ffmpegx forces 2500 bitrate

[Wizeman]

Weird, I know - but whatever I do, however I enter other values (by Calculate or by hand), the file that comes out is suspiciously large... and when asking Mpeg Info, 2500 kbps is always the answer... no wonder I couldn't tell any difference in my test encodes :P

I know it's not a bug in Mpeg Info, because I tried encoding a clip to 1500 using QT, and it identified it fine. What am I missing? (Knowing me, it's probably huge...)

/Wizeman a.k.a. El Rocho of the Movie Madhouse

[major]

Following the standard, SVCD is always encoded at bitrate 2500. If you want to change the bitrate, you should also select profile = XSVCD (non standard-SVCD) in the VCD/SVCD tab.

[Wizeman]

But when I choose XSVCD, the file format is changed to MPEG-1.

Will changing it back to MPEG-2 and then selecting another bitrate
give me a MPEG-2 file w the selected bitrate? Going to try that now...

Thanks for the answer

/W

[major]

But when I choose XSVCD, the file format is changed to MPEG-1.

No, don't choose "XSVCD mpeg-1" from the presets. I meant select "SVCD mpeg-2" from the presets as you were doing before, and then select "XSVCD" from the "mpeg-profile" drop-down in the mpeg-2 options tab.

[AntnyMD]

Choose the generic MPEG-2 option in the drop-down, not XSVCD. Set other settings as normal for SVCD standard. Doing this should produce a variable bitrate output that is also otherwise SVCD standard. I do this to produce DVD compliant streams, setting the options to DVD compliant choices.

[Wizeman]

Trying that in the background now, when a thought occured to me...

Does your reply mean that mpeg2enc through ffmpegx is CBR?

Please forgive my newbieness... I am great at many things; intuitive grasp of video software isn't one of them :P

/W

[Wizeman]

It's me again

Writing my earlier comment *while* the two others were being posted... when I updated the screen I saw that my questions had been answered already... d'oh! I promise; now I'll shut up for several hours before asking again

[AntnyMD]

Its my understanding that mpeg2enc produces variable bitrate streams for MPEG-2 and MPEG-1, which, in the latter case, causes choppy playback because it's not implemented well. Major recently added a "constant bitrate" checkbox to ffmpegX so you can get CBR streams.