Opened 13 years ago

Closed 13 years ago

Last modified 13 years ago

#1356 closed defect (wontfix)

DTVRecorder::FindKeyframes in 0.19 causes video gltiches in firewire recordings

Reported by: anonymous Owned by: Isaac Richards
Priority: minor Milestone: unknown
Component: mythtv Version: 0.19
Severity: high Keywords: firewire
Cc: Ticket locked: no

Description

In 0.18.1, DCT6200 firewire recordings work fine. In 0.19, a video glitch occurs every few seconds. I replaced the DTVRecorder::FindKeyframes? in 0.19 with the code in 0.18.1 modified to work with the changed signature. The video glitches went away. DVB recordings work fine in both 0.18.1 and 0.19.

Attachments (3)

dtvrecorder_patch (5.4 KB) - added by mark.goodman+mythtv@… 13 years ago.
Patch to restore DTVRecorder::FindKeyframes? from 0.18.1
dtvrecorder_patch.2 (6.5 KB) - added by mark.goodman+mythtv@… 13 years ago.
Patch to restore FindKeyframes? and HandleKeyframe? from 0.18.1
dtvrecorder_patch.3 (2.6 KB) - added by mark.goodman+mythtv@… 13 years ago.
Minimal patch to fix firewire recording glitches

Download all attachments as: .zip

Change History (7)

Changed 13 years ago by mark.goodman+mythtv@…

Attachment: dtvrecorder_patch added

Patch to restore DTVRecorder::FindKeyframes? from 0.18.1

Changed 13 years ago by mark.goodman+mythtv@…

Attachment: dtvrecorder_patch.2 added

Patch to restore FindKeyframes? and HandleKeyframe? from 0.18.1

comment:1 Changed 13 years ago by mark.goodman+mythtv@…

The second patch fixes the 0:01 recording length problem with the first patch.

comment:2 Changed 13 years ago by mark.goodman+mythtv@…

I see now that the 0.18.1 code never sets _last_gop_seen. I will try to produce a smaller patch when my backend is not in use.

Changed 13 years ago by mark.goodman+mythtv@…

Attachment: dtvrecorder_patch.3 added

Minimal patch to fix firewire recording glitches

comment:3 Changed 13 years ago by danielk

Resolution: wontfix
Status: newclosed

This won't work, we need to be able to handle MPEG-1 streams, and hence detect GOP's. Also this function will be slower once #799 is fixed.

What is needed is buffering between the device read and ProcessTSPacket.

See ticket #712.

comment:4 Changed 13 years ago by mark.goodman+mythtv@…

Since I don't see log messages indicating the firewire recorder is dropping packets, I fail to see how buffering will help but fixing #799 looks promising.

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