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[Sandy B Ridge]

The option to record TV in ts format rather than jtv has been around for a while. I haven't seen a good discussion of the pros and cons of either format anywhere and a search of Interact for 'jtv ts' doesn't come up with much. Recording and time-shifting seems to work with either option. The filesize for jtv seems less than the corresponding ts file, so is there any compression going on? If so, does this result in loss of quality or is it lossless?

Pros/Cons?

Any thoughts from users? Comments from JRiver? Yaobing?

SBR

[rpalmer68]

The main thing for me is the ability to to watch a recording while it's being recorded if using jtv.

I'll start watching a program when it's about 1/2 way through and then I can skips the adds and finish at the scheduled time.

I can't do this using .ts, or at least I couldn't last time I tried, especially if I want to watch on a LS client, dlna client or gizmo.

Yaobing has discussed some other reasons in the past, like being able to save part of the timeshift file from the past if you decide you want to record something you are already watching, but he'd be best explaining it....

The downside for me is the hassle if I want to burn a recording to disc (I can't), I can't use automatic add skipping and to move a recording out of the timeshift area is fiddley as using the Library tools to move it don't work.

R

[nwboater]

My big issue with recording TV with .jtv is that Comskip can not mark .jtv files.

At this point in time with our HDPVR MC can only record with .jtv. Therefore we have no way of automatically skipping commercials for recording made in MC. This is our biggest single problem with MC after our switch from SageTV.

Rod

[Yaobing]

About ComSkip, I am not sure what the solution would be.  We have a sidecar file saved with jtv recordings.  If the software that generates ComSkip codes reads our sidecar file, it will be able to determine what show is recorded.  Then perhaps it will generate proper codes?

People wanted ts recording for this reason, as well as for portability.  There is still not a reliable way of remuxing jtv into another format, but I think the situation has improved a bit.

Recording in TS format taxes your system more because while we record, we still keep time-shifting buffering (jtv format) running .  The TS file ends up larger because jtv only saves audio and video streams.  TS may contain something more.  We try to remove some packets that are not related to the recorded program, but we do not do it aggressively in order not to accidentally remove useful info.

As rpalmer68 mentioned, jtv has the advantage of recording data already buffered (in the case you start recording after having been time-shifting for a while) but TS can only be recorded from the moment record command is issued.

[nwboater]

We have a sidecar file saved with jtv recordings.  If the software that generates ComSkip codes reads our sidecar file, it will be able to determine what show is recorded.  Then perhaps it will generate proper codes?

Does this mean the the author of Comskip would have to modify his program to read jtv files?

There is still not a reliable way of remuxing jtv into another format, but I think the situation has improved a bit.
 

Can you elaborate?

Recording in TS format taxes your system more because while we record, we still keep time-shifting buffering (jtv format) running .

I believe SageTV does the same thing and it works fine on fairly modest systems. If it doesn't I certainly wouldn't mind giving up that feature to have Comskip function on MC recorded TV files.


Thanks very much for your response here Yaobing and for all your efforts to keep improving the TV experience in MC.

Rod

[BartMan01]

How 'universal' is jtv?  Does VLC play it natively?  Do third party tools allow you to chop it up and remux?  Does jtv capture the entire program stream including closed captioning?

Those are the questions that I would need to have answered before using .jtv as my recording format.  Another thing I am reading that would concern me is that even .ts seems to be dropping some content from the original program stream.

With WMC, I get .wtv files that contain either mpeg or h264 video along with the full original program stream (or at least with nothing that is actual content removed).  There are tools out there like VideoReDo that let me remux the original streams w/o the commercials for items that I want to archive.  This is a true lossless remux with only moments of video re-encoded at the cut points.

The only plus I see for .jtv from the comments so far is that it lets you record a program 'in progress'.  But if it is a proprietary format that I can't remux easily or drop in to my favorite editing tools I can't see that outweighing that flexibility.

[rpalmer68]

There is still not a reliable way of remuxing jtv into another format, but I think the situation has improved a bit.

I'm a little confused.

If I stream a JTV file to my wifes ipad it comes over as a MPEG file, so you must be abe to remux them somehow.

[Gustovier]

Why don't you always have MC record when you tune a channel. That's how SageTv works. If a user then changes the channel or stops playback without explicity pressing record then don't persist it. Or better yet persist it temporarily (til the time of when the show is supposed to be completed). If a user does does explicity choose to record the show then you permanently save the recorded show.  The goal must be to use a non propietary format and use .ts or something like it.

[Yaobing]

I'm a little confused.

If I stream a JTV file to my wifes ipad it comes over as a MPEG file, so you must be abe to remux them somehow.

That is why I said the situation has improved.  I think we do remux the recordings in some container for hand-held devices.

[Sandy B Ridge]

Why don't you always have MC record when you tune a channel. That's how SageTv works. If a user then changes the channel or stops playback without explicity pressing record then don't persist it. Or better yet persist it temporarily (til the time of when the show is supposed to be completed). If a user does does explicity choose to record the show then you permanently save the recorded show.  The goal must be to use a non propietary format and use .ts or something like it.

This is what MC does. It records what you are watching from the moment you first tune including any channel changes. I think it records the number of hours you have set it to record in the TV options. If you choose to keep a particular show you are watching, then AFAIK you can set it to permanently keep the show from the OSD menu (or from the right click menu). Pretty good.

What I was confused about (and Yaobing has now cleared up for me) was how I could still timeshift when set to record ts files. Sounds like you are recording both the ts file and the jtv timeshift file simultaneously to the HD. Presumably, therefore, if you choose to 'keep' a show that you are currently watching via the OSD menu, then it will record it in jtv format rather than ts even if ts is chosen in the options.  I'll give it a go tonight unless Y can confirm the behaviour before I get home!

SBR

[Yaobing]

When you choose to record in TS format, using right-click/OSD menu to "Record" will only let you start recording from the moment you issue the command, to TS file.  Data that is already buffered will not be saved.  On the other hand, you can use "Save time-shifting" feature to save the entire time-shifting session.

[Yaobing]

How 'universal' is jtv?  Does VLC play it natively?  Do third party tools allow you to chop it up and remux?  Does jtv capture the entire program stream including closed captioning?

jtv can be played in ZoomPlayer, Media Player Classic, Windows Media Player.

Any player/editor that uses DirectShow can handle jtv.

Closed Captioning is not captured.

[BartMan01]

jtv can be played in ZoomPlayer, Media Player Classic, Windows Media Player.

Any player/editor that uses DirectShow can handle jtv.

Closed Captioning is not captured.

Can you clarify a little?  What common/popular editors use DirectShow natively?  Also the use of DirectShow implies to me that the direct video stream is not accessible - that it must be decoded/re-encoded to edit.  Is is not possible to simply remux the .jtv content to a different container keeping the original streams or edit and save only re-encoding the sections that actually changed?

Lack of closed captioning seems like a major accessibility issue.  For families with hearing impaired members, this is a critical feature.

Correct me if I am wrong but it sounds like the options are:
.JTV, to record an 'in progress' stream but with the lack of portability to platforms/programs that do not use DirectShow and loss of Closed Captioning.
.TS if you are hearing impaired or need cross platform compatibility.  You lose the ability to capture 'in progress' stuff so you have to know ahead of time that you will need to have recorded what you are watching.

FWIW, WMC has the same issue that it doesn't' capture anything before the record button is pushed, but for those who need to there are ways to grab the buffer file and save.

[Sandy B Ridge]

When you choose to record in TS format, using right-click/OSD menu to "Record" will only let you start recording from the moment you issue the command, to TS file.  Data that is already buffered will not be saved.  On the other hand, you can use "Save time-shifting" feature to save the entire time-shifting session.

Ah OK, thanks.

SBR

[Yaobing]

Can you clarify a little?  What common/popular editors use DirectShow natively?  Also the use of DirectShow implies to me that the direct video stream is not accessible - that it must be decoded/re-encoded to edit.  Is is not possible to simply remux the .jtv content to a different container keeping the original streams or edit and save only re-encoding the sections that actually changed?

It is a problem that video editors using DirectShow are hard to find.  I never tried anything that is not free.  One editor I tried, and works, is Windows Movie Maker on Vista (not Windows Live Movie Maker).

Correct me if I am wrong but it sounds like the options are:
.JTV, to record an 'in progress' stream but with the lack of portability to platforms/programs that do not use DirectShow and loss of Closed Captioning.
.TS if you are hearing impaired or need cross platform compatibility.  You lose the ability to capture 'in progress' stuff so you have to know ahead of time that you will need to have recorded what you are watching.

You summarized it correctly.

[Gustovier]

It is a problem that video editors using DirectShow are hard to find.  I never tried anything that is not free.  One editor I tried, and works, is Windows Movie Maker on Vista (not Windows Live Movie Maker).

You summarized it correctly.

So what is SageTV doing differently? It records in TS and doesn't have the recording limitation of not being able to save the buffer. Additionally if you are using a tuner that supports it, sage is also able to store the closed caption stream in the TS file as well.