Video
Guides > Capturing/Recording > Understanding Your
Source
Article last updated 2006
Before sitting down
to capture or encode video, it is important to
understand the source. What exactly is "source"?
Source is the tv broadcasts, VHS tapes, video cameras,
Internet downloads, etc. Every source has its own unique
properties that must be understood in order to edit and
convert it to a high-quality DVD.
Video is all about decisions. It is more art than science.
Understanding your source will allow you to select proper
encode/capture resolutions, the proper interlace
settings,
and proper color management techniques.
Several concepts are explained in this guide:
(1) Theory vs. application,
(2) Analog sources,
(3) Digital sources,
(4) Interlace vs. Progressive vs.
De-Interlace,
(5) Black and white versus color,
(6) Aspect ratio,
(7) Colorspace compression,
(8) Overscan, masking, cropping,
(9) and some playback considerations
NOTE: Although this site aims to avoid technical jargon,
this page will contain several new terms that will re-appear
all the time throughout the DVD creation process. All
attempts are made to explain video theory and technological
terms while using normal language, when available. Both info
tables are thick with jargon.
Theory
vs. Application
Understand that there is a difference between THEORY and
APPLICATION. It is a contest between what is supposed to happen
versus what really does happen. There are math formulas out there that can
precisely dictate what a digital resolution SHOULD be for an
analog source. However, in PRACTICE, these numbers are never
reached. These numbers will be mentioned below, but should
not be used for your calculations when deciding on a
resolution for your new DVD. Why is there a gap? It's quite
simple, really. Analog mediums, much like the analog
information stored on it, is imperfect.
These math equations are based on varying ideas, including
TVL and its 4:3 aspect. There are also variations to include
concepts like the Kell and Nyquist principles. All in all, this is best
left to scientists that like to argue. It has no real
concern to the hobbyists and non-pro videographers.
Digital is an exercise in precision, while analog was an
exercise in controlled chaos.
Analog
Source Resolutions
There are only two kinds of source: analog and digital.
Analog source comes from tapes or analog broadcast signals, and digital source comes
from computers, digital broadcast signals or digital cameras.
Analog source
cannot be measured in the same terminology as digital
source. While resolutions, bit-rates, audio levels, etc, are
rigid measurements in the digital world, this does not hold
true in the analog world. Analog sources are measured
differently, typically using various power and output
measurements. The following table uses approximate digital equivalents
for the various analog sources. The table presents both
IN PRACTICE and IN THEORY numbers for the digital
equivalents, with theory being the higher of the two.
Information presented on this chart currently reflects only the
USA NTSC video standard. PAL and SECAM standards (outside
the USA) may be added with a future updates. In most cases,
you can simply substitute x480 with x576 and get the PAL
variants.
| Format: |
Analog
Measurement: |
Digital
Equivalent: |
Audio
and
Other Info: |
Suggested
Capture Size: |
| Broadcast
antenna television and analog cable |
Up
to 4.2 MHz, drop-frame 60hz power cycle, 300-340 lines
of resolution, interlaced |
350x480
to 400x480 interlaced |
29.97fps
NTSC, audio approximately 44.1kHz, 4:2:2 sampling |
352x480 |
Satellite
(DSS,DVB)
and digital cable |
Interlaced
digital signal, encrypted |
352x480,
412x480, 480x480, 544x480, 640x480, 704x480, 720x480,
and many others. Depends on provider and channel |
29.97fps
NTSC, audio can be MPEG audio or Dolby AC3 audio,
often at 44.1kHz, 4:2:0 and 4:2:2 sampling |
352x480
or 704x480
or 720x480
|
| VHS |
Up
to 3.0 Mhz (very weak), 240 lines of resolution,
interlaced |
250x480
to 300x480 interlaced |
29.97fps
NTSC, HiFi audio about 44.1kHz, 4:2:2 sampling |
352x480 |
Super
VHS
(S-VHS) |
Up
to 5.0 Mhz (very strong), 400-425 lines of resolution,
interlaced |
400x480
to 500x480 interlaced |
29.97fps
NTSC, HiFi audio about 44.1kHz kHz, requires S-VHS
player or SQPB, 4:2:2 sampling |
352x480
or 704x480
or 720x480 |
Super
VHS ET
(S-VHS-ET) |
Between
VHS and S-VHS measurements, interlaced |
Between
250x480 and 500x480, normally 350x480 |
Same
as S-VHS, use high grade VHS tapes only, 4:2:2
sampling |
352x480 |
| Betamax |
250
lines of resolution, interlaced |
Similar
to VHS |
This
is not the same as Betacam SP, 4:2:2 sampling |
352x480 |
| Betacam
SP |
Up
to 7.5 Mhz, 360 lines of resolution |
400x480
to 500x480, interlaced |
High
bandwidth used for color retention
and saturation |
704x480
or 720x480 |
| 8mm |
Similar
to VHS, interlaced |
270x480
to 300x480 |
29.97fps
NTSC, 4:2:2 sampling |
352x480 |
| Hi8 |
Similar
to S-VHS, interlaced |
Similar
to S-VHS |
29.97fps
NTSC, 4:2:2 sampling |
704x480
or 720x480 |
| Digital
8 |
Interlaced
digital DV signal |
DV
720x480 |
This
is digital data on an analog tape, 4:1:1 or 4:2:0 DV
sampling |
N/A
DV 720x480 |
| Laserdisc |
Up
to 5.0 Mhz, 400-425 lines of resolution, interlaced |
528x480
and 544x480 |
Analog
video on a digital media. Audio can be stored in an analog
track or in a digital track (Dolby AC3, DTS). 29.97fps NTSC, 4:2:2 sampling |
704x480
or 720x480 |
Analog source notes:
- Digital cable: Not all digital cable is a digital signal. Sometime it is a digitally-compressed analog signals being decompressed by the digital cable box. Check with your cable provider to see what you have. Although satellite systems are digital signals, encryption prevents them from being downloaded. The only way to legally record digital satellite is by using analog methods. Satellite is either on or off, and cannot be harmed by static or other noises that affect cable or broadcast. DirecTV and DISH Network typically use 544x480 and 480x480 resolutions.
- VHS/S-VHS History: The Video Home System (VHS) format was invented by Victor Company of Japan
(JVC) in 1976. Super VHS (S-VHS) format is a 1987 JVC invention that made use of s-video (“separated-video” cable that separates luma from
chroma) and incorporated a denser particle mixture on the tapes.
- S-VHS-ET and SQPB: Although some VHS units allow SQPB (S-VHS quasi-playback), it is still a VHS-quality signal being broadcast from a VHS player. VHS VCRs are unable to extract all the S-VHS information, so use an S-VHS player for S-VHS tapes. S-VHS-ET is the official name given to an old cheap trick used by many poor or cheapskate S-VHS users. In the old days, we would drill or burn holes in a VHS cassette housing, as S-VHS tapes have holes that VHS tapes do not, thus allowing players to know the difference in the equal-size tapes. In the past few years, JVC labeled it S-VHS Extended Timebase (ET mode) and has put the option onto its recorders. A VHS tape actually has more signal bandwidth available than is used by VHS players. However, it is not quite as good as a regular S-VHS tape. I highly suggest
JVC, TDK EHG or any broadcast-quality VHS tape for S-VHS-ET use.
- Satellite tv: Satellite tv is a mutant
form (DVB/DSS) of the now-popular MPEG-2 video format. Satellite
centers (like the DirecTV location in Colorado, or the DISH
centers in Wyoming and Arizona)
encode the video to MPEG-2, uplink it to a satellite, and it
is then resent to Earth and intercepted by the digital
dishes on our roof. Because the original digital files
cannot be accessed (due to encryption), footage must be captured from the analog
output given off by the satellite receivers, and this is why
"digital" satellite has been included in this
analog source list. It is often "higher
quality" than cable or broadcast because it is a
digital signal, and cannot be harmed by static or other
noise than affects cable and broadcast, and therefore
appears cleaner and crisper. Satellite signals
are either on or off (excluding macroblocking and freezing
due to signal interferences as caused by weather or aerial
objects). Some DVB and FTA signals can be
captured directly with acquisition cards (not really
capture, more like downloading data). This is because the
information is not encrypted. More information on digital satellite broadcasts can be found at:
http://www.coolstf.com/mpeg and
http://www.henry-davis.com/CSD9512:MPEG.html
Digital
Source Resolutions
Digital source is already digital. It has rigid limits,
specifications of acceptability, and resolutions and
bit-rate. Everything about a digital file can be quantified
and qualified, unlike analog. Digital formats like VCD and
DVD must adhere to certain specifications. This chart is
completely technical, contains all information about the
spec. Newbies may not understand all of this information
just quite yet, but it will be important to refer back to
when capturing, encoding and authoring.
This information appears in this "understanding your
source" guide mainly for comparisons purpose to the
analog chart above, as well as for those that desire to edit
or re-convert video already in the digital domain.
| Video
format |
File
Format |
Resolutions |
Video
bit-rates |
Audio
specs |
| DVD-Video |
MPEG-2,
sequence headers at each GOP, 4:2:0, MP@ML |
=
NTSC (4:3): 352x240, 352x480, 704x480, 720x480
= NTSC (16:9 widescreen): 704x480, 720x480
= PAL (4:3) 352x288, 352x576, 704x576, 720x576
= PAL (16:9 widescreen): 704x576, 720x576 |
Up
to 10.08Mb/s total combined bitrate. Up to 9.8Mb/s max
video bit-rate. CBR, CVBR, or VBR |
=
(1) AC3 Dolby Digital stereo or surround. Average AC3
stereo is 192-384k. Average surround is 448k or
higher.
= (2) LPCM uncompressed 1536k WAV/AIFF.
= (3) DTS, same bit-rate as AC3.
= (4) MPEG Layer II (MP2) stereo, 192-256k
bit-rate, not officially supported in the spec |
| DVD-Video |
MPEG-1,
sequence headers at each GOP, 4:2:0, MP@ML |
=
NTSC (4:3): 352x240
= PAL (4:3): 352x288 |
Between
1.150Mb/s and 1.856Mb/s CBR video bitrate |
Same
audio spec as MPEG-2 version |
| VideoCD
(VCD) |
MPEG-1
(4:2:0) |
=
NTSC (4:3): 352x240
= PAL (4:3): 352x288 |
Exactly
1.150Mb/s CBR total video/audio bit-rate |
Exactly
224k MPEG Layer II (MP2) audio |
| Super
VideoCD (SVCD), Chaoji VCD, China Video Disc (CVD) |
MPEG-2
(4:2:0) |
=
NTSC: (4:3) 480x480
= PAL (4:3): 480x576
= CVD uses 352x480 or 352x576 resolution variant |
Up
to 2.520Mb/s VBR max, total combined video/audio
bit-rate |
Exactly
224k MPEG Layer II (MP2) audio |
| XVCD |
MPEG-1
or MPEG-2, not an official "standard" |
Any,
standard disc and DVB/VR resolutions suggested |
Any,
but max 2.520Mb/s is suggested, usually VBR |
Any,
MP2 suggested |
MiniDV,
DV25, consumer DV
|
DV25
codec AVI, 4:1:1 (USA) or 4:2:0 (PAL) |
=
NTSC (4:3): 720x480
= PAL (4:3): 720x576 |
25Mb/s
combined audio/video (5:1 compression) |
LPCM
1536k uncompressed audio |
| MPEG-4,
XVID, DIVX |
FourCC
AVI codecs, often used to share files online |
Varies,
but standard resolutions includes 640x480 and 512x384
for 4:3 content |
Varies |
Typically
AC3, OGG, MP3 and MP2, stereo or mono |
| Other
formats |
Digital
video has an near-infinite amount of bit-rate,
resolution and format combinations. Other formats
include RealMedia, QuickTime and Windows Media Video (WMV).
|
Depends
on the format |
Depends
on the format |
Depends
on the format. Many formats have dedicated audio
streams. |
How to
analyze digital files:
If you're not sure what kind of file you have,
run it through the Gspot
Codec Information Appliance (use version 2.52 or higher).
As long as the file is not corrupted, it will reveal every
aspect of the file. In the example below, GSPOT show the
video file to be an MPEG-2, interlaced (I/L) top field first
(TFF), 4:3 NTSC 352x480, with 256k AC3 audio, and that
codecs are installed on the computer, allowing players and
encoders to identify the source.

Interlace
vs. Progressive vs. De-Interlace
What is interlace?
Interlacing is the method used to
play back footage on a television set. Two images are
simultaneous shown per frame, drawn in a comb method (see
images in the table below). As one
image is being drawn, the other is fading away, awaiting the
redraw cycle by the electron beam. So while it is about 30
interlaced frames per second, it's really about 60 images
per second in the weaved pattern. Interlace
"frames" are technically referred to as
"fields".
This comb pattern is only visible on a progressive
display device.
Since most people plan to view the final video on
television, it must be interlaced to retain quality. Most sources in use today
are interlaced.
Unless it was created on a computer or is an official
release of a film, then odds are that the source is
interlaced. All broadcast television, cable, satellite,
VHS, S-VHS, Beta, Laserdisc, 8mm, Hi8, Digital8
and most DV sources are interlaced.
In the digital world, only some AVI MPEG-4 codecs and MPEG-2
support interlace. The interlace barrier for MPEG-2 is at
the approximate x280 resolution. VCD and other lower-end
formats do not have the luxury of interlace.
What is progressive?
Separate images shown in progression to give the feel of
motion. All film source is progressive. Film is nothing more than a
series of still images shown one after the other. This is
progressive.
What is de-interlace?
De-interlacing is the process of
converting interlaced source into progressive source. It
is commonly referred to as de-interlaced source, but that is
a misnomer, though common
lingo of the day among hobbyist videographers. De-interlacing loses data.
It's
that simple. A de-interlace basically throws away parts of
the video signal or blends it together with other parts of
the video signal. It destroys interlaced footage. The only
use gained by de-interlacing is to remove combs on a
progressive display that has no access to on-the-fly
de-interlacing software or hardware. My biggest pet peeve is people that
mindlessly de-interlace interlaced footage. Too many users
just hit the "go" button in their software, and
never consider the source, the capture method or the actions
of the software. Recording in the wrong format will look bad
and lose quality.
There are only a few situations where de-interlacing is
necessary, and most hobbyists will never find themselves in
those situations, especially since the current trend is
converting old VHS to DVD or recording from television
directly to DVD.
There are several rules to follow: (1) Always match your
source when capturing. This means capture
interlaced footage as interlaced. And capture progressive
source as progressive. (2) Always match the output
device when encoding. This means you should
encode for viewing on the desired device. Encode interlaced
for viewing on an interlaced viewing device (tv). Encode
progressive for viewing on a progressive display (computer
monitor). Most
people should be capturing and encoding interlaced !!!
There are several ways to accomplish a de-interlace:
- Drop field. This is often known as the EVEN or ODD de-interlace
filters, as it drops the EVEN or ODD fields from the image.
-
Merge fields. This merges too fields together. This is
often called DOUBLE or BLEND in software.
-
Bob. This is not really a de-interlace filter at all,
but rather a method of playing all 59.94 fields per second,
one after another on high-frame-rate progressive devices.
However, without proper aspect being forced, it will revert
to half-height images because a field is only half of the
frame. The ATI All In Wonder card with ATI MMC use the
"bob" filter during capture preview and playback
of live source (the aspect ratio is maintained to avoid
re-size).
- Adaptive. This is a method that removes the
comb-teeth effect, but still has drawbacks with
stair-stepping and occasional blurring. Software players
like WinDVD and PowerDVD use this filter.
- Telecine. Telecine is a fake interlace used to
make 24fps film appear normal on 29.97fps interlaced display devices like
television sets. It can easily be removed with an IVTC
(inverse Telecine) filter found in many software encoders.
This will often restore the video to its original
progressive state, as well as remove extra frames inserted
to the Telecine process.
However, this being said, not all movies started as
progressive film source.
IVTC will often still leave de-interlace artifacts, just not
as many as a raw de-interlace. And once source has gone onto
analog tape or broadcast, it is interlaced from then on. The
telecine trick mainly works on converting existing DVD
footage.
NOTE:
The images below are untouched. They are simple screen
captures and the artifacts shown are full-size. These are
not blown up, but are in fact actual size (I cropped down on
his face only). What you see below will be very noticeable
on both a television and computer.
 |
 |
 |
| This
is the untouched image, a still scene from interlaced
source captured in interlaced format. Notice the
smooth curved lines, free of errors. This is how an
interlaced image will look on an interlaced display. This is good! |
This
image has had a drop field de-interlace. Half of the
video material was thrown away. Both ODD and EVEN
filters look about the same. Notice the stair-step
effect on the lines and loss of linear detail. This
is bad! |
This
is an advanced filter, often called an
"adaptation" filter. It is a variation of
ODD or EVEN, but still drops data and still throws out
video signal information. It has decent linear detail,
but the stair-step effect is still present. This is
not great! |
 |
 |
INT:

DE-INT:
 |
| This
is the raw interlaced image captured from interlaced
source. While it looks ugly on a computer monitor,
it will look fine on a television screen, as shown
in the reference image on the far right. Interlaced
footage is two images (fields) per frame. Only one
image at a time will appear on an interlaced display
device. This is good! |
This
is a blend (also called merge or double)
de-interlace filter. It will compress the two images
into one image, causing the ghost effect seen above.
This is bad! |
Reference
images of what is actually shown on the tv. |
Few more
notes on interlace:
- Progressive cameras. Though typically interlaced, some
video cameras can actually shoot progressive video. And even
in those cases, the camera normally comes with interlaced as
the default shooting method. It requires you to knowingly
alter the camera to shoot in some progressive mode. Beware:
Be aware of the frame rates too! Do not assume the
progression is full NTSC or PAL fps! And other "progressive" devices have been known to blend
fields to get the progression!
-
A computer monitor is a progressive display device. Only
encode progressive if you only plan to view it on a computer
or plan to create a progressive format like VCD.
Common questions and misconceptions:
Q1: I should de-interlace because I
want to watch it on my computer too?
A1: No. This is not true. All software DVD players come
equipped with "bob" or "adaptive" de-interlace filters.
You're better off with playback software that uses these
instead of using one of
the odd/even or blend/merge/double filters.
Q2:
De-interlace looks just fine on my interlaced footage?
A2: Not only is this a very subjective opinion, but you will
find yourself in the minority with that outlook on
video. As shown in the example above, de-interlacing
has a very negative affect on video quality.
Q3: My software gives no interlace/de-interlace option, so
it must be fine?
A3: While most good capturing and encoding software allows
for some choices in de-interlace or interlace, some do not. I suggest you carefully learn which method it
uses, or suggest dropping it for better software.
Software like WinDVR and PowerVCR II are notorious for not
giving users an option and capturing with merged fields. The
ATI MMC is known to come setup with drops, but can easily be
changed to interlace in the software options.
Q4: My software only gives an option to
"de-interlace" so what is it doing ?
A4: Almost all software that merely gives
"de-interlace" as the option will drop the even
field, with few exceptions to the rule.
Q5:
Want to learn more about
interlace theory ?
A5: Visit www.100fps.com
B&W vs
Color
When capturing
black and white source, it is highly suggested that you
either purchase a color-removal device like the Sima SED-CM,
or use a proc amp. Or if available in the capture software
(or at the encoding stage), remember to de-saturate the color 100
percent. Color
information is still present in B&W analog material. For
the cleanest, most true conversion, remove the color. Modern
VHS tapes and analog broadcasts tend to add a hue to the
B&W footage, often giving it a nasty green, red or
yellow tint. This is because analog color tv is actually
just a hack/variation of the original black and white tv
sets. NTSC television today is not really true color, but
color squeezed into a black and white signal. PAL tv can
have the same problems, though for different reasons
(source). Old film naturally turns brown or yellow with age,
and can still be seen on sloppy conversions.
Aspect
Ratio
Aspect ratio is the
dimension of length times width (L x W = AR). All fullscreen
video for
tv should playback at 4:3 ratio (widescreen content is
usually 16:9 aspect). This meaning the image is 4
units wide by 3 units high, measured with a ruler. For example, on a 19-inch tv set
(which was measured diagonally), that would show an image of 16 inches
wide by
12 inches high. It will fill the tv screen
with video. 16:12 is a ratio of 4:3. In this case, the 4:3
units were 4 inches. This may also be referred to as DAR, or
Display Aspect Ratio. Although a resolution like 480x480 may
seem to infer a square image, the pixels are rectangular and
not square. This is where the confusion often lies. Thus
480x480 is still a 4:3 image, when viewed on screen. Same
for other resolutions. Although 720x480 may look long and
flat, or 352x480 tall and skinny, both use pixel shapes that
display properly at 4:3, assuming the player respects the
4:3 information.
Colorspace
Compression
This is actually quite a bit more complex of a topic, but
for the purpose of introducing new concepts, this will
suffice:
Digital video image data is stored in
YUV format. Each of these contains data (the Y, the U and the V),
though not required to contain the same
amount of data. The "Y" is called luma, and stores
the main information. The "U" and "V" is chroma and provides additional
color information. You may also see YUV referred to as
YIQ or YCrCb.
The compression rate of YUV is
represented as Y:U:V in numbers. Some common ones:
4:4:4 = Uncompressed. Equal number of samples of Y, U and V.
4:2:2 = U and V are horizontally half of Y.
Used for VHS/cable/broadcast, etc.
4:2:0 = U and V are both vertically and horizontally half of
Y.
Used for DVD MPEG and DVB.
4:1:1 = U and V are both vertically and horizontally
one-quarter of Y.
Used in NTSC consumer DV.
Human eyes give the most important to the first two numbers
(1ST:2ND:3RD). The 3RD digit is not terribly important, and
is why it can be compressed to a ZERO value with little
visible disadvantages. The 4:1:1, however, does tend to
compress color information in the visible domain, and is why
it's often disliked by more advanced videographers and
professional video editors. It's a consumer format, and
definitely not a perfect one.
This is being added to this guide solely to demonstrate the
concept, as well as suggest high quality editors seek
formats other than consumer DV25, either for shooting, or as the
conversion method. Many of the newer consumer camera come
with 3CCDs (like Panasonic) or additional filters (like
Canon DIGIC technology) to suppress color compression loss,
so most consumers should be happy. For an analog-to-digital
conversion method (using devices like the Canopus ADVC-100),
DV is never suggested, far too lossy.
Overscan:
Masking and Cropping
What is
overscan?
A tv set only show about inside 93 percent of the available image.
The rest is hidden behind the box surrounding the tube. This
is called overscanning. Broadcasters and others in
video know full well that this happens, so rest assured that
you are not missing much. In fact, the overscan area often
contains little more than black bars or video errors, and
should be seen as a courtesy moreso than a
hindrance. Recorded formats (VHS, S-VHS, etc) suffer
the most, in terms of overscan noise. Broadcast formats often have black bars in the
overscan. Most satellite streams have noise in the upper
overscan, visual residue from non-video parts of the data
stream.
You never see this portion of the image on a tv set, however
computers have no such mechanism. So, sadly, many
people feel they must "crop" or "mask"
out the noise. In most cases, it is simply a lack of
knowledge from amateurs online, thinking they have a
"bad quality" signal. So they seek to mask it,
which is fine. Or more often, crop it, which is undesirable.
Example:

In this image, the BLUE LINE denotes the overscan boundary.
Only the data inside of the rectangle will be visible on a
tv set. The data outside is not seen on the tv, though it
will likely be visible on a computer screen. Note the
timebase flaws at the top of the signal (skewed video), the
missing image data on the left side, and the crawling errors
at the bottom of the screen. Again, none of that will be
visible on a tv set, though it will be encoded into the
video file. Also know that every tv will differ in the exact
overscan position. Some may be slightly larger, slightly
smaller, or even positioned more to one side.
What is masking?
Masking is a photo/design term, and means to "cover
something up". In video, this usually means to put
black over a portion of the image, often to hide noise. ATI
MMC has a useful feature (as discussed in the ATI AIW
capture guides) that masks while capturing. Encoders like
Procoder and TMPGENC have mask options in the crop filters.
And NLE software like Adobe Premiere have masking via the
"clip" tools. Though masking serves no visual
benefit when watching on tv, it can cover up undesirable
noise when viewed on a non-overscan device (like a computer
monitor), without a harmful crop needing to be performed. It
may also help with bit-rate allocation, since the
bit-rate-gobbling noise is no longer present. MASK
ONLY WHEN NECESSARY!
What is cropping?
Cropping is the often-harmful practice of chopping off
part of the picture. For example, if you started out with a 400x300
video, and decided to crop 10 pixels off each side, and left it at 380x280, then it would still look fine. But that
is typically not what happens. More often, the person crops
10 off each side, then allows an encoder to stretch the
remaining image back to the 400x300 size, which blurs and
distorts the image in varying ways. Many people like to
download video clips and encode them to DVD for tv viewing,
only to discover part of the signal missing. This is due to
cropping done at the time of encode, which means black
borders must be added back to the video to restore the
overscan (this is yet another reason why downloaded Internet
files are low quality and terrible to work with). TRY
TO NEVER CROP VIDEO FILES!
Playback
Considerations
Much like source,
there are also only
two kinds of playback devices, analog and digital.
Analog playback devices are normally tv sets and projection
screens. Digital devices include computer monitors and HDTV
sets. If proper playback considerations are not made, analog
source played back on a digital device will look bad. And
the opposite holds true as well, whereas digital source
played back on an analog device can look bad. Digital source
and playback devices are typically progressive, while analog
is typically interlaced.
Playback on analog
devices (television set)
A television set is
not the same as a computer monitor. A tv has exactly 525
scanlines (NTSC) on the complete tube, with a resolution of about
300/500x480. The amount of horizontal resolution depends on
both the age and size of the tv set, with most of the 21-36
inch sizes carrying about 400 lines, whereas smaller sets
with less resolution and larger ones with higher
resolutions.
Although a tv set can playback progressive source, it will
not look as good as interlace source. A tv was made to
playback interlaced analog source.
Playback on digital
devices (computer monitor)
A computer monitor has nothing in common with a
television set. It's refresh rate, resolutions and
color-depth can be altered at will. A computer monitor is
progressive rather than interlaced. While monitor can
playback interlaced footage (often using DVD player software
like PowerDVD or WinDVD), it will not look as good as
playback on an analog device because varying de-interlace
playback filters must be used. The computer is a progressive
interface and does best with progressive playback.
What Does All This Mean?
Much of this page has been written in response to the disgusting bad habits so
many newbies seem to have, be it overkill on resolution and
bit-rates, mishandling of interlace, or needlessly cropping
and chopping video. Too many users insist on
using the highest bit-rates and resolutions on their video
project, insisting that is what it takes to make "top
quality" or "professional-quality" work. It
simply is not true. The information above shows the specs of
video used
in the video industry and on the devices in our own homes.
When working with video, carefully plan out the entire
project, and ignore no details. Before tearing into that new
software and clicking (or not clicking) on all the options,
learn what they mean, and when to use or not use them.
That's really all there is to it.
This is by far the most time-consuming and in-depth page on
the site. Donations have also compelled us to regularly update this
page with the best possible information. Your dollars do go
towards the continual advancement of pages such as these.
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