Transcoding a DVD into HD resolution for viewing on S3?

[pmrowley]

Has anyone had any success in transcoding an MPEG2 file in full HD resolution and transferred it to a Tivo 3?

I realize that according to the MPEG2 specs here: http://tivosupport2.instancy.com/LaunchContent.aspx?CID=4012D160-79C3-4238-96C8-A27B323D1413
that the resolutions supported don't include HD resolutions. I'm wondering if this information is just out-of-date, and was intended for Series2 and lower.

I'd like to transcode a few DVDs into HD with 2-pass transcoding and then download to the S3 for viewing (yes, I have an HD-DVD player that upscales, but I'd prefer to do the upconversion with my Quad-Core processor for better scaling, and I also have some PAL disks that I need to transcode.) But trial-and-error is going to take days with multiple transcoding sessions, hence why I'm asking if anyone has had success with this.

Does anyone know definitively if there are any other MPEG2/MPEG4 formats that a Tivo3 natively supports, or are we stuck with DVD-quality MPEG files?

TIA,
-P

[bizzy]

When I am experimenting with encoding, I test on short clips of my content, so a mistake doesn't cost me hours.

[gatzke]

Has anyone had any success in transcoding an MPEG2 file in full HD resolution and transferred it to a Tivo 3?


I would guess you won't see much difference between upscaling on the computer and upscaling on the S3 (or even your TV). And the file size would be awful using mpeg2, especially for minimal benefit.

I use my amp to upscale DVDs and it looks good to me. 3:2 pulldown gives me greif with some judder on occasion, but it is not too bad. A 120 Hz TV might help with judder, but I am not sure if the S3 would pass through native 24 FPS video from the DVD...

[bizzy]

I thought the DVD spec only supported 30fps, hence the need for pulldown in the player?

[aaronwt]

Alot of work to go through for such a marginal improvement.
Just have the quad core pc do the scaling and watch it from there. That would be the easiest way. That's how I used to watch upconverted DVDs between 2001 and 2004.

[moyekj]

You cannot improve an mpeg recording by transcoding to another mpeg recording. Every time you go through mpeg compression you LOSE quality - you can't make a better mpeg out of an existing mpeg so making an HD mpeg out of a DVD mpeg is really a waste of time.
Convert the DVD title VOBs to a single mpeg (using DVDShrink or a host of other tools) and then use Tivo Desktop or other such programs to transfer to your S3/THD - they will look just as good if not better that way.

[Laserfan]

Has anyone had any success in transcoding an MPEG2 file in full HD resolution and transferred it to a Tivo 3?moyekj is right, you can't do better than the original.

BTW you're talking about re-encoding, not transcoding.

[gatzke]

I thought the DVD spec only supported 30fps, hence the need for pulldown in the player?

Not sure of the spec, but I thought 2:3 pulldown judder was an issue and the newer 120 Hz HDTVs had fixed that. If the DVD play only puts out 30fps, it would be a waste of cash. http://en.wikipedia.org/wiki/Telecine

And I think you could definitely get some benefit from different methods for upconversion / transcoding, even for mpeg streams. This is effectively what the old school line doublers did back in the day. I just don't see the benefit of doing it on a PC and then storing it on a HD. Let some hardware upconvert on the fly...

[pmrowley]

moyekj is right, you can't do better than the original.

BTW you're talking about re-encoding, not transcoding.

If you're going to snark, make sure you get your facts straight beforehand.

-> Definition of Transcoding (from Wikipedia) Transcoding is the direct digital-to-digital conversion from one (usually lossy) codec to another. It involves decoding/decompressing the original data to a raw intermediate format (i.e. PCM for audio or YUV for video), in a way that mimics standard playback of the lossy content, and then re-encoding this into the target format... Transcoding is extensively used by Home theatre PC software, such as MythTV and Freevo to reduce disk space of video files. The most common operation in this application is the transcoding of MPEG-2 files to the MPEG-4 format. <-

You know what, forget I ever asked. Every single answer here has basically been along the lines of "why would you want to do that bla...bla...bla..." Talk about a complete lack of imagination.

Perhaps I want to back up my DVD collection onto my multi-terabyte hard drive storage array and utilize my Tivo as a media hub so I don't have to hunt for DVDs every time I want to watch a movie? Perhaps I don't want to spend a whole bunch of money on hardware upconverters when I have more than capable hardware and software sitting in my editing lab? Perhaps I want to utilize the tools I already have to improve our viewing experience for a particular DVD that we own, and watch it on my 70" HD screen, instead of my computer (it's pretty darn hard to enjoy a movie with 2 people at a computer...) Notice that I specifically asked about anyone's experience with transcoding to MPEG4 and transferring it to Tivo. So we're talking about TRANSCODING into HD MPEG-4 format for viewing.

As for up-conversion, I have most definitely seen improved PQ by transcoding a DVD into 1080i MPEG4 and done side-by-side comparisons of the result on a pair of widescreen monitors on my editing computer. It looks far better than realtime upscaling through a Reon chip, because I can do 2-pass encoding that does pixel interpolation.

Guess I'll go figure it out for myself.

[T u r b o]

I think what they're trying to tell you is that you don't need to transcode/encode it at all.

If you take the ripped DVD VOB files directly and combine them with something like MPEG Streamclip (or even just cat), TiVo can play the resulting file back directly, and will upscale to your TVs resolution. This will provide the maximum quality available from the source DVDs...

[johnf@home]

I think what they're trying to tell you is that you don't need to transcode/encode it at all.

If you take the ripped DVD VOB files directly and combine them with something like MPEG Streamclip (or even just cat), TiVo can play the resulting file back directly, and will upscale to your TVs resolution. This will provide the maximum quality available from the source DVDs...

No it won't. There are many different ways to upscale from DVD originals to an HDTV-resolution video stream. While the upscaler in the TiVo isn't bad, I'd hesitate to claim that it's the best of all possible upscalers. So, in theory, it would be possible to get a better-quality HD recording by using an external upscaler and recording the resulting video stream for transfer to the TiVo HD.

That having been said, though, I suspect it would be fairly difficult to detect the differences, and I'd certainly question whether it was really worth all the time and effort (not to mention the increase in recording space used).

[ilh]

Notice that I specifically asked about anyone's experience with transcoding to MPEG4 and transferring it to Tivo. So we're talking about TRANSCODING into HD MPEG-4 format for viewing.
I don't believe the TiVo supports MPEG-4 at this time, only MPEG-2.