Question about encoding of tivo files

mtepper27

New member
I have VR TV Suite 5 and am just found out about and downloaded the VR TV Suite 6 trial version.

When encoding the exact same TIVO file in the exact same way, for example, as a h.264 transport stream, the resulting file from VR6 is 14mbps bitrate while the file resulting from VR5 is 10mbps.

My question is, what accounts for the vast difference in quality between files from VR6 and VR5?
 

Danr

Administrator
Staff member
Which output profile are you using? We can help you more if you provide us with your log file. The log file can be found from our help menu. Best to send the log file as an email attachment to support@videoredo.com. Mention topic 37426 in the subject.
 

Dan203

Senior Developer
Staff member
Are you sure you used H.264 in v6? In v5 profiles were codec specific so you had an MPEG-2 TS and an H.264 TS profile. In v6 all the default profiles are "match source" meaning that if the input is MPEG-2 the output will also be MPEG-2. You have to specifically change the codec to H.264 to force a recode to H.264.
 

mtepper27

New member
Thank you. I didn't realize that the changes I made to the profile output didn't save because I didn't save them. When saving a TIVO Program Stream as Match as Source, can you tell me what the difference is between MPEG-Program Stream, TIVO File, and TIVO-TS File, and what they mean in terms of transferring back to a TIVO?
 

Dan203

Senior Developer
Staff member
The Program stream option is just a generic .mpg file and will lose all the .tivo specific metadata. So you probably don't want that.

The TiVo File option ONLY works for MPEG-2 video. It's the older format originally developed for the old Series 2 TiVos. It's still supported by newer TiVos but only for MPEG-2 video. If you're editing/encoding H.264 video then you have to use the TiVo-TS option. That's what modern TiVos use by default. There is no advantage to using the old format because pyTivo remuxes as TS if you do anyway. So you're just adding extra work to the upload process if you do. We only still offer it in VRD because the older units, and some of the foreign units, only support the old format.
 

mtepper27

New member
Thank you for giving such a detailed explanation.

So, I should be saving the files as TIVO-TS files. And my final question is, does this mean there's no point to me downloading files off my TIVO via PYTIVO or Kmttg as program streams since I'm using the newer TIVO Bolts?
 

Dan203

Senior Developer
Staff member
If your channels are H.264 then there is absolutely no reason to use PS. H.264 only works with TS.

If your channels are MPEG-2 then you have a choice. PS files will not have the download errors that you commonly see in files downloaded as TS. However they have their own issues. They have issues with captions, they're slower to download, and occasionally if there is an error in the source the transfer will just stop without warning and you'll end up with a partial file and not even realize it until you go to edit/watch the file. The biggest issue with TS is those stream errors you get. Unfortunately all these errors happen on the TiVo side of things, so there is nothing that can be done to fix it. I tried a million different combinations of buffer sizes, transfer rates, etc..., etc.. when I was developing pyTivo Desktop and nothing seemed to help.
 
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