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

[Michael T. Dean]

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