CIF, D1, H.264 Mayhem!

[Soundy 1]

Has anyone tried to manipulate a Regular DVR such as a dish network or directv dvr to work for security purposes. Or the regular DVR's that are meant just to record TV shows or movies? You obviously could only use these for single channel purposes though.

If it will record from a composite input, sure, you could hook a camera up to that... or feed a camera into an RF modulator and then hook that to the PVR's cable input. Then you'd just have to select the right channel/input, and tell it to record everything.

 

That's not going to be "uncompressed" either, though. The Motorola PVRs our cable provider gives us, use MPEG-2, same as on your basic DVD (although it's encrypted, specifically to prevent copying). That will take a lot more room than MJPEG or MPEG4, and not give substantially better quality. Keep in mind too, that as with H.264, it's a codec designed for full-motion 25/30fps video, and probably won't be as efficient at lower framerates.

[SEANHAWG 1]

muy interestante.

[survtech 0]

That's not going to be "uncompressed" either, though. The Motorola PVRs our cable provider gives us, use MPEG-2, same as on your basic DVD (although it's encrypted, specifically to prevent copying). That will take a lot more room than MJPEG or MPEG4, and not give substantially better quality. Keep in mind too, that as with H.264, it's a codec designed for full-motion 25/30fps video, and probably won't be as efficient at lower framerates.

MPEG2 is closer to MPEG4 than you think and takes up far less disk space per unit of time than MJPEG. Our system uses MPEG2 and the typical D1 bitrate averages around 1.5-2mb/s. We could simulate MJPEG with it by using all I-frames but for a given picture quality, we would have to crank up the bitrate to at least 5mb/s.

[rory 0]

This may be a dumb question, but I'll go ahead and ask it anyways. Do they make DVR's that have no video compression? Sure, it would significantly take up alot of hard-drive space but surely they have security DVR's out there that can record at full video quality right? That will record exactly what it looks like when live viewing?

 

[edit - some morons on the forum are very bored and like to pick apart everything I write now, for that reason I just show you this snapshot and you figure out why I posted it, thank those morons for the lack of information in this post]

[thewireguys 3]

This may be a dumb question, but I'll go ahead and ask it anyways. Do they make DVR's that have no video compression? Sure, it would significantly take up alot of hard-drive space but surely they have security DVR's out there that can record at full video quality right? That will record exactly what it looks like when live viewing?

 

oh yeah example no compression and generic (cant recall) codec:

note: 693 mb for 43 seconds of video.

 

 

ohh the Jeep.... I miss that image

[rory 0]

ohh the Jeep.... I miss that image

the poor jeep .. the tranny went on new years so i bought a 2nd hand one here locally .. that crapped out 6 weeks later so its sitting up under a tree now .. after sitting up for over a month it still starts on a quarter turn .. thats one good american vehicle! i got a loan on a small tiny japanese truck for now only had it a few months .. looking to sell that so i can take those monthly payments and just buy a 2nd hand tranny from the US for the jeep and have a vehicle I can actually drive on these darn "roads" here, driving this little truck here is like being beat across the back with a baseball bat!

[Soundy 1]

oh yeah example no compression and generic (cant recall) codec:

note: 693 mb for 43 seconds of video.

 

Considering "codec" stands for "compression/decompression"...?

[rory 0]

oh yeah example no compression and generic (cant recall) codec:

note: 693 mb for 43 seconds of video.

 

Considering "codec" stands for "compression/decompression"...?

and your question is?

some unknown codec with little to no compression .. ?????

[Soundy 1]

oh yeah example no compression and generic (cant recall) codec:

note: 693 mb for 43 seconds of video.

 

Considering "codec" stands for "compression/decompression"...?

and your question is?

some unknown codec with little to no compression .. ?????

If there's no compression, you're not really using a CODEC.

[rory 0]

If there's no compression, you're not really using a CODEC.

 

I really have no reason to explain further.

If I did however you would run VidCap on your windows OS and find various generic codecs with little to no compression if any. Its been several years so unfortunately I cannot name them but im sure a search of the forum can answer all your questions. When capturing using VidCap as in my sample, you must select A codec and does not matter whether it compresses or not or how well it does. If you think a 43 second clip that is 693 mb is compressed in some way I would be impressed to know how.

[Soundy 1]

If there's no compression, you're not really using a CODEC.

 

I really have no reason to explain further.

Of course not, because you know I'm right. A codec, BY DEFINITION, adds compression, minimal as it may be.

 

If I did however you would run VidCap on your windows OS and find various generic codecs with little to no compression if any.

I'm quite familiar with the video encoding options in Windows. One of the defaults is "Uncompressed Video", in addition to several very ancient codecs (RLE, Microsoft Video 1, Indeo, H.263, etc.). VidCap may be prompting you to "select a codec", but that doesn't mean it's right either.

[rory 0]

Of course not, because you know I'm right.

 

Wrong again.

[rory 0]

One of the defaults is "Uncompressed Video"

Wrong again.

[ak357 0]

If there's no compression, you're not really using a CODEC.

 

I really have no reason to explain further.

If I did however you would run VidCap on your windows OS and find various generic codecs with little to no compression if any. Its been several years so unfortunately I cannot name them but im sure a search of the forum can answer all your questions. When capturing using VidCap as in my sample, you must select A codec and does not matter whether it compresses or not or how well it does. If you think a 43 second clip that is 693 mb is compressed in some way I would be impressed to know how.

 

Uncompressed Video

 

" Captured video that has not been altered by the capture device or software to compress the data"

 

Rory why do you argue ?

 

It is lots of tools available to analyse video

which will show to you was your clip compressed or not

we gladly recommend to you if u need it

if you do not know how to use it

we will gladly explain to you

[SEANHAWG 1]

I hate to break in on the heated squabble but I have been doing some research on using directtv, tivo, and dish network dvr's as security recorders. From what I understand, if it is a used DVR, it will not work because you cannot get past the pre-installed software in order to get it configured correctly to work with your camera. Apparently, on new Tivo DVR's, you can get it configured but there is really no point on spending the money to buy a new Tivo to use as a security DVR as you can probably find a good new single channel DVR out on the market for the same price.

[rory 0]

Uncompressed Video

 

" Captured video that has not been altered by the capture device or software to compress the data"

 

Rory why do you argue ?

 

It is lots of tools available to analyse video

which will show to you was your clip compressed or not

we gladly recommend to you if u need it

if you do not know how to use it

we will gladly explain to you

 

Im not going to analyze an old video just to make you and your boys happy. SIMPLE, in my experience using VidCap or AmCap (take your pick) you have to select a codec, in this case the video was hardly compressed if not at all - god its been a few years since I used it so i will not explain something that is of no importance to why i posted. The point in this little exercise was to show a snapshot of a video that was uncompressed by a DVR. Take that as you will as I am sure you will want to argue and complain and tear apart everything i said as usual ... i dont have time for people that analyze every little thing, but feel free to go start a new thread on compression and codecs if you are that interested in what I posted. Im done replying to your nonsense. And by the way your avatar really does you justice.

[koolmer 0]

Ok - if we talk about NO compression whatsoever than we should assume that the pictures are bitmaps. A bitmap has no compression and the content of a bitmap has no effect on its size. A bitmanp of the size 704 x 576 has 1216566 Bytes.

 

Lets assume we have 6 fps and now we can calculate:

 

1216566 x 6 x 60 x 60 = 26277825600 Bytes (calculation for 1 hour recording)

26277825600 : 1024 = 25661939 kB

25661939 : 1024 = 25060.5 MB

25060.5 : 1024 = 24.5 GB

 

So we would need 24.5 GB recording for 1 hour.

 

@ rory

 

You record at 720x480. Your Jeep as a bitmap has 1036854 Bytes. Now you recorded 646 frames, so let's see how bad the compression was!

646 x 1036854 = 669807684 Bytes

 

To make it short - these are 638.78 MB! rory you got 639 MB!

 

So the program REALLY didn't compress! It's a simple calculation. Ok - you used a codec, but I guess the program didn't leave you the choice to select bitmaps as outputs. Otherwise no program that I know could play that. I am actually astounded how close my calculation result and your result are! " title="Applause" />

 

koolmer

[rory 0]

Thanks Koolmer. Sounds good

Yeah I dont really remember what codec it was (or if any for that matter) as its been several years since I captured that.