delay(struct ao *ao);
@@ -403,11 +404,11 @@ static int init(struct ao *ao)
     ao->samplerate = rate;
     ao->format = format;
     ao->bps = ao->channels.num * rate * af_fmt2bps(format);
-    int buffersize = ao->bps * 0.100; // space for 100ms
+    int buffersize = ao->bps * p->cfg_buffersize / 1000;
     MP_VERBOSE(ao, "Samplerate:%iHz Channels:%i Format:%s\n", rate,
                ao->channels.num, af_fmt_to_str(format));
-    MP_VERBOSE(ao, "Buffersize:%d bytes (%d msec)\n",
-               buffersize, buffersize / ao->bps * 1000);
+    MP_VERBOSE(ao, "Buffersize:%d bytes (%f msec)\n",
+               buffersize, buffersize * 1000.0 / ao->bps);
 
     //fill waveformatex
     ZeroMemory(&wformat, sizeof(WAVEFORMATEXTENSIBLE));
@@ -636,6 +637,7 @@ const struct ao_driver audio_out_dsound = {
     .priv_size = sizeof(struct priv),
     .options = (const struct m_option[]) {
         OPT_INT("device", cfg_device, 0),
+        OPT_INTRANGE("buffersize", cfg_buffersize, 0, 1, 10000, OPTDEF_INT(200)),
         {0}
     },
 };