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HDV to Mpeg2 help needed

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Rob Anderson
HDV to Mpeg2 help needed
on Oct 23, 2006 at 6:19:40 pm

I've got some 1080 60i footage that I need to encode to standard def 16:9 Mpeg2 at 15Mb/sec. The video will be playing on a 42" LCD and viewed up-close in a museum.

I tried Sorenson without good results, so I've downloaded the trial version of "Episode" - which I like very much - but just can't find the right settings to make this footage look decent. I believe it all has to do with sizing and interlacing settings. The original tape looks awesome playing on this monitor so it seems to me that it would be best not to deinterlace. I feel like I've tried every possible combination on both Sorenson and Episode and they all look terrible! Can anyone help me?

Thanks, Rob


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Charles Simonson
Re: HDV to Mpeg2 help needed
on Oct 24, 2006 at 6:00:19 am

First, make sure you have the 4.1.3 demo version of Episode. The main reason is that you will want to use some of the new templates included and it has a small fix for deinterlacing. Select the MPEG-2>Program Stream>NTSC_HD_Mux setting and edit from there. For the MPEG-2 settings, leave it alone or adjust the bit rate as needed and select 2 pass if needed. For Frame rate, leave that the same as your input. For Deinterlace, choose your field order of the source, then select Interpolation, and choose either a complete deinterlace or deinterlace moving parts (automatic). For Sizing, choose the size you want to encode to and depending on how you set the deinterlace option, try progressive output or scale fields independently.

Now, my question to you would be why you want to compress your source HDV in the first place? If the resolution is too high for the monitor, just leave it as it is and let it play back scaled down via the player. Unless you are encoding this for a specific type of device. But most decent PCs in the last few years can handle HDV play back. And if neither of these options works for you, then I would suggest checking out another encoder, MainConcept (MPEG) Encoder for Mac.


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Rob Anderson
Re: HDV to Mpeg2 help needed
on Oct 24, 2006 at 1:33:42 pm

Charles,

Thanks much for your detailed reply.

Yes, it is a specific player: the Alcorn Macbride "Digital Video Machine" (plays Mpeg2 from Compact Flash card). It only plays Mpeg2, and only up to 15 Mb/sec. I'm sure there are many situations where it works just fine. But in my case, I'm sizing down the resolution of the tape from HDV 1080 to 480 during encode, then sizing it back up from 480 pixels to that 42" LCD (not sure of LCD's native resolution)on playback. This process is destroying the picture.

This is made worse by the fact that the video is for a virtual ride - the footage is POV driving down the street - so lots of diagonal lines and variety of trees, all coming at the viewer at 30 miles per hour. This is a very demanding encode, so I'm trying to make sure I have every setting correct.

Thanks again for your help. Please let me know if you think of anything else I can try - or if you know of a kiosk-quality HD player that's less than $5K.

Rob


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Charles Simonson
Re: HDV to Mpeg2 help needed
on Oct 25, 2006 at 1:00:15 am

For our kiosk and tradeshow purposes we use a JVC ProHD STB. You can feed it direct HDV, HD MPEG-2, and HD WMV-9 streams and it can play it back via its Component or DVI connections. It usually runs around $350 and is ideal if you just want run a loop of encoded content. It supports material from either network, DVD-R, or USB Flash drives. If you had one of these boxes, you wouldn't have to worry about re-encoding and would be able to give the display an HD signal.



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Rob Anderson
Re: HDV to Mpeg2 help needed
on Oct 25, 2006 at 1:30:04 am

Hi Charles,

Thanks for the suggestion of "JVC ProHD STB". It sounds very interesting. Could you send me a link or any other info? I've searched, but can't find exactly what you're talking about.

Thanks again, Rob


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Charles Simonson
Re: HDV to Mpeg2 help needed
on Oct 25, 2006 at 8:03:08 am

Yeah, that can be a pain to find on their site. Guess I should have stated DVD player instead of just STB. "jvc prohd dvd player" on google would have yielded this as the first result.

http://pro.jvc.com/prof/attributes/features.jsp?model_id=MDL101546&feature_...


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Johan S
Re: HDV to Mpeg2 help needed
on Oct 24, 2006 at 6:40:38 pm

Hi,

You are saying that the original material look good, so I agree with you that we try not to de- interlace.

I do not know the specs of you video player so I start out with 15 Mbit CBR. For HD you would really require more bitrate for mpeg 2 coding, but
again I think your LCD monitor is good for 1280 x 720 so I would choose that setting instead together with " scale fields independently "

Choose Assume 16:9 in the re-size filter,

size 120 x 720

In profile settings I choose display 1:1 progressive top first
in Key frame settings open gop Long gop NTSC
2 pass

how about that?




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Johan S
Re: HDV to Mpeg2 help needed
on Oct 24, 2006 at 6:43:00 pm

size 1280 x 720 ofcourse



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