hevc kernel panic in le11 ? / x265 howto or workaround ?

potfpotf · March 25, 2023 at 7:45 PM

Hello, when trying to read x265 files in local storage in le 11.0.1 on a s912 (vorkez z6 plus), I think the box hangs : gui is unresponsive and terminal no longer accepts input (had to unplug to stop)

I understand there is a problem with hevc / x265 drivers that is hard to fix with the recent kernels and with limits in amlogic builds (as per le11 announcement https://libreelec.tv/2023/03/06/libreelec-nexus-11-0-0/)

My questions would be :

- whether I could prevent in kodi from reading certain types of data based on the metadata (eg : video stream codec is hevc) or stop playback before attempting to decode streams that will hang the box.

- if the box should not hang but there is a problem with my config (approximate dtb that would cause general instability : using meson-gxm-tx9-pro.dtb with gb ethernet and wifi simultaneously)

- if there is a log that could help with the problem, or something that I can do to reproduce the problem with more info if it is interesting

Thanks in advance.

These x265 files were not a problem in CE 9.2 (retested) :

main info for video is below, audio is AAC LC

Format : HEVC

Format profile : Main@L4@Main

Width : 1 898 pixels

Height : 1 078 pixels

more info :

Code

Writing library                          : x265 1.9:[Mac OS X][clang 7.0.0][64 bit] 8bit
Encoding settings                        : wpp / ctu=64 / min-cu-size=8 / max-tu-size=32 / tu-intra-depth=2 / tu-inter-depth=2 / me=3 / subme=3 / merange=57 / rect / amp / max-merge=3 / temporal-mvp / no-early-skip / rdpenalty=0 / no-tskip / no-tskip-fast / strong-intra-smoothing / no-lossless / no-cu-lossless / no-constrained-intra / no-fast-intra / open-gop / no-temporal-layers / interlace=0 / keyint=250 / min-keyint=25 / scenecut=40 / rc-lookahead=30 / lookahead-slices=4 / bframes=8 / bframe-bias=0 / b-adapt=2 / ref=4 / limit-refs=2 / limit-modes / weightp / weightb / aq-mode=1 / qg-size=32 / aq-strength=1.00 / cbqpoffs=0 / crqpoffs=0 / rd=6 / psy-rd=2.00 / rdoq-level=2 / psy-rdoq=1.00 / signhide / deblock / sao / no-sao-non-deblock / b-pyramid / cutree / no-intra-refresh / rc=crf / crf=25.0 / qcomp=0.60 / qpmin=0 / qpmax=51 / qpstep=4 / ipratio=1.40 / pbratio=1.30

**chewitt** · March 26, 2023 at 2:32 AM

It may help to have 1080p 60/59.94/50/24/23.976 modes whitelisted and adjust refresh start/stop enabled as it will eliminate or greatly reduce the amount of correction Kodi needs to attempt; as the decoder doesn't handle correction too well (same issue as seeking). There is no known list of problem media configs/types so nothing to avoid .. it either works or doesn't.

I'd be interested in a sample of the file for long-term testing with problem media, but currently there isn't anything I can do about fixing the decoder so my advice would be to transcode the file to H264.

potfpotf · March 26, 2023 at 12:13 PM

ok, I had to do several tries to get proper logs (and removed the mouse so that no spam after evry move of the mouse in the log), the problem is a bit more complex and may be a problem of re configuration of the decoder after x264 playback + ac3

The steps to reproduce are :

- ok trying to play the x265 file the first time

- ok trying to play a x264 file, stopping the reading

this gives this log : http://ix.io/4rRo

then ko crash :

- retrying same x265 file : the machine seems to crash :

* the network is down (ssh unresponsive)

* lcd screen (vfd) still displays the time of the crash

* kodi? emits a loop sound through the screen speakers

only way to reboot is plug-pulling

the log is not very helpful as when I re read the x265 file, there is a bit of seemingly binary log at the end that is not valid utf8, and no trace of trying to read the file :

with pastebinit kodi.old.log i only got no more text information

http://ix.io/4rRw

chewitt :

- ok for the hevc analysis and media configs, my main problem is that it brings down the entire system

- thanks, i can provide you the samples hum around 500M each to reproduce, I just have not seen yet how to provide them to you (dm with cloud url ?)

- for the whitelisting, these are both 25fps videos, I'll try to play with the settings (whitelisting 1080p 60 + 50 at least)

another info for the sample 1 x264 that may put le + kodi in conditions to trigger the crash is that is is ac-3 vs aac, and maybe I am blaming the wrong cluprit (video stream)

Code

x264 mediainfo

Format profile                           : [email protected]
Format settings                          : CABAC / 5 Ref Frames
Format settings, CABAC                   : Yes
Format settings, Reference frames        : 5 frames
Codec ID                                 : V_MPEG4/ISO/AVC
Duration                                 : 22 min 56 s
Bit rate                                 : 1 875 kb/s
Width                                    : 1 280 pixels
Height                                   : 640 pixels
Display aspect ratio                     : 2.000
Frame rate mode                          : Constant
Frame rate                               : 25.000 FPS
Color space                              : YUV
Chroma subsampling                       : 4:2:0
Bit depth                                : 8 bits
Scan type                                : Progressive
Bits/(Pixel*Frame)                       : 0.092
Stream size                              : 308 MiB (83%)
Writing library                          : x264 core 164 r3086 5585eaf
Encoding settings                        : cabac=1 / ref=5 / deblock=1:0:0 / analyse=0x3:0x133 / me=umh / subme=8 / psy=1 / psy_rd=1.00:0.00 / mixed_ref=1 / me_range=16 / chroma_me=1 / trellis=2 / 8x8dct=1 / cqm=0 / deadzone=21,11 / fast_pskip=1 / chroma_qp_offset=-2 / threads=20 / lookahead_threads=3 / sliced_threads=0 / nr=0 / decimate=1 / interlaced=0 / bluray_compat=0 / constrained_intra=0 / bframes=3 / b_pyramid=2 / b_adapt=1 / b_bias=0 / direct=3 / weightb=1 / open_gop=0 / weightp=2 / keyint=250 / keyint_min=25 / scenecut=40 / intra_refresh=0 / rc_lookahead=50 / rc=crf / mbtree=1 / crf=18.0 / qcomp=0.60 / qpmin=0 / qpmax=69 / qpstep=4 / ip_ratio=1.40 / aq=1:1.00
Language                                 : English
Default                                  : Yes
Forced                                   : No
Color range                              : Limited
Matrix coefficients                      : BT.709

Audio
ID                                       : 2
Format                                   : AC-3
Format/Info                              : Audio Coding 3
Commercial name                          : Dolby Digital
Codec ID                                 : A_AC3
Duration                                 : 22 min 56 s
Bit rate mode                            : Constant
Bit rate                                 : 384 kb/s

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Skywalker07 · March 27, 2023 at 10:54 PM

Hi there,

sorry, my english is not very good and i don't know much about codecs and so on, but i think i have the same problem...

Just want to let you know this...

i have a Tictid K12 (S912) box and with Libreelec 11.0.1 i can't play 4k videos from my NAS drive.

Rebooting the Device and starting 4k Video the first time it runs.

Then Starting a 1080 Video and Stopping.

Starting the same 4k Video that runs - box is crashing - no ssh

Played with some Settings (Refresh rate) the box is not crashing but after a few seconds 4k Video plays with massive errors or stops or don't start the video. I just gave up with testing...

With Coreelec 9.2.8 Video playback 4k from my NAS drive works very well...

**chewitt** · March 28, 2023 at 6:07 AM

As per release notes; the AMLGX image is not perfect and will not be for all users. I'm not too interested in bug reports because I know the hardware decoders have bugs, there is nothing I can do about that, and comparisons with CE are meaningless since the codebase has 0% kernel and driver code in common.