Encoding from jpeg motion to x264

[w4tt4n4b3]

I am completely inexperienced in the encoding field so I would like your assistance and guidance on the following matter.
I am thinking of purchasing the BlackMagic Design Intensity Pro pci-e (http://www.blackmagic-design.com/products/intensity/techspecs/) capture card in order to capture hd from YUV analogue output.
The thing is that the software application that the card comes with leaves me with only 2 options. Either capture uncompressed hd using raid hdd's or capture in compressed jpeg motion (.avi file). The problem is I do not have any more compression options which means that the compressed jpeg motion file will have about 12mb per sec size. 1 minute will be 720mb and 100 minutes 72gb's...

What I am thinking is getting the jpeg motion avi file and encode it into x264 mp4 in order to make it around 4.4gb's.
But this means the footage will be compressed twice, from source to jpeg motion and then to x264.
Do you think it's worth buying the card under these circumstances or having to re-encode will mean so big loss of quality that it's better not to proceed with the purchase?
My pc has an AMD Phenom II 920 x4 (2.8ghz) processor and 4gbs of RAM (800, 4-4-4-12, 2.0v). And my OS is Windows XP pro 32bit.

This is what the software webpage of the Intensity pro card (http://www.blackmagic-design.com/products/intensity/software/) says about compression options:
"On Windows, Blackmagic's full resolution (1920 x 1080) professional quality compressed HD codec can capture JPEG AVI files in real time using Premiere Pro. Unlike HDV and DVCPRO HD which uses reduced resolution 1440 x 1080 video, Blackmagic's Online JPEG maintains the full resolution 1920 x 1080 resolution of HD video without the huge file size of uncompressed HD video. Blackmagic's Online JPEG is so efficient that full motion 1080i HD video can be recorded at only 12 MB per second vs. a massive 119 MB per second for uncompressed HD video."

Thank you in advance.

PS: Any comment from someone using the card for the same purpose would be mostly appreciated.

[Blue_MiSfit]

MJPG at editing-quality bitrates is quite good. It will be very transparent to uncompressed HD.

If you are thinking of converting to x264 for editing purposes I'd advise against it, unless you're planning on doing intra-frame only mode, in which case you can probably get away with it.

Keep in mind editing H.264 is very CPU intensive.

~MiSfit

[w4tt4n4b3]

Thank you for your reply.
I need the 1-2 hours footage I will be capturing to go down to 4-8 gigabytes...
What would you recommend me for that?

[nm]

Thank you for your reply.
I need the 1-2 hours footage I will be capturing to go down to 4-8 gigabytes...
What would you recommend me for that?
You still didn't say if you intend to edit those files later or are they never touched again?
Edit the captured file(s) and encode the final output with x264.

[w4tt4n4b3]

I am thinking of keeping the ads/commercials of the footage so I won't have to edit and merge the files.
I am in a dilemma between the Blackmagic Intensity Pro and a device like Hauppauge HD-pvr that has hardware encoder but is a usb 2.0 device...

[Blue_MiSfit]

The Intensity Pro is a very good card.

If you just want to encode the footage as-is, then just capture to MJPG and then encode to x264 afterwards. You should be able to get 1080i (or 1080p) down to ~ 6-10mbps, which = ~1MB / second, 60MB per minute, and 3.6GB per hour.

Much more manageable :)

~MiSfit

[w4tt4n4b3]

Ι used the MEGui application to encode a 83 minutes (several gbs) uncompressed video avi file.
Could you estimate how much time it would take to encode one of hour of footage to bring it down to 3,6gbs? We are talking fro 2 pass encoding.

I am looking into other options as well and specifically the Hauppauge HD-PVR which has hardware encoder h264.
What's your opinion?
Thank you in any case Blue_Misfit...

[Dark Shikari]

Ι used the MEGui application to encode a 83 minutes (several gbs) uncompressed video avi file.
Could you estimate how much time it would take to encode one of hour of footage to bring it down to 3,6gbs? We are talking fro 2 pass encoding.Depends entirely on the settings you use... x264 can be incredibly fast, incredibly slow, or a good balance, depending on what balance you're seeking between compression and speed.

And we're not psychic, so we can't magically divine what CPU you're using either.

[w4tt4n4b3]

Well I overestimated your powers...ahahaha
My mistake! I thought I had written the specifications of my pc previously. It must have been in another thread.
It has an AMD Phenom II x4 920 (2.8ghz) cpu, 4gbs of Ram(800mhz, 4-4-4-12, 2.0v), WD Black caviar 500gb at 7200rpm and Windows XP pro 32 bit as OS.
We are talking for low bitrate around 5-6mbps and 2 pass encoding.

If I capture uncompressed avi of several gb could that be a useful simulation? I mean could I draw some safe conclusions about the jpeg motion encoding to x264?
And as I wrote earlier I am looking into the hardware encoding option of Hauppauge HD-PVR.

[Dark Shikari]

And as I wrote earlier I am looking into the hardware encoding option of Hauppauge HD-PVR.Do note the compression is going to be vastly worse with a low-end hardware encoder like that than with x264.

[Shinigami-Sama]

any specific reason for 2 pass?
why not crf and just bump up the settings a bit more

crf = quality based one pass, a very nice feature :)

[w4tt4n4b3]

You mean the quality of the picture, right?
Why do you say it is low end hardware encoder? Is it because it's not that expensive?

[w4tt4n4b3]

any specific reason for 2 pass?
why not crf and just bump up the settings a bit more

crf = quality based one pass, a very nice feature :)
I read in some tutorials others opting for automated 3-pass and others for 2-pass stating that you get better quality and it will diminish the chance of artefacts etc.
I am completely newbie, so I depend solely on what I read.

[Shinigami-Sama]

caught me just before bed

I'd only use 2-pass if I need to hit a target size, or for streaming/VBV reasons

CRF is a 'constant' quality so you don't get to pick your size, but the movie will have the same quality through out
plus its one pass, so you don't need long long encode times, just long

[Dark Shikari]

I read in some tutorials others opting for automated 3-passAnyone who recommends "3-pass" with a straight face has no idea what they're talking about.

[w4tt4n4b3]

If I try to a encode a several gbs avi uncompressed video-file can I take it as a guide as far as the time of encoding for hd mjpeg is concerned?
I mean if it will take me 2hrs to encode a 50gb of uncompressed avi will it take the same time to encode a 50gb hd motion jpeg compressed file using the same settings of course?
The jpeg motion will be avi as well.

[Dark Shikari]

If I try to a encode a several gbs avi uncompressed video-file can I take it as a guide as far as the time of encoding for hd mjpeg is concerned?
I mean if it will take me 2hrs to encode a 50gb of uncompressed avi will it take the same time to encode a 50gb hd motion jpeg compressed file using the same settings of course?
The jpeg motion will be avi as well.The encoding time has absolutely nothing to do with the input file size and everything to do with the length of the input.

[w4tt4n4b3]

As length you mean time length?

So if I try to encode 1hr of sd footage it will take the same time with 1hr of hd footage although that the filesize of the hd footage will be larger?
Sorry if my questions are too simple or sound naive...

[Dark Shikari]

As length you mean time length?

So if I try to encode 1hr of sd footage it will take the same time with 1hr of hd footage although that the filesize of the hd footage will be larger?
Sorry if my questions are too simple or sound naive...Well obviously it depends on resolution as well; twice the pixels means twice the encoding time.

What I meant is that it doesn't matter how much your input is compressed; it'll be decompressed on the way to the encoder anyways.

[w4tt4n4b3]

I captured 1 minute of sd 720x576 video and encoded into x264.
Video: MPEG4 Video (H264) 720x576 [GPAC ISO Video Handler]
Audio: AAC 44100Hz stereo 192Kbps [GPAC ISO Audio Handler]

It took less than 30 secs for the video encoding...
I chose ABR and 1500 bitrate.

[Dark Shikari]

I captured 1 minute of sd 720x576 video into x264
Video: MPEG4 Video (H264) 720x576 [GPAC ISO Video Handler]
Audio: AAC 44100Hz stereo 192Kbps [GPAC ISO Audio Handler]

It took less than 30 secs for the video encoding...
I chose ABR and 1500 bitrate.What's your full commandline, and which version of x264?

[w4tt4n4b3]

I got these from Media Player classic properties. I used MeGui. In my pc video codecs I see x264 VFW H.264/MPEG4/AVC
In the MEgui I see I have skystrife's 1134 patched build...