The VideoLAN Forums

Posted: **05 May 2014 17:28**

LuaJIT 2.1 and LuaJIT 2.0.3 keeps crashing when trying to use the libvlc_audio/video_set_callbacks callbacks from LuaJIT. I also crash sometimes when trying to use the log callback without calling libvlc_media_player_play(media_player).

I've tested this on latest stable and latest nightly. (32bit)

I have a feeling my Lua state and VLC's Lua state are crashing. In my Lua framework (which is kind of big) I sometimes (but rarely) get absurd Lua errors just before exit.

Here's a log from when running my test script from CMD a few times:

Code: Select all

C:\Program Files (x86)\VideoLAN\VLC>luajit vlc_test.lua
[02f0092c] logger interface: VLC media player - 2.1.3 Rincewind
[02f0092c] logger interface: Copyright c 1996-2014 the VideoLAN team
[02f0092c] logger interface:
Warning: if you cannot access the GUI anymore, open a command-line window, go to
 the directory where you installed VLC and run "vlc -I qt"

[02f0092c] logger interface: using logger.
2.1.3 Rincewind
gcc version 4.8.2 (GCC)
2.1.3-0-ge6a71cc
PANIC: unprotected error in call to Lua API (bad callback)

C:\Program Files (x86)\VideoLAN\VLC>luajit vlc_test.lua
[00dd042c] logger interface: VLC media player - 2.1.3 Rincewind
[00dd042c] logger interface: Copyright c 1996-2014 the VideoLAN team
[00dd042c] logger interface:
Warning: if you cannot access the GUI anymore, open a command-line window, go to
 the directory where you installed VLC and run "vlc -I qt"

[00dd042c] logger interface: using logger.
PANIC: unprotected error in call to Lua API (bad callback)

C:\Program Files (x86)\VideoLAN\VLC>luajit vlc_test.lua
[029a07ac] logger interface: VLC media player - 2.1.3 Rincewind
[029a07ac] logger interface: Copyright c 1996-2014 the VideoLAN team
[029a07ac] logger interface:
Warning: if you cannot access the GUI anymore, open a command-line window, go to
 the directory where you installed VLC and run "vlc -I qt"

[029a07ac] logger interface: using logger.
PANIC: unprotected error in call to Lua API (bad callback)

C:\Program Files (x86)\VideoLAN\VLC>luajit vlc_test.lua
[00e0092c] logger interface: VLC media player - 2.1.3 Rincewind
[00e0092c] logger interface: Copyright c 1996-2014 the VideoLAN team
[00e0092c] logger interface:
Warning: if you cannot access the GUI anymore, open a command-line window, go to
 the directory where you installed VLC and run "vlc -I qt"

[00e0092c] logger interface: using logger.
2.1.3 Rincewind
gcc version 4.8.2 (GCC)
2.1.3-0-ge6a71cc
PANIC: unprotected error in call to Lua API (bad callback)

C:\Program Files (x86)\VideoLAN\VLC>luajit vlc_test.lua
[02d9062c] logger interface: VLC media player - 2.1.3 Rincewind
[02d9062c] logger interface: Copyright c 1996-2014 the VideoLAN team
[02d9062c] logger interface:
Warning: if you cannot access the GUI anymore, open a command-line window, go to
 the directory where you installed VLC and run "vlc -I qt"

[02d9062c] logger interface: using logger.
2.1.3 Rincewind
gcc version 4.8.2 (GCC)
2.1.3-0-ge6a71cc
PANIC: unprotected error in call to Lua API (bad callback)

C:\Program Files (x86)\VideoLAN\VLC>luajit vlc_test.lua
[01410eac] logger interface: VLC media player - 2.1.3 Rincewind
[01410eac] logger interface: Copyright c 1996-2014 the VideoLAN team
[01410eac] logger interface:
Warning: if you cannot access the GUI anymore, open a command-line window, go to
 the directory where you installed VLC and run "vlc -I qt"

[01410eac] logger interface: using logger.
2.1.3 Rincewind
gcc version 4.8.2 (GCC)
2.1.3-0-ge6a71cc
PANIC: unprotected error in call to Lua API (bad callback)

C:\Program Files (x86)\VideoLAN\VLC>luajit vlc_test.lua
[00650dac] logger interface: VLC media player - 2.1.3 Rincewind
[00650dac] logger interface: Copyright c 1996-2014 the VideoLAN team
[00650dac] logger interface:
Warning: if you cannot access the GUI anymore, open a command-line window, go to
 the directory where you installed VLC and run "vlc -I qt"

[00650dac] logger interface: using logger.
PANIC: unprotected error in call to Lua API (bad callback)

C:\Program Files (x86)\VideoLAN\VLC>luajit vlc_test.lua
[0129032c] logger interface: VLC media player - 2.1.3 Rincewind
[0129032c] logger interface: Copyright c 1996-2014 the VideoLAN team
[0129032c] logger interface:
Warning: if you cannot access the GUI anymore, open a command-line window, go to
 the directory where you installed VLC and run "vlc -I qt"

[0129032c] logger interface: using logger.
PANIC: unprotected error in call to Lua API (bad callback)

C:\Program Files (x86)\VideoLAN\VLC>luajit vlc_test.lua
[02b3042c] logger interface: VLC media player - 2.1.3 Rincewind
[02b3042c] logger interface: Copyright c 1996-2014 the VideoLAN team
[02b3042c] logger interface:
Warning: if you cannot access the GUI anymore, open a command-line window, go to
 the directory where you installed VLC and run "vlc -I qt"

[02b3042c] logger interface: using logger.
2.1.3 Rincewind
gcc version 4.8.2 (GCC)
2.1.3-0-ge6a71cc
PANIC: unprotected error in call to Lua API (bad callback)

C:\Program Files (x86)\VideoLAN\VLC>luajit vlc_test.lua
[029a0b2c] logger interface: VLC media player - 2.1.3 Rincewind
[029a0b2c] logger interface: Copyright c 1996-2014 the VideoLAN team
[029a0b2c] logger interface:
Warning: if you cannot access the GUI anymore, open a command-line window, go to
 the directory where you installed VLC and run "vlc -I qt"

[029a0b2c] logger interface: using logger.
2.1.3 Rincewind
gcc version 4.8.2 (GCC)
2.1.3-0-ge6a71cc
PANIC: unprotected error in call to Lua API (bad callback)

C:\Program Files (x86)\VideoLAN\VLC>luajit vlc_test.lua
[00cf0b2c] logger interface: VLC media player - 2.1.3 Rincewind
[00cf0b2c] logger interface: Copyright c 1996-2014 the VideoLAN team
[00cf0b2c] logger interface:
Warning: if you cannot access the GUI anymore, open a command-line window, go to
 the directory where you installed VLC and run "vlc -I qt"

[00cf0b2c] logger interface: using logger.
2.1.3 Rincewind
gcc version 4.8.2 (GCC)
2.1.3-0-ge6a71cc
PANIC: unprotected error in call to Lua API (bad callback)

C:\Program Files (x86)\VideoLAN\VLC>luajit vlc_test.lua
[00720b2c] logger interface: VLC media player - 2.1.3 Rincewind
[00720b2c] logger interface: Copyright c 1996-2014 the VideoLAN team
[00720b2c] logger interface:
Warning: if you cannot access the GUI anymore, open a command-line window, go to
 the directory where you installed VLC and run "vlc -I qt"

[00720b2c] logger interface: using logger.
2.1.3 Rincewind
gcc version 4.8.2 (GCC)
2.1.3-0-ge6a71cc

C:\Program Files (x86)\VideoLAN\VLC>luajit vlc_test.lua
[00520b2c] logger interface: VLC media player - 2.1.3 Rincewind
[00520b2c] logger interface: Copyright c 1996-2014 the VideoLAN team
[00520b2c] logger interface:
Warning: if you cannot access the GUI anymore, open a command-line window, go to
 the directory where you installed VLC and run "vlc -I qt"

[00520b2c] logger interface: using logger.
2.1.3 Rincewind
gcc version 4.8.2 (GCC)
2.1.3-0-ge6a71cc
PANIC: unprotected error in call to Lua API (bad callback)

C:\Program Files (x86)\VideoLAN\VLC>luajit vlc_test.lua
[008f0d2c] logger interface: VLC media player - 2.1.3 Rincewind
[008f0d2c] logger interface: Copyright c 1996-2014 the VideoLAN team
[008f0d2c] logger interface:
Warning: if you cannot access the GUI anymore, open a command-line window, go to
 the directory where you installed VLC and run "vlc -I qt"

[008f0d2c] logger interface: using logger.
PANIC: unprotected error in call to Lua API (bad callback)

C:\Program Files (x86)\VideoLAN\VLC>luajit vlc_test.lua
[00ea072c] logger interface: VLC media player - 2.1.3 Rincewind
[00ea072c] logger interface: Copyright c 1996-2014 the VideoLAN team
[00ea072c] logger interface:
Warning: if you cannot access the GUI anymore, open a command-line window, go to
 the directory where you installed VLC and run "vlc -I qt"

[00ea072c] logger interface: using logger.
2.1.3 Rincewind
gcc version 4.8.2 (GCC)
2.1.3-0-ge6a71cc

C:\Program Files (x86)\VideoLAN\VLC>luajit vlc_test.lua
[00d804ac] logger interface: VLC media player - 2.1.3 Rincewind
[00d804ac] logger interface: Copyright c 1996-2014 the VideoLAN team
[00d804ac] logger interface:
Warning: if you cannot access the GUI anymore, open a command-line window, go to
 the directory where you installed VLC and run "vlc -I qt"

[00d804ac] logger interface: using logger.
2.1.3 Rincewind
gcc version 4.8.2 (GCC)
2.1.3-0-ge6a71cc
PANIC: unprotected error in call to Lua API (bad callback)

C:\Program Files (x86)\VideoLAN\VLC>luajit vlc_test.lua
[02410a2c] logger interface: VLC media player - 2.1.3 Rincewind
[02410a2c] logger interface: Copyright c 1996-2014 the VideoLAN team
[02410a2c] logger interface:
Warning: if you cannot access the GUI anymore, open a command-line window, go to
 the directory where you installed VLC and run "vlc -I qt"

[02410a2c] logger interface: using logger.
PANIC: unprotected error in call to Lua API (bad callback)

C:\Program Files (x86)\VideoLAN\VLC>luajit vlc_test.lua
[00ba0a2c] logger interface: VLC media player - 2.1.3 Rincewind
[00ba0a2c] logger interface: Copyright c 1996-2014 the VideoLAN team
[00ba0a2c] logger interface:
Warning: if you cannot access the GUI anymore, open a command-line window, go to
 the directory where you installed VLC and run "vlc -I qt"

[00ba0a2c] logger interface: using logger.
2.1.3 Rincewind
gcc version 4.8.2 (GCC)
2.1.3-0-ge6a71cc
PANIC: unprotected error in call to Lua API (bad callback)

C:\Program Files (x86)\VideoLAN\VLC>luajit vlc_test.lua
[00a70d2c] logger interface: VLC media player - 2.1.3 Rincewind
[00a70d2c] logger interface: Copyright c 1996-2014 the VideoLAN team
[00a70d2c] logger interface:
Warning: if you cannot access the GUI anymore, open a command-line window, go to
 the directory where you installed VLC and run "vlc -I qt"

[00a70d2c] logger interface: using logger.
2.1.3 Rincewind
gcc version 4.8.2 (GCC)
2.1.3-0-ge6a71cc
PANIC: unprotected error in call to Lua API (bad callback)

C:\Program Files (x86)\VideoLAN\VLC>luajit vlc_test.lua
[02f4102c] logger interface: VLC media player - 2.1.3 Rincewind
[02f4102c] logger interface: Copyright c 1996-2014 the VideoLAN team
[02f4102c] logger interface:
Warning: if you cannot access the GUI anymore, open a command-line window, go to
 the directory where you installed VLC and run "vlc -I qt"

[02f4102c] logger interface: using logger.
2.1.3 Rincewind
gcc version 4.8.2 (GCC)
2.1.3-0-ge6a71cc

C:\Program Files (x86)\VideoLAN\VLC>luajit vlc_test.lua
[00890aac] logger interface: VLC media player - 2.1.3 Rincewind
[00890aac] logger interface: Copyright c 1996-2014 the VideoLAN team
[00890aac] logger interface:
Warning: if you cannot access the GUI anymore, open a command-line window, go to
 the directory where you installed VLC and run "vlc -I qt"

[00890aac] logger interface: using logger.
2.1.3 Rincewind
gcc version 4.8.2 (GCC)
2.1.3-0-ge6a71cc
PANIC: unprotected error in call to Lua API (bad callback)

C:\Program Files (x86)\VideoLAN\VLC>luajit vlc_test.lua
[00cf10ac] logger interface: VLC media player - 2.1.3 Rincewind
[00cf10ac] logger interface: Copyright c 1996-2014 the VideoLAN team
[00cf10ac] logger interface:
Warning: if you cannot access the GUI anymore, open a command-line window, go to
 the directory where you installed VLC and run "vlc -I qt"

[00cf10ac] logger interface: using logger.
PANIC: unprotected error in call to Lua API (bad callback)

C:\Program Files (x86)\VideoLAN\VLC>luajit vlc_test.lua
[00d2112c] logger interface: VLC media player - 2.1.3 Rincewind
[00d2112c] logger interface: Copyright c 1996-2014 the VideoLAN team
[00d2112c] logger interface:
Warning: if you cannot access the GUI anymore, open a command-line window, go to
 the directory where you installed VLC and run "vlc -I qt"

[00d2112c] logger interface: using logger.
2.1.3 Rincewind
gcc version 4.8.2 (GCC)
2.1.3-0-ge6a71cc
PANIC: unprotected error in call to Lua API (bad callback)

C:\Program Files (x86)\VideoLAN\VLC>

Here's relevant code:

Code: Select all

local options = {
	"-Idummy",
	"--ignore-config",
	"--extraintf=logger",
	"--verbose=4",
}
 
ffi.cdef[[int _putenv_s(const char *var_name, const char *new_value)]]
 
ffi.C._putenv_s("VLC_PLUGIN_PATH", "./plugins") -- is there an options field for this?
 
local argv = ffi.new("const char*["..#options.."]", options)
local instance = vlc.new(#options-1, argv)
 
if instance == nil then 
	print("failed to initialize vlc") 
	return 	
end
 
print(ffi.string(vlc.get_version()))
print(ffi.string(vlc.get_compiler()))
print(ffi.string(vlc.get_changeset()))
 
if false then
	-- crashes randomly
	ffi.cdef[[int _vsnprintf(char *buffer, size_t count, const char *format, va_list args);]]
	vlc.set_log_verbosity(instance, 10)
	vlc.log_set(instance, function(data, level, ctx, fmt, args)
		local buffer = ffi.new("char[1024]")
		ffi.C._vsnprintf(buffer, 1024, fmt, args)
		local str = ffi.string(buffer)
		print("[vlc] ", str)
	end, nil)
end
 
local path = ("C:/goluwa/tests/videos/casiopea.webm"):gsub("/", "\\") -- vlc doesn't replace forward with backward slashes on windows
local media = vlc.media_new_path(instance, path)
 
if media == nil then 
	print("failed to open file " .. path) 
	return 
end
 
local media_player = vlc.media_player_new_from_media(media)
vlc.media_release(media)
 
if true then
	vlc.audio_set_format(media_player, "S16N", 44100, 2)
	vlc.audio_set_callbacks(
		media_player,
		function(data, samples, count, pts)
			print("play ", data, samples, count, pts)
		end, 
		function(data, pts)
			print("pause ", data, pts)
		end,
		function(data, pts)
			print("resume ", data, pts)
		end,
		function(data, pts)
			print("flush ", data, pts)
		end,
		function(data)
			print("drain ", data)
		end,
		nil
	)
end
 
if true then
	vlc.video_set_format(media_player, "RV16", 512, 512, 512*2)
	vlc.video_set_callbacks(
		media_player, 
		function(udata, planes)
			print("lock", planes) 
		end, 
		function(udata, id, pixels)
			print("upload", id, pixels)
		end, 
		function(id)
			print("display", id)
		end, 
		nil
	)
end
 
vlc.media_player_play(media_player) 
 
while true do end -- keep the state alive

full code is here https://gist.github.com/CapsAdmin/aba53fe3b1871541baae

Other concerns:

I could not use "sprintf" on the log callback's va_list. I had to use _vsnprintf instead or else the buffer output would end up with random characters where the % symbols were.. (LuaJIT does not support "..." in callbacks properly so that's why you have to do that) In other libraries such as ffmpeg which also has a log callback printf works fine. As I'm typing this maybe it's because ffmpeg was compiled with mingw and vlc wasnt?
libvlc_media_new_path() does not convert forward slashes to backward slashes, is this intentional? for a while it had me confused as to why my file didn't exist.

Posted: **15 May 2014 17:20**

It turned out this was a luajit issue.

http://www.freelists.org/post/luajit/li ... s-crashing

Posted: **16 May 2014 04:41**

Last I checked, Lua did not support threading. Yet VLC callbacks are invoked from different threads and asynchronously.

So I think you need native glue code in any case.

The VideoLAN Forums

LuaJIT and libvlc_audio/video_set_callbacks crashing

LuaJIT and libvlc_audio/video_set_callbacks crashing

Re: LuaJIT and libvlc_audio/video_set_callbacks crashing

Re: LuaJIT and libvlc_audio/video_set_callbacks crashing