What bitrate when converting to BD?

[Cobra427]

I am using a consumer camera which shoots in Full HD, AVCHD codec at a bitrate of 13M.

My question is:
- when I use MPEG to convert to BlueRay: what bitrate do I use? I read somewhere that there is no point in using anything higher that the bitrate of my camera. That is 13M, so MPEG at 15M should be enough. No point in using 35M. Correct?
- Is MPEG the way to go for me or is there a better way. I don't care about the cost of a BD disks (filesize) or the time it takes to convert. I want good quality. (I use Edius for all my work, read somewhere that x264 is very good)

Thanks in advance.

[janstun]

BD standard

mostly I do a up-conversion by Edius to the standard speed of 25Mbps as I feel it gives the best results. You can try lower speeds by yourself without burning a disk by exporting a .m2ts file to hard-disk, playing it and see what the result is.

Is 13Mbps your highest camera speed? mostly this is for AVCHD 15-17 Mbps. check if you are filming in the best quality!

Jan

[Cobra427]

Thanks Jan,

It is an older camera and 13M is the highest.

On my computerscreen I see no diffrence between MPEG 15M and 25M (or 35M), but the quality is not as good as the orginal AVCHD material. As to be expected it is worse when there is movement in the picture.
Has anyone tried another method with this kind of material? (i.e. x264)

Thanks.

[CentralEurope]

what for Edius version have you ?

in my case, I never export with the same as the souce bitrate
always higher for to reduce the loss from render render in long GoP codecs.

h.264 is imho sharper, but with many motion in the footage or fine lines like tiled roof and zoom or pan
it tend to more flimmering as the mpeg 2

mpeg2 in the above situations is (for me) not so sharp, but smooth and constant, like a litte "antiflicker" or "blur" and without flimmering on the fine lines or edges

[Cobra427]

Thanks CentralEurope,

I have Edius 6.08 Since the camera shoots at 13M I used 15M to convert to MPEG to make a BD.
Does it makes sense to go higher than 15M?

[David Clarke]

AVCHD compression is clever than MPEG so you can compress it more - 13M in AVCHD may look good where as 13M in MPEG is going to look pretty bad. So there is a point in upping the bit rate because as you convert to MPEG: to get the same qualiity in MPEG as in AVCHD you will need a higher bit rate.

H264 will give you the best quality for the space on the disc but will take longer to make unless you have a Sandybridge or Ivybridge processor with Intel Quicksync. As long as you don't put too low a number MPEG will look as good as H264 and will be quicker to make.

Even if you make h264 (which is the same as AVCHD) then it is still worth putting in a higher number than that at which you filmed. Not all encoders are the same - some can make really good H264 as low bit rates like 13M, but many can't. I have noticed that the EDIUS encoder does struggle in green areas (the hardest stuff to make) at about 15M which is faily common with most encoders that I have used. 13M would be even worse.

Now it may be that your footage is already a bit ropey in the green areas because of the datarate of the camera but remaking it at the same rate will only make it worse. Remaking at a higher rate won't make it better but it won't make it worse either.

As to what is the correct number - there is no prefect answer. I tend to do H264 at about 25M and if I ever do MPEG (which I hardly ever use since I have Quicksync) I do it about 35M. They may be over the top but as long as I have the space I do not worry. These numbers also vary depending on what size you are filming - 1920x1080, 144x1080 or 1280x720.

[Jerry]

These numbers also vary depending on what size you are filming - 1920x1080, 144x1080 or 1280x720

Add to this how long your project is and what size BD disc you are using(25gb or 50gb). This is one of those questions with several answers.