1. Page 1
Hybrid SACD/DVD (Part 1 of 3)
By Stefan Schreiber
The present situation
The current situation is well-known and unsatisfactory: the simultaneous market-introduction
of two competing standards for high-resolution audio and surround-sound (DVD-Audio
and SACD) is leading to big problems in the audio industry - and additionally,
to frustration for audiophiles and "consumers" who are, in some cases, unable
to reproduce on their audio-players a disc available for the competing standard.
As even DVD-Video is apt to distribute audio-recordings (and, of course, music-video),
it could be said that there do exist three potential "CD successor" formats
at the same time.
While the SACD standard allows a hybrid disc-form containing a CD-layer compatible
with CD-players, DVD-Audio discs are often mastered as DVD-AudioV, containing
audio recordings for normal DVD-players (Video), often in stereo (for example,
PCM-96kHz), or in compressed surround-formats (Dolby Digital, DTS). Of course,
DVD-AudioV discs can include music-video and further "extras".
As a "general" solution for the ongoing format-war between SACD and DVD-formats,
it is often demanded that all new and advanced audio reproducers were "hybrid
players", supporting both formats. These hybrid players should support the "DSD" (kind
of high-resolution bitstream) modulation of SACD, and PCM in all quality levels
of DVD-Audio (up to 192kHz, 24Bit). Although this sounds very convincing, it
won't happen, in my opinion.
It is quite possible to equip hybrid players with chips supporting both formats,
and also to design combined DACs supporting both DSD- and PCM-modulations.
However, good reproducers will need different analogue paths after the conversions.
The price of audio reproducers is mainly a consequence of good analogue components
and DACs, not of ICs supporting two or three formats "digitally".
Some of the announcements made by Chinese manufacturers about the possibility
to offer DVD-players with DVD-Audio- and SACD-support, for maybe $100, have
to be considered from a critical point of view. The problem is not to support
a format "digitally" and to reproduce it "somehow"; you have to do it well,
especially in the case of audio. Otherwise, you wouldn't have to replace the "Compact
Disc" at all, which already can sound quite well, but certainly not "perfect
It is difficult to design a DVD-player with "good" audio-quality. It is needed
experience and know-how for this task. Up to now, hybrid SACD/DVD players are
usually better for ONE of the two formats, for example, because they convert
DSD to PCM (up to 192kH) and vice-versa. This conversion isn't completely "without
loss", and will result in "PCM with less dynamic bandwidth", or in "DSD with
less temporal resolution".
It is revealing that hardly any hybrid SACD/DVD-Audio player can be considered
to be a CD-player of "reference-class", which, considering sometimes high prices,
is quite amazing, because you can very well "upsample" PCM in 44.1kHz/16Bit
both to PCM in 96kHz (or 192kHz) AND to DSD, all in the digital domain. Expensive
CD-players are quite often doing exactly this...
The current (and maybe future) low market-share of such hybrid players has
very understandable reasons. The DVD-player market is extremely price-competitive.
If a DVD-player is also a hybrid DVD-A/SACD player, it would be too costly
and in a too high price-category for most customers. Audiophiles would consider
buying such hybrid players, but they will be normally too expensive to be competitive
in the mass-market. A DVD-player supporting both formats won't be a best-selling
model, for price-reasons. Today, and probably also in future, obviously not
every DVD-player is even supporting only ONE of the two high-resolution formats.
2. Page 2
Hybrid SACD/DVD (Part 2 of 3)
By Stefan Schreiber
The new proposal
However, there might be a "soft" solution for the ongoing format-war: the
introduction of hybrid two-sided discs, with one SACD-layer on one side (at
least) and music in the formats DVD-Video and/or DVD-Audio on the second side
(maybe the same). This solution works easily, because in the most basic case,
a SACD half-disc is glued to a DVD half-disc. The consequence is a normal optical
disc (1.2mm), containing "correct" layers for both DVD- and SACD-players. SACD-
and DVD-Audio-players will see their respective layers, with the right specifications.
Obviously, there isn't any problem concerning "compatibility".
This format (SACD/DVD) has at least two main applications. Firstly, it is
probably the only "practical" possibility to include music video into the SACD-standard.
Music video has a broad range of uses and applications (video-clips for pop/rock
music, live-concerts, musicals, ballet, operas...). In my opinion music video
on videodiscs has a great future ahead, especially combined with high-resolution
tracks and surround-sound. Philips and Sony might have thought to extend the
SACD-standard for video (using the "Extra Data Area"); however, a new standard
SACD-Video wouldn't have any chance beside the (mighty and official) DVD-Video.
Secondly, every record-label would have the possibility to release a record
on SACD/DVD-Audio (V), offering both formats in one medium. Of course, this
is an absolute future-proof solution for the customer, who knows that at least
one of both standards will survive. In this case, a further advantage for the
record-label would be that they will not have to consider parallel editions
for both DVD-Audio and SACD formats any more, which has happened in some cases
and seems to be completely unnecessary now.
Both hybrid SACD/DVD-Video and SACD/DVD-Audio discs can be produced without
big problems as "DVD 10" (double-sided DVD) on all existing DVD production
lines. A more complete SACD/DVD-Audio/Video disc, containing music and maybe
video in three formats, will be manufactured (normally) in a "DVD-14" process.
Of course, (at least) one of the used "masters"/matrices for the injection
moulding process has to be "cut" as SACD-master by a special Laser Beam Recorder
A DVD-14 (I prefer to call it more precisely a "DVD-14", because of the included
non-standard SACD-layer) goes through a more complicated process of manufacturing,
usually requiring the so-called "Surface Transfer Process" from Time Warner
(to manufacture a two-layered DVD half-disc). However, this is a commercially
used production process, and not "science fiction". For example, the DVD-Audio
editions of AIX Records are usually two-sided discs, three-layered, requiring
exactly this kind of DVD-14 manufacturing process.
A single-sided SACD/DVD (read from the same side, one layer SACD, the second
layer DVD) can't work. The first problem starts with the fact that both SACD-
and DVD-players would expect "their" respective "Lead-in" on Layer 0. DVD-
and SACD- Lead-Ins are not compatible and, additionally, a SACD Lead-In would
be encrypted. There are different file-systems, and so on.
3. Page 3
Hybrid SACD/DVD (Part 3 of 3)
By Stefan Schreiber
The benefits of the new format
In my opinion, the music market for media should be split into two separate
segments. Firstly, I think CDs should and could be offered cheaper, which could
also help to fight increasing pirating and illegal copies. The more expensive
segment would be to offer recordings in a higher quality, and maybe with a
lot of additional features (music-video, surround-sound, information about
composers, musicians and specific recording "histories", multimedia, "interactivity"...).
My proposals combine all the "versatile" DVD-possibilities with the elegance,
directness and transparency of DSD-recording, the modulation used in the SACD
standard. Secondly, DVD-Video, DVD-Audio and SACD can be offered combined on
ONE disc, effectively unifying the market of the three CD-successor formats.
Every record label can decide independently in which format(s) their records
should be published. I think the hybrid SACD/DVD proposals are helpful to both
industry and customers. The music industry should consider this new hybrid
disc - which is compatible with DVD in its various forms and SACD - not only
for their own interest, but also for the best interest of THEIR customers.
(I think somebody is still needed to listen to music...). And perhaps, it could
also offer a solution to put an end or at least "ease" an otherwise fruitless
and costly format-war, which, in the worst-case scenario, could lead to the
complete failure of both formats at some point. In any case, a clear winner
in the "format-war" between DVD-Audio and SACD is not yet to be seen. This
time it is not a case like "VHS versus Beta". I think it is worse! Because
it doesn't look like any one of the competitors will vanish. Both offer advantages
and disadvantages, and both are backed by big electronic companies AND record
If only the recording-industry (and audio industry in general) could concentrate
on other things rather than in a fight between some incompatible standards,
and think in categories such as "high-resolution music", "surround-sound", "music-video", "bonus-material",
a combined DVD/SACD format seems immediately viable and logical.
Editor's Note: The new hybrid format is patent-pending.
1. Rumours about an extension of the SACD-standards ("SACD II"), which seem
to confirm that a "SACD with video" is planned, underline the significance
of the SACD/DVD proposals, at least a potential solution for this aim.
" SACD II" (only rumoured, not "official") might be realized in two ways:
a) SACD + "SACD-video" in the SACD "Extra Data Area". Such discs would be
realized probably as Dual Layer SACDs ("DVD-9"-version). In any case, it is
not possible to have a surround-version AND music video on a "hybrid SACD" with
CD-layer. There is not enough space for it on ONE HD-layer.
b) DVD-Video + "new audio standard" (based on DSD). This "idea" could be compatible
to DVD-Video, but would break "backward-compatibility" to SACD (I). It would
be equivalent to DVD-Audio/Video, which exists already now and doesn't need
The first variant is compatible to SACD, but introduces a proprietary video-standard.
The second proposal breaks SACD into two segments, and not any person I have
asked thinks it will or "should" happen.
A SACD/DVD-Video hybrid is a "SACD" and a "DVD-Video", combining the advantages
of a) and b). It works with existing players, and it is obviously a "100% compatible" hybrid
disc, respective to the used standards. It is hard to see where SACD II could
offer (functionally) "more" than a SACD/DVD-V.
Not having seen any "specifications" of SACD II (which isn't announced officially,
but rumoured, again!), I can't say anything about aspects like copy protection
or DRM-management of SACD II. However, Super Audio CD is an extremely well-protected
format already now, whereas "advantages" of DRM will remain "abstract" or even
questionable for customers.
2. Renewed efforts to introduce a DVD-A/CD will be reviewed if something "real" is
announced, which hasn't been the case. Even if the inventor has participated
in the discussion about DVD-A/CD hybrids with industry insiders, it is not
directly related to my own proposals here.
However, the new proposal contains as special variant also an SACD/CD/DVD
hybrid. You can manufacture such a disc, if you glue to the back-side of a "hybrid
SACD" (that is, an SACD/CD) a DVD half-disc, which itself can have one or two
This disc-form is (usually) thicker than a "standard DVD", or CD. Usually
the thickness will be 1.7mm, similar to the already known DVD-plus (DVD+CD).
Both disc-forms are facing similar compatibility-problems, therefore. To be
fair, the DVD-plus is a commercially available format, even if the discs are
always out of some specifications, also thinner forms of DVD-plus! However,
they work mostly, especially as "DVD".
To me, it looks very unlikely that we will see a DVD-A/CD as "single inventory
disc", that means, as a DVD-Audio which can be sold "as CD".
3. Last, but not least, I would like to put a link to a German Internet-article
on hybrid SACD/DVD, done by Mr. Ulrich v. Loehneysen and myself. (The
last picture visualizes in a highly understandable way both forms of "hybrid
SACD" discs! It's not possible to explain it easier, I think.)
Many thanks, to Ulrich v. Loehneysen, and to my colleague Joe Coronado for