shithub: sox

Download patch

ref: caab355441e86570d9f646afc8530c1e7ccf7f6e
parent: ddb3f05af5d800611f223197eb3e6e3ad962c8bc
author: Ulrich Klauer <ulrich@chirlu.de>
date: Tue Oct 11 01:38:21 EDT 2011 

WAV format: pad to an even number of data bytes

The RIFF spec calls for "a pad byte with value zero" at the end of
chunks that would otherwise contain an odd number of bytes; this
byte is not to be included in the chunk size.

This resolves bug #3203418.


--- a/ChangeLog
+++ b/ChangeLog
@@ -18,6 +18,8 @@
 
   o Mention in man pages that WAV files support floating point encodings.
   o Add support for floating point encodings in AIFF-C files. (Ulrich Klauer)
+  o Pad WAV data chunk to an even number of bytes (as required by the
+    specification). [3203418] (Ulrich Klauer)
 
 Audio device drivers:
 
--- a/src/wav.c
+++ b/src/wav.c
@@ -1193,6 +1193,7 @@
 36 - 39    'data'
 40 - 43     dwDataLength   length of data chunk minus 8 byte header
 44 - (dwDataLength + 43)   the data
+(+ a padding byte if dwDataLength is odd)
 
 non-PCM formats must write an extended format chunk and a fact chunk:
 
@@ -1204,6 +1205,7 @@
 50 - 53    'data'
 54 - 57     dwDataLength  length of data chunk minus 8 byte header
 58 - (dwDataLength + 57)  the data
+(+ a padding byte if dwDataLength is odd)
 
 
 GSM6.10  format:
@@ -1214,8 +1216,8 @@
 48 - 51    dwSamplesWritten   actual number of samples written out
 52 - 55    'data'
 56 - 59     dwDataLength  length of data chunk minus 8 byte header
-60 - (dwDataLength + 59)  the data
-(+ a padding byte if dwDataLength is odd)
+60 - (dwDataLength + 59)  the data (including a padding byte, if necessary,
+                            so dwDataLength is always even)
 
 
 note that header contains (up to) 3 separate ways of describing the
@@ -1364,7 +1366,7 @@
     else if (wFormatTag != WAVE_FORMAT_PCM)
         wFmtSize += 2+wExtSize; /* plus ExtData */
 
-    wRiffLength = 4 + (8+wFmtSize) + (8+dwDataLength);
+    wRiffLength = 4 + (8+wFmtSize) + (8+dwDataLength+dwDataLength%2);
     if (isExtensible || wFormatTag != WAVE_FORMAT_PCM) /* PCM omits the "fact" chunk */
         wRiffLength += (8+dwFactSize);
 
@@ -1534,6 +1536,13 @@
             wavgsmstopwrite(ft);
             break;
         }
+
+        /* Add a pad byte if the number of data bytes is odd.
+           See wavwritehdr() above for the calculation. */
+        if (wav->formatTag != WAVE_FORMAT_GSM610 &&
+            ((wav->numSamples + wav->samplesPerBlock - 1)/wav->samplesPerBlock*wav->blockAlign) % 2)
+          lsx_writeb(ft, 0);
+
         free(wav->packet);
         free(wav->samples);
         free(wav->lsx_ms_adpcm_i_coefs);