The difference between original DVDs and pirated DVDs mainly lies in digital copy and simulative copy.
In picture making, the signal source of genuine DVD is the digital beatcam belt converted from up to over 1,000 lines of the original copy of the film. So genuine DVDs can easily reach 520 lines of resolution. The ordinary region-free DVDs use genius DVDs as the source of signal and then output to a lower-end of MPEG2 compressed card. Since there are two signal weakening, finally the MPEG2 video files only have about 350 lines, far below the standard 520 lines of legitimate DVDs . In fact in the production process, due to various limitations and improper setup, the pictures will be dull, wrong color and other questions. Poor region-free DVDs will have splash and mosaic like in VCDs, especially in the dynamic pictures. Since the second half of 1999, 99 percent of the legitimate DVDs use 16:9 aspect ratio, the ratio of pictures are 1.85:1 and 2.35:1. Although the region-free DVDs and legitimate DVDs have the same aspect ratio, but the picture ratio is 4:3, with up and down borders. The resolution of the same movie is only 2/3 of the original.
In capacity, the current DVD genuine basically adopted the single-sided double-layer dvd-9, the largest capacity is 8.5 G. The length of the main movie is around 5 G-7G. General there are various additional information, like the extras, some segments, comments of directors and actors and so on. They have a certain collection value. And the region-free DVDs use the single-sided single-layer DVD-5 with the maximum capacity of only 4.7 G. Due to the capacity, regardless of the length, the main movie is generally only about 4 G, but with little additional information.
In sound effect, apart from some old DVDs, legitimate DVDs have adopted a 5.1-channel dolby digital compression algorithm, some also adopt more high-end DTS compression algorithm. Region-free DVDs basically adopt 2.1-channel signal due to the limitation of equipments and technique. And then create a false 5.1-channel dolby digital with the software. Although it is shown as dolby digital on DVD machines, there is defects like inaccurate positioning and confusion sound channel. What is more, all of the voice channels are identical