[mythtv-users] Transcoding with and without cutlist

[Michael T. Dean]

On 08/31/2012 11:48 AM, Stephen Robertson wrote:
> On Fri, Aug 31, 2012 at 3:38 PM, Michael T. Dean wrote:
>> On 08/31/2012 09:42 AM, Stephen Robertson wrote:
>>
>>> On Fri, Aug 31, 2012 at 2:15 PM, Michael T. Dean wrote:
>>>> On 08/30/2012 04:59 PM, Stephen Robertson wrote:
>>>>> I was experimenting with cutlists and transcoding for the first time
>>>>> to remove some excess from the beginning and end of some recordings
>>>>> however adding the cutlist seems to cause a problem.  Below are two
>>>>> logs for a transcode job on the same recording with and without
>>>>> cutlist.
>>>>>
>>>>> Any suggestions?
>>>>
>>>> Perhaps a description of what you mean by "a problem" so that we don't
>>>> have
>>>> to guess based on your log output/know what we're looking for?
>>>>
>>>> Mike
>>> Sorry that wasn't very clear.  Though saying that I'm not sure what
>>> the problem is other than when I run transcode on the recording I have
>>> edited the log has an entry saying transcoding failed.
>>>
>>> Aug 30 21:53:32 bressay mythlogserver: mythtranscode[23758]: E
>>> CoreContext mpeg2fix.cpp:1178 (BuildFrame) avcodec_encode_video failed
>>> (0)
>>> Aug 30 21:53:32 bressay mythlogserver: mythtranscode[23758]: E
>>> CoreContext main.cpp:692 (main) Transcoding
>>> /media/disk/Recordings/1033_20120819061000.mpg failed
>>
>> Is this a lossy transcode (i.e. transcoding to MPEG-4 in NuppelVideo
>> container) rather than a lossless (MPEG-2 to MPEG-2) transcode?  I think
>> there was recently a bug fixed on the lossy encoder that caused failures
>> with some videos.  (And, FWIW, I suggest you only do lossless transcodes
>> with mythtranscode.)
>>
>>
>> Mike
> The entirely honest answer is that I don't know!!  I just hit the
> transcode menu option!
>
> Looking at the database settings using mythweb I see
>
> DefaultTranscoder is 0
> JobQueueTranscodeCommand is mythtranscode
>
> from the log I see
>
> Aug 30 21:50:25 bressay mythlogserver: mythtranscode[23628]: N
> CoreContext transcode.cpp:799 (GetProfile) Transcode: Using autodetect
> profile: MPEG2
> Aug 30 21:50:25 bressay mythlogserver: mythtranscode[23628]: N
> CoreContext transcode.cpp:1273 (TranscodeFile) Switching to MPEG-2
> transcoder.
>
> so I guess it is MPEG-2 MPEG-2.
>
> I'm not trying to save space as such so lossless would be what I was after.
>

That's only lossless if you've set the default MPEG-2 transcoder to a 
transcoding profile that specifies lossless transcoding.  Look at your 
transcoding profiles, and set up one (such as High Quality) to be 
lossless.  Then, in Watch Recordings, find the episode, then hit MENU 
(once or twice until you get the right menu) and choose Job 
Options|Transcode (or something like that) and choose the profile you 
want to use.  That way, you can see if it's only when doing the lossy 
transcodes.

Also, make sure you enable:

Save original files after transcoding (globally)
If enabled and the transcoder is active, the original files will be 
renamed to .old once the transcoding is complete.

in mythtv-setup before testing transcoding.  (And then you can put the 
original back in place and rebuild the seek table to try other options.)

Mike