Why won't .mp4 file open in QT 10.0 (or iMovie'09) and OS 10.6.8?

Wow! A lot of ifs, ands, and maybes here.

I'm trying to edit some .mp4 movie files, but I can't open them in Quicktime (10.0 or 7.6.6), or iMovie '09 (8.0.6) or Final Cut Express (4.0.1). I've got a MacBook Pro running OS X 10.6.8 (Snow Leopard). When I try to open the file in QT 10, it says "The document “name.mp4” could not be opened"; whereas in QT 7 it says "The file could not be opened. An invalid sample description was found in the movie." In iMovie, the file is greyed out when I try to import it.

To start off with, these messages and/or inability to opent/import files could stem from either security updates that see something in the file that it interprets as a possible breach of file integrity or the inclusion of data not expected in the associated file type while missing codecs are either identified and load but do not display or refuse to load but issue a message to that effect and possibly asking if you want to visit a web page containing codes you may want to add.

The file will open and play fine in VLC, but I can't do the editing I want there. The Media Information pane in VLC says: the codec is "H264 - MPEG-4 AVC (part 10)(avc1)", it is HD resolution (1920 x 1080), it has a frame rate of 59.940060, and the Decoded format is "Planar 4:2:0 YUV". It also has an audio track (MPEG audio) and a subtitle track. I also tried opening these .mp4 files on two Mac laptops that a friend of mine has. Interestingly, they would not open on one (I think running Lion with QT 10.0), but they DID open on the other newer laptop (running Mountain Lion with QT 10.2).

In the future, could you be more specific when describing the file contents. For the moment, I will assume the video is H.264 (MPEG-4/AVC) and the audio is AAC (MPEG-4) audio and not MPEG-1 layered audio. (I.e., while the former is to be expected with the MP4 file extension, some apps can "stuff" incompatible data into an MP4 container or users can manually change the file extemsion.) It also important to know if the "subtitle" track is embedded within the file or is contained in a separate file. (I.e., a screen capture of the media "info", "inspector", or "properties" window is usually the least ambiguous way to track content information.) It would also be nice to know if the VLC frame rate is for progressive or interlaced video if possible.

Basically, some apps are very touchy about file extensions and track content. iMovie '08, for instance, will not open a file containing extraneous tracks like 'tween, text, chapter, etc. embedded within the file. I assume this may also be true for "subtitle" tracks as far as your Snow Leopard players are concerned. In any case, if your version of the QT 7 player is keyed for "pro" use, I would perform a simple test here by deleting the "subtitle" track, saving the file, and then re-trying to load, open, play, and/or import the file in the various applications currently giving you problems. If this fixes the problem, then you will know the source and solution of your problem

I first assumed it was just a case of not having the right codec. So I tried copying all the codecs from the Mac laptop that *could* open them, but that didn't work. Then I searched for and downloaded codecs that I might be missing, such as "avc1Decoder.dmg" from MyCometG3 and http://www.macupdate.com/app/mac/23875/avc1decoder, and x264Encoder 1.2.27 also from MyCometG3, and I put them in my Library/Quicktime folder and restarted Quicktime, but neither solved the problem. I also tried opening the .mp4 files in MPEG Streamclip (1.9.2), but it says "File open error: unrecognized file type". When I tell it to "open anyway" it tries and then says "File open error: can't find video or audio tracks".

The indiscriminant installation of additional codecs often creates more problems than it solves owing to the logrithmic increased potential for the introduction of QT codec component conflicts. The normal "rule of thumb" here is to identify a missing codec and to then install only that specific codec component. Even then, there is a possibility that there may be a conflict but at least it is more easily identified so you can better evaluate which of the conflicting codecs to leave installed and which to swap only when needed/required. As to the use of MPEG Streamclip, it basically uses your system's QT component configuration of access of most codecs as opposed to VLC and HandBrake which contain their own, built-in codec support. So if QT is having a problem, it is often likely that MPEG Streamclip will also have problems.

I tried opening one of these .mp4 files in Handbrake (0.9.8) and it was able to open and convert the file to an .mp4 that is then openable in QT 10 with a format of H.264, AAC, and a reduced frame rate of 29.84. However, this doesn't seem like a good solution because it takes about 2 hours to convert a file with 30 minutes of video. I just want to be able to trim these big files down to some short video clips that are in an accessible format.

The HandBrake workflow forces a recompressing of the file data which is why it takse so long. That is why I suggested you try deleting any extraneous data tracks found in the source MP4 file container using QT 7 Pro and then use the "Save" or "Save As..." option to re-write the original audio and video data to a new MOV file container which takes much less time.

Am I missing the right codec? Or, as I'm beginning to wonder, is this format one that is too demanding for OS 10.6.8 and QT 10 and they just cannot handle it no matter what codecs I have on my computer (because of the 60 fps frame rate? Or is it the subtitle track?). Or is the solution to upgrade my operating system to Mountain Lion (10.8) and QT 10.2? My 15" MacBook Pro is about 2 years old with a 2.66 GHz Intel Core i7 and 4 GB of RAM (1067 MHz DDR3).

Probably not. The VLC reported data rate may either indicate the MP4 content is AVCHD/BD sourced or it is reading interlaced content as progressive which I have noted it can do on occasion when I compare the media info as read by various different apps and/or utilities. Since you indicate the file opens in Mountain Lion, my guess would be that your MP4 content is actually AVCHD/BD sourced since such support was only recently added to Mac OS X v10.8 software. As to moving up to Mountain Lion, as always, that is something you would have to evaluate for yourself. For instance, do you require PNG compression for video content? By default you would lose it under Mountain Lion and have to re-enable it manually if needed. Are there other pros and cons that you need to consider before upgrading to Mountain Lion? These are the types of questions and compatibility issues that only you can answer for yourself.

Thanks for your reply. You suggest deleting the subtitle track using QT 7 (and yes, I have Pro), but QT 7 can't open the file. Is there another way to delete the subtitle track? I'll attach an image of the VLC "media info" window from one of these movie files.

For QT 7 Pro and MPEG Streamclip, I would first duplicate the file and then try changing the file extension on the duplicate file from MP4 to MOV. If it then opens in QT 7, but the audio does turn out to be MPEG-1 Layered audio, I would use the "Properties" window to delete the subtitle track and then try a video "passthrough" while converting the audio to AAC if the MPEG-1 layer audio is supported on your system. If MPEG-1 audio layer is not supported but the file opend in QT 7 Pro and you were able to delete the subtitle track, then I would try opening the saved duplicate file without subtitle track in MPEG streamclip and re-sample the audio to AIFF or Uncompressed format and try replacing the MPEG-1 layered audio with the re-sampled audio—scaled if necessary and check to see if A/V sync was still acceptable. If neither of these options work, I would try using VLC to copy the original video to an MOV file container (without conversion) while simultaneously converting the MPEG-1 Layer audio to AAC and see if the video remains stable. (Afraid I am out of my depth here since I normally use MKV as the intermediate file container for such content and normally downconvert to 720p files for more universal compatibility with mobile/TV (iPhone 4/4s, iPad 1/2/3, and TV 2/3) devices used by myself and other members of my family.) BTW: if you get a chance to reload the file on that Mountain Lion system, I would test to see if it allows you to trim the content in the QT X v 10.2 player and then "export" the file using the "Movie" format option which saves the file to an MOV file container but in its original compression format—i.e., the equivalent of a QT 7 Pro "Save As..." option. (May not work but might be worth checking on to avoid re-compressing video.)

Afraid that is about all that I can think of at the moment.

I did discover one other piece of information though: This video file I'm trying to open is from an HD camera on an underwater robotic vehicle. The operator of the vehicle gave me a test video file several months ago that has the same codec info as the one I'm struggling with now, but it opens fine in my QT 10.0. The only difference is it has no audio track. I'll attach a snap of the VLC media info for that file to compare with the other one.

Interesting but not helpful at this point. As I previously indicated, my normal AVCHD workflow deals with AVC1 in transport stream (TS, MTS, M2TS, MPG, etc.) or MKV file containers as depicted here by VLC:

Sample MTS file from Panasonic camcorder

Sample MKV file from BD

Unfortunately, while these are suitable for my specic workflow, they may or may not work the same your MP4 files and I am currently unable to locate any similar MP4 files on the internet for testing. By this I refer to the fact tthat, while an MTS file container cannot be opened directly in QT X v10.2 under Mountain Lion, the data can, like your MP4 file, be opened indirectly and then trimmed and/or saved in an MOV file container as AVC1/AAC data as depicted in the following clip:

http://downloads.walker4.me/downloads/Temporary_files/ScreenFlow2.mov

This a screen capture of my display while I open a sample camcorder AVCHD clip downloaded from the internet (http://hownowvideo.com/download.html). In this case the MTS file data is basically contained in a BDMV file package which can be opened in the Mountain Lion QT X player app. (Hopefully this simulates your ability to open the MP4 file under OS X v10.8 as previously stated.) With the file opened in the QT X player, I then play the camcorder file to confirm that the AVCHD (AVC1/AC3) data is playback compatible under this system and using this player. Next I select the "Export" menu option and export the file using the "Movie" format option. Lastly, I close the original AVCHD data file, open the newly created MOV file, and play it back to demonstrate that the new MOV file contains the original video data but with AC3 audio transcoded to AAC audio making the file compatible with QT X v10.2, QT 7, iMovie, GarageBand, etc. (I.e., unfortunately, while I did later perform test imports of the MOV file to these other apps, I did not do so while the screen capture was in progress.) In any event, you can view, download, or open the above screen capture video file URL directly in a QT player to see how this works.

The only question remaining at this time is whether or not the same workflow can be used with your MP4 files. Since I still have not located such a sample file, I was wondering if you had a short sample that could be emailed or posted to a server for download and testing on my platform.

No audio plays when the video plays. So I wonder if there is something problematic with the audio track in these files.

As previously noted, MPEG-1 Layered is not normally found in an MP4 file container unless the data was custom multiplexed to a real MP4 file container or someone has manually changed the file extension. Since QT is a "standards" based player app, it is quite possible that it may refuse to open a file containing compression formats which are non-standard for the file container type or may dispense with audio content in order to open/process the file. (Or was this the robotic test video without audio that opens in QT X v10.0?) Have you tried to actually discover the true audio format (if present) using a utility like MediaInfo?

That said, I also know that when my friend worked with these files on his MacBook Pro (with OS 10.8 and QT 10.2) he read them in with Final Cut Pro and the audio was retained. So I still don't understand what is going on, but at least I can work with the video files now.

Was the file to which you now refer an AVCHD source file imported to FCP or the same MP4 file your are trying to open and edit? (I.e., FCP can import real AVCHD files directly to FCP as re-renderd content for editing or be re-rendered from within the FCP app if needed.) If real AVCHD files were imported for FCP editing and the content was output as AVC1/MPEG-1 layered audio in an MP4 container and passed on to you as such, how and why was this done? If you mean your friend is importing the same MP4 files as you are trying to edit and has made them edit compatible with FCP, why don't you simply have your friend export the content with edit compatible audio using the "Export as QT Movie" (MOV file) with original video unchanged?

Your postings are becoming a bit confusing here and is why I normally prefer to examine/analyze files on my own system to avoid the misunderstandings that frequently accompany unanswered or only partially answered questions and/or I remain unable to test possible workflows on the actual problematic source files.

By private email, I've sent you a link to one of these .mp4 video files on an ftp site for you to test.

Email received. File is downloading at this time.

Email received. File is downloading at this time.

FOLLOW-UP:

Posted H.264/AAC MOV file with untranscoded video to my personal server and emailed you the direct URL for viewing and/or downloading via Safari. Also explained the modulus 16 display problem which QT 7 Pro masking may be able to fix if required for your workflow.