Firefox 19/04 nightly x64-only crash MOZ_FULLDUMP analysis

0:002> !analyze -v
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*                        Exception Analysis                                   *
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*** ERROR: Symbol file could not be found.  Defaulted to export symbols for atidxx64.dll -

FAULTING_IP:
ntdll!RtlpLookupDynamicFunctionEntry+b9
00000000`776d2d89 488b5c2430      mov     rbx,qword ptr [rsp+30h]

EXCEPTION_RECORD:  ffffffffffffffff -- (.exr 0xffffffffffffffff)
ExceptionAddress: 00000000776d2d89 (ntdll!RtlpLookupDynamicFunctionEntry+0x00000000000000b9)
   ExceptionCode: 40000015
  ExceptionFlags: 00000000
NumberParameters: 0

CONTEXT:  0000000000000000 -- (.cxr 0x0;r)
rax=0000000000000001 rbx=0000000000000000 rcx=0000000018cb6820
rdx=000000000000006c rsi=00000000ffffffff rdi=00000000000001a8
rip=00000000776abd7a rsp=0000000018cb6618 rbp=0000000000000000
 r8=000000000000006c  r9=0000000000169e98 r10=0000000000000238
r11=0000000000169e98 r12=0000000000000000 r13=0000000000000000
r14=0000000018cb6820 r15=000000007764b328
iopl=0         nv up ei pl zr na po nc
cs=0033  ss=002b  ds=002b  es=002b  fs=0053  gs=002b             efl=00000246
ntdll!ZwWaitForSingleObject+0xa:
00000000`776abd7a c3              ret

DEFAULT_BUCKET_ID:  STATUS_FATAL_APP_EXIT
PROCESS_NAME:  firefox.exe
ERROR_CODE: (NTSTATUS) 0x40000015 - {Fatal Application Exit}  %hs
EXCEPTION_CODE: (NTSTATUS) 0x40000015 (1073741845) - {Fatal Application Exit}  %hs
NTGLOBALFLAG:  0
APPLICATION_VERIFIER_FLAGS:  0
APP:  firefox.exe
ANALYSIS_VERSION: 6.3.9600.17336 (debuggers(dbg).150226-1500) amd64fre
FAULTING_THREAD:  0000000000001b88
PRIMARY_PROBLEM_CLASS:  STATUS_FATAL_APP_EXIT
BUGCHECK_STR:  APPLICATION_FAULT_STATUS_FATAL_APP_EXIT
LAST_CONTROL_TRANSFER:  from 00000000776d2d89 to 000007feeb4ca3fb
STACK_TEXT:
00000000`18cb6800 00000000`776d2d89 : 00000000`00000000 00000000`00000000 00000000`00000000 00000000`18cb6e60 : msmpeg2vdec!DllCanUnloadNow+0x6bfb3
00000000`18cb6dc0 00000000`776bf86d : 000007fe`b4237b5a 00000000`18cb6f20 00000000`18cb6e60 00000000`00000000 : ntdll!RtlpLookupDynamicFunctionEntry+0xb9
00000000`18cb6df0 000007fe`eb9dc73a : 00000000`18cb73b0 00000000`00000000 00000000`000137f4 00000000`00000000 : ntdll!RtlLookupFunctionEntry+0xa3
00000000`18cb6e20 000007fe`eb9dc62f : 00000000`000012ac 00000000`00000400 00000000`00000000 00000000`00000000 : mozglue!WalkStackMain64+0x96
00000000`18cb7370 000007fe`db6047ed : 00000000`00911400 00000000`00000000 00000000`00000000 00000000`00000000 : mozglue!MozStackWalk+0x15b
00000000`18cbb490 000007fe`db609526 : 00000000`0094e000 00000000`18cbf9b0 00000000`00911400 00000000`00000000 : xul!DoNativeBacktrace+0x95
00000000`18cbf380 000007fe`db608fe0 : 00000078`4a52a86f 00000000`00000144 00000078`07b503b8 00000000`00923180 : xul!Tick+0x9a
00000000`18cbf410 000007fe`db606df5 : 00000000`000e9351 00000000`00923180 00000000`52261800 00000000`00000000 : xul!SamplerThread::SuspendAndSampleAndResumeThread+0xac
00000000`18cbf920 000007fe`db609305 : 000007fe`dc5298b0 00000000`00306e4c 00000000`0023200c 00000000`001494af : xul!SamplerThread::Run+0x125
00000000`18cbfa90 000007fe`e1cfcab0 : 00000000`00000000 00000000`00000000 00000000`00000000 00000000`00000000 : xul!ThreadEntry+0x9
00000000`18cbfac0 00000000`775559cd : 00000000`00000000 00000000`00000000 00000000`00000000 00000000`00000000 : ucrtbase!o__realloc_base+0x60
00000000`18cbfaf0 00000000`7768a561 : 00000000`00000000 00000000`00000000 00000000`00000000 00000000`00000000 : kernel32!BaseThreadInitThunk+0xd
00000000`18cbfb20 00000000`00000000 : 00000000`00000000 00000000`00000000 00000000`00000000 00000000`00000000 : ntdll!RtlUserThreadStart+0x1d


FOLLOWUP_IP:
msmpeg2vdec!DllCanUnloadNow+6bfb3
000007fe`eb4ca3fb 41b894000000    mov     r8d,94h
SYMBOL_STACK_INDEX:  0
SYMBOL_NAME:  msmpeg2vdec!DllCanUnloadNow+6bfb3
FOLLOWUP_NAME:  MachineOwner
MODULE_NAME: msmpeg2vdec
IMAGE_NAME:  msmpeg2vdec.dll
DEBUG_FLR_IMAGE_TIMESTAMP:  53a49dce
STACK_COMMAND:  dt ntdll!LdrpLastDllInitializer BaseDllName ; dt ntdll!LdrpFailureData ; ~2s; .ecxr ; kb
FAILURE_BUCKET_ID:  STATUS_FATAL_APP_EXIT_40000015_msmpeg2vdec.dll!DllCanUnloadNow
BUCKET_ID:  X64_APPLICATION_FAULT_STATUS_FATAL_APP_EXIT_msmpeg2vdec!DllCanUnloadNow+6bfb3
ANALYSIS_SOURCE:  UM
FAILURE_ID_HASH_STRING:  um:status_fatal_app_exit_40000015_msmpeg2vdec.dll!dllcanunloadnow
FAILURE_ID_HASH:  {f07df0be-e431-1f5b-0389-12e14bc04e7a}
Followup: MachineOwner