iApps: High resolution audio / video in iMovie and iTunes?

These days I have received quiet amount of e-mails from people asking how they can convert files to high resolution audio and video (CD-Audio and DV files for burning DVD’s). In this article I will try to make some things clearer for the users.

Let’s say that you have a pile of VCD’s (MPEG2) or DivX (MPEG4) videos that you want to transfer onto a DVD using the iMovie software. Before I show you how to do this, I first have to explain the difference between DV and the MPEG files. DV files are actually uncompressed video files that your Camcorder would produce. Uncompressed means that they have high picture and sound quality and they are rather big in size. MPEG 2 and MPEG 4 files on the other hand are compressed video files that uses special compression algorithm. MPEG files are smaller in size then the uncompressed RAW DV files thus more portable, but the picture and sound are not as quality as the DV. In order you can work with your MPEG files in iMovie, they have to be transfered to a DV format. The easiest way of doing this is by using Quick Time PRO or some shareware application that would do it. Conversion time will vary depends on how big is the file and how fast your computer is. Before you begin, check how much space is available on your hard drive as manipulating video files requires having huge amount of free space on your HD. Once you have your file converted to DV, you are ready to start making a DVD disc out of it (I presume that you know how to do that with let’s say iDVD so I wont be explaining it this time). When you make a DVD you can now showing off in front of your friends that you have made your file(s) being DVD quality…. or have you? Well, not quiet… Why?I have already explained above that MPEG files are compressed and that a special compression algorithm is applied so it can make them having pretty good picture and sound quality but still being much smaller in size. It is true that once you convert a file into a native DV format it size will increase and it will look like you have a high resolution video file. However, this is not quiet true because once the compression algorithm is applied, there is no way that any application can retrieve all of the compressed data. Because of this, if you have a sharp eye, you will be able to spot a difference between the original DVD and the one that had been created out of compressed files. This also can be relative to a fact that not every MPEG file has the same compression ratio so some of them might be higher quality then the others.

Same goes when you manipulate compressed audio files such as MP3,AAC and the others. Say you have your playlist in the iTunes and you burn it on a CD in the CD AUDIO format. Disc that is created by using iTunes will be indeed playable with any standalone CD player as the files are being converted from a compressed format into a RAW CD AUDIO. Again depends on the quality of the compressed music, it will sound more or less poor when played on a CD player compared to an original AUDIO CD. To conclude this, most of people wont be able to spot the difference with this but it’s good to know how all that works.Please contact me if you find some incorrect or incomplete parts in this article.