segfault while playing HD content

[Frederic Gaudet]

Hi,

After weeks of research I still doesn't understand why I can't playing HD content with my MythTV box, based on ubuntu (Point of view ION 330 mainboard, 513Mb GPU Memory).

I use to compile MythTV myself, but in order to debug my box, I have installed Mythtv and vdpau drivers (currently 190.x) from JY.Avenard repository.
Result is the same : I have no image, mythfrontend segfault immedialty after locking the channel.
However, I can record the channel with no problem, and mplayer works like a charm with HD content. So the issue seems to be related with Mythtv default player (ffmpeg?) and Vdpau driver.

I live in France, I'm not sure about the exact content of the stream, it should be H264/AVC, I can provide a few seconds of video, if requested.

Here is the log file provided when I switch to a DVB-T channel using HD stream.

I hope you'll have some brilliant idea, because I'm stuck right now

Thanks

[Stephen Warren]

Are you able to run mythtv under gdb and provide a backtrace? That will give a clue exactly which part of the software is crashing.

If not, it's probably best to ask for help in a MythTV-specific forum, since it's not immediately obvious that the problem is due to an NVIDIA driver issue, as opposed to a problem in MythTV/ffmpeg/... when VDPAU is used.

[crisalide]

Originally Posted by Frederic Gaudet

I live in France, I'm not sure about the exact content of the stream, it should be H264/AVC, I can provide a few seconds of video, if requested.

French DVB-T HD channels are h264 1440x1080@25i. Sound is mp2 for ARTE and E-AC3 (using Spectral Extension) for the others.

[Frederic Gaudet]

Hi

Thanks for your responses. As you requested, I've used gdb to run mythfrontend and here is the end of the log :

[.....]
2010-05-01 15:13:51.631 [h264 @ 0x7ffff6806940]number of reference frames exceeds max (probably corrupt input), discarding one
2010-05-01 15:13:51.631 [h264 @ 0x7ffff6806940]number of reference frames exceeds max (probably corrupt input), discarding one
2010-05-01 15:13:51.631 [h264 @ 0x7ffff6806940]number of reference frames exceeds max (probably corrupt input), discarding one

Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 0x7fffc7383910 (LWP 3487)]
0x00007ffff650f9fc in h264_v_loop_filter_luma_mmx2 () from /usr/local/lib/libmythavcodec-0.22.so.0
(gdb)

I attach the full log provided,

Thanks

Fred

[cehoyos]

Originally Posted by Frederic Gaudet

Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 0x7fffc7383910 (LWP 3487)]
0x00007ffff650f9fc in h264_v_loop_filter_luma_mmx2 ()

This indicates you were not using hardware accelerated, but software decoding. If this happens with every sample (and not a particular one), it indicates a problem with MythTV.

Carl Eugen

[Frederic Gaudet]

Originally Posted by cehoyos

This indicates you were not using hardware accelerated, but software decoding. If this happens with every sample (and not a particular one), it indicates a problem with MythTV.

Carl Eugen

That weird...

When I pick XvMC profile, I can see HD (OK, 2 images out of 3, choppy audio... ). When I choose VDPAU profile, everything crash.

In the log file I send yesterday, it indicates I'm using vdpau :

[New Thread 0x7fffc7383910 (LWP 3487)]
VDPAU capture: Enabled
vdp_imp_device_create_x11(0xf95350, 0, -, -)
-> 0, 1, 0x7fffcdd77260
vdp_get_proc_address(1, 0, -)
-> 0, 0x7fffcdb687a0
vdp_get_proc_address(1, 2, -)
-> 0, 0x7fffcdb68690
vdp_get_proc_address(1, 4, -)
-> 0, 0x7fffcdb68550
vdp_get_api_version(-)
-> 0, 1
vdp_get_information_string(-)
-> 0, "NVIDIA VDPAU Driver Shared Library 190.53 Wed Dec 9 16:28:38 PST 2009"
vdp_get_proc_address(1, 66, -)
-> 0, 0x7fffcdb64910
vdp_preemption_callback_register(1, 0x7ffff7780280, 0xa5cda0)

How can I be sure I'm using hardware decoding ?

[Frederic Gaudet]

The luma_mmx2() function seems to be related with audio processing (part of DSPutils), so I wonder if the issue depends on audio : I tried to play a recorded movie (with mythtv) with ffplay :

FFplay version SVN-r19352-4:0.5+svn20090706-2ubuntu2.2, Copyright (c) 2003-2009 Fabrice Bellard, et al.
configuration: --extra-version=4:0.5+svn20090706-2ubuntu2.2 --prefix=/usr --enable-avfilter --enable-avfilter-lavf --enable-vdpau --enable-bzlib --enable-libgsm --enable-libschroedinger --enable-libspeex --enable-libtheora --enable-libvorbis --enable-pthreads --enable-zlib --disable-stripping --disable-vhook --enable-gpl --enable-postproc --enable-swscale --enable-x11grab --enable-libdc1394 --extra-cflags=-I/build/buildd/ffmpeg-0.5+svn20090706/debian/include --enable-shared --disable-static
libavutil 49.15. 0 / 49.15. 0
libavcodec 52.20. 0 / 52.20. 0
libavformat 52.31. 0 / 52.31. 0
libavdevice 52. 1. 0 / 52. 1. 0
libavfilter 0. 4. 0 / 0. 4. 0
libswscale 0. 7. 1 / 0. 7. 1
libpostproc 51. 2. 0 / 51. 2. 0
built on Apr 23 2010 15:38:06, gcc: 4.4.1
[h264 @ 0xa87830]number of reference frames exceeds max (probably corrupt input), discarding one
Last message repeated 50 times
[eac3 @ 0xa94dc0]frame sync error
[eac3 @ 0xa94dc0]Spectral extension attenuation not implemented. Update your FFmpeg version to the newest one from SVN. If the problem still occurs, it means that your file has a feature which has not been implemented.If you want to help, upload a sample of this file to ftp://upload.ffmpeg.org/MPlayer/incoming/ and contact the ffmpeg-devel mailing list.
[eac3 @ 0xa94dc0]Spectral extension not implemented. Update your FFmpeg version to the newest one from SVN. If the problem still occurs, it means that your file has a feature which has not been implemented.If you want to help, upload a sample of this file to ftp://upload.ffmpeg.org/MPlayer/incoming/ and contact the ffmpeg-devel mailing list.
[eac3 @ 0xa94dc0]error decoding the audio block

First, the same message about "references frames" appears again, and then, eac3 processing can't be done.

[cehoyos]

Originally Posted by Frederic Gaudet

When I pick XvMC profile, I can see HD (OK, 2 images out of 3, choppy audio... ). When I choose VDPAU profile, everything crash.

In the log file I send yesterday, it indicates I'm using vdpau :

I was not claiming MythTV was not using VDPAU (which does not only hardware decoding but also presentation of decoded frames), I tried to explain that h264_v_loop_filter_luma_mmx2() is a function that is only used when (purely software-) decoding H264 with libavcodec.

Carl Eugen

[Frederic Gaudet]

Originally Posted by cehoyos

I was not claiming MythTV was not using VDPAU (which does not only hardware decoding but also presentation of decoded frames), I tried to explain that h264_v_loop_filter_luma_mmx2() is a function that is only used when (purely software-) decoding H264 with libavcodec.

Carl Eugen

Do you know if is it normal am I using this function ? I'm not sure about what to conclude with your response !

[Frederic Gaudet]

My issue is now solved.

First, ffmpeg (from the distro repo) wasn't able to manage the sound, so I downloaded the lastest version from SVN, but it still didn't work in Mythtv.
I realize that mythtv comes with an embedded ffmpeg version, so I upgraded Mythtv with the lastest code, released the 10th may, and now everything works.