1440x1080 hybrid DVD

[erdna]

I am not used to work with HDV therefore my question: did somebody ever create an hybrid DVD disc straight from a 1440x1080 (HDV) file (possible in VS), or is the usual(better?) way to first rescale to 1920x1080. Is this disc then playable on a stand-alone BD player, which normally can play the 1920x1080 versions. Any PQ difference between both possibilties

[lata]

Hi erdna

Like you i have yet to venture into the world of HD, I have however a bluray player, so nothing is stopping me in creating a hybrid disc. Its probably about time I had a go, I'll let you know how I get on.

I would have assumed if the source files are 1440 x 1080 then use that size for the disc.

I am sure others will comment on their Hybrid experiences.

[erdna]

Thanks Trevor. My question is maybe somewhat confusing. The point is that I am working for quite some time in fullHD (1920x1080) including hybrid and BD creation. Now I got a HDV (1440x1080) file, and wanted to know what people do with such a file: burn it as such, and let the player or display do the job to make it widesceen, or convert it first to 1920x1080 before creating the disc..

[Ken Berry]

I have done exactly that on many occasions and always with success. Most of my HD video is HDV taken with my Canon HV20. And I simply do the editing and jump straight to Share > Create Disc > AVCHD. It works well, and the resulting discs (with menus) play in a variety of Blu-Ray players. I have even distributed such discs to friends and family who have Blu-Ray players, with no complaints that they could not be played.

The thing to bear in mind is that HDV, while 1440 x 1080, is "anamorphic" and fully equatable to 1920 x 1080.

A couple of caveats, however. First, the Blu-Ray player has to be rated to play AVCHD hybrid discs. There should be a sticker saying "AVCHD" somewhere along the rim of the player, just like you would find "DivX". Some older players were not so rated, though most modern ones these days are. I have one of the first generation Sony Playstation 3s, and it has always played such discs, as do more recent versions of the player.

Second, I have written about this here quite a few times, but while I find the quality of the final disc to be indistinguishable from the original HDV (at least to my eyes), that is possibly because I use the highest quality AVCHD settings VS is capable of. As we all know, this is not as good as the current international standard for AVCHD (bitrate max of 28 Mbps, whereas VS can only do a max of 18 Mbps). But as I say, I cannot tell the difference. At 18 Mbps you can only burn a maximum of around 20 minutes of video to a single layer DVD. This is fine for me since very few of my projects run for more than 20 minutes... While I have in fact tried to burn more to a DVD, this of course involves lowering the bitrate. While the resulting quality is still better than a SD DVD, I find the quality drop-off unacceptable -- though I accept that other users have no trouble with this. Some here have reported burning more than 50 minutes to a disc, and said they were happy with the results. But beauty is in the eye of the beholder, I guess...

[erdna]

Thanks Ken. As you don't see any degradation with the 1440x1080 straight ot disc workflow, I suppose that first creating a 1920x1080 file and burn that file to an hybrid disc, seems to be a needless step.

[Ken Berry]

Yes, that is so. In fact when I did it that way, I thought the final quality was a little less -- and there were one or two artefacts -- than when I did it direct via Share > Create Disc... But you could try it yourself and use the 'Create AVCHD Folder' option instead of actually burning to a disc. Then you could play it and see if it were acceptable that way.

[lata]

Hi Guys

As I mentioned I was interested in progressing to HD.

Some of my findings..........
I do not have a HD camera so converted a DV.Avi project to 1920 x 1080 25fps 18000kbps Lower Field.
I then converted that to 1440 x 1080. both video files play ok on the pc with good quality.
The videos were approx 10 minutes long which allowed me to add to the same disc.
I did not think there would be any issues in doing this.
I first created the HD folder BDMV
Then burned a disc, I was a little surprised that the process rendered the videos prior to burning, I thought Do Not Convert Compliant files would work similar to using Standard Mpeg2.?

Ok the disc played but the 1440 section had a definite blip about one a second or so.
I inspected the HD folder BDMV, The 1920 file showed the properties as expected, the 1440 file showed using 24fps, now thats very strange.

I repeated the burn (create AVCHD folder) this time with a single 1440 file.
I don't understand why the Convert Title is being used, does this happen each time you burn a HD disc? If so then pre rendering to create a HD AVCHD is pointless and adding a VSP would suffice.
Anyway the completed video file again used 24 fps, so what am I missing.
---------------------------------
I repeated the burn (create AVCHD folder) using a single 1920 file.
This time the process completed as expected, no convert title, it was fast, I must admit very fast. I repeated the process just to time it at 2 minutes, the video file being 10 minutes duration.
---------------------------------

So I have only one issue, why does 1440 x 1080 force a render, I guess they are not Compliant Video Files.
But more importantly why does the frame rate change from 25 to 24 fps?

--------------------------------

Further tests, I converted to 1440 but was using Mpeg compression, when I used H264 everything seemed to work as expected. The burn completed with further render and the frame rate remained at 25fps.

Conclusion use H264..............

[Ken Berry]

Trevor wrote:

I was a little surprised that the process rendered the videos prior to burning, I thought Do Not Convert Compliant files would work similar to using Standard Mpeg2.?

First, I note that you converted the DV to HD but using Lower Field First. But you then produced a BDMV folder, which by international standard uses Upper Field First. So I expect that the need to convert arose from that. However, without more information of exactly what you did, I cannot explain why it seemed to work properly and without rendering when you used 1920 instead of 1440.

I also have absolutely no idea where the 24p came from.

I note that you refer to using "mpeg compression" in the 1440 conversion. By that I assume you were using mpeg-2 transport stream and set the codec to mpeg-2 instead of h.264. But again, that would be producing Blu-Ray compliant mpeg-2 -- which is NOT AVCHD and so needs converting before it can be burned to a hybrid AVCHD disc... While AVCHD in its own right is also Blu-Ray compliant, only AVCHD can be burned in that format to a hybrid disc. If you see what I mean...

[lata]

Hi Ken
Sorry for the lack of detail, I should know better.
I have indeed used Transport Stream

Interlacing, upper or lower field, my source video was DV-Avi from the Panasonic GS 400 so I retained the original field order, although the international standard uses Upper Field First by default does not mean you cannot use Lower Field, as far as i know. The interlacing was not an issue, i dont think

It is the first time I have tried to burn HD video to standard DVD, (hybrid) all went well, that is no errors and the disc burned ok.
However it did convert before burning, which took time and was unexpected.
After doing a further tests I found that using TransportStream Mpeg2 compression was causing the render.
Using H264 compression burned the disc/DVD Folder without conversion. As expected

PAL (25 fps)
MPEG Transport-Stream Files
24 bits, 1920 x 1080, 25 fps
Lower Field First
(HDMV-PAL), 16:9
H.264 Video
Video data rate: Variable (Max. 18000 kbps)
Audio data rate: 384 kbps
Dolby Digital Audio, 48 KHz, 2/0(L,R)

Using source as Transport Stream Mpeg 2 caused the pre render and the 24fps as below
Details taken from the Stream folder video files.

Film (24 fps)
MPEG files
24 bits, 1440 x 1080, 24 fps
Frame-based
(MPEG-2) (Transport stream), 16:9
H.264 Video
Video data rate: Variable (Max. 18000 kbps)
Audio data rate: 384 kbps
MPEG audio layer 2, 48 KHz, Stereo

I have quite a lot of test clips which are now confusing me, so I intend to start running the tests again. Just do not know where on earth the 24 fps came from.?

[erdna]

I never got 24p while testing fieldorder/conversion stuff. After manny tests, with numbered fields video, my conclusion was that field order setting is important when no rescaling is involved (DV.avi to DV.avi, DV.avi to DVD,...). When rescaling is applied (SD to 1440x1080 or 1920x1080), field order is always OK whatever the settings are (header interpretation ?). Even more confusing: deliberately wrongly set field order in SD mpeg2 files from DV. avi seem to be OK when played back by my MMplayer, while showing a wrong fieldorder when verified with PC playback (PowerDVD player field by field). I suppose that the header info which is present inall digital videofiles is being interpreted in mmplayers, and automatically shows the correct playback.

)

[lata]

Hi
As a test i used several images from the library
converted the project to Blu-ray (1920x1080), the first Bluray option

I then started a new project--Share Create Disc--AVCHD--Add Video adding my new Bluray file.
I changed nothing all settings are as default, Do Not Convert Mpeg files is checked.
I navigated to the last window where I chose to create an AVCHD folder
Again resulted in 24fps

The images show the original and the final AVCHD folder

click for larger view

I don't understand

[erdna]

Indeed lata you are right! I did the same thing using sample v20 (.wmv 29,...Hz file) and made a 25Hz (HDMV-PAL) Blu-ray file (first choice)which resulted in a high bitrate mpeg2 TS 25fps file. Used this file in a new project to create an AVCHD 25fps disc (folder), and the m2ts file in the stream folder was 24fps!!!. MediaInfo even indicated that it was (again) an NTSC file. Indeed strange...

[lata]

Hi erdna

Thanks for the conformation, at least i know it is a Video Studio problem and not my system., I did try using the wife's laptop running Windows 7 with the same results.
A little odd that nobody else has stumbled on this in the past.

At least its something to think about when users complain about poor quality AVCHD.
If you play the 24fps video, it displays a definite pulse because of the dropped frames.

Thanks again

[erdna]

The strange thing is that when I put the "24fps" disc file on the timeline that the framecounter goes from 00 to 24 indicating that it IS a 25fps file!

[lata]

Hi

The framecounter is set by the Project Properties not the files you add to the timeline, so it will always show as 25fps

If you inserted a 50 fps clip the frame counter will show as 25 till you change the project properties.