Q Give me an
overview of the HDV formats.
A The HDV format includes
the 720p and 1080i specifications. The 720p specification employs
progressive scanning with 720 vertical scanning lines (effective
scanning lines). The 1080i specification employs interlace scanning
with 1,080 lines. |
|
Q Isn't picture quality deterioration such as block noise
and errors usually a concern with MPEG-2?
A
Since a bit rate after compression of
25 Mbps has been achieved, the format allows very good picture
quality for recording and playback.
|
|
Q What companies support the HDV
standard?
A The HDV standard was
established by four companies: Canon Inc., Sharp Corporation, Sony
Corporation, and the Victor Company of Japan, Limited. Many
companies including most of the non-linear software manufacturers
have expressed their support for the HDV standard. For the latest
list of companies that support this format visit
https://www.hdv-info.org
|
|
Q What is the audio compression method for
HDV?
A The audio compression format is MPEG-1 Audio
Layer II. This format can compress and record a signal with a
sampling frequency of 48 kHz and quantization of 16 bits, at a bit
rate of 384 Kbps
|
|
Q Why are there so many companies supporting
HDV?
A This is because it is a based on the global
DV standard, and the same DV mechanisms can be used for HDV.
Moreover, since it employs the broadcast standard for image
compression, MPEG-2, it is possible to connect HDV devices with TVs
and personal computers.
|
|
Q Which has better sound quality, HDV or DV?
A With DV's 16-bit 2-ch mode sound and HDV's audio recording,
DV has better quality sound for the parts where compression is not
carried out. However, since HDV uses a very high bit rate (384
Kbps) for sound compression, the sound quality is almost on par
with uncompressed audio.
|
|
Q What kind of media is used for HDV?
A Conventional DV tapes are
used for recording in HDV.
|
|
Q Is the HDV sound quality comparable to a music
CD?
A Since HDV
audio is compressed, theoretically it is inferior to CD sound
quality. However, as mentioned above, by securing a high bit rate
after compression, the sound quality is almost on par with that of
a CD.
|
|
Q How long is the HDV recording time?
A It is the same as DV
recording time. Also, with the HDV 1080i specification, there is no
long- playing mode.
|
|
Q In the future, will the DV standard disappear and the
HDV standard become mainstream?
A Along with the widespread adoption of HD
broadcasting and HDTVs, it is expected that the HDV standard will
soon become the norm. However, DV is currently the mainstream as
far as price and the popularity of DV displays are concerned.
Nevertheless, there will soon be more models of HDV camcorders on
the market, and when the prices come down, HDV will likely replace
DV as the main standard.
|
 |
|
|
|
Q How is it possible that the large HD video data
quantity of HDV can be recorded in the same running time as the DV
standard on DV tape?
A Recording is possible in the same running time because
MPEG-2 is used. MPEG-2 is a compression system that can realize
high resolution even at a low bit rate by using information on
differences between frames.
|
|
Q What is the difference between 1080i and
720p?
A The 720p
specification employs progressive scanning with 720 vertical
scanning lines (effective scanning lines), and the 1080i
specification employs interlace scanning with 1,080
lines.
|
|
Q What is the difference between HDV and DV? Which has
better picture quality? HDV and DV have different image compression and tape recording
methods. Since HDV was developed in order to record and play back
high resolution HDTV video, HDV has higher resolution from the
standpoint of the number of pixels.
|
|
Q Why are there two specifications (1080i and 720p) for
the HDV standard?
A This is to enable the
development of products that meet different HD infrastructures
around the world.
|
|
Q What is the HDV video compression method?
A HDV uses MPEG-2 compression, and the bit rate after
compression for the 1080i specification is 25 Mbps.
|
|
Q Which has better picture quality, HDV 1080i or HDV
720p?
A The picture quality depends on the
specifications of the product. Select the specification that best
meets your needs.
|
|
Q Is it possible to record HDV and DV alternately on the
same DV tape?
A It is possible under the standard,
but it depends on whether the manufactures will develop their
products to allow mixed recording on the same tape.
|
|
Q How does the HDV error correction method differ between
1080i and 720p?
A The main difference is the
correction coding ratio, and the mechanism for error correction
over multiple tracks.
|
|
Q Can an HDV camcorder also record in DV?
This depends on the product specifications.
|
|
|
|
Playback and editing
|
|
|
|
Q If I play a DV tape containing an HDV recording on a
regular DV camcorder rather than an HDV camcorder, and then output
the signal to a TV, will it still be HD output?
A
Tapes with HDV recordings are only guaranteed for playback on HDV
camcorders. If you do try to do this anyway, either the video and
sound will not play back, or depending on the model, it will
determine that it is an HDV recording and warn you not to record
over it.
|
|
Q Can I upload HDV data to my computer and edit it? Is it
possible to edit both the video and audio just like with DV
data?
A This is possible if you have an HDV
application software on your computer. The type of editing will
depend on your software.
|
|
Q Can tapes recorded with the 1080i specification be
played back on a 720p-specification camcorder? Or vice
versa?
A It may not always be possible for a 720p
camcorder to play back a tape recorded in the 1080i specification,
and vice versa. Compatibility depends on the actual specifications
of the product.
|
|
Q Can I upload HDV data to my computer and then save it
on a DVD disc?
A If your HDV application software
allows you to convert the data to SD, you can save it as a DVD
video. Also, you can save it on a DVD data disk, which is the same
concept as data backup. However, in this case it will not be
compatible for use on a DVD player.
|
|
Q If I play an HDV recorded tape on an HDV camcorder, and
then connect it to a non-HD TV and output the signal, will it
provide better or worse picture quality than playing a DV recorded
tape?
A This depends on the product
specifications.
|
|
Q After uploading HDV data to my PC and editing it, can I
then write the data to a DV tape using the HDV or DV
standard?
A Either is possible if your HDV
application software permits it.
|
|
Q If I connect an HDV camcorder to a TV for playback,
which terminal should I connect to for the best picture
quality?
A
i.LINK(IEEE1394) connection is recommended.
|
|
Q What are the necessary PC specs to allow for uploading
and editing of HDV data?
A Pentium 4 3.06 GHz or
higher RAM: 256 MB or higher (1 GB or more is recommended) HDD:
UltraATA100 i.LINK terminal as standard equipment Display: XGA or
higher Video memory: 32 MB or higher Software: Windows XP SP2 or
higher * The above specifications are provided as a guideline. Be
sure to also check the specs required by the application
software.
|
|
Q Is it possible to store the data from a HDV recorded DV
tape on my PC hard drive? What format would the file
be?
A This is
possible using an HDV application software on your PC. The file
format will depend on your software.
|
|
Q How big is a HDV file when it is uploaded to a
computer?
A If the data is
uploaded in MPEG-2 format without conversion, the file will be
about the same size as a DV file of the same running time. A ten
minute video is about 2 GB.
|
|
|
|
What is
the different between HDR-FX1E and HVR-Z1
| |
Reading Material - About
HDV |
| |
|
“HDV: What You
NEED to Know” contains over 140 pages of HDV tech-talk,
illustrations, standards, and information about how High Definition
can be used by any video professional
Written by Douglas Spotted Eagle* and Mark Dileo*, this book is
packed with information about HDV for the videographer who wants to
move from Beta, DV, or analog into the pixel-packed world of
HDV. Illustrations depict how HDV is connected, edited,
converted, captured, and delivered in a variety of formats
including Blu-Ray,™ Standard Definition (SD) and Windows
Media Video-HD. Find simple explanations to complex concepts
relating to new pixel aspect ratios, different field order,
bandwidth, color space, MPEG-2, MPEG-1 audio, editing, codecs, and
lots more. |
| |
|
|
| |
|
Price : USD
24.99 |
|
Glossary
|
|
|
|
720p
The number "720" indicates the number of scanning
lines, and "p" indicates progressive scanning.
|
|
Hi-Vision
This is the name of the HDTV service developed by
Japan's NHK. Digital HDTV is also called Digital Hi-Vision in
Japan.
|
|
1080i
The number "1080" indicates the number of scanning
lines, and "i" indicates interlace scanning.
|
|
i.LINK
This is a standard for connecting computers to
peripheral equipment. The name i.LINK is a nickname for IEEE 1394
developed by Sony. It allows up to 63 devices to be linked
together, and has a maximum transmission speed of 400 Mbps. It has
the advantage of providing power through the connection cable, as
well as a hot plug (able to connect or disconnect without cutting
the power to the device). It is used to connect with DV camcorders.
In the DV standard i.LINK is called a DV terminal.
|
|
Aspect ratio
The aspect ratio is the ratio of the screen width
to height. Conventional TVs have an aspect ratio of 4:3, while HDTV
has a wider ratio of 16:9.
|
|
|
ATSC
This stands for "Advanced Television Systems
Committee," a committee composed of private companies that make
digital TV policies in the US. ATSC is also used to indicate the
digital TV broadcast format set by the same committee. There are
standards for both terrestrial and cable TV
broadcasting.
MPEG-2 is the video
standard, and Dolby AC-3 is the audio standard.
|
|
Interlace scanning
Interlace scanning is a method that can produce
two images in a single scan, by scanning every other line. For
example, if there are 480 scanning lines, only the oddnumbered
lines are scanned for the first image (1, 3, 5, ... 479), and all
the even-numbered lines are then scanned for the next image (2, 4,
6, ... 480). Interlace scanning has the advantage of displaying
smooth movement. However, the disadvantage is that strictly
speaking the resolution for each image is lower.
Interlace scanning is
mainly used for TV broadcasts. The reason for this is that if the
image continuity is high and interlace scanning can provide
smoother movement as mentioned previously, while the frequency
range is limited, it is adopted since the reduced resolution is not
very noticeable.
|
|
Blu-ray Disc
This is the optical disk developed by Sony,
Panasonic, and Phillips. On a disk the size of a regular DVD, 27 GB
of data or six times the data of a DVD can be stored. Using this
technology for recording, it is possible to maintain the quality of
HDTV content.
Compression
A generic term for any technology that enables data to take up less
space. Compression can be applied to data files, images, audio, or
video. Lossless compression is used for software, text
files, or any application where all the original bits must be
retained when a file is decompressed. Lossy compression is
most often used for digital audio, video, or images, where some of
the original data can be sacrificed to reduce large file sizes.
Lossy compression degrades the quality of the original data
somewhat. But the smaller file size makes the data much easier to
store and faster to transmit.
Composite
Video
A type of video signal in which all the necessary video information
is combined into one signal. This is the type of signal used for
broadcast TV in the United States. Most computer monitors use RGB
video, in which the red, blue, and green signals are sent
separately to produce a sharper image
|
|
ISDB
This stands for "Integrated Services Digital
Broadcasting", which is an HDTV broadcasting system based on a
digital format developed by the NHK Science & Technical
Research Laboratories (NHK STRL) in Japan. It includes terrestrial
and satellite transmission standards, and the main types are ISDB-T
for terrestrial digital, ISDB-S for satellite digital, and ISDB-C
for cable digital broadcasting.
For all of these
standards MPEG-2 is used as the video coding, while MPEG-2 Advanced
Audio Codec (AAC) is used for the audio coding. It has the
advantage of allowing the use of common receivers regardless of the
transmission format, as it is offered together with services such
as EPG and data broadcasting.
|
|
|
|
|
Component terminals
These terminals transmit each of the three video
chrominance difference signals: Y (luminance signal), R-Y (signal
of red signal minus luminance), and B-Y (signal of blue signal
minus luminance), through separate cables. Since three cables are
used, the terminals are also divided into three.
|
|
MPEG-2
MPEG means "Moving Picture Expert Group", and is
the name of the organization that developed the standard for
recording video and audio as digital data. It also indicates the
video and audio digitalization standard created by the same
organization. MPEG-2 is one of the standards developed by this
organization, and is used in various fields including DVDs and
digital broadcasting.
|
|
Digital cable television
This is broadcasting through digitized cable
signals. The digital cable TV standard includes ISDB and
DVB.
|
|
MUSE
This stands for "Multiple Sub-Nyquist-Sampling
Encoding", which is an HDTV broadcasting system based on an analog
format developed by the NHK Science & Technical Research
Laboratories (NHK STRL) in Japan. This format was a precursor to
today's HDTV system.
|
|
Digital satellite broadcasting
This indicates digital broadcasting from man-made
satellites orbiting the earth. The digital satellite broadcasting
standards include ISDB and DVB.
|
|
NTSC
This is the SDTV broadcasting format established
by the "National Television Systems Committee" in the US. It uses
interlace scanning with 525 scanning lines and a frame frequency of
30 Hz.
|
|
D terminal
This is a terminal that can transmit the three
chrominance difference signals that make up the video signal: Y
(luminance signal), R-Y (signal of red signal minus luminance
signal), and B-Y (signal of blue signal minus luminance signal), in
one cable. Its name comes from the fact that the shape of the
terminal looks like the letter "D." The types of terminals
include the D1 terminal for 480i, the D2 terminal for 480p and
480i, the D3 terminal for 1080i, 480p, and 480i, and the D4
terminal for 720p, 1080i, 480p, and 480i. In order to transmit the
HDTV video signal, the devices at both ends need to have D3 or D4
terminals.
|
|
Number of effective scanning
lines
This is the number of scanning lines that actually
produce the image on the screen.
|
|
PAL
PAL is an abbreviation for "Phase Alternation by
Line", which is an SDTV broadcasting format developed in the former
West Germany. It uses interlace scanning with 625 scanning lines
and a phase frequency of 25 Hz.
|
|
DVB
This stands for "Digital Video Broadcasting", and
is the digital TV broadcast format developed by the DVB project
established jointly by European manufacturers. It includes
standards for terrestrial, satellite and other forms of
transmission, and the main standards include DVB-T for terrestrial
digital, DVB-S for satellite digital, and DVB-C for cable digital
broadcasting. MPEG-2 is used as the standard for video coding, and
MPEG-2 Layer I and II are used for the audio coding standard. DVB
is not just for HDTV, but also provides a lot of services that use
the data reduction benefits of digitalization to create multiple
channels.
|
|
Progressive scanning
Progressive scanning is a display method where
lines are scanned in order from the first to the last, and one
image is produced with one scan. It is also called non-interlace
scanning. For example, if there are 480 scanning lines, the lines
are scanned in order from the first to the 480th line. The
advantage of progressive scanning is that a picture without
flickering can be achieved.
|
|
DV standard
This is the standard for videocassette recorders,
which can record images and sound in the digital format on special
compact tapes. It has the advantages of good quality through
recording in the digital format, and high compatibility with
computers.
|
|
RCA pin
This is the connector used for composite video /
audio, and component terminals. It was developed by RCA in the
US.
|
|
Field
A field indicates one image under the interlace
system. With interlace scanning, one image is one field, that is to
say, there are two fields in one frame.
|
|
Resolution
Resolution indicates the level of the picture
quality. When the resolution is high, then the picture clarity is
also high.
|
|
Field frequency
Field frequency indicates the number of fields
produced in one second.
|
|
Scanning
Scanning involves the movement of light points to
produce TV images. TV pictures are produced by the movement of
points of light, which create afterimages. The points of light move
from the left to the right side of the screen's top row, and then
repeat this movement in the next row from left to right. Once the
right side of the bottom row is reached, one image has been
completed.
|
|
Frame
A frame is an image unit where all the scanning
lines are scanned. Since one image is produced with one scan under
progressive scanning, one frame equals one image. However, with
interlace scanning, one frame equals two images, as two images are
produced with a single scan.
|
|
Scanning lines
This is the line created by the points of light
moving from left to right across the TV screen. The larger the
number of scanning lines, the sharper the picture.
|
|
Frame frequency
Frame frequency is the number of frames produced
in one second.
|
|
SDTV
SDTV stands for "Standard-definition Television",
indicating the usual TV picture quality before the development of
HDTV. It is a TV broadcasting standard with an aspect ratio of
4:3.
|
|
|
|
|
HDTV
HDTV stands for "High-definition Television",
which is a new TV technology that provides more realistic images
than conventional televisions. In order to increase the feeling of
realism, a high level of resolution needed for larger screen TVs
has been achieved, along with the adoption of a 16:9 aspect ratio.
Furthermore, HDTV is a next-generation television broadcast
standard that is a complete departure from the existing broadcast
formats of NTSC, PAL, and SECAM.
|
|
SECAM
This is the SDTV broadcasting format developed in
France called Sequential Couleur A Memoire (Sequential Color with
Memory). It uses interlace scanning with 625 scanning lines and a
frame frequency of 25 Hz.
|
|
HDTV standard for studio
production
This is the standard for studio production to
allow easy international exchange of HDTV content. It establishes
standards for the HDTV video signal including the number of
scanning lines. All the HDTV broadcasting formats follow the studio
standard so that video content can be easily exchanged from one
region to another, even though the broadcasting formats
differ.
|
|
S terminal
This is a terminal that can separate the video
signal into luminance and color signals before transmitting
them.
|
|
HDV standard
This is the videocassette recorder standard that
can record and play back HD (aspect ratio of 16:9) video and audio
using widely available DV tapes. Since it employs the MPEG-2
compression system, it can record in the same running time as the
DV standard, despite the higher resolution involved. HDV includes
the 1080i specification using 1,080 effective scanning lines
(interlace), and the 720p specification with 720 lines
(progressive).
|
|
Terrestrial digital broadcasting
This is digital broadcasting from TV towers built
on the ground. The terrestrial digital broadcasting standards
include ISDB, DVB, and ATSC.
|
|
HDV Specifications
|
|
Under the HDV standard,
there are two types of HD recording systems. The first is the 720p
specification featuring 720 effective scanning lines (progressive
scanning) and 1,280 horizontal pixels. The other system is the
1080i specification with 1,080 effective scanning lines and 1,440
horizontal pixels. Therefore, the necessary high-resolution
recording and playback system has been established for the true HD
age.
|
| |
HDV (1080i specification) |
HDV (720p specification) |
DV |
| Media |
DV tape
|
| Video
signal |
1080/50i and 1080/60i |
720/25p, 720/50p,720/30p, and
720/60p |
576/50i (PAL) and 480/60i
(NTSC) |
| Number
of pixels |
1440 x 1080 |
1280 x 720 |
720 x 576 (PAL) and 720 x 480
(NTSC) |
| Aspect
ratio |
16:9 |
4:3 (16:9) |
| Compression (video) |
MPEG-2 Video (Profile &
level: MP@H-14) |
DV |
| Sampling
frequency for luminance |
55.6875 MHz |
74.25 MHz |
13.5 MHz |
| Sampling
format |
4:2:0 |
4:2:0 (PAL) / 4:1:1 (NTSC) |
| Quantization |
8 bit |
| Bit rate
after compression (video) |
25 Mbps |
19 Mbps |
25 Mbps |
| Compression (audio) |
MPEG-1 Audio Layer II
|
48 kHz / 44.1 kHz (2-ch mode) 32 kHz
(4-ch mode) |
| Sampling
frequency |
48 kHz
|
48 kHz / 44.1 kHz (2-ch mode) 32 kHz
(4-ch mode) |
| Quantization |
16 bit
|
6 bit (2-ch mode), 12 bit non-linear
(4-ch mode) |
| Bit rate
after compression (audio) |
384 kbps |
1.5 Mbps |
| Audio
mode |
Stereo (2-ch) |
Stereo (2-ch) / Stereo x 2
(4-ch) |
| Data
format |
MPEG-2 system |
|
| Stream
type |
Packetized elementary
stream |
Transport stream |
|
| Stream
interface |
IEEE 1394
(MPEG-2-TS) |
IEEE 1394 (DV) |
| |
|
|
|
Aspect ratio :
Width and height ratio of the picture
Sampling frequency : The unit for measuring
the number of times a data sample can be output in a second,
when
converting analog signals to digital data.
Sampling format : This indicates the
frequency ratio allotted to three chrominance difference signals: Y
(luminance signal),
R-Y (signal of red signal minus luminance signal), and B-Y (signal
of blue signal minus luminance signal),
when converting analog video to digital data.
Quantization :
This indicates what level value to express the data sample with (16
bit is expressed with 216 = 65,536 level)
Bit rate : This
means the amount of data used in one second (1 Mbps means 1 megabit
of data is used in one second)
Data format :
This is the standard used when recording video and audio as digital
data.
Stream type :
This is the system for combining video and audio data into a single
set of data in the MPEG-2 system.
Stream interface
: Data transmission standard
|
