The OGM overhead thread creating, thread, comment, making, files

andy

Hopefully this will come in handy when making calculator

I used ogmuxer when creating the files and all sizes in bytes

778,011,648 Video
47,975,248 vorbis
1,014 chapters
to
830,951,943 ogm
having
4,964,033 overhead 0.597%

23.976fps, 128965frames
1:29:38

Code:
lt;input file=quot;Fast Times at Ridgemont High.aviquot;gt; lt;comment name=quot;TITLEquot;gt;Fast Times at Ridgemont Highlt;/commentgt; lt;chapters file=quot;Fast Times at Ridgemont High.txtquot; /gt;
lt;/inputgt;

lt;input file=quot;Fast Times at Ridgemont High.oggquot; offset=quot;0quot;gt; lt;comment name=quot;LANGUAGEquot;gt;Englishlt;/commentgt;
lt;/inputgt;

lt;output file=quot;Fast Times at Ridgemont High.ogmquot;gt;lt;/outputgt;
1,145,950,208 video
440,430,807 ac3
1,216 chapters
to
1,599,343,262 ogm
having
12,961,031 overhead 0.810%

23.976fps, 188569frames
2:11:04

Code:
lt;input file=quot;eg.aviquot;gt; lt;comment name=quot;TITLEquot;gt;Enemy at the Gateslt;/commentgt; lt;chapters file=quot;eg.txtquot; /gt;
lt;/inputgt;

lt;input file=quot;eg.ac3quot; offset=quot;0quot;gt; lt;comment name=quot;LANGUAGEquot;gt;Englishlt;/commentgt;
lt;/inputgt;

lt;output file=quot;eg.ogmquot;gt;lt;/outputgt;
PS: Less than 1% overhead seems impressive

the overhead is 1% more then the avi+audio, and you don't have any overhead when you use a vorbis stream in a OGM file.

If your file is 700MB, the overhead is about 8-9MB. Also keep in mind that the avi also store the index, the OGM don't.

I actually was provided with the following formula:

OGM-calculation (PAL amp; Ogg)
-------------------------------------------
kbps ~ ((TargetSize[kB]-OggSize[KB])*8*1024*25)/(frm*1010)


jepp and
to calculate overhead for ac3-overhead in ogm, use the same formula...

OGM overhead estimation doesn't seem easy. I tried to estimate it but I often am +/-10% off compared to the real overhead :/

Overhead is different when one compares a divx and a xvid stream. Divx delivers more overhead somehow.

For a recent PAL-movie I have muxed:
Xvid-Video:     1.423.038kb
Ogg-Audio:      160.061kb
.srt Subtitle:  111kb
Chapter:        ?
Total:          1.593.234
Overhead:       10.024kb
.ogm length:    2:19:16

Originally posted by frodoontop
Overhead is different when one compares a divx and a xvid stream. Divx delivers more overhead somehow.It actually seems to be true on only for OGM, but AVI container as well... (looks like XviD stream already have overhead inside...)