[mythtv-users] Preview generation failing and problems with flagging/viewing "Low Quality" recordings

mythtv at organizedinsanity.net mythtv at organizedinsanity.net
Mon May 9 05:42:42 UTC 2011


 Hi everybody. Some problems after upgrading from a perfectly-functional 
 0.21 (Ubuntu 8.04) to 0.23 (Ubuntu 10.04, then updated to the release 
 version via mythbuntu repos). I've already searched 
 archives/forums/FAQs/etc, and found nothing even vaguely related. Asked 
 on IRC, and the only suggestion was the previously-mentioned update to 
 the release version of 0.23 (which fixed a separate MythVideo issue, but 
 had no effect on either of these).

 The only common issue I've read about from doing this upgrade is 
 database-related. But I'm not aware of there having been any issues with 
 my database upgrade, and these don't seem like database issues to me... 
 they *do* seem like regressive bugs in MythTV itself, but I think my 
 configuration is far too standard for such issues to have slipped 
 through unnoticed. I welcome tips on how to further diagnose things.

 1. Both backend and frontend are now struggling with recordings made 
 from the "Low Quality" recording profile. Are there any known issues 
 related to this? Is something no longer supported? It still records fine 
 (PVR-150, btw), but the backend fails to flag commercials (job queue 
 reports that it found >100 commercial breaks for a half-hour show, but 
 the recording is left marked "not flagged" and the backend logs errors 
 including "smallbin double linked list corrupted"), and the frontend 
 plays back with the top-half of the video covered in green graphical 
 artifacts (screenshot: http://organizedinsanity.net/MythTV/green.png 
 ...you can also see here that the green doesn't always stay in the top 
 half... also, I don't recall the picture - and this affects normal 
 quality recordings too - being so jagged before, which makes me wonder 
 if this could be related to interlacing? But I ran with "--verbose 
 playback" and it didn't seem to be reporting any issues with that, and 
 different playback profiles made no difference). There are no errors in 
 the frontend log, other than "warning: first frame is no keyframe" and 
 "Warning: MVs not available." Playback is the same if I run the raw mpeg 
 through MythVideo, so it's not due to streaming from the backend. 
 Playback is perfectly fine through Totem and the Windows Mythtv Player 
 client (other than the inability to skip commercials). Same issue 
 affects recordings made with 0.21, so it's not that things are being 
 recorded any differently. Three different frontend systems show the 
 exact same issue via the Mythbuntu LiveCD, so I think that rules out 
 hardware issues. Normal quality recordings have none of these issues, 
 but besides my desire to save space, there's the fact that I already 
 have a lot of "Low Quality" recordings to go through...

 2. Preview generation always fails, for all recordings. There are lots 
 of warnings in the logfile ("MVs not available," "first frame is no 
 keyframe," "Filter dir doesn't exist?"... the latter seems odd since the 
 filters are part of the frontend package...), but I'm not sure which are 
 significant and the actual errors are generic (e.g., "Preview Error: 
 Encountered problems running '/usr/bin/mythbackend --generate-preview 
 0x0 --chanid 1029 --starttime 20110508090000 '", "MainServer: Failed to 
 make preview image"). The errors are sometimes preceded by a simple (and 
 vague) "Illegal instruction," and sometimes preceded by a crash of the 
 spawned process, reportedly due to a "corrupted double-linked list."

 That's the summary, here are some log snippets, starting with the 
 backend failing to flag commercials:

 2011-05-08 22:18:45.373 Current MythTV Schema Version (DBSchemaVer): 
 1254
 2011-05-08 22:18:45.381 ProgramInfo(): Updated pathname '':'' -> 
 '1058_20110504020000.mpg'
 2011-05-08 22:18:45.448 Filter dir '/usr/lib/mythtv/filters' doesn't 
 exist?
 2011-05-08 22:18:45.620 [mpeg2video @ 0x531a940]Warning MVs not 
 available
 2011-05-08 22:18:45.651 AFD: Opened codec 0x9e8cf30, id(MPEG2VIDEO) 
 type(Video)
 2011-05-08 22:18:45.653 AFD: codec MP2 has 2 channels
 2011-05-08 22:18:45.654 AFD: Opened codec 0x9e8d7b0, id(MP2) 
 type(Audio)
 2011-05-08 22:18:45.896 [mpeg2video @ 0x531a940]Warning MVs not 
 available
 2011-05-08 22:18:45.904 [mpeg2video @ 0x531a940]warning: first frame is 
 no keyframe
 2011-05-08 22:18:45.910 [mpeg2video @ 0x531a940]Warning MVs not 
 available
 *** glibc detected *** /usr/bin/mythbackend: malloc(): smallbin double 
 linked list corrupted: 0x09ec23e8 ***
 ======= Backtrace: =========
 /lib/tls/i686/cmov/libc.so.6(+0x6b591)[0x294a591]
 /lib/tls/i686/cmov/libc.so.6(+0x6e710)[0x294d710]
 /lib/tls/i686/cmov/libc.so.6(__libc_malloc+0x5c)[0x294ef9c]
 /usr/lib/libstdc++.so.6(_Znwj+0x27)[0x7fbbc07]
 /usr/lib/libmythtv-0.23.so.0(_ZN9__gnu_cxx13new_allocatorIPP11VideoFrame_E8allocateEjPKv+0x42)[0xee7424]
 ======= Memory map: ========
 00110000-001b9000 r-xp 00000000 08:11 18835      
 /usr/lib/libmythavformat-0.23.so.0.23.0
 001b9000-001ba000 ---p 000a9000 08:11 18835      
 /usr/lib/libmythavformat-0.23.so.0.23.0
 001ba000-001bd000 r--p 000a9000 08:11 18835      
 /usr/lib/libmythavformat-0.23.so.0.23.0
 001bd000-001c3000 rw-p 000ac000 08:11 18835      
 /usr/lib/libmythavformat-0.23.so.0.23.0
 001c3000-001c7000 rw-p 00000000 00:00 0
 001c7000-001d2000 r-xp 00000000 08:11 17846      
 /usr/lib/libmythavutil-0.23.so.0.23.0
 001d2000-001d3000 r--p 0000b000 08:11 17846      
 /usr/lib/libmythavutil-0.23.so.0.23.0
 001d3000-001d4000 rw-p 0000c000 08:11 17846      
 /usr/lib/libmythavutil-0.23.so.0.23.0
 001d4000-001d7000 rw-p 00000000 00:00 0
 001d7000-00207000 r-xp 00000000 08:11 16412      
 /usr/lib/libmythswscale-0.23.so.0.23.0
 00207000-00208000 r--p 00030000 08:11 16412      
 /usr/lib/libmythswscale-0.23.so.0.23.0
 00208000-00209000 rw-p 00031000 08:11 16412      
 /usr/lib/libmythswscale-0.23.so.0.23.0
 00209000-002b5000 r-xp 00000000 08:11 17847      
 /usr/lib/libmythupnp-0.23.so.0.23.0
 002b5000-002b6000 r--p 000ac000 08:11 17847      
 /usr/lib/libmythupnp-0.23.so.0.23.0
 002b6000-002b8000 rw-p 000ad000 08:11 17847      
 /usr/lib/libmythupnp-0.23.so.0.23.0
 002b8000-0035a000 r-xp 00000000 08:11 18838      
 /usr/lib/libmythdb-0.23.so.0.23.0
 0035a000-0035b000 ---p 000a2000 08:11 18838      
 /usr/lib/libmythdb-0.23.so.0.23.0
 0035b000-0035c000 r--p 000a2000 08:11 18838      
 /usr/lib/libmythdb-0.23.so.0.23.0
 0035c000-0035e000 rw-p 000a3000 08:11 18838      
 /usr/lib/libmythdb-0.23.so.0.23.0
 0035e000-00436000 r-xp 00000000 08:11 18836      
 /usr/lib/libmythlivemedia-0.23.so.0.23.0
 00436000-00437000 ---p 000d8000 08:11 18836      
 /usr/lib/libmythlivemedia-0.23.so.0.23.0
 00437000-0043c000 r--p 000d8000 08:11 18836      
 /usr/lib/libmythlivemedia-0.23.so.0.23.0
 0043c000-00443000 rw-p 000dd000 08:11 18836      
 /usr/lib/libmythlivemedia-0.23.so.0.23.0
 .
 .
 .
 Aborted
 2011-05-08 22:18:45.976 Preview Error: Encountered problems running 
 '/usr/bin/mythbackend --generate-preview 0x0 --chanid 1058 --starttime 
 20110504020000 '
 2011-05-08 22:18:46.044 ProgramInfo(): Updated pathname '':'' -> 
 '1058_20110504020000.mpg'


 Now, the backend failing to generate previews:

 2011-05-08 21:13:43.490 Current MythTV Schema Version (DBSchemaVer): 
 1254
 2011-05-08 21:13:43.508 ProgramInfo(): Updated pathname '':'' -> 
 '1058_20110505230000.mpg'
 2011-05-08 21:13:43.698 [mpeg2video @ 0x679d940]Warning MVs not 
 available
 2011-05-08 21:13:43.731 Filter dir '/usr/lib/mythtv/filters' doesn't 
 exist?
 2011-05-08 21:13:43.736 Filter dir '/usr/lib/mythtv/filters' doesn't 
 exist?
 2011-05-08 21:13:43.739 [mpeg2video @ 0x679d940]warning: first frame is 
 no keyframe
 2011-05-08 21:13:43.761 [mpeg2video @ 0x679d940]Warning MVs not 
 available
 2011-05-08 21:13:43.887 [mpeg2video @ 0x679d940]warning: first frame is 
 no keyframe
 2011-05-08 21:13:43.938 [mpeg2video @ 0x679d940]warning: first frame is 
 no keyframe
 2011-05-08 21:13:44.080 [mpeg2video @ 0x679d940]Warning MVs not 
 available
 2011-05-08 21:13:44.396 [mpeg2video @ 0x4be940]Warning MVs not 
 available
 2011-05-08 21:13:44.422 [mpeg2video @ 0x52e3940]Warning MVs not 
 available
 Illegal instruction
 2011-05-08 21:13:44.496 Preview Error: Encountered problems running 
 '/usr/bin/mythbackend --generate-preview 0x0 --chanid 1058 --starttime 
 20110504020000 '
 2011-05-08 21:13:44.507 MainServer: Failed to make preview image.
 2011-05-08 21:13:44.683 AFD: Opened codec 0x8b70000, id(MPEG2VIDEO) 
 type(Video)
 2011-05-08 21:13:44.692 AFD: codec MP2 has 2 channels
 2011-05-08 21:13:44.694 AFD: Opened codec 0x8b70570, id(MP2) 
 type(Audio)
 2011-05-08 21:13:44.713 AFD: Opened codec 0x9144e40, id(MPEG2VIDEO) 
 type(Video)
 2011-05-08 21:13:44.720 AFD: codec MP2 has 2 channels
 2011-05-08 21:13:44.729 AFD: Opened codec 0x91456f0, id(MP2) 
 type(Audio)
 Illegal instruction
 2011-05-08 21:13:45.299 Preview Error: Encountered problems running 
 '/usr/bin/mythbackend --generate-preview 0x0 --chanid 1029 --starttime 
 20110504210000 '
 2011-05-08 21:13:45.300 MainServer: Failed to make preview image.
 2011-05-08 21:13:45.534 [mpeg2video @ 0x52e3940]Warning MVs not 
 available
 *** glibc detected *** /usr/bin/mythbackend: corrupted double-linked 
 list: 0x08b74418 ***
 ======= Backtrace: =========
 /lib/tls/i686/cmov/libc.so.6(+0x6b591)[0x2d29591]
 /lib/tls/i686/cmov/libc.so.6(+0x6ec10)[0x2d2cc10]
 /lib/tls/i686/cmov/libc.so.6(__libc_malloc+0x5c)[0x2d2df9c]
 /usr/lib/libQtCore.so.4(_Z7qMallocj+0x1d)[0x2aa0b8d]
 /usr/lib/libQtCore.so.4(_ZN7QString17fromLatin1_helperEPKci+0x44)[0x2af3ad4]
 /usr/lib/libQtCore.so.4(_ZN7QString16fromAscii_helperEPKci+0xe4)[0x2af98f4]
 /usr/bin/mythbackend(_ZN7QStringC1EPKc+0x17)[0x807b2ed]
 ======= Memory map: ========
 00110000-001b2000 r-xp 00000000 08:11 18838      
 /usr/lib/libmythdb-0.23.so.0.23.0
 001b2000-001b3000 ---p 000a2000 08:11 18838      
 /usr/lib/libmythdb-0.23.so.0.23.0
 001b3000-001b4000 r--p 000a2000 08:11 18838      
 /usr/lib/libmythdb-0.23.so.0.23.0
 001b4000-001b6000 rw-p 000a3000 08:11 18838      
 /usr/lib/libmythdb-0.23.so.0.23.0
 001b6000-003de000 r-xp 00000000 08:11 18839      
 /usr/lib/libmythui-0.23.so.0.23.0
 003de000-003df000 ---p 00228000 08:11 18839      
 /usr/lib/libmythui-0.23.so.0.23.0
 003df000-003e3000 r--p 00228000 08:11 18839      
 /usr/lib/libmythui-0.23.so.0.23.0
 003e3000-003e8000 rw-p 0022c000 08:11 18839      
 /usr/lib/libmythui-0.23.so.0.23.0
 003e8000-003e9000 rw-p 00000000 00:00 0
 003e9000-003eb000 r-xp 00000000 08:06 110324     
 /lib/tls/i686/cmov/libdl-2.11.1.so
 003eb000-003ec000 r--p 00001000 08:06 110324     
 /lib/tls/i686/cmov/libdl-2.11.1.so
 003ec000-003ed000 rw-p 00002000 08:06 110324     
 /lib/tls/i686/cmov/libdl-2.11.1.so
 003ed000-003f0000 r-xp 00000000 08:11 16268      
 /usr/lib/libavc1394.so.0.3.0
 003f0000-003f1000 r--p 00003000 08:11 16268      
 /usr/lib/libavc1394.so.0.3.0
 003f1000-003f2000 rw-p 00004000 08:11 16268      
 /usr/lib/libavc1394.so.0.3.0
 003f4000-003f5000 r-xp 00000000 00:00 0          [vdso]

 ...and so on... (I'm guessing the memory maps aren't that useful 
 here...)



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