[mythtv-users] Recoding in native TS format and Setup with ATSCasDVB card

[Andrew Chung]

I had hoped Howard's response was what I thought it was but I wanted to be
double sure.  I just opened the file in VLC and HDTV2MPEG and walla!  It
sees all the goodies in the stream.

I didn't realize that Myth would not be able to handle the file without it
having the .nuv file extension.  Thanks for the information on that.

Changing the file name is probably useful for me since I want to be able to
view the file outside of Myth.  Moving the file and then creating a symlink
in the Myth directory is probably the way to go for me.  I also see that the
SQL database is the location of the actual program information for a given
stream which is nice.

-----Original Message-----
From: mythtv-users-bounces at mythtv.org
[mailto:mythtv-users-bounces at mythtv.org] On Behalf Of Michael T. Dean
Sent: Thursday, May 05, 2005 23:59
To: Discussion about mythtv
Subject: Re: [mythtv-users] Recoding in native TS format and Setup with
ATSCasDVB card

On 05/06/05 02:25, Andrew Chung wrote:

>Howard wrote:
>
>>--- Andrew Chung <acchung at techie.com> wrote:
>>
>>>Is it possible to have MythTV record to a raw .TS file instead of its 
>>>native .nuv format?  What is the difference between these two file 
>>>formats?  My goal is to archive shows on a permanent basis and I 
>>>would prefer to get either a raw .TS or a pure MPEG-2 from the 
>>>transport stream.
>>>Also I'm checking the option on the video input to save as .ts 
>>>instead of .ps.  What does this actually do?
>>
>> AFAIK myth does record from ATSC cards in either ts or ps, the nuv
>>
>>extension doesn't affect what the file actually is.  
>>file 2005_20050427220000_20050427230000.nuv
>>2005_20050427220000_20050427230000.nuv: MPEG transport stream data
>>
>>I record mine using .ts simply because my box is underpowered to begin 
>>with and I think that recording in .ps involves more processing but a 
>>smaller file.
>
>So the .nuv file format is just a wrapper over the real .TS?
>
No.  Re-read Howard's response.  The ".nuv" is just the last four characters
of the filename.  The filename has absolutely nothing to do with the
contents of the file.  The file is an MPEG-2 Program Stream or an MPEG-2
Transport Stream if recorded from an ATSC/DVB card or a hardware encoder
(like the PVR-x50).

>If that's the case that would be great!  Would the myth transcoder tool be
able to unmunge the file?  Is it possible to automatically do this?
>
If the file is currently "munged," all it takes to "unmunge" it is:

FILE=<name of your .nuv file>
mv ${FILE}.nuv ${FILE}.mpg

(Note, however, that the file won't be usable by Myth if you rename it, so I
suggest you do a cp instead if the extension really bothers you.)

>What is the benefit of keeping the recoding in .nuv format?
>  
>
See above.

To answer a slightly different question, though, the benefit of using the
".nuv" filename extension even though it's not a NuppelVideo file is that
MythTV was written to use a ".nuv" extension since originally all files were
written in NuppelVideo format.  When support for MPEG cards (hardware
encoders and DVB cards) was added, keeping the extension the same meant no
changes were required to the Myth code.  Also, since the filename extension
doesn't mean anything, it doesn't detract from the effectiveness of the
application.

Totally off-topic rant about filename extensions:
Unfortunately, though Bill G. has taught the world that a filename extension
is important because he couldn't figure out how to determine a file type
correctly, so he punted and used an ugly hack where he
*forces* the user to know the filetype at the time of saving the file and
know the appropriate extension for that file type (as defined in the
*local* registry--meaning that file may have to be renamed to be usable on
another system).  Then, around about Win95 days, he decided that the user
shouldn't have to know this, so--instead of fixing the OS--he started
rewriting all his applications (from Notepad to WordPad/Write to Word to
Excel, etc.) so that--regardless of what the user tries to name a file--the
application adds the extension it thinks is correct.  
Therefore, users now end up with filenames like "myprog.c.txt" and
"quicknotes.txt.doc", but since Windows Explorer typically does not show the
extension, the user can't figure out why when he/she double-clicks the file
it opens in the wrong application or why an application says the file
doesn't exist (it's right here--why can't the app see it?).  
Now that's what I call an easy to use OS...

Mike

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