Re: [PATCH] cx88-dvb.c: DVB net latency using Hauppauge HVR4000

2010-12-26 Thread Heino Goldenstein
Hello,

Am Freitag, 24. Dezember 2010 20:28 schrieb Goga777:

 will your patch useful for dvb sat tv ?

   We are from School On Internet Asia (SOI Asia) project that uses
  satellite communication to deliver educational content. We used Hauppauge
  HVR 4000 to carry IP traffic over ULE. However, there is an issue with
  high latency jitter. My boss, Husni, identified the problem and provided
  a patch for this problem. We have tested this patch since kernel 2.6.30
  on our partner sites and it hasn't cause any issue. The default buffer
  size of 32 TS frames on cx88 causes the high latency, so our deployment
  changes that to 6 TS frames. This patch made the buffer size tunable,
  while keeping the default buffer size of 32 TS frames unchanged. Sorry, I

FWIW in the DVBlast subversion is a similar patch [1] touching the same
value. See the reason for this in the README [2].

Tjuess
  Heino

[1]http://svn.videolan.org/filedetails.php?repname=DVBlastpath=%2Ftrunk%2Fextra%2Fkernel-patches%2F03-cx88.patch
[2]http://svn.videolan.org/filedetails.php?repname=DVBlastpath=%2Ftrunk%2Fextra%2Fkernel-patches%2FREADME
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Re: [PATCH] cx88-dvb.c: DVB net latency using Hauppauge HVR4000

2010-12-24 Thread Goga777
will your patch useful for dvb sat tv ?

  We are from School On Internet Asia (SOI Asia) project that uses 
 satellite communication to deliver
 educational content. We used Hauppauge HVR 4000 to carry IP traffic over ULE. 
 However, there is an issue
 with high latency jitter. My boss, Husni, identified the problem and provided 
 a patch for this problem.
 We have tested this patch since kernel 2.6.30 on our partner sites and it 
 hasn't cause any issue. The
 default buffer size of 32 TS frames on cx88 causes the high latency, so our 
 deployment changes that to 6
 TS frames. This patch made the buffer size tunable, while keeping the default 
 buffer size of 32 TS
 frames unchanged. Sorry, I have to use attachment for the patch. I couldn't 
 figure out how to copy and
 paste the patch without converting the tab to spaces in thunderbird.
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[PATCH] cx88-dvb.c: DVB net latency using Hauppauge HVR4000

2010-12-23 Thread Ang Way Chuang

Hi linux-media developers,
We are from School On Internet Asia (SOI Asia) project that uses satellite 
communication to deliver educational content.
We used Hauppauge HVR 4000 to carry IP traffic over ULE. However, there is an 
issue with high latency jitter. My boss, Husni,
identified the problem and provided a patch for this problem. We have tested 
this patch since kernel 2.6.30 on our partner
sites and it hasn't cause any issue. The default buffer size of 32 TS frames on 
cx88 causes the high latency, so our deployment
changes that to 6 TS frames. This patch made the buffer size tunable, while 
keeping the default buffer size of 32 TS frames
unchanged. Sorry, I have to use attachment for the patch. I couldn't figure out 
how to copy and paste the patch without
converting the tab to spaces in thunderbird.

Signed-off-by: Achmad Husni Thamrin hu...@ai3.net

diff --git a/drivers/media/video/cx88/cx88-dvb.c b/drivers/media/video/cx88/cx88-dvb.c
index 367a653..90717ee 100644
--- a/drivers/media/video/cx88/cx88-dvb.c
+++ b/drivers/media/video/cx88/cx88-dvb.c
@@ -67,6 +67,10 @@ static unsigned int debug;
 module_param(debug, int, 0644);
 MODULE_PARM_DESC(debug,enable debug messages [dvb]);
 
+static unsigned int dvb_buf_tscnt = 32;
+module_param(dvb_buf_tscnt, int, 0644);
+MODULE_PARM_DESC(dvb_buf_tscnt, DVB Buffer TS count [dvb]);
+
 DVB_DEFINE_MOD_OPT_ADAPTER_NR(adapter_nr);
 
 #define dprintk(level,fmt, arg...)	if (debug = level) \
@@ -80,10 +84,10 @@ static int dvb_buf_setup(struct videobuf_queue *q,
 	struct cx8802_dev *dev = q-priv_data;
 
 	dev-ts_packet_size  = 188 * 4;
-	dev-ts_packet_count = 32;
+	dev-ts_packet_count = dvb_buf_tscnt;
 
 	*size  = dev-ts_packet_size * dev-ts_packet_count;
-	*count = 32;
+	*count = dvb_buf_tscnt;
 	return 0;
 }