[mythtv-users] Transcoding SD MPEG2 to H.264---recommendations?

[D. R. Newman]

On 26/11/10 22:39, f-myth-users at media.mit.edu wrote:
> I have a large number of PVR-x50 recordings that I'd like to transcode
> to H.264 to save disk space [1], for eventual playback under VDPAU on
> a GeForce 9500 GT-class device (and, eventually, maybe a GT220-class
> device if that would help [2]).
> 
> Two questions:
> (a) What's the current favorite way to do this?  I'd like to run some
> tests standalone, and then I'd like to integrate this going forward
> as a user job under Myth.  Command lines and/or scripts that have
> worked for you would be an excellent starting point; the search space
> of transcoders and options for them is rather large.

I have been doing this kind of transcoding for some years. I don't know
if this is the best way to do this, but this is what I do.

1. For each TV series or film, I save an Avidemux script, including the
conversion parameters, and filters (typically deinterlace, then crop,
them remove logo, with a denoise filter for the older recordings). I
delete from the scripts the hard-coded references to the filename, so
that I can use each script on a whole series (e.g.
TheBigBangTheory.E4.js). If your recordings all came from NTSC with no
black borders, you might get away with one Avidemux script for
everything. Here in the UK, each series, on each channel, has different
black borders inside PAL.

2. I have written Perl scripts that take a recording, run Avidemux, save
the output in the video directories, and add an entry in the
videometadata table.

3. I call these Perl scripts as user jobs from MythTV. You could do it
automatically, but I normally start them manually after I have removed
the adverts using Avidemux.

Avidemux uses ffmpeg or x264, so the speed of conversion depends on how
fast they run on your machine. Currently, conversion times range from
real time to half real time, on a T7400 Core 2 Duo Mobile Intel
processor, using both cores.

--
Dave Newman