M4S2 (MPEG-4) ASF on the Mac (MobiDV / iJoy DV cam)

posted in Video Codecs

I recently bought the iJoy DV cam on woot. It works nicely, and the specs say it records MPEG4 files. I expected them to play directly in QuickTime Pro on the mac. unfortunately they don’t. Furthermore the file extension is .ASF. That alone confuses me.

They do play with VLC (yeah VLC), but they don’t play in either Quicktime Player (QT Pro version 7.02) or in WMP 9.0 (build 3307). I have all kinds of codecs installed including DIVX and 3iVX.

Of course I’d like them in a format that QuickTime can use so I can use them in iMovie, see finder previews, etc.

Please help. Thanks.

PS: running Tiger 10.4.2 reply

further info: VLC shows these files as M4S2 codec. is this the same as M2S4? reply


more info:

i installed everything I could related to this and no luck ... ie, both the casio codec and the one written by the japanese developer that I found in this link:


ffmpegx plays it fine but no audio. ffmpeg lists the input as:

adpcm_ima_wav, 16000 Hz, mono, 64 kb/s

mpeg4, yuv420p, 640x480, 1000.00 fps reply


pls, anyone? reply


>> Furthermore the file extension is .ASF. That alone confuses me.
.asf and .wmv are the file extensions for the Windows Media container. QuickTime Player can’t play Windows Media files. I was originally surprised you stated Windows Media Player for the Mac couldn’t, so I went back on Microsoft’s site (it’s THEIR codec and THEIR container after all) to check. http://www.microsoft.com/windows/windowsmedia/software/Macintosh/osx/default.aspx It doesn’t appear M4S2 is supported (see the section that says “Comprehensive List of Codecs Supported”). I’d urge you to send Microsoft support a request to support M4S2 for Mac users.

>> i installed everything I could related to this and no luck ... ie, both the casio codec and the one written by the japanese developer that I found in this link (...)
The links you tried (I’m reposting them for Mac users who need to decode M4S2 in an AVI in case they stumble upon this thread)
http://www.canon-europe.com/Support/Patches/MPEG4_ASF/index.asp?ComponentID=146683&SourcePageID=26346 (Canon’s QuickTime Plugin)
http://emonkid.hp.infoseek.co.jp/EX_M4S2/index_e.html (the Japanese guy’s QuickTime Plugin)
http://world.casio.com/qv/download/en/avi/ (Casio’s M4S2 AVI importer)
are for decoding M4S2 in an AVI container only. QuickTime can play AVI’s, Windows Media Player for the Mac cannot.

>> ffmpeg lists the input as: audio: adpcm_ima_wav, 16000 Hz, mono, 64 kb/s
That’s IMA ADPCM (tag 0x11 I think). I’m not very knowledgeable with audio, but you might find more help in the audio forums.

>>VLC shows these files as M4S2 codec. is this the same as M2S4?
There is no M2S4. The OreillyNet page had a typo.

The reason why ffmpegx and VLC can play the file is M4S2 (Microsoft ISO MPEG-4 version 1.1) is a flavor of MPEG-4 (other flavors are DivX, XviD, 3ivx, Apple MPEG-4, MP4S, etc.).

I don’t have any experience with Mac OS or ffmpeg, but you should be able to do something using ffmpeg, such as rip the video stream and transcode it to a different container (avi, mp4) or something (it’s a very powerful tool). You might find more information on this in the doom9.org or 3ivx.com forums.

Wizardry stuff: (don’t try this if you’re a newbie) First make a backup copy of the video file. Then get your hands on a hex editor, and try this: replace all the occurences of M4S2 in the video with MP4S and see if Windows Media Player will play it. I’m not guaranteeing results, but it’s worth a shot.
Reminder: MP4S = Microsoft ISO MPEG-4 version 1 and M4S2 = Microsoft ISO MPEG-4 version 1.1

Snide aside: This reminds me of the WMV3 (Windows Media Video 9) in an AVI container problem. Microsoft has yet to provide an easy solution for Mac users. (on that one, ffmpeg comes to the rescue too - but as you probably found out by now, it’s hardly a tool your average computer user can figure out) reply


thanks for the response. i will investigate the hex edit option and report back if it works. (if no post back, didn’t work). i reported this to MS support as suggested. reply


interesting results. the hex edit suggested worked for the video but:

1. no audio
2. still get warning message about unsupported codec, and a short black period at the beginning of playblack. but then the video plays fine. not sure if this means first part is cut off.

at any rate because of issue #1 still not viable, all the more so because i can’t batch process this hex edit on all files (AFAIK).

maybe a similar hex replace would work for the audio too?

if i could get them both to work maybe it would be worth looking for a batch drag & drop hex replace tool. probably something like that around. reply


You might want to tap GaryT in this thread http://www.moviecodec.com/topics/8929p1.html
He came up with a batch tool for SEDG to DIVX. You could ask him to customize it for you to do M4S2 to MP4S (be sure you state you need it customized for ASF, not AVI!) Actually when I said use MP4S I just wanted to see if it would play in WMP. Technically you *could* change it to any other flavor of MPEG-4 (DivX,XviD,3ivx) - but I’m not sure how it would behave in a WMP (which obviously doesn’t support DivX, Xvid, etc.)
What I keep thinking you should do is transcode (losslessly copy the video and audio stream) your video file to AVI. If you had a PC you could do it with asftools - you’d get an M4S2 AVI, which as mentioned above has quite a few Mac tools developed for it already. If you have VirtualPC, you could run PC apps (that’s kind of far-fetched, but it’s an idea). The other way is to use ffmpeg. I do not know how ffmpeg works, but other people have done the opposite before. They converted WMV3 (Windows Media Video 9) AVIs to ASF/WMV to get WMP to play them, and were successful with it. (See http://www.moviecodec.com/topics/1912p2.html - the dumpstream option from mplayer might work too)

As for the audio stream, I think IMA_ADPCM should be supported by QuickTime Player. The key would be to get the audio stream (originally in .asf) into a container QuickTime can read (.mov or .avi). I don’t know much, but ffmpeg or mplayer using the dumpstream option could do it. reply


Thanks very much, anon. that’s a very comprehensive response. it’s a bit over my head. ideally i’d like to have an avi rather than .asf anyway, and i could probably use ffmpegx if i could figure out the settings. i did manage to convert one this way by sheer poking around (i recall i had to specifically set audio channel 1 rather than the default 0). however i was confused by the conversion because the video was very different. it came out narrower than the original (as played in VLC) and worse, the color quality was washed out.

I’ll head over to the thread you mention and see if GaryT can do something like what you mention with this information. reply


From a Mac, I haven’t found a converter that works. But, that’s because I cheated. I’m running VMware Fusion so I can run Windows XP Pro on my MacBook 2GHz with Leopard. I found a great program that converts directly to MOV, MPEG4, etc... for only $59.99. It’s called AVS Video Converter. reply


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