Computer Science, asked by shashikewat, 1 year ago

storing a film in high definition

Answers

Answered by MacintoshTavish
3
Most DVDs store movies in the standard MPEG-2 format (aka H.262) defined by the Motion Pictures Expert Group, though MPEG-1 is also supported. The video is held in VOB (Video Object) files. The video is interlaced for display on ordinary TV sets. The result is a resolution of 720 x 576 pixels at 25 frames per second, for 50Hz TV sets, or a resolution of 720 x 480 pixels at 29.97 frames per second, for 60Hz TV sets.

MPEG-2 was the obvious choice for DVDs as it was already being used for broadcast and cable television. The 720 x 480 format came from America's NTSC television system and 720 x 576 from Europe's PAL.

ISO or MPEG?

If you want to preserve everything on a DVD, then the simplest option is to copy the whole disc as an ISO disc image. You could burn this copy to another DVD for backup purposes. You could also play the ISO disc image using a software DVD player, including VideoLan's VLC, or rip it using your choice of DVD ripping software.

What you have done so far is to rip a couple of DVDs to MPEG-2 (.mpg), so you may have the full original video, but de-interlaced so it is now in the progressive display format used by computer monitors and HD TVs. However, you will probably have lost any extras, including VMG (video manager) files, subtitles, hidden files, adverts and alternative audio formats. DVDs can have audio tracks in PCM, DTS, MPEG-1 Audio Layer II (MP2), or Dolby Digital (AC-3) format. MP2 and AC-3 are the most common, and if you have to pick one of those, choose AC-3. It is much more efficient (smaller files) and sounds better than MP2, which is antique – though, sadly, it's still used in Britain's antique DAB radios.

For future-proofing, MPEG-2 files are the next best thing to ISO images, and I don't foresee a time when PCs will be unable to play them. As with MP3 audio files, there are just too many around.

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