Two pass encoding: how important? at DVinfo.net

Kevin Carter · September 30th, 2007, 11:28 AM

I got flip for mac studio pro. If I get the HD version $80 more they have two pass encoding. Is this a great feature? anyone know?

Martin Pauly · September 30th, 2007, 03:17 PM

Kevin,

I cannot speak for this version of Flip4Mac specifically, but in general two pass encoding gives you better quality (compared with single pass encoding) at the same average bitrate by analyzing the whole video in a first pass, computing where it pays off most to spend a little (or a lot of) extra bandwidth. If you want best quality at low file sizes, two pass encoding helps a lot. An example of where you wouldn't care is if you just need to create (as quickly as possible) a temporary file that stays on your computer - just choose a higher bitrate, and one pass encoding will be fine.

- Martin

Meryem Ersoz · September 30th, 2007, 03:21 PM

flip4mac seems to be an exception to this rule however. i can't seem to get clean 2-pass encoding. their default settings are set to 1-pass encoding and seem considerably better than my tweaks. i don't know how, i don't know why, but after a good bit of experimenting with their 2-pass settings, thinking i could improve on the defaults, i gave up and now just use their default setting. fortunately, it looks decent.

Kevin Carter · September 30th, 2007, 07:40 PM

Interestng Myrem:

It's a bit over my head, but the flip for mac rep explained it that with two pass the software, I think reviews and then decides what to do in a more accurate way. Of course, that's why I'm posting here.

Meryem Ersoz · October 1st, 2007, 08:48 AM

well, i would love to hear from someone who might have different experiences, who was actually successful using the two-pass settings to make a cleaner image. i spent about a day on this, trying various 2-pass compression settings, and none of them improved the image over the single-pass default. in the end, i simply needed to get the project out the door to the client, so i defaulted to the defaults, and that put an end to my mad scientist experiments, for that round. so if someone had more success than i did with alternative compression schemes, lay it on us, please!

Kevin Carter · October 1st, 2007, 04:48 PM

Meryem:
So you did back to back tests, and found little improvement?

Martin/others: Did you to likeminded tests?

September 30th, 2007, 11:28 AM	#1
Kevin Carter Major Player Join Date: Apr 2006 Location: los angeles, CA Posts: 235	Two pass encoding: how important? I got flip for mac studio pro. If I get the HD version $80 more they have two pass encoding. Is this a great feature? anyone know?

September 30th, 2007, 03:17 PM	#2
Martin Pauly Major Player Join Date: Apr 2006 Location: Cedar Rapids, IA Posts: 563	Kevin, I cannot speak for this version of Flip4Mac specifically, but in general two pass encoding gives you better quality (compared with single pass encoding) at the same average bitrate by analyzing the whole video in a first pass, computing where it pays off most to spend a little (or a lot of) extra bandwidth. If you want best quality at low file sizes, two pass encoding helps a lot. An example of where you wouldn't care is if you just need to create (as quickly as possible) a temporary file that stays on your computer - just choose a higher bitrate, and one pass encoding will be fine. - Martin __________________ Martin Pauly

September 30th, 2007, 03:21 PM	#3
Meryem Ersoz Wrangler Join Date: Jan 2005 Location: Boulder, CO Posts: 3,015	flip4mac seems to be an exception to this rule however. i can't seem to get clean 2-pass encoding. their default settings are set to 1-pass encoding and seem considerably better than my tweaks. i don't know how, i don't know why, but after a good bit of experimenting with their 2-pass settings, thinking i could improve on the defaults, i gave up and now just use their default setting. fortunately, it looks decent.

September 30th, 2007, 07:40 PM	#4
Kevin Carter Major Player Join Date: Apr 2006 Location: los angeles, CA Posts: 235	Interestng Myrem: It's a bit over my head, but the flip for mac rep explained it that with two pass the software, I think reviews and then decides what to do in a more accurate way. Of course, that's why I'm posting here.

October 1st, 2007, 08:48 AM	#5
Meryem Ersoz Wrangler Join Date: Jan 2005 Location: Boulder, CO Posts: 3,015	well, i would love to hear from someone who might have different experiences, who was actually successful using the two-pass settings to make a cleaner image. i spent about a day on this, trying various 2-pass compression settings, and none of them improved the image over the single-pass default. in the end, i simply needed to get the project out the door to the client, so i defaulted to the defaults, and that put an end to my mad scientist experiments, for that round. so if someone had more success than i did with alternative compression schemes, lay it on us, please!

October 1st, 2007, 04:48 PM	#6
Kevin Carter Major Player Join Date: Apr 2006 Location: los angeles, CA Posts: 235	Meryem: So you did back to back tests, and found little improvement? Martin/others: Did you to likeminded tests?