Opened 13 years ago

Closed 13 years ago

Last modified 13 years ago

#2085 closed defect (fixed)

Changing channels unreliable on cable (QAM)

Reported by: mrussotto@… Owned by: danielk
Priority: minor Milestone: 0.21
Component: mythtv Version: head
Severity: medium Keywords:
Cc: Ticket locked: no

Description

When changing channels on a system set up for QAM cable on a PCHDTV 5500, I would often either get failure or the wrong channel (right frequency, wrong program ID). I traced this to the cached PMT/PAT from the old channel being used to select the PID for the new channel. Attached is a suggested fix, though I am not sure this is the best way to fix it.

Attachments (4)

chanfix (494 bytes) - added by anonymous 13 years ago.
chanwithreset (60.3 KB) - added by mrussotto@… 13 years ago.
Channel change with reset
chanwithoutreset (89.7 KB) - added by mrussotto@… 13 years ago.
Channel change without reset
2085.patch (1016 bytes) - added by danielk 13 years ago.
possible fix

Download all attachments as: .zip

Change History (12)

Changed 13 years ago by anonymous

Attachment: chanfix added

comment:1 Changed 13 years ago by danielk

Milestone: 0.21
Owner: changed from Isaac Richards to danielk
Version: head

comment:2 Changed 13 years ago by danielk

Resolution: invalid
Status: newclosed

I'm going to need "mythbackend -v record,channel,siparser" logs from changing from one channel to another with this problem. The reset in your patch should not be needed, and it would break quick channel changing for everyone else...

Changed 13 years ago by mrussotto@…

Attachment: chanwithreset added

Channel change with reset

Changed 13 years ago by mrussotto@…

Attachment: chanwithoutreset added

Channel change without reset

comment:3 Changed 13 years ago by mrussotto@…

Resolution: invalid
Status: closedreopened

I have attached requested logs. Both logs show changing the channel from channel number 240 (WHYY-DT, channel 119, serviceid 1) to channel number 246 (WPVI-DT3, channel 118, serviceid 4).

In the log with reset, it changed channels properly.

In the log without reset, it changed instead to channel 118, serviceid 1 (WPVI-DT).

Changed 13 years ago by danielk

Attachment: 2085.patch added

possible fix

comment:4 Changed 13 years ago by danielk

mrussotto, can you try the attached patch and tell me if it fixes the problem for you?

comment:5 Changed 13 years ago by danielk

Resolution: fixed
Status: reopenedclosed

(In [10793]) Fixes #2085. Adds some resets to make digital tuning more reliable with wonky feeds.

comment:6 Changed 13 years ago by danielk

(In [10794]) Refs #2085. Additional frequency table fixes..

comment:7 Changed 13 years ago by danielk

[10794] should have referenced #2087.

comment:8 Changed 13 years ago by mrussotto@…

Yes, this fixes it. Thanks.

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