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View Full Version : tytool, tystudio vs tmpg encoder



panjabi
09-21-2005, 06:19 PM
forgive me for not understaning this properly.

Tivo stores video as ty files, is that mpeg2 or is it some raw format or is it mpeg format

when we use tytools or tystudio, are they actually encoding video from ty files to lets' we selected mpeg with sound or are they just changing to mpeg from ty format without encoding.

if it is re encoding the video, does the quality degrades?
ty format is it interlased or deinterlased

i have heard tmpg encoder is the far best in the industry, why are not people using tmpg to encode ray ty video

correct me if im wrong

eastwind
09-21-2005, 06:25 PM
TiVo's files are mpeg2 (program streams, I think) wrapped by TiVo superblocks and chunk headers that let the TiVo do it's "trickplay" stuff. The tools you mentioned (tystudio and tytool) strip the extraneous wrapping and leave the mpeg2 video/audio without re-encoding.

ew

panjabi
09-21-2005, 06:45 PM
cool man thanks for the tip is the video interlased or deinterlased

cheer
09-21-2005, 08:40 PM
cool man thanks for the tip is the video interlased or deinterlased
Interlaced, generally. (I can't comment on the HDTivo files but I would presume it would depend on how they were broadcase -- 1080i, 720p, and so on.)

Anyway SD DTivo videos are all (so far as I have seen) 480 x 480, interlaced MPEG2. The best way to handle them depends on what you want to do with them:

Burn to DVD: simplest way I've found is to just use TyTool, multiplex to VOB, and burn with Nero.
Burn to DVD with edits: editing compressed video is always dicey. TyTool does not do encoding, so if you make (frame accurate) edits you can end up with P or B frames that reference a missing I frame. This can cause video weirdness at the edit point. I don't like that, so instead I use TyProcess (part of TyStudio) to convert to .MPG, then I bring the file into VideoReDo and make my edits there. VideoRedo will re-encode at the edit points, giving cleaner (but, admittedly, with some loss) edits. Then I pull it into DVD-Lab Pro and author.
Convert to MPG for viewing on a PC. Of course, your PC has a progressive display but the file is interlaced. I used to deinterlace, but that looks like crap. I then tried using a decomb filter with Avisynth, which looked better, but then FredThompson turned me on to just using Media Player Classic with ffdshow set to deinterlace on the fly. It's not perfect, but it's better.
Convert to Divx/Xvid/3ivx/whatever for viewing on a PC. I don't do this often, but when I do I just use AutoGK. Results are decent enough. Note that you're re-encoding here (duh) so you will take a quality hit.
Play on an Xbox using XBMC. This is a whole can of worms all its own, so let me know if you're interested and I'll post my experiences with this effort.

More than anything else, I recommend experimentation. I spent about six or seven months trying various combinations before I settled on the methods I prefer. Even now, nothing is perfect, and the whole interlacing thing makes me batty. It's not so bad on an analog TV, but when I got my nice new plasma I spent another few weeks experimenting before I came to the conclusion that it's best to just feed the darned TV interlaced video and let its circuitry decomb accordingly. (In fact, I get better video when I turn OFF progressive scanning in my DVD player, 'cos the TV does decombing much better than the DVD player does.)

Note also that a DVD with 480 x 480 video is nonstandard and some DVD players don't like it. My older Pioneer doesn't, but my newer players seem fine with it.

Finally, things are different with SA Tivos. As I understand it you can have the Tivo record at (roughly) DVD resolution. I have no experience with SA Tivos, so take that for what it's worth.

YMMV.