Comparison of NLE HD to SD downconversion quality

[Ken Jarstad]

Oh my, something yet more to learn! Never had to concern myself with transport/program streams - always worked with analog and DV "streams".

I tried three different ts/ps converters and coudn't get any to work for me. But then, I downloaded several .m2t files - so (scratch head). I don't have an HDV cam yet.

Since this subject is off-topic for this thread perhaps someone could direct me to a suitable forum for such conversions.

Meanwhile, has anyone used Nero to convert HD sources and make a "wonderful" standard-def DVD?

[Ervin Farkas]

Yeah, HDV is no easy cake... there is a lot to learn.

Another way to bring the m2t files into clean mpeg acceptable for VDubMPEG is MPEG Streamclip, a small app you don't even need to install under Windows, it runs off of a folder you save it in - you will have to have QT installed though, which, chances are, you already have. You simply load the file into MPEG Streamclip, choose > Save as MPEG and boom! you're done, extremely fast and reliable.

[Scott Holgate]

Hello Matrox uses,

Can anyone confirm the best way to down convert HDV to SD for DVD using the Matrox RT.X 2?

I have recently been importing the Matrox HDV .avi file into Virtual dub to resize it to 720 X 576 (Pal 16:9) and then encode to mpeg 2 using TMPGEnc. However I still get the jaggies! The colour and picture looks great however.

Anyone have a better solution?

Regards Scott.

[Ken Jarstad]

Well, I tried the OP's best method and got very poor results. Here is what I did:

I captured an HDV file in HDVSplit and after much fiddling I was finally able to get Mpeg_Streamclip to convert the m2t file to mpg. Then I loaded it into VirtualDubMod and used Lanczos3 resize (Interlaced) to change from 1440x1080 to 720x480. I also used the Panasonic DV codec since I certainly didn't want to deal with an uncompressed file!

If this method is superior to downrez in the camera I sure don't see it. I'm a retiree on a meager budget so I was looking forward to getting superior DV video via VDubMod.

I used VDubMod instead of VDub the OP used because VDub won't read in MPG files. And, to my way of thinking, if the frameserved file is superior quality then the AVI should be too! I would like to know where in this process I went wrong.

[Ervin Farkas]

Ken, some of the best things in life are free - the beauty of this method is that all the software you need is free.

Your mistake is probably the use of the Panasonic codec. If you don't want (or can't) work with uncompressed files, then go for the (free) HUFFYUV codec, one of the very few visually lossless codecs. I use it all the time even for SD work and love it.

[Brad Kirby]

DVDs sourced from Progressive sources look supremely sharper.

If you would like progressive picture quality on you DVDs from 1080i HDV source material this is what I do. All these are free tools. After using HDTV2MPEG2, I am able to open up the HDV material in VirtualDub MPEG-2 version. This can take 10 minutes to open for 1 hour of HDV material.
At this stage it will be 1080 X 1920 interlaced. (The true horizontal resolution is 1440)
In VirtualDub I use the following filters to get to pure 720 X 480 progressive.
Using the deinterlace filter select Discard field 2.
At this stage it will be 540 X 1920 pure progressive at 29.97 frames per second.
I use Lancoz3 resize to 540 X 810 to obtain the anamorphic DVD aspect ratio. (Horizontal resize only)
Using the crop option I crop 30 off both the top and bottom and 45 off both the left and right. This cuts 1/16 off each edge.
This gets me to 480 X 720 so that each of the 480 horizontal scan lines remain intact. (i.e. no vertical scaling just horizontal scaling)
This really helps in maintaining prestine quality of the picture. You might like to add some sharpening at this stage to suit your own preferences.

To avoid generation of large avi files, use frameserving from Virtual to avi2mpg2_vfw making sure you run virtualDub auxiliary setup and install the handler first.
Within avi2mpg2_vfw settings set your output mpg file to be a progressive sequence at 29.97 frames per second with 16:9 aspect ratio (Read the avi2mpg help)
Last step is the use ifoedit to create your dvd compatible files. Place them in a folder called VIDEO_TS and burn the VIDEO_TS to a DVD using DeepBurner.

The resulting DVD has a sharpness equal to any Hollywood progressive sourced DVD. but it will be 29.97 frames per sec instead of 24 for most film titles. It will play like any Hollywood progressive widescreen DVD offering (i.e. set DVD player to progressive scan output to enjoy the full quality)

Everyone I show these DVDs to is really impressed with the detail and sharpness that is non existant in standard interlaced home made DVDs.

[Ken Jarstad]

I'm now in the middle of a project, but I wanted to acknowledge your replies.

Thanks Ervin for the encouragement. Mpeg_Streamclip seems to be unreliable. If it detects any problems with the mpeg stream it refuses to load, crashes or just ties up the CPU at nearly 100 percent. I plan to search for better mpeg tools.

Brad, thanks for the procedure! I used to write some procedures as an IT manager but retirement becomes me! I have noticed on commercial std-def TV lately that a few programs and a few commercials seem to have better resolution images of landscapes and mountains than they *ought* to. I wondered how they did that - and that is why I was so emthused about this topic. I plan to try your procedure soon but may not get there until after Christmas.

[Ervin Farkas]

Ken, I'm surprised to hear that MPEG Streamclip is not working for you - I use it on 3 different computers with outstanding results, in fact I use it for a lot more than the topic of this particular discussion: preparation of DVD video for posting on the internet (VOB to various other formats), audio extraction/decompression from DVDs (AC3 to WAV), simple edits (cut/paste) at GOP boundary of MPEG files, transcoding of MAC-originated video files to work on PCs, broken time code repair and the list goes on!

Maybe you downloaded a new beta version instead of a stable version? Beta versions are usually buggy...

[Ken Jarstad]

Hi Ervin. I have all three versions of Mpeg_Streamclip - 1.1, which crashes on evrything, and 1.2 beta 1 and beta 2. At least the beta versions don't crash on std-def mpeg files. BTW, these are Windoze versions. And, I am trying to load m2t files from my HV20 captured via HDVSplit.

Brad, looking over your procedure I wonder why you throw away one field? In my understanding (perhaps meager) you are throwing away half the picture information. Certainly the video will run smoother if we simply double the field 1 lines but, in theory for me, losing half the original information to do so is pretty drastic! From an engineering standpoint, I wish they had never decided to use interlacing. It has been nothing but a hassle - full of artifacts. Also seems to me that you are throwing away half the chroma info. I will certainly try your method but I'm not understanding it yet. Ken

[Ervin Farkas]

I would not even waste my time with Brad's method - that sounds a lot like "how to save files copied off of high definition television to standard definition DVD" than anything else - he's not only throwing away every other horizontal line, but also the sides of the picture, so I am not sure what's left... a little of the center of the image?

It's certainly not a video editing workflow, rather something that belongs to the videohelp.com enthusiasts in my opinion.

[Danny Hidalgo]

Using the XHA1 with FCS1 on an iMac, try David Chuas conversion on the XHA1 forum. It is by far the best quality DVD and h.264 conversion fromHd to SD I have seen to date on a Mac. Initial files are large using export to 10 bit uncompressed ( ie 20 sec = 500 mb) but after conversion for DVD or download file is crystal clear without artifacts at a smaller file size ( 20 sec now 15 mb). Wild but true. For me, its the best and clearest HDV to SD conversion on the Mac.
Peace an Blessings,
Hidalgo

[Ken Jarstad]

To me, this is the holy grail, so to speak. I am driven to get the OPs 10/10 picture quality. It would also be quite accurate to say I have champagne tastes on a beer budget.

I discovered that Avidemux does a great job of converting transport steams to program streams. Great price, too!

I tried to replicate Brad's procedure and I think I was mostly successful but when I checked the vob I found it was still interlaced! The images looked pretty poor. I did buy Nero 8 a few weeks ago and, using Nero Vision, I was able to burn a progressive DVD. The video looked reasonable but I don't think it was the 10/10 the OP is claiming.

So far, the best SD images I have been able to get from a Canon Hv20 is to downconvert in camera - which the OP rates as 5/10. That 10/10 still eludes me.

[Devin Kelley]

Ervin (or anyone for that matter), what would the workflow be for HDV footage captured from a Sony HVR-V1U via Premiere CS3 and a Matrox RT.X2 when wanting to completely edit in HDV but then export to MPEG2 for burning to a DVD with MPEG Streamclip? Mainly, what would be the optimum settings and export method from Premiere CS3, and then the settings to use in Streamclip so that it could then be imported into Encore. Any advice would be much appreciated!

[Brad Kirby]

Originally Posted by Ervin Farkas

I would not even waste my time with Brad's method - that sounds a lot like "how to save files copied off of high definition television to standard definition DVD" than anything else - he's not only throwing away every other horizontal line, but also the sides of the picture, so I am not sure what's left... a little of the center of the image?

It's certainly not a video editing workflow, rather something that belongs to the videohelp.com enthusiasts in my opinion.

My source material is 25Mbps HDV from my Canon HV10. The only reason I use HDTV2MPG is to remove the transport stream outer wrapping to enable it to open in Virtualdub MPEG2.

I am throwing away the even numbered scan lines, but I end up with the 540 odd numbered scan lines which are all captured in once instance of time 30 times per second - hence true 540 progressive full resolution 30 frames per second. DVD players will only decode progressive sourced material that is 30 frames per second or less. (Just like film sourced DVDs, the material is put on the DVD at 60 interlaced fields per second, but with the caveat that the odd and even field are captured at the same instance in time, this allows the DVD player to reinterleave the fields to produce a clear frame with out combing)

Yes 5.5 % of the the picture is cropped from each side, but this is only because the HD size is not 960 X 1440 originally (which would easily scale to 480 x 720). This cropping enables the picture's original scan lines (the odd numbered ones) to have a one to one mapping without the degradation that (non interger) scaling would create.

I am extremely satisfied with the detail of the DVDs produced. The only other DVDs with equivalent quality that I know of is that produced from my friends 480p camcorder when recorded at 30 frames per second. This camcorder was 4 times the price of my HV10.

Read my previous post again and carefully try to see why this workflow will yield the best possible 480p DVDs that can be had from and 1080i source. I have produced 10 DVDs using this method and I was ecstatic at the detail and sharpness that was achieved when I produced the first DVD using this workflow.

If anybody want to ask me any specific questions or needs to get more details on the workflow please post your questions as I may not have given the full details of the work flow.

If anyone doubts the quality output of this workflow, I will post a short sample .vob file (720 x 480) if push comes to shove.

[Ervin Farkas]

Brad, I would love to watch a demo footage, and also some stills off of your final video. Although HD to SD is less and less relevant as more people move to HD, I am among those who love experimenting, so a step by step workflow would be helpful. By the way, I'm using MPEG Streamclip for the same reason you use HDTV2MPEG - the only drawback is that you have to have QT Alternative installed, but on the plus side, Streamclip gives me a ton of additional options; check it out.

How happy are you with the temporal resolution of the resulting video on pans/tilts and rapid movement?

[Sorry for the delay, I just got back from vacation].