Super Video CD

The Super Video CD (SVCD) standard upgrades the Video-CD (VCD) format. It allows better video and audio quality, including extensions for surround sound, multi-channel audio and provisioning for PC playback. It's based on variable bit rate (VBR) MPEG-2 coding for more efficient use of optical disc capacity.
  1. Super-VCD standard
  2. Super-VCD players
  3. XSVCD format

1. Super-VCD standard

The Super Video-CD is based on the CD-ROM XA disc format. All tracks are data tracks, the first track is a special DATA track with data retrieval information and interactive playback MPEG sequences. The MPEG-2 streams are recorded in the following tracks and are intended to be played sequentially starting from track #2. A movie could have different coded parts: INTRO, COPYRIGHT, FILM, CREDITS; each stored on a separate track. The film itself can be stored on one track with the possibility to be subdivided into chapters within the one track. The layout will be handle by an SVCD Authoring software like I-Author.

The DATA track ( #1 ) uses Mode 2, Form 1 data sectors ( 2,048 bytes ) and MPEG files use Mode 2, Form 2 MPEG sectors ( 2,324 bytes ). 

The Super Video-CD 1.0 features ( IEC 62107 standard ) are given in the table below: 
 
 
Features Super Video CD 1.0
Video
bit rate
resolution NTSC
resolution PAL 
MPEG-2
variable up to 2.6 Mbps
480x480 interlaced, 29.97Hz
480x576 interlaced, 25Hz
Still picture (photo)
resolution NTSC
resolution PAL
MPEG-2 ( I Frame )
480x480, 704x480
480x576, 704x576
Audio
sampling
bit rate
audio channels
surround sound
MPEG-1 layer II
44.1 KHz
from 32 to 384 Kbps
up to 2 stereo or 4 mono
MPEG-2 ( 5+1 ) extension
Overlay graphics and text
sub-channels
coding 
overlay video plane
<=4
4 color CLUT ( 2bits/pixel )
 

The Program Stream contains two audio streams, usually for two separate languages. Audio streams are MPEG-1 audio formats, given in the table below:
 
 
MPEG-1 (ISO 11172-3) audio formats
Layer layer II only
Bit Rate may vary from frame to frame
single channel mode
dual channel mode
stereo mode
32 to 192 Kbps
64 to 384 Kbps
64 to 384 Kbps 
Sampling frequency 44.1 KHz
 

The video MPEG-2 streams are defined by the constraints of Main Profile at Mail Level ( MP@ML ):
 
 
MPEG-2 video MP@ML profile
B-frames YES
Chroma format 4:2:0
Scalabilty NONE
Intra DC precision 8, 9, 10 bits
Buffer size 1,835,008 bits
Luminance sample rate 10,368,000
Horizontal vector range -512..+511.5
Vertical vector range (frame pictures) 128..+127.5
 

The interlaced nature of the video signal is preserved. This results in smoother-looking motion for video footage that was originally shot with a field-based video camera.

The typical running time of an SVCD disc (with full resolution and quality) is about 35-45 minutes, although it can be extended to over 70 minutes by compromising image and sound quality. 

For PC playback, the format allows storing applications or setup files in the EXT directory. The main root can even contain autorun enabling files.

An SVCD detailed technical explanation is available from Philips licensing page and a copy is also available from our documentation at sl00811.zip (86.5KB) in Acrobat PDF format. Jukka Aho has published a very good Super Video CD Overview.

2. Super-VCD players

SVCD can be played on PC platforms with a CD-ROM (or DVD-ROM) drive and appropriate software like WinDVD and STHSVCD (also named STHSDVD sometimes). 

In general, people want to play Super-VCD on a TV-set with a standalone DVD player. Most DVD players sold in Asia can read SVCD but in America and in Europe only a few players are SVCD compliant.

Because some identical DVD player platforms are used all over the world, one can sometimes upgrade it's firmware and hack the player to make it read SVCD. One example is given at Leon's Lab for the Philips DVD-950 shipped in Europe.

3. XSVCD format

You may see or hear about an extension of the SVCD format called XSVCD. Because SVCD uses the MPEG-2 decoder of the PC, or the standalone DVD player, XSVCD tries to get the maximum from the decoder:
  • Higher resolution up to DVD resolution at 720x480 for NTSC (720x576 for PAL)
  • Higher bit rate up to 9.8Mbps (DVD bit rate) for standalone or 15Mbps for PC (MP@ML constraint) 
For example, the Philips DVD-950 (with firmware 7.12) can play XSVCD at 720x576 and 2.9Mbps .
 


Bibliography
On labDV.com : Relevant links: Author: Jim & Stan (April 6, 2001)
Please visit Leon's Lab and VCDHelp.com
 


Top | Back to DV-NLE