CVD Related Formats: SVCD, Chaoji VCD and Neighbours
CVD in the family of CD video formats
China Video Disc (CVD) is easiest to understand as one neighbour among several CD-based video formats rather than as an isolated invention. It inherits White Book Video CD’s physical geometry and disc-bridge conventions, fights government and Philips Super Video CD (SVCD) over resolution and subtitles, shares a Chaoji VCD player-compatibility umbrella in China, and later collides in hobbyist language with XVCD, XSVCD, KVCD templates and half-D1 DVD. This post keeps those relatives distinct: what each name means, which parameters actually differ, and which naming collisions still confuse collectors.
White Book VCD: the baseline CVD set out to beat
Video CD was defined in 1993 by Sony, Philips, JVC and Matsushita. VCD 2.0 (1995) added playback control, still images and clearer PAL/NTSC variants; a VCD-Internet extension followed in 1997; SVCD was published as a White Book extension in 1998. The White Book itself is not freely available and must be licensed from Philips.
| Parameter | VCD 1.1 / 2.0 |
|---|---|
| Video | MPEG-1, constant bitrate 1,150 kbps (1,151.9 max) |
| Resolution | 352×240 at 29.97 or 23.976 fps (NTSC); 352×288 at 25 fps (PAL) |
| Audio | MPEG-1 Layer II, 224 kbps CBR, 44.1 kHz stereo |
| Playing time | About 74-80 minutes per disc |
| Directory | /VCD (INFO.VCD, ENTRIES.VCD, PSD.VCD, LOT.VCD), /MPEGAV, /SEGMENT, /CDI, /EXT |
| PBC | VCD 2.0 onward |
| Chinese quality perception (1998) | About 240-280 lines horizontal; “similar to watching TV” (Jinzheng) |
VCD’s resolution is a quarter of standard-definition television-the problem CVD set out to fix. In China the White Book was complemented by domestic “VCD 3.0” player features, which 1998 press credits SVCD (not CVD) with supporting. CVD therefore improves picture by moving to MPEG-2 at half-D1 while keeping the same CD Form 2 world that VCD already occupied in Chinese living rooms.
Three things called “SVCD”
It is important to keep three different SVCD-labelled objects apart, plus the later international text:
| Name | What it is | Date |
|---|---|---|
| Government SVCD (超级VCD draft) | MII / National Recording Standards Committee programme, ESS-supported | Draft mid-1998 |
| Philips / VCD Consortium SVCD 1.0 | Government SVCD after HQ-VCD features were merged; White Book extension distributed by Philips | 1998 |
| SJ/T 11196-1998 “Chaoji VCD” | Chinese industry standard and player-compatibility regime covering SVCD and CVD discs | Announced 29 Sep 1998; effective 1 Nov 1998 |
| IEC 62107 | International standard for SVCD (and VCD) | 15 Jul 2000 |
SVCD parameters-the base from which CVD differs-are MPEG-2 VBR video at a maximum of about 2.6 Mbps, 480×480 (NTSC) or 480×576 (PAL), MPEG-1 Layer II audio at 44.1 kHz with up to two stereo or four mono tracks (MPEG-2 multichannel allowed), up to four OGT subtitle streams, and about 35-45 minutes per CD at full rate. Chinese press claimed about 350 lines of horizontal resolution. Philips later added an SVCD logo to its Compact Disc logo family. Western “SVCD-compatible” DVD player claims usually referred to the Philips disc format, which is why Region 1 players could claim SVCD support without CVD support.
HQ-VCD
HQ-VCD (High-Quality Video CD) was the Video CD Consortium’s own proposal, released in March 1998 and merged into SVCD in July 1998. It survives as a disc-type variant: VCDImager can build HQ-VCD images (-t hqvcd) carrying INFO system ID “HQ-VCD”, system profile tag 1, mandatory /EXT/SCANDATA.DAT and optional SEARCH.DAT. No commercial HQ-VCD title releases were found in the gathered material. For identification work, “HQ-VCD” in INFO is therefore a rare system-ID cousin of SUPERVCD, not a synonym for CVD.
CVD versus SVCD: the engineering trade-off
| Factor | CVD | SVCD | Comment |
|---|---|---|---|
| Horizontal resolution | 352 | 480 | SVCD has 36% more columns |
| Pixels per frame (PAL) | 202,752 | 276,480 | CVD spends the same bits on 27% fewer pixels |
| Bits per pixel at 2.5 Mbps | ≈ 36% more than SVCD | baseline | Fewer blocking artefacts in motion |
| Scaling to DVD-player output (720/704) | Exact ×2 | Non-integer ×1.5 | SVCD “foldover” aliasing on many players |
| DVD-legal video | Yes | No | CVD video can move to DVD without re-encoding |
| Interlace | Full lines kept | Same | Both better than VCD, which discards a field |
| Visible detail on 1998 CRT TVs | Close to TV limit (makers’ claim) | Above what many TVs resolve | noulakaz argument |
| Player support outside China | Lower | Higher | Community reports vary |
| 1998 line-count claims | 280 (hostile) to 400 (makers) | 350+ | Partisan figures |
The 1998 Chinese makers argued that CVD’s resolution was “exactly at the upper limit of the TV set,” so the extra pixels of SVCD-or even DVD-would only show on fully digital televisions (Shenghuo Shibao, 29 July 1998). A later VideoHelp user with a large player-testing background summarised the practical bitrate result: DVD at 720×576 “will almost always look better than CVD… except at below 4,000 kbs bitrates at which point CVD can look better than SVCD and DVD is likely to show macroblocks.” Those claims are kept as community engineering arguments, not as laboratory measurements.
Community variants: XVCD, XSVCD, KVCD and “CVD on DVD”
These names are not standards but community labels for non-compliant variants.
- XVCD (eXtended VCD): VCD structure with MPEG-1 (or MPEG-2 at VCD resolution) above 1,150 kbps, often up to about 2,500 kbps. Uses SUPERVCD-style or VCD INFO; player tolerance varies.
- XSVCD (eXtended SVCD): MPEG-2 in Mode 2/XA at SVCD resolution but not meeting the SVCD standard (higher bitrate, larger GOPs, custom matrices). A 352-wide XSVCD is structurally a CVD.
- KVCD / KSVCD / KDVD: Kwag’s TMPGEnc templates with custom quantisation matrices, long GOPs and low VBR rates (examples include 528×480 and 352×240). Marketing claims of “near DVD quality” for 120+ minutes are the template author’s, not measured results.
- MVCD (Mole VCD): an XSVCD variant from the MVCD template set.
- “CVD on DVD” / half-D1 DVD: 352×480/576 MPEG-2 authored as DVD-Video with 48 kHz audio-fully DVD-compliant, used for VHS archives and packing several films per DVD.
mjpegtools’ anytovcd.sh script has a cvd profile that actually means half-D1 DVD (mpeg2enc -f 8, AC-3 at 48 kHz, up to 7,500 kbps, with SARs 20:11 / 59:27 for 4:3 or 80:33 / 236:81 for 16:9). That is “CVD-resolution DVD,” not a CD-based CVD. The naming collision causes confusion in tutorials and must be read carefully whenever a guide says “author CVD.”
DVD-Video and why 352 is legal
DVD-Video permits MPEG-2 at 720×480/576, 704×480/576, 352×480/576 and 352×240/288 (MPEG-1 is also allowed at 352×240/288). The 352×480/576 case is the half-D1 resolution C-Cube already supported in its CLM4400 encoder. Audio for DVD must be 48 kHz (LPCM, AC-3, MPEG audio or DTS), so the only change needed to move CVD video to DVD is audio resampling and DVD authoring (IFO/VOB structure). As one VideoHelp user put it: “CVD, if done correctly, complies to the DVD standard (low res DVD video streams).”
Master comparison
| Format | Status | Video | NTSC / PAL | Typical ceiling | Time / 80-min CD | DVD-legal video |
|---|---|---|---|---|---|---|
| VCD 1.1/2.0 | White Book (1993/1995) | MPEG-1 CBR | 352×240 / 352×288 | 1,150 kbps | ~80 min | Yes (audio no) |
| CVD | C-Cube/OEM 1998; inside Chaoji VCD | MPEG-2 VBR | 352×480 / 352×576 | ≤~2.6 Mbps (2.52 typical) | 35-45 min | Yes (audio no) |
| SVCD | IEC 62107; SJ/T 11196 | MPEG-2 VBR | 480×480 / 480×576 | ≤~2.6 Mbps | 35-45 min | No |
| HQ-VCD | IEC 62107 variant | MPEG-2 | as SVCD | as SVCD | as SVCD | No |
| XVCD / XSVCD | Non-standard | MPEG-1/2 | VCD or SVCD (or other) | above White Book / SVCD | varies | Depends |
| KVCD family | Templates | MPEG-1/2 | e.g. 528×480, 352×240 | low VBR | claimed 120+ min | KDVD yes |
| DVD-Video | DVD Forum | MPEG-2 (MPEG-1 allowed) | 720/704/352×480; 352×240 | ≤9.8 Mbps | n/a (4.7 GB) | – |
| EVD (2003) | Chinese | VP5/VP6 (On2) | up to HD | – | n/a (DVD disc) | No |
| CBHD (2009) | Chinese | AVS / H.264 / VC-1 | up to 1080 | up to ~28 Mbps video | n/a (blue laser) | No |
CVD sits between VCD and SVCD on the CD-era ladder: same physical CD and roughly the same bitrate budget as SVCD, half-D1 instead of 2/3 D1 video, and a path into DVD-Video without re-encoding the pictures. Chaoji VCD is the Chinese player-compatibility umbrella that required both CVD and SVCD discs to play; IEC 62107 is the later international SVCD text that does not include CVD-style subtitles. Later Chinese formats-EVD and CBHD-repeat the political pattern of seeking domestic control over the next optical generation, but they leave the CD Form 2 world entirely. For collectors and archivists, the practical neighbour set is VCD for installed-base context, SVCD for file-system identity, HQ-VCD for the rare system-ID variant, and half-D1 DVD for the modern reuse of CVD’s resolution.
Further reading on historic video formats
If you want to learn more about historic video formats, get The History of Physical Video Formats from the Frontier by Stephen Driver on Amazon: