[Bug]: Dangling pointer access when starting NDI output #908
Description
Operating System Version
Fedora 37
OBS Version
29.1.3-modified
NDI Tools Version
5.5.3
Describe the bug
NDI output does not start with a warning below after restarting video subsystem.
unsupported pixel format -842150451
Log file: https://obsproject.com/logs/KSSuk3oBMBsYYy3T
Steps to reproduce
Add a modification to libobs as below.
diff --git a/libobs/media-io/video-io.c b/libobs/media-io/video-io.c
index afa0fe5c4..996637cbc 100644
--- a/libobs/media-io/video-io.c
+++ b/libobs/media-io/video-io.c
@@ -231,6 +231,8 @@ int video_output_open(video_t **video, struct video_output_info *info)
if (!out)
goto fail0;
+ blog(LOG_INFO, "video_output_open video=%p", out);
+
memcpy(&out->info, info, sizeof(struct video_output_info));
out->frame_time =
util_mul_div64(1000000000ULL, info->fps_den, info->fps_num);
@@ -281,7 +283,8 @@ void video_output_close(video_t *video)
pthread_mutex_destroy(&video->data_mutex);
pthread_mutex_destroy(&video->input_mutex);
- bfree(video);
+ blog(LOG_INFO, "video_output_close video=%p", video);
+ memset(video, 0xCD, sizeof(*video));
}
static size_t video_get_input_idx(const video_t *video,Also added modification to obs-ndi-output.cpp to log some information.
diff --git a/src/obs-ndi-output.cpp b/src/obs-ndi-output.cpp
index 5b851bf..6cca20e 100644
--- a/src/obs-ndi-output.cpp
+++ b/src/obs-ndi-output.cpp
@@ -131,6 +131,7 @@ bool ndi_output_start(void *data)
uint32_t flags = 0;
video_t *video = obs_output_video(o->output);
audio_t *audio = obs_output_audio(o->output);
+ blog(LOG_INFO, "ndi_output_start data=%p video=%p", data, video);
if (!video && !audio) {
blog(LOG_ERROR, "'%s': no video and audio available",- Start OBS
- Change video settings (for example, change frame rate.)
- Click
Tools->NDI Output settings - Enable
Main Outputcheckbox
Expected behavior
NDI output starts.
Screenshots
No response
Additional context
Found this issue while debugging recording and streaming on OBS Studio that I reported here
Decklink output and AJA output call obs_output_create just before starting it's output so the same issue does not appear.
Using OBS 30.0.0-beta2, above step will cause OBS to crash instead of just not starting NDI output.