Format wars are common today
But this one should'nt even be.
Beautifully interlaced DV camcorder footage
"I am amazed that anybody would
consider launching new services based on interlace. I have spent all of
my life working on conversion from interlace to progressive. Now that I
have sold my successful company, I can tell you the truth: interlace to
progressive does not work!” - Yves FAROUDJA
Once upon a time, interlaced video was a fantastic idea, a beautiful trick that brought 2 things :
1 - Use half the bandwith for transporting a given resolution : only
half the picture (this is called a field) is transmitted for each frame
(even lines first, then odd ones, and so on).
At that time, the diffusers had also the ability to BE "interlaced" :
cathod ray tubes (CRTs), beamed only even lines at first, then odd
ones, by just ajusting the electronic beam displacement.
2 - If the "scan lines" are close enough, even a single "half-frame" is
seen by the eye as an entire one : so a moving object, thus split in 2
different "half-images", produces a 2-times-faster, 2-times-smoother
animation (the whole image is animated at 25Hz (for PAL), but the
half-images are animated at 50Hz) : You can see perfectly smooth
scrollings only on CRTs (25Hz is not enough).
But now we are in the 21st century.
Digital panels are going to replace old CRTs, trading interlaced nature for progressive.
This has not only advantages, but anyway it is a fact.
On the other side, video camera sensors are ALSO progressive by nature
: filmed images are not "scanned", but "stamped" on the sensor(s).
More, video is often digitally modified (special effects for instance) : al this is added in a "naturally progressive" way.
Nevertheless, for some reason I will try to explain later, some people want to sell us progressive video : 1080i
They propose us to gain some more resolution, regardless to whatever we lose for that :
1 - Images being progressive by nature, "interlacing" is an artificial
process : Pixar masterpieces like Toy Story have to be CONVERTED (or
recomputed but I don't think so), to create a nonsense interlaced video
DVD (yes I checked) :
Wonderful Toy Story with awful FORCED interlacing !
2 - Such resolution forces to continue using lossy color encoding schemes like 4:2:0
3 - Diffusers being progressive by nature, converting back the
interlaced signal to a progressive one require complex and costly
manipulations that will lead anyway to an unpredictable result.
4 - All this (crap) to gain some more resolution that will hardly be
seen on giant displays (I have to make a real effort to distinguish
pixel structure in 720p on my 2-meters-wide screen, at a viewing
distance of 3 meters - and I consider myself as a perfectionist)
So what are the reasons for this ? Let me try to found explanations :
- Companies want to continue using/sell their "interlaced" (low bandwidth) stuff (see below)
- They want us to buy "full HD" displays
- They want us to buy deinterlacers (chips)
..and overall : 1080i is CHEAPER ! :
In fact, 1080i "high-definition" camcorders record each
frame in 1440x540 (instead of the advertised "full-HD" 1920x1080),
compressing the
video even more than DV, still in lossy 4:2:0.
For reproduction, each frame is then streched horizontally and
vertically deinterlaced, "blendind", "bobbing", or "weaving" 2 adjacent
frames to obtain a full-artificial 1920x1080 picture from a 1440x540
pixels recorded material (more than 250% pixels have to be interpolated
!)
Let's summarize this offer : 15% LESS pixels than 720p for each frame but with interlacing+resizing artifacts !
Forced higher compression and still bad color encoding.
Stop this crap ! Bring us 720p (or 1080p ;-) camcorders for masses !
- 20070619 :
Things are changing and companies are starting to sell "Full HD"
camcorders. Unfortunately, they are in fact still limited to 1080i, using either HDV, AVCHD or MPEG2, yet no MPEG4 :
Some brands claim Full-HD 1080p while they still film in interlaced (Panasonic HDC-SD1) !
Others use 1920x1080 "Progressive Scan" CCD (I didn't know "interlaced" CCD did exist ;-) but still record in 1440x1080 (Canon HV-20).
This one is offering 25p mode - cool - framerate as low as in the
movies :-(
For me, it's clear that future is (Full-)HD progressive camcoder, with no moving part (no more recording on HDD, Disc or tape - Memory Card rules).
So what are Sony, Canon, JVC and Panasonic doing ? Maybe they want us
to buy "Fake-HD" camcorders now, in order to be able to sell us
"HD-Pro" (progressive ;-) camcorders in a near future and so making
more money ? I don't know.
So I'm still waiting using my "NTSC-progressive camcorder" - see below :
- Update !
I was forced to buy a new camcorder
(my old one was a Sony DCR-TRV20), so I browsed camcorder prosumer
market for everything available for my budget (with an upper limit of
€1500), and here is the choice I had : - A budget Mini-DV camcorder for €200-300, no DV input, no widescreen, nothing... - DVD camcorders - worst quality guaranteed for €400 - A middle-high range one of around €500, no progressive mode and looks and feel more like a toy than a camcorder - Higher range for €800 : no more kidding, bigger and 3CCD, but still no progressive mode and still DV - For €1000, progressive mode is
here and also almost everything a prosumer can dream of...but it's
still DV and we are above €1000!! - For a little more, HDV camcorders, good look and feel, but NO PROGRESSIVE ! It's Back to the future...
So try to guess how much I spent to replace my old camcorder ?
€80 : 2 x 2Gb High-Speed Compactflash for my Fujifilm S9500 (S9000) camera. Even if I live in a PAL country, I decided to shoot with it and convert my 640x480@30fps AVI MJPEG videos to 720x480@29.97 PROGRESSIVE NTSC DVD, without dropping frames nor losing vertical resolution ! Image is slightly more pixelated than
DV and not in 16/9, focus and exposition are not as accurate, but video
is smooth and...no more interlaced ! I cannot ask more from a €80 camcorder ! ;-)
I will live with this during my quest for a 720p camcorder, that will match my LCD projector and (future) TV. Maybe at that time Blu-Ray/HD-DVD authoring tool will also be available, that will be great !
- Update again (20080505) !
The only camcorder that matches my wishes is the Sanyo Xacti HD1000 !!!!
It is 720p@60 frames per second, not fields per second, which means
there are 60 full images per second, while competitors stills tick to
1080i (beuark !).
Pros : 720p@60Hz (!), price quite low, small size, sleek design,
records on memory card (less moving parts), H264 standard format
readable by my PS3 ! Cons : Autofocus and auto-exposure a bit slow, anti-shake feature not perfect.
