[macdummy]

I'm wondering if there is a way to merge video files with quicktime pro while maintaining the original file format rather than creating a new .mov format without the need to transcode.

For example I like downloading flv files from youtube which I then convert to mp4s via isquint and then I merge the mp4s into a single movie file with quicktime pro. Then I would like to copy the .mov file into my ipod video but I have to convert that file once more so that it is even readable by the ipod. By transcoding the .mov file again to an mp4, isn't that degrading the video quality even further (which is already so-so quality when d/ling directing from youtube)?

And while I'm on the subject, what the heck is a .mov file anyway? Is it just a shell/container or an actual video codec?

I have the same question about merging music files as well.

[Uncle Skeleton]

What you're talking about is a "passthrough" encode, where the encoded data is not changed, only the container. QT's mp4 encoder includes a passthrough option, but only if the bitstream is compatible with QT's mp4 encoder. I don't know about iSquint or its mpeg-4 spec compliance, but QT's encoder is strict simple profile as far as I know, so no advanced simple profile features allowed (although if you had those I would expect QT wouldn't open the file in the first place, so I'm expecting you can passthrough just fine). As for other file types, MPEG StreamClip comes with a QT avi component that includes a passthrough capability, and divx.com's component did too between versions 5.0.3 and 5.0.6 I believe. Also ffmpeg has one (use the flags -acodec copy -vcodec copy). MEncoder has one but I don't know the flags. For MPEG 1/2 passthrough, use MPEG StreamClip to edit (select multiple clips in the Open dialog if you like), then export to program stream. ASF/WMV I don't know about, but ffmpeg might help there as well, or flip4mac pro or whatever their pay version is called. Other file formats are pretty uncommon.

mov is indeed a "shell" format, but a very advanced one. Few of the advanced features are ever used, but the options are there. You can write whole programs within the QT file format's interactivity and scripting capabilities.

You can merge aac mp4 files with QT pro and passthrough. Mp3 is tougher. There's a trick where you save a self-contained mov file, then open in a hex editor and delete everything up to and including the second 'mdat' instance (I think that's it), but that doesn't always work. Nor does ffmpeg's passthrough. Combined, they work about half the time in my experience. Of course, if you own the music, you can edit them in lossless compression and encode an mp3 when you have what you want.

[Jacke]

Originally Posted by Uncle Skeleton

QT's mp4 encoder includes a passthrough option, but only if the bitstream is compatible with QT's mp4 encoder.

I think that the video streams need to have the same properties too, like size and bitrate.

Another option if Quicktime deems the streams incompatible is to use ffmpegX (or plain ffmpeg) and passthrough to AVI, then use the AVI merge function and see if you can open it in Quicktime and passthrough. You will probably have to change the fourcc to something Quicktime can passthrough first. (Hint: the 3ivx codec will read Advanced Simple profile video streams, if the streams are in an AVI file then it sidesteps Apple's MPEG-4 parser.)

[angelmb]

Originally Posted by macdummy

For example I like downloading flv files from youtube which I then convert to mp4s via isquint and then I merge the mp4s into a single movie file with quicktime pro. Then I would like to copy the .mov file into my ipod video but I have to convert that file once more so that it is even readable by the ipod.

I have done something similar some weeks ago. A friend asked for to get as a single file something like 30 video clips he got from youtube (those had to be converted to another format as you say) and several other sources, they were, as one can suppose, on different formats, I tried to merge all them with several freeware-shareware apps and even QT Pro, sadly I was not able to do it. So under a frustration-mode I though about iMovie, it worked and it was rather easy, drag & drop all the clips and export them as a single QT movie, later I had to convert the file with QT to be iPod friendly. Great… if only youtube quality wasn't so bad that is embarrasing