[MPlayer-dev-eng] WMA MAX_CODED_SUPERFRAME_SIZE too small
Mark Weaver
mark at npsl.co.uk
Mon Jun 27 16:37:49 CEST 2005
I have a few WMA file examples where there are superframes >4K. (These
files were created with WMP 10, but playback ok with WMP 9/10). I have
placed a short sample at http://www.blushingpenguin.com/mark/test.wma
that exhibits the glitch. I chopped the file off at 128K but there is
enough there to show the problem.
On playback these frames are simply dropped causing audio glitches.
During testing I have seen frames of about 8,900 bytes. The resolution
is pretty straightforward -- just increasing the
MAX_CODED_SUPERFRAME_SIZE fixes it. I picked 16K, but there's no real
rationale behind that.
The code is in libavcodec/wmadec.c, patch is simply:
--- wmadec_org.c 2005-06-27 15:34:31.114852300 +0100
+++ wmadec.c 2005-06-27 15:05:31.149199000 +0100
@@ -47,7 +47,7 @@
#define NB_LSP_COEFS 10
/* XXX: is it a suitable value ? */
-#define MAX_CODED_SUPERFRAME_SIZE 4096
+#define MAX_CODED_SUPERFRAME_SIZE 16384
#define MAX_CHANNELS 2
HTH,
Mark
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