GH1 Target Bitrate Settings

D

d1rockwild

Well-known member
Hey everyone. I'm trying to burn a video to blu ray disc, but the 1 hr. and 17 min. of GH1 footage will take up more memory than the BD disc can hold (close to 30 gb). So I'm thinking the best way to compress the footage is to lower the target bitrate to about 17Mbps, as opposed to the recommended 25Mbps under the MPEG2 Blu-ray Export Settings. Logic being the GH1 records at a 17 Mbps bitrate. Hoping not to lose minimal to any quality loss, but was just checking to see if anyone had any advice on what I am doing. Thanks guys. I'm testing out a small portion of the video now, so, I'll have something to look at in a few hours, but maybe there's more for me to know.

btw, I am using the HDTV 1080i 29.97 High Quality preset under the MPEG2 Blu-ray Format.
 
d1rockwild said:
Hey everyone. I'm trying to burn a video to blu ray disc, but the 1 hr. and 17 min. of GH1 footage will take up more memory than the BD disc can hold (close to 30 gb). So I'm thinking the best way to compress the footage is to lower the target bitrate to about 17Mbps, as opposed to the recommended 25Mbps under the MPEG2 Blu-ray Export Settings. Logic being the GH1 records at a 17 Mbps bitrate. Hoping not to lose minimal to any quality loss, but was just checking to see if anyone had any advice on what I am doing. Thanks guys. I'm testing out a small portion of the video now, so, I'll have something to look at in a few hours, but maybe there's more for me to know.

btw, I am using the HDTV 1080i 29.97 High Quality preset under the MPEG2 Blu-ray Format.
Click to expand...

Doesn't Bluray have a 24 p option... if so, there's 20% savings... provided you shot it in 24 p... As for artifacts and 17 Mbs. The 'standard' for ATSC HD Broadcast TV is 20 Mbs...

Are you selecting constant bit rate, or variable bit rate. The latter 'may help', if your material is mostly 'static', and can take advantage of lower bit rates in such static portions.

One problem with lower bit rate is if you have any effects/transitions that require a higher bit rate for a 'clean' play.
 
Though it can be a challenge to set up and get running, try encoding using one of the free x264 encoders. You'll probably get a better image than the MainConcept encoder can produce. And if you look for an x264 encoder with CQ mode, that can allow for smaller file sizes, as CQ mode only uses the minimum bits it needs to produce the desired quality level.
 
@j1clark@ucsd.edu - True, I did try the 720p setting at 23.976, but, it just didn't look good. Almost like there was ghosting. I definitely need to get NeoScene (again). Also, I haven't looked recently, but that there's always an open argument about Adobe'a ability to remove pulldown accurately, I'd rather not deal with it.

I decided to go with CBR encoding, so I know it's not as good as VBR, but its so time consuming and I really need to move on to other projects. When you click on CBR, you have to pick a constant bitrate, not variable. So yeah, I entered 17 Mbps. Thanks for letting me know about the 20Mbps, I'll try to get as close to that as possible, and I'll pay attention to my transitions as well. Gonna burn what I encoded thus far to a rewritable BD disc and watch on my TV as VLC doesn't play HD files very well (a lot of heavy interlacing that I don't see from my PS3.)

@Jim Simon - I REALLY wish I could encode in H.264, but Adobe Encore is giving me problems, So I'm using Nero 10 to try and get this BD out. And as such, Nero 10 can't seem to be recognize H.264 files even though it says it can. Therefore, I'm using MPEG2 Blu Ray.

Thanks for all the advice guys.
 
You must log in or register to reply here.
Back
Top