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TheSpaz

macrumors 604
Original poster
Jun 20, 2005
7,032
1
When I edit an already encoded video like a .mp4 file with QuickTime Pro and try to save it, it saves as a QuickTime .mov file by default. So here's a few questions about doing that.

1. It seems to still be a .mp4 file but, with the extension .mov now. Does this change the file at all? When I change the extension back to .mp4, it no longer will open and play in QuickTime.

2. How come I can't re-save it as a .mp4 file without re-encoding it (such as when I cut out extra unwanted bits.

3. For some reason I like my files to stay in the original format that they were encoded in. How do I modify a .mp4 file without having to save it as a .mov file?

I've always been kinda confused about how QuickTime re-saves a file as a .mov file. What format is this really? If the file was unaltered (still has the same encoding information and everything) then why can it have the .mov extension. I don't get it. Does anyone else do this? Or should I stay away from re-saving in QuickTime.
 
I believe you have to use the File > Export... function every time you change and want to save as mp4. Don't forget to select the Options in the "Save exported file as..." By default, QT saves files as QT .mov files.
 
QuickTime (.mov) is a container for multimedia files, including video and audio in lots of different formats.

.mp4 is one of these formats!

If you want a .mp4 file: In QT Pro go to export, there you can select Film->MPEG-4. Or you can go into detail about the compression format under the options dialogbox.
 
QuickTime (.mov) is a container for multimedia files, including video and audio in lots of different formats.

.mp4 is one of these formats!

If you want a .mp4 file: In QT Pro go to export, there you can select Film->MPEG-4. Or you can go into detail about the compression format under the options dialogbox.

Is it safe to use .mov for anything? You said it's a container... so really... it's just a generic file with the same encoding information as the original file right? The thing is... I don't think it's good to take a .mp4 and re-encode it again (the quality would decrease by adding compression to an already compressed file). But, saving as a .mov would keep the file unchanged.
 
If you are doing some editing and such and don't want to encode it yet, you can do a save as and uncheck making the movie self contained. This will make a small (probably about 150k) file that just has your changes to the video.

P-Worm
 
If you are doing some editing and such and don't want to encode it yet, you can do a save as and uncheck making the movie self contained. This will make a small (probably about 150k) file that just has your changes to the video.

P-Worm

Lemme explain exactly what I'm doing.

I'm ripping TV shows from a DVD but, I get credits or intros in some of them. I first have to rip it to an mpeg4 file and then edit it afterwards in QuickTime so I have no choice but to start from an already compressed format. I would like to try to avoid having to compress it again, so what I'm really saying is do is save the edited file without re-compressing it... so I would have to use .mov format. Now that it's a .mov format, it will only play in QuickTime player right?
 
Yes it is just a 'generic'. Check the file information of your movies in both .mov and .mp4. You'll see that both files have the same format.

Here is a picture of a movie originaly in .m4v, I trimmed a little off in QT and hit save. The new file now is .mov, but as the info-palette prooves they are the in the same format. QT did not re-incode the information.
 

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