Some simpleton questions on Transcoding and Burning DVD's

[jksmurf]

I am full up to the gills with reading and trying and transcoding. Since having kids 3 years ago I haven't played around with the PC much (used to a lot) but it looks like I missed the "rip DVD's and transcode" revolution. There's a truckload to learn!

Well, I now have 4 coasters and a succesful burn (yippee!). I have been trying MyVideos which to be fair to reven is pretty damn good, it's just my own inexperience that hasn't got me to actually perform the final step and burn a DVD with it yet, it got all the way to making the DVD's IFO and VOB files then stopped as (a) it was still slightly too big for a DVD and (b) the first time I ran out of disk space and got an ugly exit.

So my questions are all related ot a 2 hour show which I'm trying to squeeze onto a DVD5. I tried both my MyVideosRC3 and ConvertXtoDVD. I used ConvertXDVD (Trial, it is quite good, I had previously tried the free XVIDtoDVD version too) as although MyVideos worked well, it doesn't have auto-shrink (you need to make sure the thing will fit on a 2GB). Bearing in mind that:

1. A 0.9GB Xvid file of a show took 9hrs to to author a DVD and burn it, using ConvertXtoDVD.
2. A 5GB MPEG2 file of the same show took just 4hrs to author a DVD (but not burn it, although that step is very quick) using MyVideos.
3. A 5GB MPEG2 file of the same show took 6hrs to author the DVD (but not burn it, although that step is very quick) using ConvertXtoDVD. I didn't burn it as I was testing ConvertXtoDVD which has a watermark.

ConvertXtoDVD can shrink it automatically, so I guess that takes time too.

Q1. Presumably a 2 hour show does not fit on a DVD which has "120mins" stamped on it as there are simply many many different quality settings in GBPVR and by reducing the MPEG quality settings I can get it to fit? Would it possible to have GBPVR's default quality setting for high quality encoded by a PVR-150 to be just high enough to fit on a DVD5 disk?

Q2. Why did the 5GB MPEG2 file take less time to convert to DVD than the 1/5 size (0.9GB) XVID file? Is XVID encoding so complicated that it takes that long to convert it to a DVD.

Q3. I'm trying to send these shows to a friend. If he has a DVD Player than can play XVID/DIVX natively, can I just simply burn a (or even 4) 0.9GB file(s) onto a DVD and say here you go, play these, as that will be much faster than making a DVD, either from MPEG2 or XVID. Of course the transcoding from MPEG2 to XVID takes a wee while, but not that long. Do DVD players (not PC ones) recognize different files and ask which ones fo you want to play?

Q4. How much faster can I expect a "modern day CPU" to perform these tasks? Clearly 9 hours is a bane if I intend to do this on a regular basis.

Ta!

k.

[jc8472]

Q1) The mpeg you mentioned must be approx 4.7 Mbps VBR.
2.1 Mbps VBR = approx 4 hours on a 4.7 dvd disc,
3.1 " " would yield around 3 hrs on a " ", and so on.
. I think GBPVR's default quality should suffice. I use set top dvd recorder bitrates/resolutions as a basis.

Q2) I believe that the complexity lie in the fact that the xvid file must be transcoded to mpeg2 THEN converted to dvd. Compiling the files + plus the burning time will be the variables. Compiling time is the most difficult part for me because I dont want to waste a megabyte of space on a dvd writable disc. Squeeze in some mp3 and apps to fill in the space and let er rip. Burning a data disc is far less time consuming than authoring a dvd. Mpeg2 is most suitable for dvd-video format. Xvid is heavily compressed, so yip indeed.

Q3) Yip, you can burn it with any data disc burning app nero, deepburner,etc. Before I purchased a mediamvp, I used a philips dvp 642 player to play my mpegs,divx,xvids, it was very choosy with microsoft mpeg4. I still remember playing mpeg1/2,xvid and divx files. Only certain set top dvd players can playback divx xvid mpeg files, they usually display all the "SUPPORTED" files at a browsing menu with icons so that one can choose at his or her leisure.

Q4) A modern cpu should be quicker, I have an sempron 2400 (1.6 Ghz) processor and it takes only 17 minutes to transcode the mpegs from GBPVR to dvd and 15 mins to burn with my cheapol 4x media. I'm sure a AMD 4800 would cut that time in half or less. Also, I'm using the Ulead MovieFactory 3 program that came with the retail pvr 150 nonmce. It's a great thing GBPVR outputs DVD compliant files, wintv2000 rarely outputs compliant files.

I help this helps.

[jksmurf]

Thanks JC, you have provided some very clear answers on all this.

Q1. GBPVR quality settings give 5.5~9.0MBits/s for High Quality and 3.5~7.2 for Medium. I guess I could play around with these in future. Not sure how it decides when to use which rate though.

Q2. Ah, that's GREAT to know. I mostly record to MPEG2 anyway as I use the MVP almost exclusively, and it plays them natively. So that's good, I was wondering if transcoding then converting to DVD would be better/faster but apparently not!

Q3. He doesn't have XVID/DVIX as it turns out and neither do I (obviously), but in terms of HD space, I now see the advantage of native XVID/DVIX players (like fvfv's little purr over on the xbox ) .

Q4. LOL. 17 mins. How embarrassing. Maybe I should join the hot CPU society. I just get a somewhat perverse kick out of utilising my old system to it's maximum capacity (like running all night to make a DVD..yeah...)

It's almost there, when I use comskip+comclean it almost makes it to 4.7GB, just a little bit too big. I tried DVDShrink to cut out some of the half time babble but there is only one MPEG file in DVD shrink (and one set of start and end points), and so far I can't work out how to do multiple cuts eg. snip off the game intro and a bit in the middle and a bit at the end. I am happy with what comskip/comclean does, all I need to do is being able to chop out a little extra.

So all it seems I need to do is take the original MPEG, run comskip/comclean, then check the size before the DVD convert (hopefully the resultant VOB will not be bigger unless lots of chapters added) and if still too big, find a program which can simply chop out the bits I can live without to squeeze it onto a DVD while still maintaining the original 100% quality. I am loathe to allow DVDshrink to compress due to quality loss. I had hoped DVDShrink was such a program, maybe it is, I just can't work it out yet!

Cheers again,

k.

[HtV]

So all it seems I need to do is take the original MPEG, run comskip/comclean, then check the size before the DVD convert (hopefully the resultant VOB will not be bigger unless lots of chapters added) and if still too big, find a program which can simply chop out the bits I can live without to squeeze it onto a DVD while still maintaining the original 100% quality. I am loathe to allow DVDshrink to compress due to quality loss. I had hoped DVDShrink was such a program, maybe it is, I just can't work it out yet!

Cheers again,

k.

I would really try to keep the mpg-size small enough, so that it doesn't have to be re-encoded, because that's what takes so much time. You probably can turn off re-encoding somewhere in settings. If afterall the dvd-files are too big for burning to a 4.7-dvd, then you should use dvd-shrink to shrink the files to a size that fits. Dvd-shrink does a wonderful job with dvd's upto 20%too big. Also depends ofcourse on the quality of the source material.

So to start I would set the medium-recording-setting (that is the setting gbpvr uses by default) in GBPVR to a setting that it gives the right size for your needs.

[jksmurf]

I would really try to keep the mpg-size small enough, so that it doesn't have to be re-encoded, because that's what takes so much time. You probably can turn off re-encoding somewhere in settings.

That's my thoughts too. A lot of reading later and it seems what I need is a simple MPEG editor with which I can cut out bits, one that doesn't change the sync of Audio/video and is fast (e.g. TMPGEnc, which I understand doesn't re-encode the whole thing, just the frames either side of the cut). I really want to do what you suggest and NOT re-encode if I can get those bits cut out.

I am going to have a crack at a few of the freeware ones, cuttermaran perhaps. MPEG2Schnitt looks good too, some commercial ones out there too, that do not re-encode (VideReDo, Womble's MPEG-VCR, TMPGEnc e.g.)

btw when you say " re-encoding somewhere in settings" in what program?

k.

[HtV]

btw when you say " re-encoding somewhere in settings" in what program?

k.

I mean in the dvd-authoring program. There are (a lot?) programs like Nero for example that re-encode anyay even when it's not needed. often there is a setting for that, so that it only re-encodes when needed.

for the editing programs I found videoredo very good (but not free), cuttermaran is very good too but less intuitive. Both can be used in (automated) combination with comskip.

Maybe you already found it but I'll mention it anyway: http://www.videohelp.com/ is a very good site for info on all this.
Good luck.

[HtV]

You might want to take a look at Rejig http://www.videohelp.com/tools?tool=ReJig

I had a 2 GB mpg file (GBPVR), Rejig demuxed it, dvdauthored it to dvd-structure. It took just over 10 mins to do that, no re-encoding ofcourse. With Nero it took over an hour.
When your mpg file is to big Rejig can transcode it to a smaller size. It should be good at that too. I know it was always put at the same level as DVD-shrink, which is the best.
Only problem might be the automation of it. For the occasional dvd I think it works very well.

[jksmurf]

You might want to take a look at Rejig

Cheers HtV, I'll have a look. Overwhelmed with options right now!

k.

[HtV]

Well, I think it's our obligation to keep each other busy, isn't it. When we sit down and start watching/listening shows the waf might go down very quickly.

cya Hans

[jc8472]

One point I forgot to mention is; Convertx M402U recordings use 17 mins (over 4 gigs of video), whereas my Emuzed Maui III recordings consumes only 9 mins to convert to dvd (over 4.1 gigs). No more "converting to dvd compliant format" message from MFactory3, which by the way "with wintv2000 mpegs" took a day and a half. That's one of the many reasons I use GBPVR.