Blender crashes randomly when editing video #95688

New Issue

Rainer · 2022-02-10T22:48:56+01:00

Rainer commented

2022-02-10 22:48:56 +01:00

System Information
Operating system: Linux-5.16.8-arch1-1-x86_64-with-glibc2.33 64 Bits
Graphics card: NVIDIA GeForce GTX 1060 6GB/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 510.47.03

Blender Version
Broken: version: 3.0.1, branch: makepkg (modified), commit date: 2022-01-25 17:19, hash: dc2d180181
Worked: Crashes randomly in all versions I tried

Short description of error
While editing videos I experience in average one crash every hour. The crashes happen quite randomly and cannot really be reproduced.
I have the feeling that the likelihood of a crash increases after I just added a new video strip (referring to a mp4 video file on my disk) and are especially high while blender is "Building Proxies".

Exact steps for others to reproduce the error
Cannot exactly reproduce the error.
Simply try to cut together a video from multiple external video files for some time and observe about one crash every hour.

Attached you can find the crash.txt and the .blend file (however I don't know how much help the .blend file is as is refers tu many gigabytes of external mp4 files)

keller_bohrung_2546_autosave.blend

keller_bohrung.crash.txt

**System Information** Operating system: Linux-5.16.8-arch1-1-x86_64-with-glibc2.33 64 Bits Graphics card: NVIDIA GeForce GTX 1060 6GB/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 510.47.03 **Blender Version** Broken: version: 3.0.1, branch: makepkg (modified), commit date: 2022-01-25 17:19, hash: `dc2d180181` Worked: Crashes randomly in all versions I tried **Short description of error** While editing videos I experience in average one crash every hour. The crashes happen quite randomly and cannot really be reproduced. I have the feeling that the likelihood of a crash increases after I just added a new video strip (referring to a mp4 video file on my disk) and are especially high while blender is "Building Proxies". **Exact steps for others to reproduce the error** Cannot exactly reproduce the error. Simply try to cut together a video from multiple external video files for some time and observe about one crash every hour. Attached you can find the crash.txt and the .blend file (however I don't know how much help the .blend file is as is refers tu many gigabytes of external mp4 files) [keller_bohrung_2546_autosave.blend](https://archive.blender.org/developer/F12861111/keller_bohrung_2546_autosave.blend) [keller_bohrung.crash.txt](https://archive.blender.org/developer/F12861110/keller_bohrung.crash.txt)

Rainer commented

2022-02-10 22:48:56 +01:00

Added subscriber: @Rainer

Rainer commented

2022-02-10 23:00:00 +01:00

Just hit another crash.
Had just added another video strip (drag and drop a file), then enabled "Display waveform" on the audio track and then immediately started cutting the fresh strip (While proxies were still building)

keller_bohrung_6623_autosave.blend

keller_bohrung.crash.txt

Just hit another crash. Had just added another video strip (drag and drop a file), then enabled "Display waveform" on the audio track and then immediately started cutting the fresh strip (While proxies were still building) [keller_bohrung_6623_autosave.blend](https://archive.blender.org/developer/F12861124/keller_bohrung_6623_autosave.blend) [keller_bohrung.crash.txt](https://archive.blender.org/developer/F12861123/keller_bohrung.crash.txt)

Omar Emara commented

2022-02-11 08:13:51 +01:00

Added subscriber: @OmarEmaraDev

Omar Emara commented

2022-02-11 08:13:51 +01:00

I can't reproduce on either 3.0 or master. But the stack trace indeed indicates that the crash happens after it finish building the proxies.

Germano Cavalcante commented

2022-02-11 17:00:52 +01:00

Added subscribers: @iss, @mano-wii

Germano Cavalcante commented

2022-02-11 17:00:52 +01:00

Changed status from 'Needs Triage' to: 'Needs Developer To Reproduce'

Germano Cavalcante commented

2022-02-11 17:00:52 +01:00

The crash is random and may depend on the hardware.
I don't see much option to investigate other than relying on backtrace:

# backtrace
blender(BLI_system_backtrace+0x38) [0x558da7de49d8]
blender(+0xec8e06) [0x558da702de06]
/usr/lib/libc.so.6(+0x3cda0) [0x7f66ccb2bda0]
blender(SEQ_proxy_rebuild_finish+0x50) [0x558da76e0940]
blender(+0x157b9f5) [0x558da76e09f5]
blender(wm_jobs_timer+0xd2) [0x558da7218e62]
blender(wm_window_process_events+0x2e2) [0x558da723a8d2]
blender(WM_main+0x19) [0x558da71f7139]
blender(main+0x372) [0x558da6ff1222]
/usr/lib/libc.so.6(__libc_start_main+0xd5) [0x7f66ccb16b25]
blender(_start+0x2e) [0x558da7020b0e]

@iss, any idea what might be going on?

The crash is random and may depend on the hardware. I don't see much option to investigate other than relying on backtrace: ``` # backtrace blender(BLI_system_backtrace+0x38) [0x558da7de49d8] blender(+0xec8e06) [0x558da702de06] /usr/lib/libc.so.6(+0x3cda0) [0x7f66ccb2bda0] blender(SEQ_proxy_rebuild_finish+0x50) [0x558da76e0940] blender(+0x157b9f5) [0x558da76e09f5] blender(wm_jobs_timer+0xd2) [0x558da7218e62] blender(wm_window_process_events+0x2e2) [0x558da723a8d2] blender(WM_main+0x19) [0x558da71f7139] blender(main+0x372) [0x558da6ff1222] /usr/lib/libc.so.6(__libc_start_main+0xd5) [0x7f66ccb16b25] blender(_start+0x2e) [0x558da7020b0e] ``` @iss, any idea what might be going on?

Richard Antalik commented

2022-02-14 16:11:13 +01:00

Will check this, Could be use after free as SEQ_proxy_rebuild_finish may need to access original data. I thought that d7f0de0e3a, could be related, but 3.0.1 is more recent.

Will check this, Could be use after free as `SEQ_proxy_rebuild_finish` may need to access original data. I thought that d7f0de0e3a, could be related, but 3.0.1 is more recent.

Richard Antalik commented

2022-02-14 18:43:14 +01:00

I checked this quickly and wasn't able to reproduce crash. @Rainer just to clarify, are you using automatic proxy building? See preferences > System > Video Sequencer

Rainer commented

2022-02-15 10:28:23 +01:00

Hi @iss Yes Problem is not easy to reproduce. Correct I use automatic proxy building.
I have the feeling that I sometimes experience crashes also when no proxies are building. Will be cutting another video end of the Week, when crashes happen again, I will upload the crash.txt here. Maybe you can get additional info from multiple reports, to see if callstack is similar / same.

Thanks for looking into this :-) I know problems like this are hard to debug...

Hi @iss Yes Problem is not easy to reproduce. Correct I use automatic proxy building. I have the feeling that I sometimes experience crashes also when no proxies are building. Will be cutting another video end of the Week, when crashes happen again, I will upload the crash.txt here. Maybe you can get additional info from multiple reports, to see if callstack is similar / same. Thanks for looking into this :-) I know problems like this are hard to debug...

Rainer commented

2022-02-27 18:44:10 +01:00

OK, I did some more video editing the last days. I noticed the following:

The crash can be reproduced with a high likelyhood:

Drag/Drop a large video file into the Sequencer (>1Gbyte H.264 MPEG-4 file).
Then Proxy-Building starts automatically.
Now wait until Proxy is almost complete (95...100%) Not sure when exactly.
Then in the freshly added clip do a cut while Proxy is still building (Select Video and Audio, Place cursor somewhere and press K).
Observe nice crash

Also see this on different machines (also Arch-Linux but completely different HW (AMD GPU, Ryzen CPU vs Nvidia GPU, Intel CPU))

I disabled automatic proxy building and did not observe any crash until now (not building any proxies).

OK, I did some more video editing the last days. I noticed the following: The crash can be reproduced with a high likelyhood: - Drag/Drop a large video file into the Sequencer (>1Gbyte H.264 MPEG-4 file). - Then Proxy-Building starts automatically. - Now wait until Proxy is almost complete (95...100%) Not sure when exactly. - Then in the freshly added clip do a cut while Proxy is still building (Select Video and Audio, Place cursor somewhere and press K). - Observe nice crash Also see this on different machines (also Arch-Linux but completely different HW (AMD GPU, Ryzen CPU vs Nvidia GPU, Intel CPU)) I disabled automatic proxy building and did not observe any crash until now (not building any proxies).

Richard Antalik commented

2022-02-28 20:47:35 +01:00

I wasn't able to reproduce this even with clarified steps.

I can see how crash could be caused if you would split strips at exact moment when proxy building finishes, but this would be quite difficult to reproduce. Also if this would be actual issue it would be nearly impossible to fix

I have created test build to check this.
First please download latest alpha build from https://builder.blender.org/download/daily/ and check if you can reproduce. It may be, that proxies won't build, because now process is optimized to only build proxies for "slow" files. If this happens, please try starting proxy building manually.
If you was able to reproduce crash in latest alpha, download build D14209 from https://builder.blender.org/download/patch/ and try to reproduce again. I have "protected" splitting to not crash. Please do not try to delete strips only split, same with alpha, otherwise I can't be sure whether I located the problem correctly. crash logs for both tests would be appreciated.

Note for me mainly: In meanwhile I will investigate whether accessing seqbase from thread is necessary. Locking with mutex is not really great fix as there are many functions modifying it and it is DNA member so it can be accessed pretty much from everywhere in codebase.

I wasn't able to reproduce this even with clarified steps. I can see how crash could be caused if you would split strips at exact moment when proxy building finishes, but this would be quite difficult to reproduce. Also if this would be actual issue it would be nearly impossible to fix I have created test build to check this. First please download latest alpha build from https://builder.blender.org/download/daily/ and check if you can reproduce. It may be, that proxies won't build, because now process is optimized to only build proxies for "slow" files. If this happens, please try starting proxy building manually. If you was able to reproduce crash in latest alpha, download build [D14209](https://archive.blender.org/developer/D14209) from https://builder.blender.org/download/patch/ and try to reproduce again. I have "protected" splitting to not crash. Please do not try to delete strips only split, same with alpha, otherwise I can't be sure whether I located the problem correctly. crash logs for both tests would be appreciated. Note for me mainly: In meanwhile I will investigate whether accessing seqbase from thread is necessary. Locking with mutex is not really great fix as there are many functions modifying it and it is DNA member so it can be accessed pretty much from everywhere in codebase.

Richard Antalik commented

2022-02-28 21:20:47 +01:00

I have created another build, D14210. This should be technically complete fix with no ifs and buts, so please check mainly this one and latest alpha as I described above.

I have created another build, [D14210](https://archive.blender.org/developer/D14210). This should be technically complete fix with no ifs and buts, so please check mainly this one and latest alpha as I described above.

Rainer commented

2022-02-28 21:47:30 +01:00

Hi Richard,
Thank you for looking into this.
I just tried to reproduce again and finally have a refined process of reproducing the problem in ALL attempts (still using stock Arch linux provided blender v3.0.1):

Open Blender and do File->New->Video Editing
Drag/Drop video file into Sequencer for which no proxies are built yet (Size does not really matter, but not too small, so that proxy building can be observed (50...150Mbyte h264 is good for me))
Carefully observe Proxy building progress
Now while proxy is still building, move FrameMarker/Cursor to a place in the clip and press K to cut both audio and video
Now still while proxy is building select the LEFT part of the cut (audio + video with left-click-drag box select) and press "del" key to delete. It won't reproduce when deleting the "right" part of the video
Now wait for proxy building to complete to 100%
Observe when Proxy building hits 100%, Blender fill freeze up and crash

Tried this about 5 times on both my PCs and hit the bug in all 5 times.
Was not able to reproduce without deleting the clip.
Could you try this procedure again and tell me if you succeeded to reproduce? If not, I can try with your builds.

Hi Richard, Thank you for looking into this. I just tried to reproduce again and finally have a refined process of reproducing the problem in ALL attempts (still using stock Arch linux provided blender v3.0.1): - Open Blender and do File->New->Video Editing - Drag/Drop video file into Sequencer for which no proxies are built yet (Size does not really matter, but not too small, so that proxy building can be observed (50...150Mbyte h264 is good for me)) - Carefully observe Proxy building progress - Now while proxy is still building, move FrameMarker/Cursor to a place in the clip and press K to cut both audio and video - Now still while proxy is building select the LEFT part of the cut (audio + video with left-click-drag box select) and press "del" key to delete. It won't reproduce when deleting the "right" part of the video - Now wait for proxy building to complete to 100% - Observe when Proxy building hits 100%, Blender fill freeze up and crash Tried this about 5 times on both my PCs and hit the bug in all 5 times. Was not able to reproduce without deleting the clip. Could you try this procedure again and tell me if you succeeded to reproduce? If not, I can try with your builds.

Richard Antalik commented

2022-02-28 22:13:31 +01:00

I am not able to reproduce this with 3.0.1

Rainer commented

2022-02-28 22:55:11 +01:00

Ok, I tried again and performed more repros:

On blender-3.0.1-stable+v30.dc2d18018171-linux.x86_64-release I can reproduce it 100% (9 of 9 attempts):
I found a small video file and attached it here with which I reproduced the problem and also the corresponding crash file:
blender-3.0.1-stable+v30.dc2d18018171-linux.x86_64-release_blender.crash3.txt
DJI_0804_decke_sagen.MP4

I also tried
blender-3.1.0-beta+v31.4ee4b61dd8d3-linux.x86_64-release
and
blender-3.2.0-alpha+master.63891f9dad93-linux.x86_64-release

I cannot reproduce the problem in either of those (5 attempts each).

Either the problem was fixed or moved/hidden by other changes.

Ok, I tried again and performed more repros: On blender-3.0.1-stable+v30.dc2d18018171-linux.x86_64-release I can reproduce it 100% (9 of 9 attempts): I found a small video file and attached it here with which I reproduced the problem and also the corresponding crash file: [blender-3.0.1-stable+v30.dc2d18018171-linux.x86_64-release_blender.crash3.txt](https://archive.blender.org/developer/F12891563/blender-3.0.1-stable_v30.dc2d18018171-linux.x86_64-release_blender.crash3.txt) [DJI_0804_decke_sagen.MP4](https://archive.blender.org/developer/F12891555/DJI_0804_decke_sagen.MP4) I also tried blender-3.1.0-beta+v31.4ee4b61dd8d3-linux.x86_64-release and blender-3.2.0-alpha+master.63891f9dad93-linux.x86_64-release I cannot reproduce the problem in either of those (5 attempts each). Either the problem was fixed or moved/hidden by other changes.

Richard Antalik commented

2022-02-28 23:59:08 +01:00

Thanks for checking, I think that d7f0de0e3a then fixed the issue. Not quite sure why this commit is not in 3.0 branch.

Thanks for checking, I think that d7f0de0e3a then fixed the issue. Not quite sure why this commit is not in 3.0 branch.

Richard Antalik commented

2022-03-01 00:04:12 +01:00

Changed status from 'Needs Developer To Reproduce' to: 'Archived'

Richard Antalik closed this issue

2022-03-01 00:04:12 +01:00

Richard Antalik commented

2022-03-01 00:04:12 +01:00

Sorry, was meant to close this report since you can't reproduce with later versions. But what is also strange is, that I have checked 3.0.1 with your file and was able to reproduce crash, then repeated same steps with file I tested before and also was able to reproduce.

In any case since 3.1 and 3.2 is fixed, will close this report.

Sorry, was meant to close this report since you can't reproduce with later versions. But what is also strange is, that I have checked 3.0.1 with your file and was able to reproduce crash, then repeated same steps with file I tested before and also was able to reproduce. In any case since 3.1 and 3.2 is fixed, will close this report.

blender-admin commented

2022-03-01 23:35:21 +01:00

This issue was referenced by 4491c62260

This issue was referenced by 4491c6226051799f4415ba50abbc4861e09af862

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Blender crashes randomly when editing video #95688