Why can't I do a typical Mp4 file import of a file on my HDD

Hi All,
Been googling for a bit on this and can't get any useful answers (I think my search terms overlap too much with another query).

So, I have a flash based HD camcorder. It apparently created files using the AVCHD codec. The files have the MP4 extension. Up until I bought my shiny new first mac last week I was using linux, so to get the files off a memory card I'd just copy them to my harddrive. The files wouldn't play properly (like the vertical resolution was cut in half) unless I did an extra re-encoding step using ffmpeg... but that's doesn't matter.

Now I have the MAC, which is awesome, and I just noticed today that if I use iMovie to import the clips from a memory card the clip gets converted to normal looking video. Sweet. But if I use iMove to import the exact same format file directly off the harddrive the video has half vertical resolution (same as in the Linux case) 😟. And if I take that exact same file and move it to an SD card, THEN try to import from iMovie the video get imported properly.

SO, I don't get it. iMovie is doing something to the imported video to correct it, but it only does it when I import from a memory card. That seems weird to me. Is there some way I can force the harddrive import to behave the same wasy as the SD card import?

Macbook Pro, Mac OS X (10.6.5)

Posted on Dec 3, 2010 4:35 PM

Reply
10 replies

Mar 22, 2011 6:59 AM in response to BigStuWaterloo

So, I'm still picking away at this issue and haven't got a great workflow solution.

What I've learned in the mean time is:
1. Its possible there's something about the folder hierarchy of the SD memory card that iMovie makes use of. I still don't get it though. When I copy the files back to an SD card for import purposes I'm not re-creating this folder structure.
2. The Panasonic AVCHD format is using some sort of "anamorphic" flag to signal to the decoder information about the aspect ratio of the video. I'm guessing iMovie doesn't have the right support for this flag (neither does the Google Docs video player... it leaves the video squished too).
3. When importing using iMovie is uses the AIC (Apple Intermediate Codec) format that makes editing easier. It also takes up at least 10x the harddrive space, which is not feasible for me on my tiny MBP 320GB HDD. So I'll be using the un-optimized format for now.

Anyway, at this point I would love to be able to import my MP4 video files directly from the harddrive and have iMovie understand/display the aspect ratio correctly. that's all I ask!

Anyone have any thoughts or suggestions?

Mar 22, 2011 7:34 AM in response to BigStuWaterloo

Oh yeah, I also learned that:
Video software that plays my files correctly (correct aspect ratio):
Apple:
-VLC
-Handbrake (seems to ahve settings that allow me to convert to the right aspect ratio video
Linux
-VLC
-Handbrake (seems to ahve settings that allow me to convert to the right aspect ratio video

Video software that squishes the files:
Apple:
-iMovie
-QuickTime
Linux:
-Totem Movie Player

Mar 22, 2011 7:44 AM in response to Tom Wolsky

Hi Tom... thanks for weighing in.

1. I'm trying to understand that very question. For some reason when I import the movies off my macbook pro harddrive the video appears in the Event library with the wrong aspect ratio. If I take that same file and copy it to the memory card, then do an import from the memory card the aspect ratio looks correct. The series of dialogs I pass through are slightly different on each appraoch, and I don't see any way to make the the same. For example, when importing from the memory card I get a "preview" style dialog that shows all the clips on the card, and I can select which ones I want to import, and choose things like stability and face detection. But when I import from the harddrive I don't get this dialog. it just jumps right into importing the video, and the result is clips that don't have the correct aspect ratio.

2. This panasonic camera gives me 2 optiosn for HD capture. 720p 60, and 1080i 30. There's never any mention of anamorphic from what I've seen. Incidentally, the camera comes with its only "Import" software stored on the actual camera that is supposed to be used for imprting the video (windows only though). I'm assumign this software knows how to adapt the codec parameters on import to make the aspect ratio look right.

3. I'm considerintg this. Its just nice to have most of the video on hand and portable for editing purposes.

Mar 22, 2011 9:04 AM in response to BigStuWaterloo

1. That's wrong. The folder structure contains metadata that's needed to interpret the files. You could use MPEG Streamclip to convert the media to AIC for iMovie.

2. Unfortunately it doesn't look as if this is a supported camera in iMovie so the best you can do is workarounds, either converting the media or changing the display in the QuickTime pro player.

Mar 22, 2011 9:33 AM in response to Tom Wolsky

1. Ummm... "wrong"... as in, "you shouldn't be doing it this way"? Or as in "iMovie is doing things wrong"? Not sure you mean? Right or "wrong" it appears to work for me. Maybe there are metadata elements that are wrong in my imported iMovie events? E.g, every movie I imported using the "copy to SD card, then import" method would report the metadata for the last few movies I actually captured on that card? Doubtful as I would expect the metadata info would be indexed by filename. UNLESS.... all the metadata for every video I've ever captured is still sitting in place on the card, so when I copy the files back to the card all the info iMovie needs is there?

2. I checked the supported camera list and don't see mine, but it DOES support the files (correct aspect ratio) when I import off SD card, just not directly from HDD. That seems very strange. iMovie has the capability of importing those files, why the heck would the storage medium matter? Its like there are import "tools" that only kick in for the SD card import, not the harddrive import. Then again, if my big "UNLESS" from point 1) is true, then maybe this isn't so strange after all. I'll have to test this out when I get home.

Thanks

Mar 22, 2011 4:06 PM in response to Tom Wolsky

1. I gotcha that it doesn't take much more disk space. I guess this is an approach I can shift to. But it still seems strange that VLC (and as it turns out, Picasa for MAC) have no issue handling this file type. When I "sync'ed a video to Picasa WEB albums the aspect ration was wrong, but in the Picasa Desktop app the video looked fine.

Actually ,I looked at what else is on the SD disk after capturing videos and the only thing that could possibly consist of "meta" data for the video files is a file:
<root of SD card>/misc/VIDEO0.IDX (or VIDEO1.IDX)

Its a binary format, 21MB file, and a quick glance in a text editor didn't uncover any evidence that it was useful info, but I guess it still could be.

Anyway, I guess I"M looking at converting all my current videos using some other tool like Handbrake or ffmpeg, the importing into iMovie.

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Why can't I do a typical Mp4 file import of a file on my HDD

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