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

[John Pilkington]

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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>>
> 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.