Announcement: New open source DV codec (VfW) - Page 4

Wilbert · 15th August 2006, 19:50

Quote:

If fed with YV12 (DV), what is the output from ConvertToYV12(interlaced=true)

If you open YV12 (DV) in AviSynth and use ConvertToYV12(interlaced=true) nothing will happens because the color format is the same (although the chroma positions are different). It becomes a problem if you convert to YUY2 *in* AviSynth, because in that case the wrong placement (that is the wrong coefficients) is used.

As for Fizick's comment:

Quote:

I see Fizick has looked at the Cedocida source code and concluded that the conversion from YV12 (DV) to YV12 (MPEG2) actually proceeds via a YUY2 intermediate

That might be true (if Fizick checked the source i'm sure it's true). I know for sure that the chroma is correctly reinterpolated.

WorBry · 15th August 2006, 20:02

Thank-you Wilbert. Now I've learned something.

Boulder · 20th August 2006, 10:22

Quote:

Originally Posted by Fizick

If output format is not YV12-DV, Cedocida always convert this DV-frame to YUY2. (YUY2 is formed correctly, by averaging, and Reinterpolate420 is not needed).
If output format is YUY2, Cedocida output this YUY2.

If we talk about PAL DV, should we use scharfis_brain's ReYV12 function to get the YV12 output or is the internal ConverttoYV12(interlaced=true) enough?

That is,
should we a) enable YV12 and MPEG2 interlaced output or b) enable YUY2 output and use ReYV12 in the script?

WorBry · 20th August 2006, 13:24

I was wondering the same myself, but on checking the ReadMe for ReYV12 it states:

''reverts YUY2 decoded PAL-DV to its native DV-YV12''

I seem to recall some side note that the function was primarily created for re-conversion of processed YUY2 output from the Canopus decoder. Correct Scharfis?

Edit: there it is in the MVBob script notes:

#revert PAL-DV to YV12 for quality reasons; needs yuy2 input (ie. canopus-dv-decoder)

Presumably Cedocida carries out a similar routine to encode DV(YV12) from YUY2 input?

henryho_hk · 21st August 2006, 06:44

Both ReYV12() and ConvertYV12(interlaced=true) are intended for field-based materials. ReYV12() uses point sampling and picks up the chroma information of even rows (row 0, 1, 2, 3....) of every _field_. For some DV codecs such as Canopus, the discarded chroma info. are simply duplicates. On the other hand, ConvertYV12(interlaced=true) generates the chroma pixels by interpolation according to the defined chroma sample positions in MPEG2/4 4:2:0 Interlaced.

I would say Cedocida's Interlaced MPEG2 YV12 output is appropriate for most purposes. Use ReYV12() when you need original chroma for some specific purposes.

Jumbie · 15th October 2006, 07:17

Hi guys. Was previously using the Panasonic DV codec but thought I'd give this a try since I end up converting to YV12 in order for some of my filters to work in avisynth.

The thing is that I just tried a short 5-second test capture and when I tried convolution3d on it, an error spit out about how it "supports YV12 only".

How do I change the settings to make my clips get recorded in YV12? Is this possible to do even? My camera is a Sony DCR-PC330.

I've used vcswap.exe to access the configuration settings of Cedocida and checked "force input format" and selected YV12. That didn't seem to help so I did the same for "force output format".

Any help would be appreciated. Thanks.

WorBry · 15th October 2006, 16:59

Jumbie,

Changing the Cedocida 'input' settings will not affect the outcome because they only influence the DV encoder component of the codec. Certainly, for final rendering to (non-DV) YV12 format (MPEG-4, MPEG-2 etc), "forced" YV12 output with "MPEG2 interlaced" sampling is recommended.

Can’t see why you're getting an error with Convolution3D-YV12 though. Are you sure you have uninstalled or inactivated the Panasonic codec or any other DV codec that could be over-riding Cedocida? Easy enough to do with VCSwap - just drag the codec entry from the active to the inactive window. By the same token, make sure Cedocida is ‘active’.

That’s the only thing I can think of.

Jumbie · 15th October 2006, 17:22

Hi WorBry. Yeah, I'm pretty positive that I have uninstalled the Panasonic DV codec. I actually did that before finding VCSwap and, upon loading VCSwap, it does not show up.

Here is a screenshot of my currently installed codecs:

And here is one with my current settings for Cedocida:

I changed the YV12 chroma sampling to DV cause I figured that's what I'm recording in. I am actually recording straight to a hard drive with WinDV and not using any tapes. So should I change that to MPEG2 interlaced instead as my output will actually be MPEG-4 (using x264)?

What if I record in progressive mode (30p) as my camera has this ability? Does it matter then and should I perhaps change it to MPEG2 noninterlaced (if leaving it in DV is not correct)?

Dunno what's up with Convolution3D. I checked to make sure it was using the YV12 version and I am. Using converttoyv12() lets the script work.

Anyway, thanks for the reply and for clearing up what the "input" settings do. Sorry about all the questions but there's no documentation that I'm aware of and I'm not sure of the proper settings to use. Obviously...

WorBry · 15th October 2006, 18:10

Well, there's your problem right there. If those are the decoder setiings you're using, then you are outputting (default) YUY2.

Tick the 'Force Output Format' box, select YV12* and, under *YV12 Chroma Sampling, select MPEG-2 Interlaced.

I think the 30fps progessive option you are referring to must be the 'Movie Ex' mode for recording short (jittery) MPEG-1 clips to Memory Stick. Would you really want to use that when you've got DV?

Jumbie · 15th October 2006, 18:16

Quote:

Originally Posted by WorBry

Well, there's your problem right there. If those are the decoder setiings you're using, then you are outputting (default) YUY2.

Ooops, I had changed the settings back to default. I believe I had YV12 selected before. I'll try again later when I get the chance. Not home at the moment.

Quote:

Tick the 'Force Output Format' box, select YV12* and, under *YV12 Chroma Sampling, select MPEG-2 Interlaced.

Will do.

Quote:

I think the 30fps progessive option you are referring to must be the MPEG-1 ('Movie Ex') mode for recording short (jittery) clips to Memory Stick. Would you really want to use that when you've got DV?

I don't think that's the case. While my camera can indeed record to the memory stick and produce low-quality clips, the manual says this about the progressive mode:

Quote:

This feature is useful for movies you intend to import to your computer to produce still images.
You can record pictures with less blurring than recording in normal mode, producing pictures suitable for analyzing high-speed action such as sports. To enjoy a movie, it is better to record the picture in normal mode, since the image is recorded only evern 1/30 of a second in the progressive recording mode.

Note on the progressive recording mode
In a normal TV broadcast, the screen is divided into 2 finer fields and these are displayed in turn, every 1/60 of a second. This, the actual picture displayed in an instant covers only half of the apparent picture area. In progressive recording, the picture is fully displayed with all the pixels. A picture recorded in this mode appears clearer, but a moving subject may appear awkward.

Anyway, like I said, I'll try again later and see if changing the settings to force YV12 in output will sort my problems out.

Thanks again.

Jumbie · 15th October 2006, 18:58

I think I figured it out. I was using DirectShowSource to load my clip instead of AviSource.

When I do an info() command after DirectShow it lists the colourspace as YUY2 but it shows it as YV12 after AviSource. So that's why Convolution3D wasn't working. If I use AviSource, it does.

WorBry · 15th October 2006, 19:25

Well there you go. Still dont understand this 'progressive' mode though. Cant be DV (which is interlaced) and you say it's not MPEG-1. So what is the format?

Also, I'm a bit perplexed that the Cedocida 1.6 dll appears with 3 FourCC entries on your VCSwap screen shot (YV12, dvsd and YUY2), whereas I only see dvsd in mine. Can anyone explain that?

Jumbie · 15th October 2006, 19:29

Quote:

Originally Posted by WorBry

Cant be DV (which is interlaced) and you say it's not MPEG-1. So what is the format?

Does DV have to be interlaced by definition? Haven't had the camera long but thought it was just a "progressive DV" format just going 30p instead of 60i.

Quote:

Also, I'm a bit perplexed that the Cedocida 1.6 dll appears with 3 FourCC entries on your VCSwap screen shot (YV12, dvsd and YUY2), whereas I only see dvsd in mine. Can anyone explain that?

Right click on it and select "Scan Codec for FOURCCs" that's what I did and then activated them.

JohnnyMalaria · 15th October 2006, 21:43

Quote:

Originally Posted by Jumbie

Does DV have to be interlaced by definition? Haven't had the camera long but thought it was just a "progressive DV" format just going 30p instead of 60i.

No, it doesn't.

The DV specification supports both progressive and interlaced (IEC 61834-4, page 122). The way in which the video frame is compressed is identical, though. e.g., for NTSC, it doesn't matter whether the 720x480 frame is progressive or interlaced - the information is encoded the same way. The DV data stream contains a variety of flags, including progressive vs interlaced. This is really to tell the video hardware how to regenerate the video signal correctly.

WorBry · 15th October 2006, 22:30

By Jolly-Wingo, you're right. Just encoded a pure 576p25 avi source to DV (Cedocida) and it's lo and behold, its progressive. And there was me thinking all this time that DV has to be interlaced

bb · 16th October 2006, 06:22

Many people say DV is interlaced, but this is plain wrong. This prejudice probably comes from the fact that most DV camcorders don't have a progressive scan option. Jumbie's camcorder is obviously one of the rare models that support progressive video (mine does, too).

Regarding compression, DV can support interlaced video by using different sizes of macroblocks; besides the standard 8x8 there's the combination of two 4x8 blocks as well ("2-4-8-DCT mode"). And there's the adaptive interfield compression, which treats interlaced frames as progressive frames, if the encoder detects little difference between the two interlaced fields.

The DV specs require the video stream to be compressed in frames, not in fields. This is contrary to MJPEG, where most codecs compress interlaced video on a field basis. Thus I am tempted to say that DV is more a progressive format with an interlaced support addon rather than an interlaced format.

bb

JohnnyMalaria · 16th October 2006, 11:35

Quote:

Originally Posted by bb

Regarding compression, DV can support interlaced video by using different sizes of macroblocks; besides the standard 8x8 there's the combination of two 4x8 blocks as well ("2-4-8-DCT mode"). And there's the adaptive interfield compression, which treats interlaced frames as progressive frames, if the encoder detects little difference between the two interlaced fields.

The 2-4-8 DCT mode *is* the adaptive interfield compression....(but it isn't compulsory).

zambelli · 28th October 2006, 10:12

Just curious: have there been any tests done of the Cedocida ENcoder in terms of generational quality loss? How does it compare to MainConcept, Canopus or Panasonic? Is it safe to use it for DV editing projects?

zambelli · 5th November 2006, 14:49

Quote:

Originally Posted by zambelli

Just curious: have there been any tests done of the Cedocida ENcoder in terms of generational quality loss? How does it compare to MainConcept, Canopus or Panasonic? Is it safe to use it for DV editing projects?

OK, I can't seem to get PAL 4:2:0 DV encoding to work. Whenever I try to recompress a YV12 Avisynth output to PAL DV with MPEG-2 interlaced input option enabled - the resulting stream has strange flashes, macroblocks and errors. Has anybody been successful in encoding PAL DV with Cedocida?

Ngr · 5th November 2006, 18:04

I, too had the same problem last week that i tried using it as an alternative to huff. Decoding had no problem.

15th August 2006, 20:02	#62 \| Link
WorBry Registered User Join Date: Jan 2004 Location: Here, there and everywhere Posts: 1,197	Thank-you Wilbert. Now I've learned something. Last edited by WorBry; 15th August 2006 at 20:29.

20th August 2006, 13:24	#64 \| Link
WorBry Registered User Join Date: Jan 2004 Location: Here, there and everywhere Posts: 1,197	I was wondering the same myself, but on checking the ReadMe for ReYV12 it states: ''reverts YUY2 decoded PAL-DV to its native DV-YV12'' I seem to recall some side note that the function was primarily created for re-conversion of processed YUY2 output from the Canopus decoder. Correct Scharfis? Edit: there it is in the MVBob script notes: #revert PAL-DV to YV12 for quality reasons; needs yuy2 input (ie. canopus-dv-decoder) Presumably Cedocida carries out a similar routine to encode DV(YV12) from YUY2 input? Last edited by WorBry; 20th August 2006 at 18:59.

15th October 2006, 18:10	#69 \| Link
WorBry Registered User Join Date: Jan 2004 Location: Here, there and everywhere Posts: 1,197	Well, there's your problem right there. If those are the decoder setiings you're using, then you are outputting (default) YUY2. Tick the 'Force Output Format' box, select YV12* and, under YV12 Chroma Sampling, select MPEG-2 Interlaced. I think the 30fps progessive option you are referring to must be the 'Movie Ex' mode for recording short (jittery) MPEG-1 clips to Memory Stick. Would you really want to use that when you've got DV? Last edited by WorBry; 15th October 2006 at 18:16.*

21st August 2006, 06:44	#65 \| Link
henryho_hk Registered User Join Date: Mar 2004 Posts: 889	Both ReYV12() and ConvertYV12(interlaced=true) are intended for field-based materials. ReYV12() uses point sampling and picks up the chroma information of even rows (row 0, 1, 2, 3....) of every _field_. For some DV codecs such as Canopus, the discarded chroma info. are simply duplicates. On the other hand, ConvertYV12(interlaced=true) generates the chroma pixels by interpolation according to the defined chroma sample positions in MPEG2/4 4:2:0 Interlaced. I would say Cedocida's Interlaced MPEG2 YV12 output is appropriate for most purposes. Use ReYV12() when you need original chroma for some specific purposes.

15th October 2006, 07:17	#66 \| Link
Jumbie Registered User Join Date: Feb 2005 Posts: 31	Hi guys. Was previously using the Panasonic DV codec but thought I'd give this a try since I end up converting to YV12 in order for some of my filters to work in avisynth. The thing is that I just tried a short 5-second test capture and when I tried convolution3d on it, an error spit out about how it "supports YV12 only". How do I change the settings to make my clips get recorded in YV12? Is this possible to do even? My camera is a Sony DCR-PC330. I've used vcswap.exe to access the configuration settings of Cedocida and checked "force input format" and selected YV12. That didn't seem to help so I did the same for "force output format". Any help would be appreciated. Thanks.

15th October 2006, 16:59	#67 \| Link
WorBry Registered User Join Date: Jan 2004 Location: Here, there and everywhere Posts: 1,197	Jumbie, Changing the Cedocida 'input' settings will not affect the outcome because they only influence the DV encoder component of the codec. Certainly, for final rendering to (non-DV) YV12 format (MPEG-4, MPEG-2 etc), "forced" YV12 output with "MPEG2 interlaced" sampling is recommended. Can’t see why you're getting an error with Convolution3D-YV12 though. Are you sure you have uninstalled or inactivated the Panasonic codec or any other DV codec that could be over-riding Cedocida? Easy enough to do with VCSwap - just drag the codec entry from the active to the inactive window. By the same token, make sure Cedocida is ‘active’. That’s the only thing I can think of.

15th October 2006, 17:22	#68 \| Link
Jumbie Registered User Join Date: Feb 2005 Posts: 31	Hi WorBry. Yeah, I'm pretty positive that I have uninstalled the Panasonic DV codec. I actually did that before finding VCSwap and, upon loading VCSwap, it does not show up. Here is a screenshot of my currently installed codecs: And here is one with my current settings for Cedocida: I changed the YV12 chroma sampling to DV cause I figured that's what I'm recording in. I am actually recording straight to a hard drive with WinDV and not using any tapes. So should I change that to MPEG2 interlaced instead as my output will actually be MPEG-4 (using x264)? What if I record in progressive mode (30p) as my camera has this ability? Does it matter then and should I perhaps change it to MPEG2 noninterlaced (if leaving it in DV is not correct)? Dunno what's up with Convolution3D. I checked to make sure it was using the YV12 version and I am. Using converttoyv12() lets the script work. Anyway, thanks for the reply and for clearing up what the "input" settings do. Sorry about all the questions but there's no documentation that I'm aware of and I'm not sure of the proper settings to use. Obviously...

15th October 2006, 18:58	#71 \| Link
Jumbie Registered User Join Date: Feb 2005 Posts: 31	I think I figured it out. I was using DirectShowSource to load my clip instead of AviSource. When I do an info() command after DirectShow it lists the colourspace as YUY2 but it shows it as YV12 after AviSource. So that's why Convolution3D wasn't working. If I use AviSource, it does.

15th October 2006, 19:25	#72 \| Link
WorBry Registered User Join Date: Jan 2004 Location: Here, there and everywhere Posts: 1,197	Well there you go. Still dont understand this 'progressive' mode though. Cant be DV (which is interlaced) and you say it's not MPEG-1. So what is the format? Also, I'm a bit perplexed that the Cedocida 1.6 dll appears with 3 FourCC entries on your VCSwap screen shot (YV12, dvsd and YUY2), whereas I only see dvsd in mine. Can anyone explain that?

15th October 2006, 22:30	#75 \| Link
WorBry Registered User Join Date: Jan 2004 Location: Here, there and everywhere Posts: 1,197	By Jolly-Wingo, you're right. Just encoded a pure 576p25 avi source to DV (Cedocida) and it's lo and behold, its progressive. And there was me thinking all this time that DV has to be interlaced

16th October 2006, 06:22	#76 \| Link
bb Moderator Join Date: Oct 2001 Location: Germany Posts: 2,665	Many people say DV is interlaced, but this is plain wrong. This prejudice probably comes from the fact that most DV camcorders don't have a progressive scan option. Jumbie's camcorder is obviously one of the rare models that support progressive video (mine does, too). Regarding compression, DV can support interlaced video by using different sizes of macroblocks; besides the standard 8x8 there's the combination of two 4x8 blocks as well ("2-4-8-DCT mode"). And there's the adaptive interfield compression, which treats interlaced frames as progressive frames, if the encoder detects little difference between the two interlaced fields. The DV specs require the video stream to be compressed in frames, not in fields. This is contrary to MJPEG, where most codecs compress interlaced video on a field basis. Thus I am tempted to say that DV is more a progressive format with an interlaced support addon rather than an interlaced format. bb

28th October 2006, 10:12	#78 \| Link
zambelli Doom9ing since 2001 Join Date: Oct 2001 Location: Seattle, WA, USA Posts: 2,002	Just curious: have there been any tests done of the Cedocida ENcoder in terms of generational quality loss? How does it compare to MainConcept, Canopus or Panasonic? Is it safe to use it for DV editing projects?

5th November 2006, 18:04	#80 \| Link
Ngr Registered User Join Date: Nov 2004 Posts: 26	I, too had the same problem last week that i tried using it as an alternative to huff. Decoding had no problem.