audio: write pad byte when data length is odd.
This is specified in RIFF format, but I forgot to implement.
ckData Binary data of fixed or variable size. The start of
ckData is word-aligned with respect to the start of the
RIFF file. If the chunk size is an odd number of bytes, a
pad byte with value zero is written after ckData. Word
aligning improves access speed (for chunks resident in
memory) and maintains compatibility with EA IFF. The
ckSize value does not include the pad byte.
(From http://www.kk.iij4u.or.jp/~kondo/wave/mpidata.txt)
Dmitry Chestnykh dmitry@codingrobots.com
Sun, 01 May 2011 12:33:27 +0200
1 files changed,
9 insertions(+),
0 deletions(-)
jump to
M
audio.go
→
audio.go
@@ -86,18 +86,27 @@
// WriteTo writes captcha audio in WAVE format into the given io.Writer, and // returns the number of bytes written and an error if any. func (a *Audio) WriteTo(w io.Writer) (n int64, err os.Error) { + // Header. nn, err := w.Write(waveHeader) n = int64(nn) if err != nil { return } + // Chunk length. err = binary.Write(w, binary.LittleEndian, uint32(a.body.Len())) if err != nil { return } nn += 4 + // Chunk data. n, err = a.body.WriteTo(w) n += int64(nn) + // Pad byte if chunk length is odd. + // (As header has even length, we can check if n is odd, not chunk). + if n % 2 != 0 { + w.Write([]byte{128}) + n++ + } return }