[mythtv-users] transcode not working

[Raymond Wagner]

On 1/5/2012 13:01, Josh Rosenberg wrote:
> On Thu, Jan 5, 2012 at 12:31 PM,  Raymond Wagner<raymond at wagnerrp.com>  wrote:
>> On 1/5/2012 09:18, Josh Rosenberg wrote:
>>> I'm attempting to transcode recordings for size.  (A 4 hour sports
>>> program in raw QAM is 68 GB, which seems excessive for long-term
>>> storage.)  When I tell the frontend to transcode a recording (using,
>>> for example, medium quality), it apparently fails; nothing happens at
>>> all.
>> You've got something seriously funky going on there.  That_really_is_
>> raw QAM, all 38.4Mbps of it.  A typical HD recording should be closer to
>> 16Mbps, or maybe 25-30GB for the whole 4-hr recording.
> So it seems that I accidentally picked an atypical example; most of my
> recordings are closer to either 3.8 GB/hr or 5.6 GB/hr.

Accidental or not, that's downright broken.  If you happen to have any 
logs from that incident, or any other recordings displaying that 
behavior, it would be very interesting to see.  Do you ever access the 
device with QuickTV or something else that may have disrupted the PID 
filtering?

> Regardless, though, there are some things that I'd be happy to keep
> around at a rate closer to 1 GB/hr, and transcoding isn't doing
> anything now.

If you really want to transcode, don't use mythtranscode.  You're just 
going to end up with clumsy MPEG4 in a NUV.  No one else plays NUV, no 
one likes NUV, and on the occasions there have been discussions among 
the developers about replacing it with something else, the only 
opposition tends to be (the lack of) motivation.  Use something 
external.  Transcode to h264, and a more common container like mp4 or 
mkv.  There are various scripts floating about to do this using ffmpeg, 
mencoder, or handbrakecli.

Alternatively, rather than cut the data rate, cut the duration.  Soccer 
(football) is the only sport I know of off hand where the clock never 
stops, and that's limited to 90 minutes.  Football (handegg) might be 60 
minutes on the clock, but it's all of 15-20 minutes of gameplay drawn 
out to three hours.  Basketball might 50 minutes when you add in free 
throws and throw ins.  An average baseball game might be 80 at-bats for 
20 minutes of pitching or running, and three hours of the pitcher and 
catcher making suggestive glances at each other.

Long story short, if you intend to store these long term, why not just 
put cut points around everything that's not actual gameplay, and use the 
lossless transcoder?