I'm attempting to join / merge two mp4 files in Quicktime Player 7 Pro which works great, i believe i have an issues when i export the clips as judging by the exported file size, it seam like its being compressed.
The "Export" File menu option unconditionally forces a re-compression of your merged files. Use the "Save As ..." File menu option to see if you can combine the files without re-compressing them into a self-contained "standalone" file or create a "reference" file that combines the playback of two or more individual files. Even then, if the specs for the individual files vary greatly, QT 7 Pro may force a "standalone" re-compression of the data or the results may spread data across multiple tracks which other players/apps may not like/support.
For example, i have one mp4 clip which is 2.5gb and another mp4 clip which is 2gb. They join seamlessly and when i export to mp4 i'm expecting the file size to be approximately 4.5gb - instead the exported mp4 clip is 70.3mb...
Your workflow is flawed here. More than likely, you are using a targeted MPEG-4 preset that limits the combined average data rate of the new file to approximately 1/64th the combined average data rate of the two individual source files. If you want the file sizes and quality to remain reasonably consistent, you must re-set the output data rate to roughly match that of your original files.
The two files where previously compressed and exported in Final Cut Pro X, so further compression isn't needed nor wanted as i want the exported file to be as high quality as possible...I realise the obvious answer is to join the two clips (timelines) in Final Cut Pro and export - but it's for a whole series to the would take a huge amount of time.
If you adopt "less than optimum" editing workflows, then you must accept the possible "less than optimum" results they produce.
Having said that... There may be a possible alternative that allows you use your original workflow but only requires a single compression export. Have yet to switch from the older FCP app to FCPX so I don't know if you still have the option of creating intermediate reference edits that resource the original compressed data and can be merged and compressed using QT 7 Pro as a single, final editing step. If you can, then simply create intermediate "reference" files that contain the edit references to the original raw file data, merge the "reference" files in QT 7 Pro, and then export the merged edit references to a single standalone file compressed to a specific target compression format. The advantage of such a workflow is that the merged reference file can be compressed to multiple final compression formats as needed for different purposes—e.g., sharing via email, posting to a web site, optical disc storage for playback on a computer, etc. The disadvantage is that all raw, intermediate, and merged files must be stored in a manner to prevent orphaning any of the resource references which is often a problem for novice QT 7 Pro users.
