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needo
01-05-2005, 04:54 PM
Which will provide me the best quality at the end of the day? Using the GOPEditor that comes with TyTools or TMPGEnc MPEG Editor?

captain_video
01-06-2005, 09:06 AM
I don't have much experience using the TMPGEnc editor but I seem to remember that I didn't care much for it when I tried it. GOPEditor works fine most of the time but does tend to cause some pixelisation at certain cut points. The only tool I've found so far that gives me perfectly clean frame-accurate edits with ty-mpegs is VideoReDo. You can download a full working evaluation copy for 21 days from their website. I ended up purchasing it after about two days once I saw how good it was. Cost is about $50 for the program.

ADent
01-13-2005, 03:20 AM
I have had good luck with TyTool, but since I am running a Celeron I have to edit Tytool to use a q2 on the reencode (there is a bug in tool used relating to certain chip families so that q1 produces crap).

But that is for FAE cuts. Not sure why GOP is pixilating for you.

captain_video
01-13-2005, 09:49 AM
Sorry, I should have specified that the pixelisation only occurs when making some frame accurate cuts. GOP edits are fine.

jkrell
01-13-2005, 03:29 PM
Sorry, I should have specified that the pixelisation only occurs when making some frame accurate cuts. GOP edits are fine.

What's the difference between a frame accurate cut and a GOP edit? I don't get it. I was experimenting with GOP editor last night and my main complaint is the lack of precision of the cuts. I am a perfectionist, and I want the full fade out/fade in at commercial breaks, as you have when you buy DVDs of TV shows. At least as far as I can tell, this is often simply not possible in GOP editor.

TMPGEnd MPEG Editor, on the other hand, does this very easily, as you can cut at any point. Plus, as far as I can tell, there is no loss of quality because it only re-encodes where cuts have been made -- to seamlessly connect the two cutpoints together.

It would be one thing if the GOP editor were much simpler to use, but that is not the case. You have to make the key file, then go edit it, and then multiplex the file. It is the making of the key file that I find annoying. The process I use now is to get the files to my PC using MFS FTP, use tyTool to quickly convert to MPEG-2, and then use TMPGEnc MPEG Editor to cut commercials out. I also like the batch tool in TMPGEnc, which enables me to quickly cut as many shows as I want, and then start it up and go to sleep, watch TiVo, or do whatever. When I come back, my movies are all ready to go in my video folder.

I have taken the same file and used GOP Editor on one and TMPGEnc on the other, and found no noticeable difference in quality.

digital_b
01-13-2005, 05:14 PM
I would love to be able to edit using this tool but there is no help file. at least not with the version I have anyway. simply put: how do I set the points, assuming there are 2 points to each cut, for the places I want to remove from the video file? is it safe to assume that once all the parts I want to cut are out that the video is then recompiled to reflect my finished copy so I can then make a dvd? I am sorry if this has been asked/answered before but I cannot find the solution.

captain_video
01-13-2005, 05:15 PM
I'm no expert on mpeg2 and there are lots of posts that discuss the topic but I'll try to explain it as best I can so take it with a grain of salt. GOP stands for Group Of Pictures. With mpeg2 compression, the video is compressed such that there is a main picture that is the GOP header and all subsequent frames in that group only contain difference data from the previous frame. This allows much more data to be compressed into a smaller bandwidth. Each frame is reproduced as a full image by calculating the delta between the current frame and the previous one (or possibly the main frame or GOP header).

GOP edits are simple and cleaner because the cut is made at the point where there is a full image. Frame accurate cuts are performed where there are only partial frames. The complete image must be reconstructed at the cut point to provide a clean transition. When the reconstruction is not done properly the image becomes garbled at the cut. GOP Editor does not always appear to perform this reconstruction properly, resulting is some pixelisation at the frame where the cut occurs.

Tivo mpegs do not adhere to the mpeg standard such that there is usually only about 15-18 frames between each GOP header. Tivo mpegs can have many, many more frames between GOP headers. This was implemented this way to allow Tivo features like forward and reverse scanning to work the way that they do. Due to this variance from the mpeg standard, normal editing programs don't always work with Tivo mpegs. TyTools has always been a work in progress so what may not work 100% today will hopefully work as designed sometime in the near future. You can set up the extraction options so it will automatically create the key files immediately following extraction.

TMPGEnc may not always work with ty mpegs for this reason. The only commercial editing program I've found that was designed to work with PVR mpegs to dat has been VideoReDo. There are no pixelisation issues with frame accurate cuts and it also repairs any timestamp issues that result from cutting segments from a video clip. I extract my ty files with TyTools and then mux them to mpegs without having to create key files. I then edit and remux with VideoReDo and then import the new mpegs into DVD-Lab for authoring.

toppel
01-18-2005, 03:27 PM
Sorry for the stupid question, but your method seems the most straight forward so I wanted to make sure I have it right. When you say "I extract my ty files with TyTools and then mux them to mpegs" I assume you use the VOB-Mux process in Tytools and then it's ready to go into videoredo for edits? Meaning no other steps necessary in Tytools?
Also there is the VOB Mux option, then the VOB Mux (New Format) option. I have been using the new format option. Is that correct?

Thanks alot.

zmerch
01-19-2005, 08:16 PM
This is what I do -- I do this because:

1) I still put stuff on SVCD,
2) I'm a quality freak ;)
3) I find it's the quickest workflow for the quality I can't live without. :cool:

Here's my workflow:

I use TyTool to download, split & annotate (audio offset, etc.) my TyStreams; once downloaded, I use several programs to edit out the commercials:
1) DVD2AVI to make a 'project' of the video file -- I have a custom Python script to go through the files in a directory to make the .d2v files;
2) VirtualDub to actually scroll through the files & find the frame numbers I want to break on;
3) AviSynth to do any resizing, deinterlacing, decimating & whatnot;
4) TMPGEnc to do the actual MPEG transcoding;
5) A custom Python GUI bitrate calculator that can account for 1/2 and 1 hour shows, and spits out the .AVS files needed by VirtualDub and TMPGEnc. I don't mind sharing the source code, but be warned, the code is *not* complete -- I got as far as "it works for me" and it worked well enough that I never bothered to finish it. :o

I use the batching system in TMPGEnc to set up many shows, and let 'er rip. The last time I timed myself, I could set up 12+ shows to encode in an hour of furious keyboard-banging -- and yes, that would still keep my dual Athlon 2600+ beastie busy for quite a while churning shows. If anyone has any experience/benchmarks with the new Athlon64's in TMPGEnc, I would appreciate hearing from you. It's hard to believe that I've had my duallie system for over 3 years ( :eek: ) and yet it's hard to justify a new box to my wife... :cool:

Laterz, and HTH!
Roger "Merch" Merchberger

captain_video
01-20-2005, 09:14 AM
Sorry for the stupid question, but your method seems the most straight forward so I wanted to make sure I have it right. When you say "I extract my ty files with TyTools and then mux them to mpegs" I assume you use the VOB-Mux process in Tytools and then it's ready to go into videoredo for edits? Meaning no other steps necessary in Tytools?
Also there is the VOB Mux option, then the VOB Mux (New Format) option. I have been using the new format option. Is that correct?
No, you need to use the Multiplex File(s) option, not the VOB-Mux File(s). You only need to use the VOB-Mux option if you are using TyTools to create the DVD. The Multiplex option will convert the ty file to one with a *.mpg extension that will be recognized by VideoReDo and other programs.

You can also work with VOB files as they are just a different form of mpeg file that contain additional information. I'd stick with the old formats unless you have a problem using them with certain programs. It certainly couldn't hurt to experiment with them but I've never used the new format options myself since the old ones work fine for me.

Editing and remuxing the files is only one part of the process and not the final step. You still need to import the mpg files into your authoring program to create the DVDs. If you want to use TyTools for this process then you can do a VOB-Mux to the mpg file to create the VOBs and then create the IFOs/Dirs. The final result is a VIDEO_TS folder containing *.IFO, *.BUP, and *.VOB files. This is what you burn to a DVD.

toppel
01-20-2005, 01:05 PM
Great! Thanks alot for the response. One quick question. In transfering the file from the tivo, there is three options. Transfer as Tystream, Multiplex or vsplit. I have always downloaded in tystream. Should I change that to Multiplex, then use the Multiplex File option to process or should I still download in tystream format or should I only download in Tystream if I plan to build the DVD with TyTool?

Thanks alot for your help. It's greatly appreciated.

captain_video
01-20-2005, 02:28 PM
Stick with tystream mode and then perform the multiplex option after you've transferred the files to your PC. The multiplex mode for extraction doesn't always behave itself. Vsplit mode is for extracting and splitting the ty files into elemental streams (i.e., separate audio and video files). This is required for importing the files into some DVD authoring programs. If you use vsplit you won't be able to edit the clip so you're better off muxing the shows to an mpeg first and then demux them using TMPGEnc or other demuxing utility. DVD-Lab allows you to import the files as mpgs and then demuxes them on the fly.

toppel
01-20-2005, 05:07 PM
Excellent. Thanks again. I really appreciate the information. I definitely think I've got it now. I will download VideoReDo tonight. Just to make certain, the DVD-Lab program you are using is by Media Chance, is that correct? I just wanted to make sure their wasn't another program by the same name by as coincidence. I want to make sure I pick up the right one.

This should be the last question. Thanks alot for helping me out on this. It's appreciated.

Tim

captain_video
01-21-2005, 09:07 AM
Yes, it is by MediaChance. When you compile the DVD make sure you're selected the alternate/relaxed muxing engine in the compile window when compiling shows from a Tivo.

toppel
01-21-2005, 02:31 PM
Thanks again for all your help. It will be a DVD burning weekend!

Greatly appreciated!

pwantzel
01-25-2005, 12:06 PM
Stick with tystream mode and then perform the multiplex option after you've transferred the files to your PC. The multiplex mode for extraction doesn't always behave itself.

I've just started using this, and so far everything I've transferred with Multiplex mode has worked fine. The .mpg file that I get when I transfer with tystream mode and then process it to .mpg afterwards is, so far as I can tell, identical to the one I transferred in multiplex mode. You state that the multiplex transfer mode doesn't always behave itself. What does it do (when it misbehaves)? Will it be obvious? That is, if I transfer in multiplex mode, and it makes what appears to be a good .mpg file, am I safe? I'm just trying to avoid the need for an extra step, and I don't intend to edit or make a DVD within TyTool.

captain_video
01-25-2005, 12:33 PM
I couldn't say for sure what it does. I'm just letting you know what has been reported in the TyTools support thread. jdiner may have fixed the mux mode extraction issue with the current release so you might want to look at his release notes to see if this has been covered.

spaceman1013
01-26-2005, 11:13 AM
captain, What specific version of DVD-Lab do you use? I have heard that with teh newer versions it actually broke the relaxed import for Tivo mpegs. Have you tried your process with the just released DVD-Lab Pro release yet?

Also, are you editing SA Tivo streams or are these DTivo streams?

captain_video
01-26-2005, 02:39 PM
I'm still using 1.3.1. The current version of DVD-Lab standard is 1.4, I believe. I have not tried any of the DVD-Lab Pro versions yet but I have one waiting in the wings to audition when I get the urge. 1.3.1 is working fine so I haven't felt the desire to switch at this point.

dave4089
01-26-2005, 04:03 PM
Captain,

I agree with you, VideoReDo and DVD-Lab are a great combination. I use them exclusively now for making DVDs.

Let me know if you try DVD-Lab Pro. I though I understood that it did not support the Alternative (Relaxed) encoding method. This is the only way I have had success with DVD-Lab.

Dave


I'm still using 1.3.1. The current version of DVD-Lab standard is 1.4, I believe. I have not tried any of the DVD-Lab Pro versions yet but I have one waiting in the wings to audition when I get the urge. 1.3.1 is working fine so I haven't felt the desire to switch at this point.

captain_video
01-26-2005, 05:16 PM
I though I understood that it did not support the Alternative (Relaxed) encoding method.
That's what I have heard. It's probably the only reason I haven't tried it yet. I'm not exactly sure what the extra features are that make it the "Pro" version. I keep my DVDs pretty basic except when I'm archiving a TV series. I usually create a template with a lot more thought put into the development of the menus and such for this purpose. The basic version of DVD-Lab has served me well for this purpose so far.

spaceman1013
01-30-2005, 06:15 PM
captain, I do alot of TV series also and woudl be interested in getting your template for DVD-Lab. Can you post it here, please.

captain_video
01-30-2005, 10:51 PM
I don't have a specific template that I use for DVD-Lab. I create a new one for each TV series I archive. The template is saved as a *.dal file and contains pointers to the background bitmaps and info regarding the placement of menu items, objects, video clips, text and any assets saved with the project.

Play around with the settings in DVD-Lab and I think you'll realize it's fairly user-friendly once you get the hang of it. Look on the mediachance website for tips on creating all kinds of menus. Once you realize how everything fits together you can do pretty much whatever you want with it. Attached is an example of a menu I did for The Simpsons. This is the main menu that contains links to each of the episodes included in the DVD. It consists of a captured frame used as a background. I imported frames from the objects assets, resized them, and spaced them evenly about the screen using the grid layout button. Each frame contains a smaller captured image from each episode that was dragged to the screen from the images assets window and then placed behind the frame using the buttons in the toolbar just above the menu window. Text frames were added to provide a description of the episode number and title for each episode. Links for navigation within the menu were created by unchecking the Auto-Route option and using the buttons just to the right of it. You won't be able to add these links until you assign a movie or link some other asset to each of the frames. This is done simply by dragging the movie from the left column to the frame you want to associate it with using you left mouse button.

captain_video
01-30-2005, 10:53 PM
Here's what the connections screen looks like without any video clips loaded into the assets window. Note how the individual movies are linked together.

captain_video
01-30-2005, 10:59 PM
You'll notice in the previous screenshot that there are actually two menus in my project. The first menu is a motion menu set as the first play item but it also has a button linked to the second main menu. This allows the motion menu to play automatically when the DVD is inserted but gives the viewer the option to skip past it and go directly to the main menu containing links to the individual movies. The motion, or root menu as it is called, will automatically link to the second menu when it has finished playing. The motion menu consists of the opening sequence that starts off each Simpsons episode and was imported into the assets window just like any other video clip. The motion menu was created by simply dropping the audio and video file onto the blank menu screen. You'll notice there are two bars below the menu that indicate an audio and video asset that belong to the menu.

captain_video
01-30-2005, 11:13 PM
Here's a shot of what the movie asset looks like when you've imported it to one of the movie screens. The tabs along the bottom of the main window will select the screen you want to display. To add a movie asset to a movie screen just drag and drop it from the assets window to the filmstrip at the top. Pull down the Movie menu at the top if you want to select automatic chapter stops. You can also set them manually by dragging the chapter bar inside the movie strip and clicking on the + sign at the top of the bar.

captain_video
01-30-2005, 11:21 PM
If the attached images aren't looking too good in your browser you can right-click and save them to your desktop. Use Photoshop or other jpeg viewer to see them in finer detail.

Your project may not be as ambitious as the one I did for The Simpsons so you'll want to tailor it to suit your needs and tastes. I've done similar projects for Babylon 5, Sex and the City, Curb Your Enthusiasm, Seinfeld, and several others. Each time I used different variations of still and/or motion menus that were appropriate to the DVD set I was compiling. I used the motion menu on The Simpsons because it saved me about 20MB for each episode by only using it once. Some shows, like Babylon 5, had longer and much larger intro clips so I saved even more with those compilations. With some shows I had to try and save as much space as I could to fit the maximum number of episodes I could onto a DVD.

zmerch
01-31-2005, 06:53 PM
Vsplit mode is for extracting and splitting the ty files into elemental streams (i.e., separate audio and video files). This is required for importing the files into some DVD authoring programs. If you use vsplit you won't be able to edit the clip
Directly, yes. However, with vsplit it will give you the offset to audio to video, and using AviSynth & VirtualDub you can open the seperate elemental streams as one .AVS file and edit it there; and encode/transcode in TMPGEnc. That's what I do and it works quite well.

so you're better off muxing the shows to an mpeg first and then demux them using TMPGEnc or other demuxing utility. DVD-Lab allows you to import the files as mpgs and then demuxes them on the fly.
Well, DVD-Lab demuxes on the fly, but not in memory. It basically demuxes the streams to the %temp directory, then uses them. Essentially, you have 2 copies of the video/audio streams on your machine at once; so use this option if you have lots of spare room. :) If you're encoding with TMPGEnc anyway, you can tell it to encode to seperate streams (the {.mp2 & .m2v} option) that can be directly opened in DVD-Lab, thus saving you a sometimes lengthy step & hard drive space to boot.

Hope this helps,
Roger "Merch" Merchberger

zmerch
01-31-2005, 08:40 PM
Some shows, like Babylon 5, had longer and much larger intro clips so I saved even more with those compilations. With some shows I had to try and save as much space as I could to fit the maximum number of episodes I could onto a DVD.
That is why I do what I do - I have no intro clips at all { OK, I guess I'm a liar. I don't take the time to snip out the intro clip for my Good Eats episodes; as it's *very* short and not punctuated with commercials; it's the only exception...} no commercials, no "coming next week" and I try (but sometimes fail) to get the "On previous episodes" lead in, so I can re-encode at a higher rate (sometimes much higher).

A lot of people will just set chapters around the commercials which makes DVD navigation simple, but you still have to encode them (CPU time) and it takes up space, even if it is easier to 'skip ahead'. Many DVD players also do not support chapters on SVCDs which was the bulk of my archiving for 3 years, before DVD burners and media became affordable. (It was also helpful that my now ancient Apex DVD player could play a piece of cheese if you could format it... :D )

Again, I'm not saying "I'm right" -- just that I choose to do things a little differently than most, and it works well for me. :cool:

Laterz,
Roger "Merch" Merchberger

captain_video
01-31-2005, 11:09 PM
Different strokes, etc. There are lots of ways to the same end so do what works for you. There is no absolute "right" way of creating a DVD but there are definitely some wrong ways to go about it. If you've got a favorite method that yields good results and you're happy with it then stick with it. My methods are definitely not the final word on editing or authoring but only offered as one method to achieve the desired results.

Merch - Didn't you have a website for creating tyDVDs a while back? I seem to remember a site that I used to visit from time to time with your name on it. :D

zmerch
02-01-2005, 12:48 AM
Different strokes, etc.
Yup. Heard ya there! ;)

Merch - Didn't you have a website for creating tyDVDs a while back? I seem to remember a site that I used to visit from time to time with your name on it. :D
Noper -- not DVDs -- but SVCDs. The site isn't that active anymore, but it used to be one of the 'bibles' out there -- it was at http://tivo.30below.com/zmerch -- a few others had pages out there as well. It's still there, but the counters have been inactive and I haven't updated the page in quite some time. Altho my methods haven't deviated that much from the last updates, I do have a few differences in my toolchain, not the least of which is a custom python GUI bandwidth calculator that automatically writes my AVS scripts that I never quite 'completed' -- at least enough for prime-time. Once it got good enough to work for me, I never really followed thru to spit-n-polish it. If there's any interest, I could update the site & upload my 'alpha code' for the util...

Anywho, y'all have a good nite!
Roger "Merch" Merchberger

spaceman1013
02-01-2005, 04:03 AM
Captain, thanks for the great DVD-Lab info. I will definitely give this a try.

Are you importing SA Tivo streams or are these DTivo streams into DVD-Lab?

captain_video
02-01-2005, 12:18 PM
Primarily DTivo streams. I have also done some SA Tivo recordings to DVD. I picked up a used S1 SA Tivo a while back and I'm using it to transcribe all of the home videos I've accumulated on S-VHS and 8mm tape over the past 20 or so years and eventually author them to DVD.

Merch - Yep, it was definitely SVCDs. I just checked the How Tos Only sticky in the series 1 support forum and saw that I had posted a link to your site back in August of '02. I guess I'll have to go back and update some of the links as I'm sure many of them are now dead.

cheer
04-05-2005, 07:20 AM
This is what I do -- I do this because:

1) I still put stuff on SVCD,
2) I'm a quality freak ;)
3) I find it's the quickest workflow for the quality I can't live without. :cool:

You, sir, are clearly the person I am looking for. I am not happy with the video quality of the TyTool-generated MPGs. :)



Here's my workflow:

I use TyTool to download, split & annotate (audio offset, etc.) my TyStreams;
(Dumb newbie question) OK so does that mean you get the files in VSplit mode?


once downloaded, I use several programs to edit out the commercials:
1) DVD2AVI to make a 'project' of the video file -- I have a custom Python script to go through the files in a directory to make the .d2v files;
2) VirtualDub to actually scroll through the files & find the frame numbers I want to break on;
3) AviSynth to do any resizing, deinterlacing, decimating & whatnot;
4) TMPGEnc to do the actual MPEG transcoding;
5) A custom Python GUI bitrate calculator that can account for 1/2 and 1 hour shows, and spits out the .AVS files needed by VirtualDub and TMPGEnc. I don't mind sharing the source code, but be warned, the code is *not* complete -- I got as far as "it works for me" and it worked well enough that I never bothered to finish it. :o

I would love to see what you've got. What is more, I'd be happy to polish/finish/whatever the script, as well as write up some modified docs based on your website (http://tivo.30below.com/zmerch/).

Couple of notes:

I watch most videos using an Xbox w/XBMC. Extracted my first video last night, using TyStream mode in TyTool. Made the key files, edited, and output to MPG. Transferred to my media server, and fired up XBMC. I was a bit disappointed in what I got...the video was certainly watchable, but there was obvious pixelization, especially during fast-moving scenes. I'd like to give your method a try to see the results. My final destination isn't SVCD, but that's not critical to me. I may toy with finishing up in Xvid (for the file size mainly) but SVCD-compliant MPEGs will certainly work.

Have you done any work with Dolby Digital recordings? My Tivo isn't digitally connected to my amp, but my Xbox is, and I'd love to record shows with DD audio and preserve it.

If anyone has any experience/benchmarks with the new Athlon64's in TMPGEnc, I would appreciate hearing from you. It's hard to believe that I've had my duallie system for over 3 years ( :eek: ) and yet it's hard to justify a new box to my wife... :cool:
Ah yes, it's always critical to get buy-in from the CFO.

I have a new Athlon 64 box I built for my daughter that I'd be happy to run this through for comparative purposes.

--chris

FredThompson
04-06-2005, 10:55 PM
You, sir, are clearly the person I am looking for. I am not happy with the video quality of the TyTool-generated MPGs. :)...and you won't be happy with anything derived from them, either. You cannot increase quality beyond what you start with. Anything which re-encodes degrades quality, regardless of the filters. MPEG is lossy encoding. Re-encoding is the equivalent of making a photocopy of a photocopy.

cheer
04-06-2005, 11:24 PM
Yeah, I figured that out after I posted. I was originally thinking that TyTool was somehow "converting" a nonstandard file to MPG, but then I did some reading.

OK, so, realistically, what sort of quality can I expect from a DTivo extraction? By way of experimentation, I tried using MFS_FTP. I pulled the ty file off, dumped it straight down to my server, and played it with XBMC, and it looked pretty much the same. Any scene with fast motion seems pixelated. I tried an episode of Star Trek: The Next Generation, and during the credits when the scene pans the stars, it's horribly obvious -- blotchy, jerky, smear-y.

I'm going to try a couple of others (different shows, etc.) to see if maybe it's just that channel's feed, or something, although when I've watched it live or recorded on the DTivo it's never looked like that.

Any idea what the "native" resolution is of a DTivo video? I thought I had read 480x480 (similar to SVCD)...if that's true, then it certainly wouldn't make sense to VOB it or otherwise end up with DVD resolution, because then you're just blowing it up, right?

Sorry, all dumb questions. I just want to set my expectations properly.

--chris

FredThompson
04-06-2005, 11:42 PM
Quality varies depending on the source and bandwidth. I record multiples of stuff I like becuase the file sizes vary. The larger the file, the higher the quality, in general. Water, smoke, fire, gauze, etc. all look like crap with MPEG, no matter which flavor. There's just too much variation for the data compression. Star Trek is notoriously bad inside the U.S. because they mix all kinds of sources and do really stupid stuff to the streams. Pixelation is typical in the overscan areas on the edges. If you are deinterlacing, you will be creating pixelation artifacts in almost every situation.

Grab something from the National Geographic Channel during prime time and compare it with a morning network-affiliate chat show.

DTiVo is almost always 480x480. One of my local PBS stations broadcasts at 352x480. Bleech!!! 480x480 is the minimum needed to replicate S-VHS source. (Just take my word for it, ok?)

Quality isn't just the broadcast resolution and data rate, it's also the source material. If you reocrd the show "Icons" on G4Tech TV you'll see where they have a computer graphics logo ad just before some of the lead-in video for older episodes. The contrast is evident. If you have a premium movie channel like HBO, record something from it and compare the file size. Same thing with PPV.

TyTool has it's own server routine to extract for a reason. If you want to use TyTool, use its routines. If you want to archive ty files for reinsertion, use MFS_FTP.

TyTool VOBs use a common header "trick" so they will play properly by DVD players. It does NOT expand the data to 720x480. Every so often you'll see someone post here who is doing that. That's a horrible, horrible mistake. All that does is degrade quality and increase storage requirements.

Deinterlacing is also a mistake. If the source is film, decombing should recover the original 24fps feed. But you'd have to re-encode again. NTSC video consists of 2 streams of ~30 fps each. A "frame" of NTSC video has 2 fields which represent different times. Look at a stream in the Field Accurate Editor of TyTool and you'll see changes happen between fields, not just between frames.

Media Player Classic and ffdshow on the PC can give higher-than-DVD resolution. However, they can't remove corruption.

XBMC must be doing something to modify the output. If you burn a TyTool DVD and play it in a hardware DVD player, the recording should look identical to the original broadcast.

cheer
04-07-2005, 12:20 AM
Quality varies depending on the source and bandwidth. I record multiples of stuff I like becuase the file sizes vary. The larger the file, the higher the quality, in general. Water, smoke, fire, gauze, etc. all look like crap with MPEG, no matter which flavor. There's just too much variation for the data compression.
Yeah, after a few days of Tivoing stuff I've noticed wide variations. One Trek I recorded is 792m, another is 976! Yikes.

Star Trek is notoriously bad inside the U.S. because they mix all kinds of sources and do really stupid stuff to the streams. Pixelation is typical in the overscan areas on the edges.
Good to know. I'll try a variety of other sources.

If you are deinterlacing, you will be creating pixelation artifacts in almost every situation.
Nononono, definitely not deinterlacing. Read several other posts (most yours, I think) instructing in no uncertain terms NOT to deinterlace.

DTiVo is almost always 480x480. One of my local PBS stations broadcasts at 352x480. Bleech!!! 480x480 is the minimum needed to replicate S-VHS source. (Just take my word for it, ok?)
Don't need to; I understand that part. (352x480? YUCK. Sounds barely better than VCD.)

Quality isn't just the broadcast resolution and data rate, it's also the source material. If you reocrd the show "Icons" on G4Tech TV you'll see where they have a computer graphics logo ad just before some of the lead-in video for older episodes. The contrast is evident. If you have a premium movie channel like HBO, record something from it and compare the file size. Same thing with PPV.
I'll grab a couple things off of HBO for comparative purposes.

TyTool has it's own server routine to extract for a reason. If you want to use TyTool, use its routines. If you want to archive ty files for reinsertion, use MFS_FTP.
Unlikely I'll do reinsertion. My DTivos are ultimately going to be just "content gathering" devices, with networked Xboxes being used to view the vids (or listen to music, or...). But we'll see how that works...I need to upgrade the house backbone to gigabit Ethernet to support all this. :)

TyTool VOBs use a common header "trick" so they will play properly by DVD players. It does NOT expand the data to 720x480. Everyso often you'll see someone post here who is doing that. Horrible, horrible mistake. All that does is degrade quality and increase storage requirements.
Well that's what I thought. Can't make something out of nothing.

XBMC must be doing something to modify the output. If you burn a TyTool DVD and play it in a hardware DVD player, the recording should look identical to the original broadcast.
I'll try that. I dunno that XBMC is doing anything special to the output; I think it just uses linux mplayer as its playback engine. But I don't really know XBMC under the hood, so I could easily be mistaken.

Thanks very much for all the information!

--chris

FredThompson
04-07-2005, 12:34 AM
352x480 was actually the "original" SVCD and comes from S-Cubed. About 12 years ago my best friend handed me an article about their compression. It was incredible, a whole hour of VHS on a CDR! Actually getting the equipment was impossible, though. They were selling playback devices in China then 480x480 was pushed by the larger megaconglomerates and some money changed hands (imagine that!) then China made 480x480 SVCD, after the fact. Of the two, 480 width truly is better for replicating S-VHS.

The idea that video should always be deinterlaced probably goes back to early forms of computer video like MPEG1 which didn't give support for interlaced source. It's become one of those urban myths which won't die like the idea that scanning should be done at 75 dpi because 72 dpi is a common screening resolution. Try laying a piece of paper on a scanner with no angle and perfectly aligned at 1/72 of an inch!

The only reason I mention XBMC may be messing with the stream is the pixelation you mention. I don't have an XBox so can't offer any experience other than what I see on my PCs. When I send S-Video from my ATI cards they add black in the overscan area. Maybe XBMC or the XBox do something similar.

mbriody
04-07-2005, 05:09 AM
The only reason I mention XBMC may be messing with the stream is the pixelation you mention.

I also use XBMC as described earlier and have had pixellation. I cured it by switcing on one of the video options in XBMC - it may have been the deinterlace filter (sorry but it was a while ago).

Try playing with the filters until it improves. You'll be able to tell straight away when you've got the right one.

cheer
04-07-2005, 09:33 AM
I also use XBMC as described earlier and have had pixellation. I cured it by switcing on one of the video options in XBMC - it may have been the deinterlace filter (sorry but it was a while ago).

Try playing with the filters until it improves. You'll be able to tell straight away when you've got the right one.

Actually I think Fred may have hit on it earlier.

I went upstairs to the hacked DTivo and played the video directly there. Looked like crap. So it's bad from the get go, and has nothing to do with extraction, or XBMC, or anything else. Either it was just a bad feed, or something is horribly, horribly wrong with this particular DTivo unit.

I set up an HBO movie to record downstairs (on the non-hacked DTivo) and upstairs (on the hacked one) last night. When I get home from work today, I am going to extract it from the hacked one, toss it down onto my video server, fire it up via XBMC, AND fire it up off the non-hacked DTivo. I can then do a comparison just by toggling the video input on the TV. Should sort this out once and for all; will post the results.

(My wife's theory is that I am scrutinizing the video far more than I did before I started this project. She may have a point. Stupid subjective criteria...)

I will check the filters on XBMC though. Thanks!

--chris

cheer
04-08-2005, 09:57 PM
Follow up:

I set a movie on HBO to record on the downstairs (unhacked Tivo) and upstairs (hacked Tivo) units. Downstairs is hooked up to a 36" non-HD TV. From the upstairs, I extracted via TyTool as a .ty file, then dumped it down to my media server. Played it back on the downstairs TV via XBMC.

Result? No difference, or at least no significant one (and the differences I did see were likely subjective). My problem, thus, was a combination of (A) a poor-quality source (one of Spike's ST:TNG episodes) and (B) excessive scrutinization on the part of the viewer.

Time to really get busy with TyTool now!

Thanks to everyone for all the help.

--chris

FredThompson
04-08-2005, 11:31 PM
Glad to hear it. It was confusing, to say the least, when I first saw the huge quality differences. Variable bitrate and crappy feeds to DirecTV were the last things I'd have expected.

If you're watching the other ST shows, please drop me a line when Tribbles and Tribbelations are coming up. I'd love to have those. There's a real cool site which discusses how the DS9 one was made at http://www.skotophile.com/StarTrek/