[mythtv-users] Suggest transcode settings

jedi jedi at mishnet.org
Wed Feb 12 15:51:04 UTC 2014


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]


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