Video conversion question

[andrewducker]

My phone produces .3gp files when it takes videos. They're about 90k.

I can then convert them to quicktime files, also under 100k.

I can then convert them to .mp4 files which are around 170k.

But if I then convert them to AVI files they swell to 2MB.

What the hell is going on in there that takes up that kind of space? And is there any way I can stop it?

If anyone out there fancies taking a look, the files are up in 3gp format and quicktime format.

(It's Meredith with new baby, who is stretching cutely)

Comments

[themongkey.livejournal.com]

The AVIs are probably uncompressed. Try encoding them with DivX or XviD?

videohelp.com has loads of info, or just google "avi to divx" (or xvid).

Of course, then people trying to play them will need the right codecs installed or they'll just get a blank movie.

[andrewducker]

I've tried compressing with both DivX and XVID, and that's what's producing the current size.

If I don't compress it ends up as 6MB.

[jccw.livejournal.com]

1. AVI is a pretty old format. Thus, its overall compression performance is unlikely to be as good as more recent formats such as mp4, or "formats" like quicktime or wmv that (I think) really consist of a lot of individual codecs. This is part of why people keep inventing all these new formats.

2. Highly compressed video is going to have artifacts which may make it difficult for other formats (even more advanced ones) to do better. This is especially true if you chain several steps together as you have done. One thing you could try is uncompress the original to some raw format, smooth it (using e.g. Gaussian filtering), and re-compress directly to the target format. (I could be talking through my hat here, my computer vision class was ages ago).

[andrewducker]

It's compressing to an MPEG4 format internally, so that's ok. But the artefact thing sounds entirely possible.

I shall have a further play with it.

[figg.livejournal.com]

Avi is a container format, not a codec though. (Like Mov, mkv, and ogg (yes ogg is a container (it's ogg vorbis that is the sound codec))).

I don't know what codec you are using with AVI - it could be anything from mpeg to divx to xvid.

[andrewducker]

See here:
http://andrewducker.livejournal.com/1096416.html?thread=5823712#t5823712

[kashandara.livejournal.com]

I care not for the tech of your post but just wanted to say 'Aw! Cute baby!'

Aw! Cute baby!

Send my congratulations to the new Mom and Pop won't you.

[andrewducker]

Will do - I've already passed on the presents from you Mr Laury. They were rather pleased with them, and unsurprised by the cephelapod theme.

[moniqueleigh]

*squee* Darling little one!

[octopoid-horror.livejournal.com]

How do you convert them from 3pg format?

[andrewducker]

Quicktime seems happy to open 3GP files and then save them as .MOV files.