[mythtv-users] Suggest transcode settings

[HP-mini]

On Wed, 2014-02-12 at 09:51 -0600, jedi wrote:
> On Wed, Feb 12, 2014 at 01:10:30PM +0000, John Pilkington wrote:
> > On 12/02/14 12:49, Phil Wild wrote:
> > >Hi,
> > >
> > >I have a heap of home video I want to transcode. Currently the files are
> > >consuming around 12GB per hour. I'd like to get that down to around
> > >2-3GB/hour without losing too much quality. I'd also prefer not to drop
> > >the resolution but rather increase/change compression algorithms etc.
> > >
> > >I've been googling but haven't found anything really helpful yet. I'm
> > >sure one of the very smart people on here can give me an answer from
> > >their heads and save me a heap of time trial/erroring etc.
> > >
> > >I'm guessing ffmpeg is the best tool for the job?
> > >
> 
> ...assuming you're not willing to just Google for suggestions, you could
> play around with Handbrake and see what kind of results you get and then
> find out what those command line options are (or just keep on using 
> Handbrake).
> 
>     h264 encoding options are quite numerous and subtle. They are a rabbit 
> hole unto themselves. What's below are some options based on what I dug up 
> with a Google search when I started doing this sort of thing.
> 
>     If you don't like what you've found on Google, Handbrake presets may be
> the best way to go.
> 
> ---------------------------------------------------------------------------
> 
> BITRATE=800
> BITRATE=1200
> BITRATE=1500
> THREADS="threads=auto"
> 
> ### subq=6:partitions=all:8x8dct:me=umh:frameref=5:bframes=3:b_pyramid:weight_b
> ### subq=5:8x8dct:frameref=2:bframes=3:b_pyramid:weight_b
> ### subq=4:bframes=2:b_pyramid:weight_b
> 
> ###OPTIONS="-x264encopts subq=6:4x4mv:8x8dct:me=3:frameref=5:bframes=3:b_pyramid:weight_b:bitrate=$BITRATE "
> 
> 
> ### h264 High Quality options, 2 pass
> ### This is the default setting
> b_pyramid="normal"
> X264_PASS1="-ovc x264 -x264encopts subq=4:bframes=4:b_pyramid=$b_pyramid:weight_b:pass=1:psnr:bitrate=$BITRATE:turbo=1"
> X264_PASS2="-ovc x264 -x264encopts subq=5:partitions=4x4:8x8dct:frameref=3:me=hex:bframes=4:b_pyramid=$b_pyramid:pass=2:psnr:bitrate=$BITRATE"
> 
> if [ "$THREADS" != "" ]; then
>     X264_PASS1="$X264_PASS1:$THREADS"
>     X264_PASS2="$X264_PASS2:$THREADS"
> fi
> 
> [deletia]
> _______________________________________________

The original source is interlaced and the "best" result can be to keep
it that way by putting x264 into interlaced input mode with "--tff" or
"--bff" & using "--interlaced --output <outfile>".

When using HandBrake you need to specify ":tff" & ":interlaced" in the
encoder extra parameters.