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Opened 3 years ago

Last modified 21 months ago

#12467 new Bug Report - General

Analog video stopped working after kernel version 3.17.1 (green picture image)

Reported by: Joel Snape <joel.snape@…> Owned by:
Priority: minor Milestone: unknown
Component: MythTV - DVB Version: 0.27.4
Severity: medium Keywords: analog saa7134 kernel 3.17.1 v4l decoding
Cc: Ticket locked: no

Description

I have an Pinnacle PCTV 310i (saa7134) and it was working fine, however, when I updated my kernel from the 3.17.1 version, the analog tv decoding stopped working correctly, the audio works but the picture is mostly green with some frames occasionally showing the actual video. The error occurs both for direct video playback and recordings regardless of the encoding I use (I tried with mpeg-4 and with the default rtjpeg).

The only change I make is the kernel, if I start my machine with the 3.17.1 version, it works fine, if I start the machine on a more recent version, (3.18, 3.19 or 4.0) the tv decoding stops working.

The logs were made by starting the systems, opening the "watch tv", waiting a few moments for the tv decoding errors and closing the applications (using the 4.0.1 kernel version and "-v all" option). The v4l2 playback works well using mpv (with some strange log messages) but also fails with vlc ("rawvideo decoder warning: invalid frame size (622080 < 933120)" ).

Attachments (5)

mythbackend.20150701234655.12712.log (250.2 KB) - added by Joel Snape <joel.snape@…> 3 years ago.
mythfrontend_verbose_all.log (1.1 MB) - added by Joel Snape <joel.snape@…> 3 years ago.
watchtv_image.png (193.9 KB) - added by Joel Snape <joel.snape@…> 3 years ago.
mythbackend_version.txt (2.2 KB) - added by Joel Snape <joel.snape@…> 3 years ago.
mythfrontend_version.txt (1.4 KB) - added by Joel Snape <joel.snape@…> 3 years ago.

Download all attachments as: .zip

Change History (7)

Changed 3 years ago by Joel Snape <joel.snape@…>

Changed 3 years ago by Joel Snape <joel.snape@…>

Changed 3 years ago by Joel Snape <joel.snape@…>

Changed 3 years ago by Joel Snape <joel.snape@…>

Changed 3 years ago by Joel Snape <joel.snape@…>

comment:1 Changed 3 years ago by Joel Snape <joel.snape@…>

After a litle more tinkering I managed to get vlc to work... I just had to use "YUY2" chroma instead of the default "YU12"... Is there a way I can force MythTV to use "YUY2" and see if I can use it as a workaround?

comment:2 Changed 21 months ago by Joel Snape <joel.snape@…>

I revisited this issue recently e found that the problems in VLC were fixed in the kernel version 4.6 (this commit: https://github.com/torvalds/linux/commit/3e71da19f9dc22e39a755d6ae9678661abb66adc), however MythTV still had issues so I had to dig around until I found that VBI is broken and caused the VIDIOC_DQBUF call to send only two frames per second (instead of the usual 25)... I don't know if the bug is in the driver or in MythTV but changing the VBIMode to "none" in MythTV solved the problem so for me issue to resolved.

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