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authorWim Taymans <wim.taymans@collabora.co.uk>2012-10-17 14:23:01 +0200
committerWim Taymans <wim.taymans@collabora.co.uk>2012-10-17 14:23:01 +0200
commite9040e90a59c4f540a03e10566e8c227a8f6d93f (patch)
tree247442838667d4572f949a4be132e78d31843b50
parentd5fd524a0c831836d2fe66fa482dede0591d0c47 (diff)
jpegdepay: store quant tables in zigzag order
-rw-r--r--gst/rtp/gstrtpjpegdepay.c15
1 files changed, 13 insertions, 2 deletions
diff --git a/gst/rtp/gstrtpjpegdepay.c b/gst/rtp/gstrtpjpegdepay.c
index 0ea3303a5..693df8230 100644
--- a/gst/rtp/gstrtpjpegdepay.c
+++ b/gst/rtp/gstrtpjpegdepay.c
@@ -154,6 +154,17 @@ gst_rtp_jpeg_depay_finalize (GObject * object)
G_OBJECT_CLASS (parent_class)->finalize (object);
}
+static const int zigzag[] = {
+ 0, 1, 8, 16, 9, 2, 3, 10,
+ 17, 24, 32, 25, 18, 11, 4, 5,
+ 12, 19, 26, 33, 40, 48, 41, 34,
+ 27, 20, 13, 6, 7, 14, 21, 28,
+ 35, 42, 49, 56, 57, 50, 43, 36,
+ 29, 22, 15, 23, 30, 37, 44, 51,
+ 58, 59, 52, 45, 38, 31, 39, 46,
+ 53, 60, 61, 54, 47, 55, 62, 63
+};
+
/*
* Table K.1 from JPEG spec.
*/
@@ -198,8 +209,8 @@ MakeTables (GstRtpJPEGDepay * rtpjpegdepay, gint Q, guint8 qtable[128])
Q = 200 - factor * 2;
for (i = 0; i < 64; i++) {
- gint lq = (jpeg_luma_quantizer[i] * Q + 50) / 100;
- gint cq = (jpeg_chroma_quantizer[i] * Q + 50) / 100;
+ gint lq = (jpeg_luma_quantizer[zigzag[i]] * Q + 50) / 100;
+ gint cq = (jpeg_chroma_quantizer[zigzag[i]] * Q + 50) / 100;
/* Limit the quantizers to 1 <= q <= 255 */
qtable[i] = CLAMP (lq, 1, 255);