commit b0519667da8edcea1592a0ba7b0dfa4b4709e034
Author:     Simon Howard <fraggle@gmail.com>
AuthorDate: Sun Mar 6 20:59:51 2011 +0000
Commit:     Simon Howard <fraggle@gmail.com>
CommitDate: Sun Mar 6 20:59:51 2011 +0000

    Discard very short sound effects and strip lead-in / lead-out samples
    that apparently aren't played by Vanilla Doom (thanks Quasar).

    Subversion-branch: /trunk/chocolate-doom
    Subversion-revision: 2291
---
 NEWS             |  5 +++++
 src/i_sdlsound.c | 14 +++++++++++++-
 2 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/NEWS b/NEWS
index ad358aed..3983ac76 100644
--- a/NEWS
+++ b/NEWS
@@ -1,5 +1,10 @@
 1.6.0 (2011-??-??):

+    Compatibility:
+     * Very short sound effects are not played, to better emulate the
+       behavior of DMX in Vanilla Doom (thanks to Quasar for help in
+       investigating this).
+
     Bugs fixed:
      * Menu navigation when using joystick/joypad (thanks Alexandre
        Xavier).
diff --git a/src/i_sdlsound.c b/src/i_sdlsound.c
index a26a81dd..14a5147f 100644
--- a/src/i_sdlsound.c
+++ b/src/i_sdlsound.c
@@ -359,7 +359,13 @@ static boolean LoadSoundLump(int sound,
     // greater than the length of the lump itself, this is an invalid
     // sound lump.

-    if (*length > lumplen - 8)
+    // We also discard sound lumps that are less than 49 samples long,
+    // as this is how DMX behaves - although the actual cut-off length
+    // seems to vary slightly depending on the sample rate.  This needs
+    // further investigation to better understand the correct
+    // behavior.
+
+    if (*length > lumplen - 8 || *length <= 48)
     {
 	W_ReleaseLumpNum(*lumpnum);
 	return false;
@@ -368,6 +374,12 @@ static boolean LoadSoundLump(int sound,
     // Prune header
     *data_ref += 8;

+    // The DMX sound library seems to skip the first 16 and last 16
+    // bytes of the lump - reason unknown.
+
+    *data_ref += 16;
+    *length -= 32;
+
     return true;
 }