[Naplander]

I have an mpeg which is 7mb - I need to get it down to around 3mb in size.

I have quicktime pro, but am struggling to suss it out.

Any ideas? Apps?

[Nap]

You could try editing out parts using ffmpegX but I can't swear that will work. I have heard it will edit mpegs between Groups of Pictures, which is roughtly equivalent to keyframe intervals in .mov files. Never used it so can't guarantee it will work.

[Naplander]

cheers - will check it out.

Nice username - reminds me of mine

[bmedina]

The original is MPEG1? The best route would be to compress to MPEG4 using the 3ivx component (3ivx.com). The problem is that Quicktime Pro doesn't preserve the audio when you export MPEG1 files. You could use ffmpeg to split the audio and video and process them individually, then remux in Quicktime Pro at the end.

[k_munic]

Originally posted by Naplander:
I have an mpeg which is 7mb - I need to get it down to around 3mb in size.

I have quicktime pro, but am struggling to suss it out.

Any ideas? Apps?

re-encoding compressed video means allways loss of quality.
mpeg isn't mentioned to be processed, it is just a playback format.
to edit (reformat, recompress, whatever) you need to convert into a processable format:
with bbdemux you can produce two files, the audio the video; with QTpro you can combine this two files; with Qtpro you can try to make it smaller by exporting.

you plan to make the file half the size - easiest way: half resolution (640x400>>320x200); sound: instead of stereo use mono; use a lower quality (24Khz>>8KHz); use a lower frame rate (25>>15)...

tough job, anyhow...

or give as mentioned mpeg4 a try

[Naplander]

Thanks for your help guys.

I never thought that it would be so tricky to do - and the loss of audio was a definate surprise.

Strange that.

I'll have another go

[Nap]

Can any one confirm whether ffmpegX can edit mpegs without re-compressing by limiting the edits to entire Groups of Pictures? I know it is technically possible because I have a PC application (I use it in VirtualPC) that does it. It is basically the same process as removing an entire keyframe interval in a .mov file. If done properly it should play without any problems. I would try it myself but ffmpegX seems to require a newer version of OS X than I have installed on my eMac.

[demograph68]

I have better solution. Put mpeg1 in bbDEMUX. Then compress audio steam to mp3 with iTunes. Compress video steam with Quicktime. then combine both processed files in Quicktime. (Add video into audio, not vice-versa)

[bmedina]

Originally posted by demograph68:
I have better solution. Put mpeg1 in bbDEMUX. Then compress audio steam to mp3 with iTunes. Compress video steam with Quicktime. then combine both processed files in Quicktime. (Add video into audio, not vice-versa)

Yes, bbdemux would be much simpler than compiling ffmpeg and figuring out how to use it at the command line. I would use 3ivx MPEG4 and Quicktime's AAC for the video and audio codecs, respectively. And it shouldn't matter whether you add the video to the audio or vice-versa, as long as you don't add scaled.