How do I tell what the bitrate is...??

Z

zendelinquent

New member
Hi all

I may well be being utterly thick here, but can any kind soul enlighten me as to how you are supposed to tell what bitrate your hacked GH1 footage has been recorded at/is actually running at?

I appreciate that it depends on the complexity and motion of the scene you've shot but what do you use to tell you? I've tried checking via FCP, Premiere, Neoscene - even Quicktime's own info - etc but the bitrates it records when I check the info on the files always seems to be no different to what it was before the hack. I'm pretty sure I've applied the hack correctly (several times) and the footage looks sweet enough but how can I check the 'real' bitrates? I've seen people saying on here 'yeah I get 35-45 mps' but what actually tells you this??? How do you know?!?

Any help very much appreciated!
 
how do I know what bitrate question

how do I know what bitrate question

Hi there - thanks for that!

On a mac but used winewrapper to install...now the next point of confusion is at what stage do I check the bitrate at? I'm presuming it is on the original file on the camera before I import it? Or is it after I import it? And if so, does anyone have any recommendations as the best software/methods to import and convert the original AVCHD files off the camera? Am currently using Premiere and converting out to either 50mps XDCAM or HQ Pro Res but obviously as soon as you convert it it has the bitrate settings of whatever format you've converted it to.

Sorry if this is nursery stuff and am being an utter numpty!
 
You can use MediaInfo on Mac to check bitrates. This program displays a lot of information incorrectly on PCs, but it was confirmed that it mostly works correctly on Macs.

Always make sure to analyse original MTS files, otherwise you are getting information on transcoded footage. For your other questions please check the "Workflows" section in main GH1 forum.
 
zendelinquent said:
I may well be being utterly thick here, but can any kind soul enlighten me as to how you are supposed to tell what bitrate your hacked GH1 footage has been recorded at/is actually running at?
Click to expand...

If you need only average bit rate, it's simple:

8 times file size in MB divided by clip length in seconds:

8*size[MB]/length

And you get average bitrate in Mb/s (megabits/second).
 
crunchy said:
If you need only average bit rate, it's simple:

8 times file size in MB divided by clip length in seconds:

8*size[MB]/length

And you get average bitrate in Mb/s (megabits/second).
Click to expand...



But wouldn't this formula depend on the codec (AVCHD VS MPeg)? Afterall, AVCHD does result in smaller file sizes than MPeg.
 
DanDOF said:
But wouldn't this formula depend on the codec (AVCHD VS MPeg)? Afterall, AVCHD does result in smaller file sizes than MPeg.
Click to expand...

They're both variable bitrate codecs so you will only know the average unless you run it through a parser.
 
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