Angles using freeware - is it possible?

[Qun Mang]

I have just made a couple of slideshows using DVD slideshow GUI. As a bonus to the ones I'm giving it to, I want to add versions of the slideshows using weird post-processing filters that they can select with the angle button while the slideshow is playing. What I have for each slideshow right now is the original and three filtered versions, in .m2v format, and one .ac3 music track. I know some professional authoring software can do this, but I am looking for a freeware alternative as I can't afford any commercial software right now. If not, is there any way I can do it by hand, maybe by converting them to .vob format and then using PGC Edit? If this fails, does any of the commercial software have trial versions that will allow me to do this without disabling saving, adding watermarks, limiting me to 5 min, etc. (the slideshows are only 7min). Thanks.

[guns1inger]

If it is for a one-off then you could use the 30 day free trial of DVD Lab Pro. I don't know of any freeware software that makes it easy.

There are a couple of limitations that you need to be aware of when prepping your assets for multi-angle work.

1. Must be closed GOPs
2. GOPs must be identical - closed and fixed
3. Video bitrate must be under 8000 kbps, and works best if closer to 6500 - 6800 max

[Qun Mang]

I'm not sure what you're talking about with the identical GOPs- I am unfortunately not too experienced at this, even though my having used programs like PGCEdit might seem to indicate otherwise. As far as I know, none of the freeware I've used has ever addressed GOPs, though I did look up info on closed GOPs just now (still not sure I understand the concept, but I suppose would have to trust DLP to take care of this). DSG should have made the videos identical, just with different filters, so they should be the exact same length.

As for the bitrate, I just checked one of the files and of course DSG encoded it at 8500kbps, so it looks like if I use this option I would have to reencode everything. What happens with DLP if the bitrate is too high?

[guns1inger]

The issue isn't a DLP issue, but a playback issue. Because of the way the angles are loaded, higher bitrates can cause stuttering in the playback as the angles switch. Smoothest playback seems to come from bitrates around the 6500 mark, and this can be seen in the fact commercial discs use lower bitrates for multi-angle as well.

I don't know who or with what DSG encodes, so I could not guarantee that it uses a fixed GOP structure or closed GOPs. You may have to re-encode with something else anyway just to guarantee that your assets are correct.

[Qun Mang]

It uses HCEnc, but looking through DSG, it seems there is no option to change the bitrate. It looks like I will need to use another application to re-encode them, or presumably a program like DLP should do it for me. I also could use Mediacoder, which primarily uses ffmpeg for encoding.

[guns1inger]

DLP is an authoring tool. It can transcode down, but that isn't what you want here. You need to re-encode it using HCEnc manually.

[Qun Mang]

Ok then, I'll give this whole thing a go and let you know.

[Qun Mang]

DLP is really a very nice program. Still a couple of bugs here and there (mostly text getting cut off when using italics and two videos made with WinDVD creator had no sound- DLP demuxed them to .mpv/.mpa, but I had to transcode the .mpa to .ac3 before it worked), but worlds apart from any other program I have used. I did find out to change the bitrate and close GOPs using HCEnc, so that is taken care of. One thing- there is a very noticeable wait time after pressing the angle button before it changes angles. I wonder if this is because I used the AutoGOP parameter when making the slideshows. Here is what the report says about one of the multiangle movies:

<<< VTS Number 2 >>>
Number of Titles: 1


Title 01 - Type - Multi Angles
Angle 1, Video File C:\Downloads\CampLife2.m2v
	Frame size: 720 X 480
	Frame rate 4   		[1--23.976, 2--24, 4--29.97, 3--25, 5--30]
	Aspect Ratio: 43   	[43--4:3, 169--16:9]
	MPEG Video Type: 2   	[1--MPEG 1, 2--MPEG 2]
	Chroma: 1   		[1--4:2:0, 2--4:2:2, 3--4:4:4]
	GOP 1, size - 160322
	GOP 2, size - 160322
	GOP 3, size - 160322
Angle 2, Video File C:\Downloads\CampLife-a2.m2v
	Frame size: 720 X 480
	Frame rate 4   		[1--23.976, 2--24, 4--29.97, 3--25, 5--30]
	Aspect Ratio: 43   	[43--4:3, 169--16:9]
	MPEG Video Type: 2   	[1--MPEG 1, 2--MPEG 2]
	Chroma: 1   		[1--4:2:0, 2--4:2:2, 3--4:4:4]
	GOP 1, size - 156656
	GOP 2, size - 156656
	GOP 3, size - 156656
Angle 3, Video File C:\Downloads\CampLife-b2.m2v
	Frame size: 720 X 480
	Frame rate 4   		[1--23.976, 2--24, 4--29.97, 3--25, 5--30]
	Aspect Ratio: 43   	[43--4:3, 169--16:9]
	MPEG Video Type: 2   	[1--MPEG 1, 2--MPEG 2]
	Chroma: 1   		[1--4:2:0, 2--4:2:2, 3--4:4:4]
	GOP 1, size - 80135
	GOP 2, size - 80135
	GOP 3, size - 80135
Angle 4, Video File C:\Downloads\CampLife-c2.m2v
	Frame size: 720 X 480
	Frame rate 4   		[1--23.976, 2--24, 4--29.97, 3--25, 5--30]
	Aspect Ratio: 43   	[43--4:3, 169--16:9]
	MPEG Video Type: 2   	[1--MPEG 1, 2--MPEG 2]
	Chroma: 1   		[1--4:2:0, 2--4:2:2, 3--4:4:4]
	GOP 1, size - 27176
	GOP 2, size - 391875
	GOP 3, size - 16158
Audio File C:\Downloads\CampLife.ac3
	Audio type: AC3_Mot, Channel: 2, Sampling: 48000, Bitrate: 384000

The GOP size should be the same for all, right?

UPDATE: Okay, I re-encoded them again, this time using *GOP 15 2 instead of *AUTOGOP 15. Unfortunately the results are the same. The GOP sizes are identical, except for the last angle for some reason, though like before on that one the 3 GOPs are different (GOP 1, size - 25603; GOP 2, size - 375248; GOP 3, size - 353305).

[guns1inger]

What are you testing on ? Angle switches will not be seamless. True seamless branching is not covered by DLP yet. However I have found on most players that RW discs are slower to switch than - or + R discs. So if you use an RW for testing then the switches (between anything - angles, menus etc) will be slower than the final burned disc.

[tin2tin]

On DVD slideshow GUI and HCenc settings: You can change the HCenc settings in the HC.ini file located in the DVD slideshow GUI - main folder. Check out the HCenc doc for the options.

The default settings are:

*cq_maxbitrate 3.0
*dc_prec 10
*WAIT 0
*BITRATE 7500
*MAXBITRATE 8500
*AUTOGOP 15

[Qun Mang]

Actually, I've been testing using WinDVD, before burning, but it is good, though a little disappointing, to know that seamless transitions are not yet possible. I think I will consider this project done then, as soon as I look into why I get a split second of another angle after the video ends. I wonder if DSG or HCEnc is adding an extra couple frames to one of the angles? That would be very strange. Or maybe it's just WinDVD <shrug>

EDIT: The glitch at the end of the slideshows are definitely present on a real DVD player, and the video lengths are exactly the same to the frame. That means it is DLP that is doing it. Well, angles are only a recent addition to the program, right? Anyway, too bad I can't just lop off the last half-second of these videos since they are four angles in one video.

@tin2tin: Yes, that is what I did to close the GOPs and change the bitrate. Thanks. Good program by the way- just a few niggling bugs to squash- [s:480da450e6]see the DSG thread for a couple I brought up, though whether they were known bugs I'm not sure.[/s:480da450e6] EDIT: I see you've read it 8)