Should i call it Ramani's blog

Friday, February 27, 2004



Everyone knows whats a VCD? Any idea whats VCD1.1 or VCD 2.0?


VCD stands for 'Video Compact Disc' and basically it is a CD that contains moving pictures and sound. A VCD has the capacity to hold up to 74/80 minutes on 650MB/700MB CDs respectively of full-motion video along with quality stereo sound. VCDs use a compression standard called MPEG to store the video and audio. The quality of a very good VCD is about the same as a VHS tape based movie but VCD is usually a bit more blurry.

Technical details about VCD 1.1 and VCD 2.0:

Video CD 1.1

This is the most basic Video CD specification dating back to 1993-94 , which has the following characteristics:

  • One mode 2 mixed form ISO-9660 track containing file pointers to the information areas.

  • Up to 98 multiplex-ed mpeg-1 audio/video streams or cd-da audio tracks.

  • Up to 500 mpeg sequence entry points used as chapter divisions.

  • The Video CD specification requires the multiplex-ed mpeg-1 stream to have a cbr of less than 174300 bytes (1394400 bits) per second 5 in order to accommodate single speed cd-rom drives.
    The specification allows for the following two resolutions:
    ~ 352 x 240 @ 29.97 Hz (ntsc sif).
    ~ 352 x 240 @ 23.976 Hz (film sif).

  • The cbr mpeg-1, layer II audio stream is fixed at 224 kbps with 1 stereo or 2 mono channels.It is recommended to keep the video bit-rate under 1151929.1 bps

Video CD 2.0

About two years after the Video CD 1.1 specification came out, an improved Video CD 2.0 standard was published in 1995. This one added the following items to the features already available in the Video CD 1.1 specification:

  • Support for mpeg segment play items (SPI ), consisting of still pictures, motion pictures and/or audio (only) streams was added.

  • Support for interactive playback control (PBC) was added.

  • Support for playing related access by providing a scan point index file was added.(‘/EXT/SCANDATA.DAT’)

  • Support for closed captions.

  • Support for mixing ntsc and pal content.

  • By adding PAL support to the Video CD 1.1 specification, the following resolutions became
    available:
    ~ 352 x 240 @ 29.97 Hz (ntsc sif).
    ~ 352 x 240 @ 23.976 Hz (film sif).
    ~ 352 x 288 @ 25 Hz (pal sif).

  • For segment play items the following audio encodings became available:
    ~ Joint stereo, stereo or dual channel audio at 128, 192, 224 or 384 kbs bit-rate.
    ~ Mono audio streams at 64, 96 or 192 kbit/sec bit-rate.

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