[FFmpeg-cvslog] png: Minor whitespace change and added missing comment

[Donny Yang]

ffmpeg | branch: master | Donny Yang <work at kota.moe> | Sat Mar 28 15:14:22 2015 +0000| [fe57514f8a665d95091bd2da607d99043e6c7fc2] | committer: Michael Niedermayer

png: Minor whitespace change and added missing comment

Signed-off-by: Donny Yang <work at kota.moe>
Signed-off-by: Michael Niedermayer <michaelni at gmx.at>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=fe57514f8a665d95091bd2da607d99043e6c7fc2
---

 libavcodec/pngenc.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavcodec/pngenc.c b/libavcodec/pngenc.c
index 0231bf7..d6233d0 100644
--- a/libavcodec/pngenc.c
+++ b/libavcodec/pngenc.c
@@ -399,9 +399,9 @@ static int encode_frame(AVCodecContext *avctx, AVPacket *pkt,
     s->buf[10] = 0; /* compression type */
     s->buf[11] = 0; /* filter type */
     s->buf[12] = is_progressive; /* interlace type */
-
     png_write_chunk(&s->bytestream, MKTAG('I', 'H', 'D', 'R'), s->buf, 13);
 
+    /* write physical information */
     if (s->dpm) {
       AV_WB32(s->buf, s->dpm);
       AV_WB32(s->buf + 4, s->dpm);