is it REALLY true? I don't believe...

[hardrock]

From huffyuv official site:

Huffyuv is a very fast, lossless Win32 video codec. "Lossless" means that the output from the decompressor is bit-for-bit identical with the original input to the compressor. "Fast" means a compression throughput of up to 38 megabytes per second on my 416 MHz Celeron.

Huffyuv is intended to replace uncompressed YUV as a video capture format. It is fast enough to compress full-resolution CCIR 601 video (720 x 480 x 30fps) in real time as it's captured on my machine.



How is possible to capture at 720 x 280 x 30fps with Huffyuv with a 416 MHz Celeron??? With my Pentium III 500MHz I can't capture with Huffyuv at 640 x 480...

Tell me what do you think!

[hardrock]

any idea?

[BJ_M]

i used to capture full D1 @ 15meg/s on a 400pII intergraph machine -- the cpu didnt mater , but it had 2 scsi drives striped together and a good capture card (optibase) .. any good capture card today is the same thing ... you dont need a powerfull cpu for capturing and as long as you are not doing heavy compressing if you are not using hardware compression..

[jkl]

no compression has no loss .and if you check out the homepagehttp://math.berkeley.edu/~benrg/index.html
you'll see that this is just a opinion by a former student at berkly.and how old is this site anyway. he is giving a translation patch for tmpgenc. there is no way to compress and not loose something.and technically, "lossless" means little loss, not no loss. what does "lossful" mean, complete loss.

[BJ_M]

you can compress a lot of things and NO LOSS .. i mean if what you were saying was true all zip files and rar files would be corrupted, which certainly isnt the case ... lossless compression means exactly that -> NO LOSS

[hardrock]

i used to capture full D1 @ 15meg/s on a 400pII intergraph machine -- the cpu didnt mater , but it had 2 scsi drives striped together and a good capture card (optibase) .. any good capture card today is the same thing ... you dont need a powerfull cpu for capturing and as long as you are not doing heavy compressing if you are not using hardware compression..

I'm not using hardware compression. Are you used to capture with Huffyuv or uncompressed?

[snowmoon]

Ok to answer the original question.

It's not your CPU it's your harddrive. Huffyuv was designed to serve a need. Full D1 video runs 19+MB/s not uncluding audio. Most CPU and PIC busses can move that kind of data no problem, but the hard drive was the weakest link. Only being able to handle between 5-10MB/s is nowhere near fast enough to handle the data load. Huffyuv strove to create a lossless codec that required very little overhead and could cut 99.99% of video stream in half ( note that no compression scheme can work on arbatrary data, I'm sure that comressing random noise with huffyuv will not produce stellar results. ).

So basicly it's you harddrive that can't keep up, not your CPU.

And for those who are arguing semantics... here is what webster has to say

Main Entry: -less
Function: adjective suffix
Etymology: Middle English -les, -lesse, from Old English -lEas, from lEas devoid, false; akin to Old High German lOs loose, Old English losian to get lost -- more at LOSE
1 : destitute of : not having <witless> <childless>

So Lossless would be without loss.

[jkl]

all zip files and rar files would be corrupted, which certainly isnt the case ... lossless compression means exactly that -> NO LOSS

maybe you should be at ziphelp.com. anyway post a screenshot in high detail from a source. then compress(with a video codec nat a zip or rar) it however you want and post the same scene at high detail and let the forum compare. then you can show me lossless. high action please.

[BJ_M]

i used to capture full D1 @ 15meg/s on a 400pII intergraph machine -- the cpu didnt mater , but it had 2 scsi drives striped together and a good capture card (optibase) .. any good capture card today is the same thing ... you dont need a powerfull cpu for capturing and as long as you are not doing heavy compressing if you are not using hardware compression..

I'm not using hardware compression. Are you used to capture with Huffyuv or uncompressed?

that card captured to mpeg2 .. the card i use now for analog and sdi capture is a reeltime system which captures with mjpeg

w/o hardware compression you still do not need a powerfull cpu - see snowmoon's post as he/she is right on .. all older good capture systems and NLE systems required min. of 2 scsi (only) drives striped together plus a 3rd drive for audio most of the time .. with that setup you can capture full D1 with no problems -- also we used NT4 which does even today a better job of both video capture and editing in terms of throughput and speed as nt4 has very little overhead .

[snowmoon]

all zip files and rar files would be corrupted, which certainly isnt the case ... lossless compression means exactly that -> NO LOSS

maybe you should be at ziphelp.com. anyway post a screenshot in high detail from a source. then compress(with a video codec nat a zip or rar) it however you want and post the same scene at high detail and let the forum compare. then you can show me lossless. high action please.

Look, huffyuv is a lossless codec, that means NO LOSS. a codec is just a compression/decompression engine for video, huffyuv uses a good predictor and huffaman encoding of the entropy. When the predictor and entropy are added back together you get the original. It's not an opinion it's a fact. If you would like to show US otherwise fine.

Personally I use huffyuv all the time for intermediary files. I would use if for capturing too, but my HD can't do D1 even with huffyuv either.

[BJ_M]

if you would like futher proof - here is the chapter out of the defacto bible of video and image compression taught at most universities (Steinmetz and Nahrstedt )

http://www.cs.sfu.ca/CourseCentral/365/li/material/notes/Chap4/Chap4.1/Chap4.1.html

http://www.cs.sfu.ca/undergrad/CourseMaterials/CMPT479/material/notes/Chap4/Chap4.2/Chap4.2.html

and

http://www.autosophy.com/videcomp.htm

http://www.vodeosolutions.com/tec_lossless.htm

by the way - just to shake things up -- there is accually LOSSLESS MJPEG (which i use) and also even LOSSLESS JPEG (used in medical fields mostly) as well as the newer jpeg2000 wavelet compression which can be LOSSLESS or LOSSY

Targa files can be compressed with LZW compression and most often are -- this is a LOSSLESS compression

LZW , Huffman and arithmitic are the three most well known LOSSLESS compression methods but if you read all the data above you will see there are others with wavlet compression being a big buzzword right now ..

[hardrock]

that card captured to mpeg2 .. the card i use now for analog and sdi capture is a reeltime system which captures with mjpeg

w/o hardware compression you still do not need a powerfull cpu - see snowmoon's post as he/she is right on .. all older good capture systems and NLE systems required min. of 2 scsi (only) drives striped together plus a 3rd drive for audio most of the time .. with that setup you can capture full D1 with no problems -- also we used NT4 which does even today a better job of both video capture and editing in terms of throughput and speed as nt4 has very little overhead .

With a 40Gb 7200RPM HD and with my system, I can't do it?

[snowmoon]

hardrock:

Specs can be deceiving. Get yourself a good HD performace meeter, reformat the drive so it's totally clean and do a seqential write throughput test. If you are not getting 11-15mb/s consistantly then huffyuv @ D1 will fail.

If you feel their is something wrong the I suggest you look into making sure your chipset, and HD firmware is up to date.

[BJ_M]

that card captured to mpeg2 .. the card i use now for analog and sdi capture is a reeltime system which captures with mjpeg

w/o hardware compression you still do not need a powerfull cpu - see snowmoon's post as he/she is right on .. all older good capture systems and NLE systems required min. of 2 scsi (only) drives striped together plus a 3rd drive for audio most of the time .. with that setup you can capture full D1 with no problems -- also we used NT4 which does even today a better job of both video capture and editing in terms of throughput and speed as nt4 has very little overhead .

With a 40Gb 7200RPM HD and with my system, I can't do it?

drives are a whole lot faster today -- i can capture at 9meg/s D1 on a single ata100 ide drive w/ mjpeg with never a drop frame for some really long captures.

with two ide drives i can capture at over 25meg/s though it takes a lot of room ..

[jkl]

show me pictures, not charts and graphs.

[snowmoon]

show me pictures, not charts and graphs.

If you cannot take the word of people that have been doing this for years, you will spend alot of time spinning your wheels. I know huffyuv is lossless from examining the theory of operation and from my own use over the past 2 years.

Prove it to yourself, the software is free.

[jkl]

in other words, no proof

[BJ_M]

im not sure what you want to see as proof ? how about a video made from 4k scans of a film negitive compressed in huffyuv avi , a targa still lzw compressed - a targa still uncompressed and uncompressed avi .. i can even throw in high def mpeg 2 and dvd mpeg 2 and what ever else you want .. mjpeg you need a non free codec as well as wavelet compression codecs you need non free codec's .. but i can make them pretty quick .. can even do some from original cgi for 70mm large format screen - either scanned or source files..

[jkl]

that's cool, if that is what you got to compare. i do believe huffyuv is great but never seen it with the exact same quality as the original. but if you don't want to do it i'll take your word for it.i know that different settings can give you different results. so tell me what settings you use and i'll try it later on a capture from t.v. if it's the same i'll post to say that i was wrong.

[adam]

Saying there is no such thing as lossless compression is like saying there is no such thing as gravity. It exists, check any encyclopedia, dictionary, or book on fractal compression.

The way lossless compression works is by not preserving all the data from the source, but by retaining all the information from that data, so that the data can be recovered perfectly during decompression. Essentially the quality is identical and the result is an identical copy of your original.

http://www.dictionary.com/search?q=lossless read the 2nd definition.

[jkl]

i retract my statements

[GiantRobo]

I'm not sure why Hardrock can't cap at 720x480 at 29.97 FPS. I can capture at that rate for a good 15 minutes before dropping one frame with VirtualDub. I do have faster machine than he one he spec'd.
P4 1.3 GHz
640 MB RDRAM
7200 RPM HD
I only have 13 GB free space however. So as the free space comes lower it does seriously start dropping frames.

BTW it was never clear in what way you cannot cap at 720x480. Just seriouly dropped frames or no picture at all?

I have to defrag several times and have plenty of open space > 50% of Total HD to get reliable results. Having one dedicated drive just for capture is probably a good idea.

[hardrock]

Man, I have only a Pentium III 500MHz with 256MB ram! I want to know who haves the same system (or similar) and captured at that rate.