[mythtv-users] Question on recording sizes and DVD burning

Tue Jan 21 23:17:28 UTC 2014

On 1/21/2014 2:03 PM, Joseph DeGraw wrote:
> On 01/21/2014 04:16 PM, John Finlay wrote:
>> On 1/21/2014 8:51 AM, Joseph DeGraw wrote:
>>> On 01/21/2014 11:32 AM, John Pilkington wrote:
>>>> On 21/01/14 15:21, Joseph DeGraw wrote:
>>>>> On 01/21/2014 09:56 AM, John Pilkington wrote:
>>>>>> On 21/01/14 14:27, Joseph DeGraw wrote:
>>>>>>> On 01/21/2014 09:08 AM, Joseph DeGraw wrote:
>>>>>>>> A while ago I upgraded my hardware to include HD recording with a
>>>>>>>> ceton
>>>>>>>> card and its been great. However, My girlfriend wants to burn
>>>>>>>> some of
>>>>>>>> her shows to DVD that are 2 hours long. However the size of the
>>>>>>>> files
>>>>>>>> are like 10 gigs. In mytharchive they can come down to just over 5
>>>>>>>> gigs.
>>>>>>>> The shows are 1920x? HD from comcast provider. I was thinking that
>>>>>>>> reducing them to 720i would be fine to make them smaller to fit on
>>>>>>>> DVD.
>>>>>>>> This brings up transcoding (which Im looking into right now) and
>>>>>>>> profiles.
>>>>>>>>
>>>>>>>> How do you handle this?
>>>>>>>>
>>>>>>>> jdegraw
>>>>>>> Ok, I have gone into the menu in mytharchive after reading an older
>>>>>>> thread and selected a recording profile. I guess my only question
>>>>>>> is :
>>>>>>> What do the different profiles mean?
>>>>>>>
>>>>>>> HQ, EP, LP, SD
>>>>>>>
>>>>>>> I know if I select a SD setting it will not finish and stalls out. I
>>>>>>> dont even get an error message. Therefore, Iam trying the LP one
>>>>>>> for a
>>>>>>> single sided DVD for a 10 gig, 2 hour Lifetime Network movie.
>>>>>>>
>>>>>>> MythTV .27 / Mythbuntu 12.04 based
>>>>>>>
>>>>>> With much of the USA now apparently HD only this is clearly
>>>>>> getting to
>>>>>> be a common problem, and at present I don't think MythArchive handles
>>>>>> it well.  The encoder options are defined here: (Fedora build)
>>>>>>
>>>>>> /usr/share/mythtv/mytharchive/encoder_profiles/ffmpeg_dvd_ntsc.xml
>>>>>>
>>>>>> and are used within /usr/share/mythtv/mytharchive/scripts/mythburn.py
>>>>>>
>>>>>> I suspect that the best option would be two-pass specifying the
>>>>>> required file size; a fairly minor edit of the HQ option, probably,
>>>>>> but requiring some research in the ffmpeg documentation or code.
>>>>>>
>>>>>> As far as I can see the -b:v value doesn't do much.  The pal-dvd
>>>>>> profile, which I use, seems to focus on a q value of 2 as its guiding
>>>>>> light.  That isn't specified in the file above.
>>>>>>
>>>>>> If at present you are getting a 5 GB file the m2vrequantiser option
>>>>>> within MythArchive will shrink that quickly with a quality that
>>>>>> should
>>>>>> be acceptable, but I wouldn't like to rely on it for much higher
>>>>>> ratios.
>>>>>>
>>>>>> HTH
>>>>>>
>>>>>> John P
>>>>>>
>>>>>>
>>>>>> _______________________________________________
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>>>>>> mythtv-users at mythtv.org
>>>>>> http://www.mythtv.org/mailman/listinfo/mythtv-users
>>>>>>
>>>>> Thank you John,
>>>>>
>>>>> So, It seems that SP is the profile to use on these large HD
>>>>> recordings.
>>>>> Iam having a problem that it seems to take a rather long time to run
>>>>> mytharchive and it seems to be stuck at this point:
>>>>>
>>>>> *mythffmpeg -threads 6 -v 1 -i
>>>>> "/var/lib/mytharchive/temp/work/1/newfile.mpg" -r ntsc -target
>>>>> ntsc-dvd
>>>>> -b:v 4771k -s 720x480 -acodec copy -copyts -aspect 16:9
>>>>> "/var/lib/mytharchive/temp/work/1/newfile2.mpg" -map 0:0 -map 0:1 *
>>>>>
>>>>> I see that mythmmpeg is still running and taking up ALOT of CPU time.
>>>>> Using 'Top' it shows approximately 200 in cpu usage. Seems to just sit
>>>>> there for hours. Is this normal? I dont have any error messages in any
>>>>> of the logs - mythburn.log, progress.log, kern.log.
>>>>>
>>>>> What does show in 'top' is that mythmmpeg is still running and
>>>>> sometimes
>>>>> will spawn another mythmmpeg process.
>>>>>
>>>>> jdegraw
>>>>>
>>>> Yes, I think it's normal.   That's one of the problems.  Try
>>>>
>>>> mythffmpeg  -v verbose -i "infileHD.mpg" -target ntsc-dvd
>>>> "outfileSD.mpg"
>>>>
>>>> on a short recording and see how it goes.  I'm not sure how far my
>>>> experience, with h264 recordings, relates to yours, but the -copyts
>>>> seemed to be the main problem for me.  ffmpeg -i <filename> should
>>>> show what you're dealing with.
>>>>
>>>>
>>>> _______________________________________________
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>>>> mythtv-users at mythtv.org
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>>>>
>>> I will give that a try. Thank you very much for your responses.
>>>
>>> I did try it earlier on a 1/2 show and it did a good job and burned the
>>> cd. Currently, mythffmpeg is still running but at a lower cpu use. But I
>>> dont see any disk activity. So, Im going to just let it run till this
>>> afternoon. I will also try your suggestion and see what I get.
>>>
>>> Last time I actually ran out of swap space. So, I bought an additional 4
>>> gigs to boost me to 8 gigs. Now that is not a problem anymore :)
>>>
>>> Nothing in the error logs and mytharchive log still shows the mythffmpeg
>>> command line in the log as the last entry. Perhaps I assumed that
>>> something was going wrong and killed the process, removed the lock file
>>> and cleaned up the temp directory when I should have just let it run
>>> instead?
>>>
>> I gave up using mytharchive and use mythffmpeg to transcode my HD
>> programs for making DVDs and use a command line like:
>>
>> mythffmpeg -i <inputfilename>.mpg -map 0:0 -map 0:<1 or 2>
>> -deinterlace -target ntsc-dvd -aspect 16:9 -acodec copy
>> <outputfilename>.mpg
>>
>> The -map 0:<1 or 2> is used to select the best audio channel which
>> usually is ac3 5.1. I leave out the -deinterlace if the program is
>> 720p. I copy the audio since I see no reason to transcode it to mp2.
>> For a 120m movie in 1080i it takes about 140m using my old dual core
>> AMD and produces a file which is about 4.1G. The transcode uses about
>> 120% CPU according to top.
>>
>> Then I use dvdauthor and mkisofs to gen the ISO.
>>
>> John
>> _______________________________________________
>> mythtv-users mailing list
>> mythtv-users at mythtv.org
>> http://www.mythtv.org/mailman/listinfo/mythtv-users
>>
> Ok, Adding to my last post (sorry) I guess the reason it takes soooooo
> long for me is that Iam rescaling a 1920x<whatever> recording with a bit
> rate of 9000 to a 720 resolution and a bit rate of 4771.
>
> I will just let it run and see how long this thing goes. Probably look
> around to see if this thing is broadcast in 720 instead. Then I dont
> have to convert the video and it will probably take alot less time.
>
> jdegraw
> _______________________________________________
>

Actually it seems that you are transcoding to 480 not 720. The confusion 
is that you are going from 1920x1080 (1080i) to 720x480 (480i) . Try a 
command similar to mine and see if that works better. If so then the 
command generated by mytharchive is likely the problem.

John