Posted by Tomi Engdahl (184.108.40.206) on September 18, 2003 at 13:30:26:
In Reply to: Brief notes on vcd Player working, & Circuit diagram, posted by M.Awais HAbib on September 18, 2003 at 10:46:24:
: i want notes on VCD PLAYER Working & circuit diagram,
: please help me.
VCD stands for 'Video Compact Disc' and basically it is a CD that contains moving pictures and sound. VCDs look exactly like a CD or CD-ROM except that it stores video/audio clips using the compressed and standardized MPEG 1.
A VCD has the capacity to hold up to 74 minutes on of full-motion video along with quality stereo sound (this is 650 MB of data). VCD can store up to 80 minutes of full-motion video along with quality stereo sound to a 80 minute CD (700 MB CD). In addition to those a VCD can also inclue menus, chapters, photo albums and slide shows with background audio. VCD resolution is 352x288 for PAL and 352x240 for NTSC. VCDs use a compression standard called MPEG-1 to store the video and audio. The picture quality of VCR is generally considered to be about the same as VHS tape, but not always as good as VHS. Video CD (VCD) is used as a low-cost alternative to DVDs in Asia.
A VCD can be played on almost all standalone DVD Players and on practically all computers with a DVD-ROM or CD-ROM drive with the help of a software based decoder / player. . However not all DVD players will play VCD's - this is not the fault of the VCD but the compatibility of the DVD player.
My quess of construction of a videoCD player nowadays:
- the CD rotation hardware is similar to CD-ROM drive used on PC (1x reading speed is enough)
- MPEG video deciding IC that takes in MPEG data and outputs video signal
- there is a microprocessor/microcontrolelr that runs the control program. This control program takes user controls, reads data from CD-ROM drive and sends this data to MPEG decoder
This is basically how those are propably made nowadays.
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