[FFmpeg-cvslog] rtpdec_jpeg: Clarify where the subsampling magic numbers come from

[Martin Storsjö]

ffmpeg | branch: master | Martin Storsjö <martin at martin.st> | Tue Sep 11 12:52:55 2012 +0300| [31adff08a14b7cd3f4097a4f912108cd64472069] | committer: Martin Storsjö

rtpdec_jpeg: Clarify where the subsampling magic numbers come from

Write out the numbers the way they are constructed, not just the
final values.

Signed-off-by: Martin Storsjö <martin at martin.st>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=31adff08a14b7cd3f4097a4f912108cd64472069
---

 libavformat/rtpdec_jpeg.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/libavformat/rtpdec_jpeg.c b/libavformat/rtpdec_jpeg.c
index 4d8523d..20bb356 100644
--- a/libavformat/rtpdec_jpeg.c
+++ b/libavformat/rtpdec_jpeg.c
@@ -166,13 +166,13 @@ static int jpeg_create_header(uint8_t *buf, int size, uint32_t type, uint32_t w,
     bytestream2_put_be16(&pbc, w);
     bytestream2_put_byte(&pbc, 3);
     bytestream2_put_byte(&pbc, 1);
-    bytestream2_put_byte(&pbc, type ? 34 : 33);
+    bytestream2_put_byte(&pbc, (2 << 4) | (type ? 2 : 1)); /* hsample/vsample */
     bytestream2_put_byte(&pbc, 0);
     bytestream2_put_byte(&pbc, 2);
-    bytestream2_put_byte(&pbc, 17);
+    bytestream2_put_byte(&pbc, 1 << 4 | 1); /* hsample/vsample */
     bytestream2_put_byte(&pbc, nb_qtable == 2 ? 1 : 0);
     bytestream2_put_byte(&pbc, 3);
-    bytestream2_put_byte(&pbc, 17);
+    bytestream2_put_byte(&pbc, 1 << 4 | 1); /* hsample/vsample */
     bytestream2_put_byte(&pbc, nb_qtable == 2 ? 1 : 0);
 
     /* SOS */