what is the difference between MPEG1,MPEG2 and DVD format ?

Answer 1

MPEG1/2 are complimentary to each other, MPEG1 handles lower quality while MPEG2 handles higher; those are generic statements, if you are willing to tweak the encoding setting you could end up with a lower quality MPEG2.

DVD is MPEG2 in disguise, DVD has the extra requirement of menus, options and the stuff.

Answer 2

ISO is not a movie format in itself, it is a format that simulates an entire real DVD disc. This type of file is called a 'DVD image file'. Apart from ISO, DVD image files can also have the extensions IMG, NRG, etc. As you probably know, a regular DVD disc can contain other files than movies as well. But when an ISO file contains a DVD movie, the actual movie files inside the ISO are the same VOB files that also occur separately. This means the quality of the video is the same, regardless if the VOB video file is on its own, or embedded in an ISO file. AVI is a 'container format' that can also contain several different types of actual video files. The word 'container' is good because just like a physical container, you can put anything inside as long as it fits. The most commonly used video files inside AVI containers are XviD and DivX, (codecs which are part of the MPEG4 standard). DivX, and later XviD, have been the most popular formats for compressing DVD video to a smaller size file (typically 700MB or 2 x 700MB - this is so they can be burned to CD) while maintaining as much of the quality as possible. But when compressing, the quality will suffer. So to answer your question, in conclusion, the quality of the most commonly occuring AVI files is not as good as that of VOB files (which are the basic format for DVD video). But for smaller TV screen sizes, the difference is not so noticeable. And the smaller size saves you hard disk space obviously - more movies on less space. It was more important before when large capacity hard drives were more expensive. Hope that clears some of it up.

Answer 3

MPEG-1 defines a group of Audio and Video (AV) coding and compression standards agreed upon by MPEG (Moving Picture Experts Group). MPEG-1 video is used by the Video CD (VCD) format and less commonly by the DVD-Video format. The quality at standard VCD resolution and bitrate is near the quality and performance of a VHS tape. MPEG-1, Audio Layer 3 is the popular audio format known as MP3. As cheaper and more powerful consumer decoding hardware became available, more advanced formats such as MPEG-2 and MPEG-4 were developed. These newer formats are more complex and require more powerful hardware, but the formats also achieve greater coding efficiency, i.e., quality per bitrate.

MPEG-2 is a standard for "the generic coding of moving pictures and associated audio information". [1] It describes a combination of lossy video compression and lossy audio compression (audio data compression) methods which permit storage and transmission of movies using currently available storage media and transmission bandwidth.

DVD
The DVD standard uses MPEG-2 video