[mythtv] Live transcode while recording

Chase Douglas chasedouglas.lists at gmail.com
Tue Dec 2 17:06:34 UTC 2008

On Dec 2, 2008, at 11:49 AM, Michael T. Dean wrote:
> On 12/02/2008 11:01 AM, Oliver Brown wrote:
>> On Tue, Dec 2, 2008 at 2:29 PM, Chase Douglas wrote:
>> <snip>
>>> The downside is
>>> that if you watch a stream twice transcoding on the fly to the same
>>> codec, then you will have transcoded the same video twice, which  
>>> uses
>>> more processing time.
>> It doesn't even necessarily need this downside since some on disk
>> caching could be part of it (writing the stream to the file while
>> serving it)...
> Which is exactly what Chris Pinkham's patch for keeping multiple files
> per recording is meant to solve.  When a show is transcoded--even if
> just for "Live" streaming--the copy is kept in case it's needed again
> (with appropriate expiration rules to allow it to be deleted as  
> necessary).

Without having looked at his patch, some things he has noted were big  
red flags for me though. For instance:

"Keep in mind that this is only for the software recorder (aka
NuppelVideoRecorder), it is not for cards/devices that do compression in
hardware).  Recording from a hardware-compression device to another
format not supported by that device is best left to the post-recording
transcoder.  It probably would be possible for someone to give the
transcoder the ability to transcode an in-progress recording, but that
might depend on the "multiple files per recording" patch which I still
haven't had time to finish."

That to me makes it sound like he isn't really doing what I need,  
which is to be able to transcode on the fly from any format to any  
format. If I have an OTA digital tuner, I want to be able to transcode  
livetv from it to something my iPhone can watch. His comment seems to  
say that his patch won't do that.

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