MJPEG capture questions

[mracer]

Since I confirmed that the MJPEG DC10+ always captures in 4:2:2, I want to do some experimentation to compare it to 4:1:1 DV captured through an ADVC-100. I want to see for myself if the 4:2:2 vs. 4:1:1 to DVD 4:2:0 problem is all that some make it to be.

What bitrate MJPEG would be the equivalent of DV? In NTSC mode, the DC10+ is capable of up to 640x480@6000kbps. I know DV is 3600kbps but I heard that MJPEG is not as good as DV at the same bitrate.

Those of you who capture picvideo, morgan, or mainconcept MJPEG with other types of cards, what bitrate do you use for your full resolution captures(720/704/640x480)?

[iantri]

Look at this:

http://forum.matrox.com/rt2000/Forum8/HTML/000052.html

and this:

http://www.chumpchange.com/parkplace/Video/DVPapers/dv-beta.htm

and this:

http://www.tvtechnology.com/features/Tech-Corner/f-RH-4.2.2-07.10.02.shtml

BTW, full resolution in NTSC is D1 -- that is, 720x480.

That said, the difference between these different colour samplings is not major..

Comparing bitrates is not signifigant in this instance -- DV compression is geneally unnoticable. Capture the MJPEG at a really high bitrate to prevent DCT blocks, and compare a colourful surface.

[FulciLives]

I use PICVideo MJPEG on the 19 quality setting (with 20 being the best).

When you capture you don't set a bitrate that is done when you convert your AVI file (PICVideo MJPEG codec) to another format like MPEG-2

So capture at 720x480 using PICVideo MJPEG at the 20 level (highest quality level) and compare that AVI to your DV AVI from the Canopus ADVC-100

If you want to convert both AVI files to MPEG-2 to compare (MPEG-2 from PICVideo MJPEG vs MPEG-2 from DV AVI) then use the same MPEG-2 settings for each file in terms of bitrate etc.

- John "FulciLives" Coleman

P.S.
There is a VirtualDub filter and an AviSynth filter for converting DV AVI 4:1:1 to MPEG 4:2:0 format. It attempts to "smooth" out the errors of the original 4:1:1 capture. I can't remember the links or what they are called but there is some info on this in that huge ass STAR WARS thread. I never used the filters because I don't capture DV AVI so I cannot comment on their effect.

[mracer]

iantri and John, thank you for the replies. John, I have the advc-100 and the Pinnacle DC10+ in my video system. When I do MJPEG capture, I don't capture with the PICVideo MJPEG codec because I have the DC10+. It captures in hardware with the Pinnacle MJPEG hardware codec. When I capture with the DC10+, I can set the bitrate to any value I wish, such as 3000, 3600, or more, to a maximum of 6000kbps.

If I understand you correctly, you only set the PICVideo MJPEG codec to an arbitrary quality value such as 19 and not the bitrate? Is that correct? So you don't really know at what bitrate you are capturing MJPEG, just that it is set to quality "19"?

If you all don't mind the trouble, can you or anyone else tell me the file size of a 1 minute PICVideo MJPEG capture at quality 19? That way I can figure out the approximate MJPEG bitrate you are using for capture. This will be very helpful in figuring out the bitrate I should use with the DC10+.

[junkmalle]

1 min DV file 720x480 30 fps converted to PicVideo MJPEG at quality settings (no audio):

20 -> 484 MB
19 -> 190 MB
18 -> 122 MB

At 18 there is a sligtly noticable loss of detail. At 19 I can't really see much difference, even with a 4x zoom.

[mracer]

Well, I have just finished tonights grand experiment:

NTSC DV 4:1:1 vs. NTSC MJPEG 4:2:2 rendered to NTSC MPEG 4:2:0

The particulars:
DC10+ MJPEG capture, 640x480, video 3600kbps, 48Khz 16-bit audio
ADVC-100 DV capture, 720x480, video 3600kbps, 48Khz 16-bit audio

Video source: s-video and analog audio from Toshiba DVD player
DVD: Super Speedway
MPEG encoder: Canopus Procoder 2.01
MPEG settings: DVD, CBR 7000kbps, highest quality, mp2 audio 224

Subjective picture quality testing done by observering encoded MPEG's using WinDVD 5 software DVD player on 19" Sony Trinitron monitor. I also compared bmp stills of the same frame from each source captured from the MPEG files.

And the winner is:
based on picture quality it is a very, very tight race. Neither capture method suffered from any dropped frames, noise, blockiness, or other major defects. The DC10+'s drawback is the maximum capture resolution of 640x480 in NTSC mode. It's greatest strengths are it's 4:2:2 color sampling and adjustable video and audio bitrates.

After careful consideration, I must declare the ADVC-100 the absolute winner for the following reasons:

1. I cannot see the degradation of color in the ADVC's 4:1:1 DV capture or MPEG encoded from ADVC DV capture
2. Twice as fast encoding to MPEG using same settings in Procoder 2.01
3. slightly higher resolution
4. guaranteed locked audio
5. compatibility with all manner of OHCI DV editing software

[mracer]

junkmalle, thank you. Unfortunately the file size is not useful to me without audio. I should have asked for the file size of a one minute PICVideo MJPEG avi on the 19 quality setting with stereo 48Khz, 16-bit audio tracks.

[junkmalle]

junkmalle, thank you. Unfortunately the file size is not useful to me without audio. I should have asked for the file size of a one minute PICVideo MJPEG avi on the 19 quality setting with stereo 48Khz, 16-bit audio tracks.

Audio size isn't dependent on the video codec. For 48KHz, 16 bit, stereo, uncompressed audio add about 11 MB to each.

[mracer]

Yes junkmalle, you are correct. However, if audio was there it would make the direct comparison easier. But, hold the press, I just found that I have the PICVideo MJPEG codec on my system, and I can render to it to find out for myself. It seems that somehow Pinnacle Studio 9 or the Pinnacle DC10+ driver must also install the PICVideo MJPEG codec. So anyway, without further complicating things it seems (unless I have lost my mind) that PICVideo at quality 19 is somewhere around 3400-3500kbps. I believe quality 19 for you PICVideo fellas is video bitrate just a little smaller than the 3600kbps bitrate of DV.

[junkmalle]

it seems (unless I have lost my mind) that PICVideo at quality 19 is somewhere around 3400-3500kbps. I believe quality 19 for you PICVideo fellas is video bitrate just a little smaller than the 3600kbps bitrate of DV.

Keep in mind those are k BYTES per second, not the k BITS per second that DVD/MPEG are usually measured in.

[FulciLives]

When using the software version of the PICVideo MJPEG codec you set the quality on a scale with 20 being best. I always use the next step down (quality setting 19) ... I would do 20 but I drop frames at 20 since my computer is a bit slow. There is no BITRATE setting. Just this quality scale.

So I don't know how this compares to the DC10+

Also with a PCI type capture card (I have an Avermedia AverTV Stereo PCI capture card) I can capture more than 640x480 ... although due to the particulars of my capture card and driver I must capture at 688x480 then pad it up to 720x480 but that really doesn't affect quality in a negative way.

Here is something to consider ... This is the MAJOR point of my post ...

PICVideo MJPEG be it hardware (like the DC10+) or the software codec EITHER WAY this is just an intermediate stage. It is your "RAW" capture. You should set your capture settings to the highest level that you can in order to get the best quality capture that you can.

You should not limit your MJPEG settings unless you MUST due to computer speed (in my case I can't use the best 20 setting and instead use the 19 quality setting).

After all you will be converting to DVD or whatever other format is your target (such as DivX etc.) so you will then be deleting the MJPEG capture file. So no good will come of limiting your capture set-up.

Hope that makes sense.

- John "FulciLives" Coleman

[mracer]

PICVideo MJPEG be it hardware (like the DC10+) or the software codec EITHER WAY this is just an intermediate stage. It is your "RAW" capture. You should set your capture settings to the highest level that you can in order to get the best quality capture that you can.

John, Good points but I need this to be clear. PICVideo is always software MJPEG and it is not the same as Pinnacle hardware MJPEG captured with DC10+. Yes the PICvideo software codec is installed by the Pinnacle Studio 9 or the DC10+ driver, but when capturing with the DC10+, you don't have a choice. You have to capture Pinnacle hardware MJPEG with that card.

You should not limit your MJPEG settings unless you MUST due to computer speed (in my case I can't use the best 20 setting and instead use the 19 quality setting).

I agree with you on this to a point. I can capture hardware MJPEG with the DC10+ at 6000kbps with no problem, which would be like PICvideo at 30. The problem with that is the out of control file size. One hour is over 20GB if I remember correctly. That's just way to much space and way, way to much render time for longer projects. Not to mention the nightmare of editing such huge files.

[FulciLives]

You should not limit your MJPEG settings unless you MUST due to computer speed (in my case I can't use the best 20 setting and instead use the 19 quality setting).

I agree with you on this to a point. I can capture hardware MJPEG with the DC10+ at 6000kbps with no problem, which would be like PICvideo at 30. The problem with that is the out of control file size. One hour is over 20GB if I remember correctly. That's just way to much space and way, way to much render time for longer projects. Not to mention the nightmare of editing such huge files.

Well I guess you need to figure out which bitrate setting on the DC10+ is more-or-less the same as the 20 quality setting on the PICVideo MJPEG software codec.

I have no idea what that setting would be though in terms of bitrate as used by the DC10+

- John "FulciLives" Coleman

[mracer]

I didn't test it to find out but my guess would be that Picvideo MJPEG at quality 20 would be about 3800-3900kbps.

[junkmalle]

I didn't test it to find out but my guess would be that Picvideo MJPEG at quality 20 would be about 3800-3900kbps.

There's no need to guess -- look at the numbers I gave you. The file size more than doubles between Q19 an Q20, even if you add another 11 MB for the audio. It's around 8000 kBytes/sec.

Another thing to note is that DV is always the same bitrate whereas MJPEG will vary depending on content.

[disturbed1]

I agree with you on this to a point. I can capture hardware MJPEG with the DC10+ at 6000kbps with no problem, which would be like PICvideo at 30. The problem with that is the out of control file size. One hour is over 20GB if I remember correctly. That's just way to much space and way, way to much render time for longer projects. Not to mention the nightmare of editing such huge files.

The render time is from using the DC10 hardware codec to decode the stream. It's slow, make that very slow. You can have the DC10 installed, and install a software decoder, like Pic Video, or Morgan Mulitmedia. Both of these are 2-3x faster than the hardware codec at decoding.

I use a DC30 Pro to capture (704x480 7100KB/s) to networked hard drives in 2gig chunks, and process those chunks on 1-6 PCs. Each PC uses Pic Video software decoder. I can tell you that DV is faster to render to MPEG, but it isn't that big of a difference when using Pic Video as your MJPEG decoder. The big difference is in the color bleed of red when converting anolouge footage with a DV converter. The easiest way to see it is if you happen to have a shot of a RED ballon on a solid background. Once the wind blows the ballon around, it changes from a smooth rounded shape to a polygon, and just looks flat out awfull.

[mracer]

disturbed1, junkmalle, FulciLives, and iantri

Thank you for your contribution to this thread. I learned a lot about MJPEG. I found through my experimentation:
much new to me info about PICvideo MJPEG
how to change the field order of Pinnacle MJPEG to bottom field first.
DC10+ at 3600 bitrate is approximately equal to PICvideo at quality 19
The ADVC-100 is my best route to success, but I can go MJPEG if I want
DC10+ at 3600 is good enough for high quality video sources

disturbed1, I believe you about the Pinnacle hardware codec being slow to decode. I accidentally found a problem I have with Procoder 2 and PICvideo MJPEG. Last night I edited one of my Pinnacle DC10+ files and accidentally saved it using the PICvideo MJPEG codec. When I went to transcode that file in Procoder 2 it forced me to use PICvideo to decode and I got a mostly green screen with pink oozing around in movement. This does not happen with native DC10+ files decoded by the Pinnacle hardware. I like the quality of Procoder 2, so I may have to stick with Pinnacle hardware decoding, even though it is slow.