obs-v4l2sink
obs-v4l2sink copied to clipboard
CatxFish
OBS crashes in libswscale when starting with changed resolution
When the canvas/output resolution is set to 1920x1080, v4l2sink works fine. But when I stop, change the canvas/output resolution to 1620x1080 and then start v4l2sink again, OBS segfaults:
Signal: 11 (SEGV)
Timestamp: Sun 2020-04-05 00:29:56 CEST (17s ago)
Command Line: obs
Executable: /usr/bin/obs
Control Group: /user.slice/user-1000.slice/session-2.scope
Unit: session-2.scope
Slice: user-1000.slice
Session: 2
Owner UID: 1000 (user)
Boot ID: 269f686e36dc488a99dbd078988ec827
Machine ID: e69d99a0d54a4b27a05fb1eb0a876c83
Hostname: x2000
Storage: /var/lib/systemd/coredump/core.obs.1000.269f686e36dc488a99dbd078988ec827.90018.1586039396000000000000.lz4
Message: Process 90018 (obs) of user 1000 dumped core.
Stack trace of thread 90024:
#0 0x00007fe06fb77f36 n/a (libswscale.so.5 + 0x57f36)
Not sure if this is related to #13.
Let me know if I should build the tool with debug symbols to get a nicer stack trace.
I have the same problems. Here the back trace: backtrace.log And debugger output: Reading symbols from obs... Reading symbols from /usr/lib64/debug//usr/bin/obs.debug... (gdb) r Starting program: /usr/bin/obs [Thread debugging using libthread_db enabled] Using host libthread_db library "/lib64/libthread_db.so.1". [New Thread 0x7fffc9b13700 (LWP 21827)] [New Thread 0x7fffbde67700 (LWP 21831)] Attempted path: share/obs/obs-studio/locale/en-US.ini Attempted path: /usr/share/obs/obs-studio/locale/en-US.ini Attempted path: share/obs/obs-studio/locale.ini Attempted path: /usr/share/obs/obs-studio/locale.ini Attempted path: share/obs/obs-studio/locale/fr-FR.ini Attempted path: /usr/share/obs/obs-studio/locale/fr-FR.ini info: Using preferred locale 'fr-FR' Attempted path: share/obs/obs-studio/themes/System.qss Attempted path: /usr/share/obs/obs-studio/themes/System.qss info: CPU Name: AMD Phenom(tm) II X6 1100T Processor info: CPU Speed: 3350.034MHz info: Physical Cores: 6, Logical Cores: 6 info: Physical Memory: 15887MB Total, 2126MB Free info: Kernel Version: Linux 4.19.72-gentoo info: Distribution: Gentoo Unknown info: Window System: X11.0, Vendor: The X.Org Foundation, Version: 1.20.7 [New Thread 0x7fffb6d61700 (LWP 21832)] info: Portable mode: false Attempted path: share/obs/obs-studio/themes/Dark/no_sources.svg Attempted path: /usr/share/obs/obs-studio/themes/Dark/no_sources.svg QMetaObject::connectSlotsByName: No matching signal for on_advAudioProps_clicked() QMetaObject::connectSlotsByName: No matching signal for on_advAudioProps_destroyed() QMetaObject::connectSlotsByName: No matching signal for on_actionGridMode_triggered() QMetaObject::connectSlotsByName: No matching signal for on_program_customContextMenuRequested(QPoint) info: OBS 25.0.3 (linux) info: --------------------------------- info: --------------------------------- info: audio settings reset: samples per sec: 44100 speakers: 2 [New Thread 0x7fffb5ea5700 (LWP 21833)] info: --------------------------------- info: Initializing OpenGL... [New Thread 0x7fffa1f76700 (LWP 21885)] [New Thread 0x7fffa1634700 (LWP 21886)] [New Thread 0x7fffa0e33700 (LWP 21887)] [New Thread 0x7fff93fff700 (LWP 21888)] [New Thread 0x7fff937fe700 (LWP 21889)] info: Loading up OpenGL on adapter X.Org AMD TURKS (DRM 2.50.0 / 4.19.72-gentoo, LLVM 9.0.1) info: OpenGL loaded successfully, version 3.3 (Core Profile) Mesa 19.3.5, shading language 3.30 info: --------------------------------- info: video settings reset: base resolution: 1920x1080 output resolution: 1148x646 downscale filter: Bicubic fps: 60/1 format: NV12 YUV mode: 601/Partial [New Thread 0x7fff92ffd700 (LWP 21890)] info: NV12 texture support not available [New Thread 0x7fff925dc700 (LWP 21891)] info: Audio monitoring device: name: Par défaut id: default info: --------------------------------- warning: Failed to load 'en-US' text for module: 'decklink-ouput-ui.so' [New Thread 0x7fff90e4c700 (LWP 21892)] libDeckLinkAPI.so: Ne peut ouvrir le fichier d'objet partagé: Aucun fichier ou dossier de ce type warning: A DeckLink iterator could not be created. The DeckLink drivers may not be installed info: No blackmagic support info: FFMPEG VAAPI supported [New Thread 0x7fff7b127700 (LWP 21893)] [New Thread 0x7fff7a926700 (LWP 21894)] [Thread 0x7fff7a926700 (LWP 21894) exited] warning: Failed to load 'fr-FR' text for module: 'v4l2sink.so' [Thread 0x7fff7b127700 (LWP 21893) exited] info: VLC found, VLC video source enabled info: --------------------------------- info: Loaded Modules: info: vlc-video.so info: v4l2sink.so info: text-freetype2.so info: rtmp-services.so info: obs-x264.so info: obs-transitions.so info: obs-outputs.so info: obs-libfdk.so info: obs-filters.so info: obs-ffmpeg.so info: linux-v4l2.so info: linux-pulseaudio.so info: linux-decklink.so info: linux-capture.so info: linux-alsa.so info: image-source.so info: frontend-tools.so info: decklink-ouput-ui.so info: --------------------------------- info: ==== Startup complete =============================================== info: All scene data cleared info: ------------------------------------------------ [New Thread 0x7fff7a926700 (LWP 21895)] info: pulse-input: Server name: 'pulseaudio 13.0' info: pulse-input: Audio format: s16le, 44100 Hz, 3 channels info: pulse-input: Started recording from 'alsa_output.pci-0000_00_14.2.analog-surround-21.monitor' info: pulse-input: Server name: 'pulseaudio 13.0' info: pulse-input: Audio format: s16le, 8000 Hz, 1 channels info: pulse-input: Started recording from 'alsa_input.usb-046d_08da-01.mono-fallback' info: v4l2-input: Start capture from /dev/video0 info: v4l2-input: Input: 0 info: v4l2-input: Resolution: 640x480 info: v4l2-input: Pixelformat: 21UY info: v4l2-input: Linesize: 640 Bytes info: v4l2-input: Framerate: -nan fps [New Thread 0x7fff7922d700 (LWP 21896)] [New Thread 0x7fff78a2c700 (LWP 21897)] info: Switched to scene 'Scène' info: ------------------------------------------------ info: Loaded scenes: info: - scene 'Scène': info: - source: 'Périphérique de capture vidéo (V4L2)' (v4l2_input) info: ------------------------------------------------ Attempted path: share/obs/obs-studio/images/overflow.png Attempted path: /usr/share/obs/obs-studio/images/overflow.png info: adding 69 milliseconds of audio buffering, total audio buffering is now 69 milliseconds (source: Mic/Aux)
info: adding 23 milliseconds of audio buffering, total audio buffering is now 92 milliseconds (source: Mic/Aux)
info: adding 23 milliseconds of audio buffering, total audio buffering is now 116 milliseconds (source: Mic/Aux)
Thread 11 "video-io: video" received signal SIGSEGV, Segmentation fault.
[Switching to Thread 0x7fff92ffd700 (LWP 21890)]
0x00007fffec347187 in ff_nv12ToUV_sse2.loop_u () from /usr/lib64/libswscale.so.5
(gdb) bt
#0 0x00007fffec347187 in ff_nv12ToUV_sse2.loop_u () at src/libswscale/x86/rgb2rgb.c:183
#1 0x00007fffec34cd83 in deinterleaveBytes_sse2 (src=
Interesting observation I had is that it seems to be something to do with the OBS config files. These steps got me predictable behavior.
- Delete the OBS config (
~/.config/obs-studio, this will delete scenes so you may want to make a backup if you care about them) - Run OBS and change the resolution of the scene
- Add at least one source to the scene
- Start v4l2sink, it works without crashing
- Stop v4l2sink/close OBS, it crashes due to #10
- Restart OBS
- Start v4l2sink with the same configuration, it now crashes
- Restart OBS
- Change the output resolution to 1920x1080
- Start v4l2sink, it doesn't crash
I suspect it may be linked to OBS being unable to gracefully exit due to #10, I'm going to try to apply the patch for that issue and see if I can still reproduce.
Applying #21 to allow OBS to exit gracefully seems to make the non-crash behavior persist across multiple launches. I suspect this doesn't actually solve the underlying issue (configs being corrupted causing a crash), but it makes it usable in 99.9% of situations.
Hello, I had a problem today where OBS would crash when I started V4L2 Video Output, I can confirm that going on Settings and changing Base Canvas Resolution and Output Scaled Resolution to 1920x1080 solved the problem for me and I am now able to start V4L2 Video Output, without any problems.
