diff -r -u -X diff.exclude myth.15740.0203c/mythtv/libs/libmyth/audiooutputdigitalencoder.cpp myth.15740.0203d/mythtv/libs/libmyth/audiooutputdigitalencoder.cpp
--- mythtv/libs/libmyth/audiooutputdigitalencoder.cpp	2008-02-01 15:36:44.000000000 -0600
+++ mythtv/libs/libmyth/audiooutputdigitalencoder.cpp	2008-02-07 13:28:47.000000000 -0600
@@ -239,6 +239,8 @@
 #ifdef ENABLE_AC3_DECODER
         enc_len = ac3_sync(
             data + 8, &flags, &sample_rate, &bit_rate, (int*)&block_len);
+        // ac3_sync returns block_len = 1536, which doesn't work
+        block_len = MAX_AC3_FRAME_SIZE;
 #else
         enc_len = a52_syncinfo(data + 8, &flags, &sample_rate, &bit_rate);
         block_len = MAX_AC3_FRAME_SIZE;