Opened 20 years ago

Closed 20 years ago

Last modified 20 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@… 20 years ago.
Patch to restore DTVRecorder::FindKeyframes from 0.18.1
dtvrecorder_patch.2​ (6.5 KB ) - added by mark.goodman+mythtv@… 20 years ago.
Patch to restore FindKeyframes and HandleKeyframe from 0.18.1
dtvrecorder_patch.3​ (2.6 KB ) - added by mark.goodman+mythtv@… 20 years ago.
Minimal patch to fix firewire recording glitches

Download all attachments as: .zip

Change History (7)

by mark.goodman+mythtv@…, 20 years ago

Attachment: dtvrecorder_patch​ added

Patch to restore DTVRecorder::FindKeyframes from 0.18.1

by mark.goodman+mythtv@…, 20 years ago

Attachment: dtvrecorder_patch.2​ added

Patch to restore FindKeyframes and HandleKeyframe from 0.18.1

comment:1 by mark.goodman+mythtv@…, 20 years ago

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

comment:2 by mark.goodman+mythtv@…, 20 years ago

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.

by mark.goodman+mythtv@…, 20 years ago

Attachment: dtvrecorder_patch.3​ added

Minimal patch to fix firewire recording glitches

comment:3 by danielk, 20 years ago

Resolution: → wontfix
Status: new → closed

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 by mark.goodman+mythtv@…, 20 years ago

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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