How to convert to MPEG4 SP without increasing size?

[bjornkeizers]

I bought an Archos Gmini 400 multimedia player, but alas, a lot of stuff doesn't work on it. I'm no encoding expert, so I need your help

It'll only accept MPEG4 simple profile movies with an MP3 or IMA-ADPCM audio track. It uses the XVID or DIVX4/5 MPEG4 codecs. They also have to be smaller then 640x480 @ 30 FPS. (that's the manual talking)

Now, it does come with virtualdub and its own little front end, but when I convert a 40 mb south park episode to a file with a lower bitrate and smaller resolution, I end up with a 124 mb file. Three times the size, and lower quality.

Who oh who will explain to me how to properly re-encode to simple profile MPEG4 with Divx/Xvidwithout increasing the file size?

[JvanEkris]

Hi Bjorn,

DivX is a very compact format. I store all my movies in Avi (=DivX) format on my homeserver. With DivX5, it should be as compact as any other format.

I use a framerate of 25 fps (normal for PAL televisions), and encode for 720x576 (standard PAL television). For TV-output i use 700Kbs 2-pass DivX5 video and 128 Kbs 1 pass MP3 audio. Audio and video are good then. Most people consider this near DVD quality. At these settings, a 2 hour movie is about 700 Mb.

But i guess when you want to play movies specifically for the Archos screen itself, you could go to 220x176. This means that the surface of the video is roughly 9 times smaller (3 times in the length, 3 times in length). So you could drop the framerate of the video and size of the video accordingly (Making it about 128kbs is quite acceptable: i use 128 kbs video MPEG2 for streming to my PocketPC, and it works verry well as well).

For encoding you could look for other Encoders as well. A very user-friendly encoder is DavideoDVD. Another is PocketDivXEncoder.

Jaap

[bjornkeizers]

Yeah, I've re-encoded several movies to the lower resolution - and they look fantastic on the Archos - but you can't really play them on TV at that size. If I wanted to keep the same quality, the movie would be a gig and a half at least, and you'd burn through that 20 gig pretty fast :D

To me, it just doesn't sound that logical. All the stuff I have already is in avi format and encoded with Divx 4/5 or Xvid with an MP3 audio codec. Is MPEG4 SP so different as to explain the much bigger files?....

Well, I'm sure Archos or some tinkerer will fix that in time. Either that, or I'm out of luck on the large res movies.

For now, I'll try fiddling with the bitrates and stuff and see if I can find some middle ground.

[PetiteFlower]

You can try asking at digitalmediathoughts too :)

[bjornkeizers]

I've already asked at other places and did some more research into MPEG4 SP - what little I could find.

Apparently, it's physically impossible to compress to the same quality without increasing filesize. Oh well. Archos are pretty good about firmware updates so I'm keeping fingers crossed.