On Wed, 15 Apr 2015 16:23:39 GMT, RIB <rib@rack.com> wrote:
>In reply to "Knotty Bitz" who wrote the following:
>
>> On Wed, 15 Apr 2015 07:56:50 GMT, RIB <rib@rack.com> wrote:
>>
>> > You are welcome.
>> >
>> > I've managed to get the file size down to about 650 megs for the AVIs But
>> > strangely I can't go much smaller than that for H.264
>> >
>> > The files on the DVD9s are way too big for the quality of the clips which
>> > means
>> > it's very difficult to get a good size/quality ratio. I swear this is done
>> > on
>> > purpose.
>> >
>> > I'll post one of each when I have more time and then you can tell me if you
>> > are
>> > interested in the rest.
>> >
>> > RIB.
>>
>> My prediction of 2/3 smaller was based on doing the one episode, which
>> happened to compress well. I was probably too optimistic. ;-)
>>
>> You know, it probably shouldn't be surprising when we consider that
>> 50% or more consists of old archival footage - raw, unprocessed, noisy
>> material, and lots of it taken from analog TV. In fact, I've seen
>> docs get larger not smaller for this reason. I cranked the xvids
>> through HB at CRF 23 and got an average of 534 MB per ep. If I'd gone
>> for CRF 24, the average might have slipped under 500. And that was for
>> resolution of 640x480. You're probably going for the max (PAL)
>> resolution, closer vto 720x576. Therefore, if I had the original
>> DVD-9s, I'd go for the better resolution, use a setting of CRF 24, and
>> accept what resulted with the filesize.
>>
>> BTW I misspokie yesterday. I said that the original poster did the
>> audio at 81Kbps. I must have had a brain fart. When I looked again it
>> was actually 192K stereo.
>>
>> KB
>
>---------------------------------------------------
>
>I did do a trial with a CRF of 24 and thought it looked pretty good although the
>resulting file was about 800 megs. I'll play around with it a bit and post what
>I think is the best quality over size. I'm sure you'll let me know if it's crap
>:-)
>
>RIB.
FWIW -
Using Part 8 as a test, I encoded at CRF 24 but with different audio
settings. Then I demuxed and measured:
H.264 video = 438 MB
ac3 passthrough (448Kpbs) = 269 MB
aac stereo (192Kbps0 = 117 MB
So, at least 150 MB of the file's size is attributable to sticking
with AC3 5.1 channel soundtrack. I question whether 5.1 is really
needed (someone who did want it would probably rather download the
DVD-9). If the track is downmixed to Stereo, even 192K may be slightly
overkill.
Splitting the difference, I'd consider Dolby ProLogic II at 192K.
http://en.wikipedia.org/wiki/Dolby_Pro_Logic
|
|