Windows 7, Firefox and H.264

[Lex]

Here is "my story", I really hope you will be able to help me.

Some time ago, when I had Twitch stream in one of Firefox's tabs, my Firefox crashed and since that time I'm not able to use Firefox to view any Twitch streams nor Youtube live videos. All streams and videos work ok when I use external VLC media player to play them.

Twitch streams display "Your browser does not support playback of this video. (Error #6000)" message and when I'm opening https://www.youtube.com/html5 webpage I can see one red "!" near H.264 (the rest are all blue "ok" marks). This last webpage also says: "Firefox - H.264 playback depends on hardware and operating system support".

What I did try so far:

- I did reinstall my Firefox two times - first time it was with usage of "fresh start" option, second time it was full deinstallation-reinstallation with deleting all the data I was able to manually find on disk drive which was related to Mozilla/Firefox (including profiles). As of now I'm using Firefox Quantum 67.0.1.

- Browsing the web I noticed many posts like this one: https://www.reddit.com/r/Twitch/comments...r/dq5e2ny/ - to (re)install Media Feature Pack. I tried to use this: https://www.microsoft.com/en-US/download...x?id=16546 but it says: "This update is not applicable to your computer." - My OS is Windows 7 x64 Ultimate.

- In a last few days I found a few posts like this one: https://windowsforum.com/threads/where-c...dec.46515/ - so I installed your ADVANCED Codecs, but they did not help me either.

Do you have any other suggestion for me what I should do next? I would prefer to not reinstall my OS.

Thank you very much in advance for any help or guide.

[Shark007]

Your issue is not related to 'Directshow Codecs' and that is what my software installs.
My software is mostly a playback solution for files stored on your system or home network.

Check C:\Windows\System32 for a file named msmpeg2vdec.dll
That is what firefox uses to display h264 video.
There is a utility called MCDU which can screw things up and renames this file with a mcdu extension..
If it is there but the extension doesn't match exactly, try making it match.

There is also a file named msmpeg2adec.dll - dont mess with it - that is used for audio

[Lex]

Your issue is not related to 'Directshow Codecs' and that is what my software installs.
My software is mostly a playback solution for files stored on your system or home network.

Thank you for these clues as I had no idea where and what should I look for.

Check C:\Windows\System32 for a file named msmpeg2vdec.dll
That is what firefox uses to display h264 video.
There is a utility called MCDU which can screw things up and renames this file with a mcdu extension..
If it is there but the extension doesn't match exactly, try making it match.

I found this file in the directory you mentioned.
Its name is the correct one (msmpeg2vdec.dll), size is 2646528, md5 hash is 3b1295afff2f942ddf5411ab6e8ab377 and creation time is connected to the date of installation of my OS.

There is also a file named msmpeg2adec.dll - dont mess with it - that is used for audio

Here is a weird thing - I can't find this file in this directory. The only other file with similar "family name" is msmpeg2enc.dll - its size is 1160192, md5 hash is 8f30cc11e2d2953f977ad31c8dc391c1 and creation time is, again, connected to the date of installation of my OS.

Maybe this missing file is the culprit of my situation? How can I "reinstall" it? Also, should I?

[Shark007]

I have a Windows 7 setup for testing with.
I'll send you a private message with a link to download that audio decoder file.
just place it into that system32 directory and then test.

[Lex]

I have a Windows 7 setup for testing with.
I'll send you a private message with a link to download that audio decoder file.
just place it into that system32 directory and then test.

It works! I have now "ok" mark on Youtube's webpage near H.264 and Twitch streams are playing without problems. Thank you so much for your help! I'm so happy now.

Do you have any idea why / how did that happen? Was Firefox tab crash able to delete that file?

[Shark007]

I have no clue why that file was missing from your system.
I do not use Firefox or twitch and rarely go to youtube.
I personally do not watch video's in a web browser, ever.
but . . .its not my 1st time at the rodeo.

Glad to hear its working again.

[Sergunka00]

I have a Windows 7 setup for testing with.
I'll send you a private message with a link to download that audio decoder file.
just place it into that system32 directory and then test.

Hello! I have the same problem!! Help me, please.

And second problem: Playback stopped working after the last update .mkv files via DLNA. In Media Player, the files are played, but when you try to send the video to TV player, it writes that it does not find the media file. On TV plays back .avi, .mov. MKV-no. Already many times reinstalled. Windows 7 x64

[Shark007]

check for the file, msmpeg2adec.dll in the Windows\SysWOW64 directory.
If that file is missing, I can make it available to you.
Be sure it just isn't renamed to something like msmpeg2adec.dll.bak or msmpeg2adec.dll.mcdu
If it is there but just has some extra extension like above, remove the extra extension yourself.

As for your 2nd issue, I no longer offer support for mkv over dlna on Windows 7.
Version 1170 of the Advanced codecs and version 8.1.0 of the Standard codecs are the last versions supporting mkv over dlna for Windows 7.
Just a FYI, Windows 10 supports this natively.

[Sergunka00]

check for the file, msmpeg2adec.dll in the Windows\SysWOW64 directory.
If that file is missing, I can make it available to you.
Be sure it just isn't renamed to something like msmpeg2adec.dll.bak or msmpeg2adec.dll.mcdu
If it is there but just has some extra extension like above, remove the extra extension yourself.

As for your 2nd issue, I no longer offer support for mkv over dlna on Windows 7.
Version 1170 of the Advanced codecs and version 8.1.0 of the Standard codecs are the last versions supporting mkv over dlna for Windows 7.
Just a FYI, Windows 10 supports this natively.

thanks. I will try to install the old version of shark007. As for the msmpeg2adec.dll I have it in SysWOW64. But it is not registered in the system and I am unable to execute regsvr32? How can I register it in the system? Help please

[Shark007]

It is not a a file that can be registered. It just needs to exist.