Convert MPEG-1 to a Pocket PC Viewable Format?

[midwinter]

Hi all.

I have a ton of mpeg-1 video (from an Eye TV). I have an iPaq 1945 that can view all kinds of files (WMV, mpeg-1, avi, divx, etc).

Is there a way I can use ffmpegx to transcode these mpeg-1 files into something smaller and viewable on the Pocket PC? Ideally, I want something low bitrate (200 or so), low fps (12-15), with low audio overhead.

I managed to take an MPEG episode of Survivor and get it to 31 MB, but that was using my wife's PC, which I'd like to avoid.

Thanks in advance!

Cheers
Scott

[thoughton]

About 15 lines below your topic title there is a topic called 'PDA movies'. Probably worth a look :P

[midwinter]

Yes, I had seen that. That would *probably* work for the MPEG-1 video I have that is already on DVD (mpeg-1 DVD, no re-encoding of video). My specific question was whether or not anyone knew of a way to take pre-existing (and of course muxed) MPEG-1 video and transcode it using ffmpegx. What I didn't say, and probably should've, was that I know that I can demux it, convert the audio to aiff and then recombine in QT, then export as something like DV, THEN convert to whatever. I'm just wondering whether ffmpegx might be able to work some kind of magic.

Cheers
Scott

[thoughton]

Not really following ya, to be honest

But if your question is "Can ffmpegx encode directly from mpeg1 to something else" (probably divx in your case), then the answer is yes.

[midwinter]

Not really following ya, to be honest

But if your question is "Can ffmpegx encode directly from mpeg1 to something else" (probably divx in your case), then the answer is yes.

Great! That was exactly my question. The next part is this: how nasty does video transcoded from MPEG-1 to something like divx look?

[thoughton]

It won't look any better obviously, but it shouldn't look any worse either, all depends on how much you reduce bitrate, size, fps, etc.

[VideoJockey2002]

Maybe TMPGEnc? It's slow, but, seems to excel with high quality output when low bitrates and low frame rates are a requirement. It can even convert MPEG 1 or 2 as source material if you get the proper free plugins from the web. I think that it natively does MPEG 1 as a source to re-encode to different frame rate and bit rate. There is a plugin available that allows TMPGEnc take MPEG 2 as a source for re-encoding as well. It natively takes most *.avi as source if you have that particular *.avi codec on your machine (DivX, Huffy, XviD, etc.) It will also take Apple *.mov files if you find the proper plugin from the web. There may be many other types of source files that it can use once you discover how to frame serve to TMPGEnc.

I do like the MPEG 1 format for things as you describe because it is universal. You can beam that video to others and, chances are, they will have a MPEG 1 codec installed on their machine by default--doesn't matter if the recipient is Mac, Unix, or Windows, Pocket, Tablet, or PC.

When I put video on business card CDR's, I use MPEG 1 at 15 frames per second with monophonic sound so I can crunch the file size to fit on a 50MB BizCard disc. For me, TMPGEnc offers some high quality settings that help to provide smooth motion at low framerates.

I sold my last car using Business Card CDR's. People who were interested got one of my BizCard CDR's. It gave them a video tour of the automobile to let them decide if it was worth the trouble to make an appointment to see it.

I knew that almost everyone would be able to view my video without the troublesome task of downloading and installing the proper codec. Keeping the frame rate and bit rate low allowed even the oldest of computers to render the video.

--vj2k2

[thoughton]

Maybe TMPGEnc?

It's a shame to have to say this, especially after you clearly spent quite a bit of time typing, but someone's in the wrong forum, and it isn't me

[VideoJockey2002]

It's a shame to have to say this, especially after you clearly spent quite a bit of time typing, but someone's in the wrong forum, and it isn't me

Sorry. Got carried away. Forgot Hori didn't port TMPGEnc to Mac.

--vj2k2

[midwinter]

Turns out ffmpex will transcode MPEG-1 directly into a divx file playable on my Pocket PC into a MUCH smaller (430 mb MPEG-1 --> ~60 mb DIVX) and completely watchable file. And it's damned fast, too!

Thanks for all the advice. I'm going to see if I can batch convert a bunch of video to take on a trip with me in a few weeks.

Cheers
Scott

[midwinter]

OK. So here's what I'm doing:

440 MB MPEG-1 video into ffmpegx. I select Divx3 (ffmpeg) as my codec.
Video bitrate: 200 kpbs
Keep at: 65 MB
FPS: 29.97
Video size: 320x240 cropped to 320x176
Audio: mp3
Audio bitrate: 48 kbits/s
Sampling: 12K
CBR

The resulting video is fantastic. Glorious. Highly watchable on my iPaq. It's going to save me money in CDs, too, since now I can just dump video on the iPaq rather than burning it to a VCD which I'll just throw away.

There are only two problems, and I'm hoping the folks here can help. I searched the forums and looked at the manuals/walkthroughs, and nothing I saw was on point. Here they are:

1) if I do*anything* to the FPS, the video gets slowed down considerably while the audio continues. Is this just a problem with dealing with MPEG-1 video as a source? I'd really like to bump this down to 15 fps to save some space. Any ideas what's going on here?

2) There is a *slight* audio sync issue that gets gradually worse over the course of watching video. It's never so bad that it's unwatchable, but it is still annoying. I know this is a perennial issue with video work, but I couldn't find anything on point vis a vis this, either.

Can anyone recommend either a fix or better settings?

Thanks in advance.

Cheers
Scott

[NightWing]

Have you tried the MS Windows Media Encoder 9? Not bad and free. It has a entry to do WMV for a PPC 2003 both as Wide Screen 320 x 240 and Standard 208 x 160 at 20fps. About 25mb for 20~22 minutes of play time.

I think most are using Divx5 with one of the players avaiable. Like PocketMVP or betaplayer?

[thoughton]

Have you tried the MS Windows Media Encoder 9?

How about a link to the Mac version of that? :P

What is it with this topic that keeps making people post in the wrong forum?

To the original poster, sorry don't have any experience with reducing FPS myself. Also not too much help with the dreaded sync problems, all I can think of is that if your original mpeg came from a VCD then perhaps your audio sampling should be 44.1 and not 48KHz. This would cause a gradual loss of sync. Are you sure your original file has a 48KHz sample rate?

[thoughton]

Euh, sorry. That's my bad eyesight again

I see you wrote 48k bitrate and 12khz sample rate. What happens if you keep all other values the same but set the sample to match whatever the original file was? Do you still lose sync?

[midwinter]

Euh, sorry. That's my bad eyesight again

I see you wrote 48k bitrate and 12khz sample rate. What happens if you keep all other values the same but set the sample to match whatever the original file was? Do you still lose sync?

That did the trick! Thanks! Now I need to figure out how to get the file size down a little more. The resulting divx file this time was 70 MB. I'd like to get that to about 50....

Any ideas?

Thanks, again, for all the help!

Cheers
Scott

[thoughton]

Hmm. This is all guesswork

How much of the 70MB is audio at the moment? Just wondering how much you could potentially save by changing the sampling (but need to figure out how to sync it). Also changing it to ac3 might shrink it a few percent (or maybe not).

Also what FPS is your 70MB file?

Other possibilites that come to mind are reducing video bitrate (but quality might suck), using VBR if your player can handle that, and trying the xvid codec and lowering bitrate if your player can handle that.

If it was me I'd try the xvid thing first probably, but it'll probably be a lot of trial and error either way

[midwinter]

Hmm. This is all guesswork

How much of the 70MB is audio at the moment? Just wondering how much you could potentially save by changing the sampling (but need to figure out how to sync it). Also changing it to ac3 might shrink it a few percent (or maybe not).

Also what FPS is your 70MB file?

The output is 29.97 fps. Any change to that really slows down the video. It's bizarre. Audio is mp3.

Other possibilites that come to mind are reducing video bitrate (but quality might suck), using VBR if your player can handle that, and trying the xvid codec and lowering bitrate if your player can handle that.

At the moment, a video bitrate of 125 is acceptable.

If it was me I'd try the xvid thing first probably, but it'll probably be a lot of trial and error either way

Well, the issue is that I'm playing these on a pocket pc, so I'm at the mercy of the player.