why do programs working in H264 make the same information come out in different file sizes?

View previous topic View next topic Go down

why do programs working in H264 make the same information come out in different file sizes?

Post by williah on Sun Oct 13, 2013 4:09 am

Ok, nubbie to codec info, so I'm looking for help understanding something, please.

I have taken an mov, H264 file in Final Cut Pro, shifted the sound track slightly, and exported the file.
The orig file was around 2 gig.  This new file comes out 4-5 gig.

The reversed has happened in After Effects, where the file was exported and came out 1/2 to 1/3 the size of the original.

In both cases, the file was an mov, H264 codec.  If both are using the same codec, which I take to mean the code that's used to provide the image data, shouldn't the file sizes be close to the same size?  If not, what's missing or added to account for the differences in file size?

As I said, I'm new to this and looking for clearer explanations than the normal, general.

Thanks.

williah

Posts : 2
Join date : 2013-10-13

View user profile

Back to top Go down

Re: why do programs working in H264 make the same information come out in different file sizes?

Post by Admin on Mon Oct 14, 2013 2:51 am

It is the same formats, but not the same information. There are several encoding parameters that control the amount of compression. Higher compression means lower quality and smaller filesize.

You should be able to configure the encoding settings somewhere. Look for the keywords "bitrate" and "quantinizer". Higher bitrate = lower compression. Higher quantinizer = higher compression.

Admin
Admin

Posts : 2977
Join date : 2011-06-17

View user profile http://codecs.forumotion.net

Back to top Go down

Re: why do programs working in H264 make the same information come out in different file sizes?

Post by williah on Tue Oct 15, 2013 7:21 am

Thank you! This is the kind of answer I appreciate.

Cheers.

williah

Posts : 2
Join date : 2013-10-13

View user profile

Back to top Go down

Re: why do programs working in H264 make the same information come out in different file sizes?

Post by Sponsored content Today at 4:36 am


Sponsored content


Back to top Go down

View previous topic View next topic Back to top


 
Permissions in this forum:
You cannot reply to topics in this forum