[mythtv] transcoding suggestion

[Geoffrey Hausheer]

On 13 Jun 2003 23:08:12 -0700, "Chris Petersen lists-at-forevermore.net
|mythtv/1.0-Allow|" <o8f8hesx3k0t at sneakemail.com> said:
> What I'm thinking is that I could go in and set up my cutlist, and then
> mark the recording to be transcoded into whatever format I want, with or
> without then removing the .nuv data.  The transcoding would happen ONLY
> when myth isn't actually doing anything (or attached to a nice process),
> as an option called from mythbackend itself (or a cron'd process).

I will be working on something like this after I'm finished with my
current stuff.  Today I am trying to get mythbackend/mythtranscoder to
play nice with the commercial code and user-editing.  I am nearly
finished with that now.
The next step is to add he ability to manualy start a transcoding.  This
shouldn't be too difficult to do, and I'll try to roll it into the patch
I am currently doing.

The end result won't work quite as you suggested, but it is close.  Once
a transcoding is requested, it gets added to the queue.  When that
program is not in use, the transcoding will start (niced down suibtably).
 The user can control how many simultaneous transcodings can happen per
backend (I don't recomend more than 1 on a single-processor machine). 
Checking whether myth is doing anything else is doable, and pausing the
transcoder if so, is doable, but I'm not going to add it right away.  If
linux properly handles the nice, it shouldn't really be needed anyway.

> 
> And on this note, is there any idea when actual cutting will be
> available in the cutlist?  By this, I mean the ability to re-save (but
> not re-encode) recordings according to the cutlist, for space
> conservation, etc.

This will also be later (unless someone else does it).  ReencodeFile (the
guts of the transcoder) already stores audio and video frames in the
'raw' form (i.e. compressed).  Currently we always decompress/recompress
the video, but not necessarily the audio.  To add the support you want
would mean writing the raw frames except when a commercial gets in the
way, and then reencoding the frames around the commercial (new key-frames
will likely be needed).  It is very doable, and has always been in the
plan, it just requires some thought as to how to make it work correctly.

.Geoff
-- 
  Geoffrey Hausheer
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