Bitrates
Posted: Sat Feb 25, 2023 2:47 am
Hi all,
as I'm a new user here, let me introduce myself.
I'm Richard from Brazil. I used to be an editor as a student, but things led me to film festivals, from 35mm print traffic to video projection. I used to work at small festival playing files from a tvix box, later I started working as some kind of QC and print traffic in bigger festivals, that's where i met DCPs.
I'm just starting creating dcps, mostly to small advertising in festivals and some old films from low quality files or dvds.
In the time i worked with the Tivx the files were limited to 40 mbps, not that that bad i used to think, because blurays were about 25mbps. Most of the times I had to convert something (the player wont play avi, prores or 2K) I had 2 options: keeping the low bitrate from original file or reducing it to less then 40mbps.
As DCPs bitrates are sugested to be at 250 mbps maximun I use to trust the 100 mbps or 150mbps DOM sugests as default, most of the times it's 5 or 10 times more then the original files.
But today I had 2 situations that made me come here to ask if there's some kind of logic i should follow to choose bitrats in DOM: a 173 mbps full hd prores (that i just repeated the number in DOM) and a 38mbps 4K feature. I had to encode both 2k and 4k dcps from the prores (as it takes too long here to proccess the 4k one i did the 2k just in case the 4k ingest fails), and choose the same bitrate, generating files with the same size. That's what made me think if the 4k shouldn't be larger or if it doesn't make any sense as the source is already so compressed that I'm just generating useless aditional data in both 2k and 4k.
Can anyone light my path? sorry for the long text, im not a native english speaker! Hope DCPs get bigger for me and I can join this community
as I'm a new user here, let me introduce myself.
I'm Richard from Brazil. I used to be an editor as a student, but things led me to film festivals, from 35mm print traffic to video projection. I used to work at small festival playing files from a tvix box, later I started working as some kind of QC and print traffic in bigger festivals, that's where i met DCPs.
I'm just starting creating dcps, mostly to small advertising in festivals and some old films from low quality files or dvds.
In the time i worked with the Tivx the files were limited to 40 mbps, not that that bad i used to think, because blurays were about 25mbps. Most of the times I had to convert something (the player wont play avi, prores or 2K) I had 2 options: keeping the low bitrate from original file or reducing it to less then 40mbps.
As DCPs bitrates are sugested to be at 250 mbps maximun I use to trust the 100 mbps or 150mbps DOM sugests as default, most of the times it's 5 or 10 times more then the original files.
But today I had 2 situations that made me come here to ask if there's some kind of logic i should follow to choose bitrats in DOM: a 173 mbps full hd prores (that i just repeated the number in DOM) and a 38mbps 4K feature. I had to encode both 2k and 4k dcps from the prores (as it takes too long here to proccess the 4k one i did the 2k just in case the 4k ingest fails), and choose the same bitrate, generating files with the same size. That's what made me think if the 4k shouldn't be larger or if it doesn't make any sense as the source is already so compressed that I'm just generating useless aditional data in both 2k and 4k.
Can anyone light my path? sorry for the long text, im not a native english speaker! Hope DCPs get bigger for me and I can join this community