DivX created by ffmpegX doesn't work on player?

[ambrosechapel]

I've got some VOB files I want to convert to DivX AVI.

I have a standalone player (CONIA brand) which plays any DivX AVI I've ever downloaded: TV shows, movies, etc., never had a problem.

But when I create a file from the VOB using the ffmpegX defaults for DivX, the player chokes on them. It does what it normally does for a supported file, which is to say "loading..." for a while (if it doesn't like the format it instantly says "unsupported"). But after the "loading..." message goes away, I just get a black screen.

What's the likely cause of this? Bit-rate? Resolution? Frame-rate? There are so many options, that's the thing.

[tomlee59]

More information, please. What were the settings you used? "ffmpegx defaults" is not quite what we're looking for. You tell us the bitrate, resolution, audio codec, etc.

And if you happen to have the other avi's that do work, why don't you take a look at how they're encoded (bitrate, resolution, audio, etc.)? Since that's a combination that's known to be good, it would seem logical to set up ffmpegx to do the same. If you still encounter difficulties, that would give us valuable information for the next stage of troubleshooting.

[ambrosechapel]

Well what I meant by "ffmpegX defaults" was, what you get when you choose a pre-set from the "Target Formats" on the Summary tab.

To be specific...

INPUT (a VOB file), VideoSpec:

*** Video Track Parameters ***
- Video track format: MPEG-2 Video
- Video stream size: Undefined
- FourCC: 0x10000002
- Video track number(s): 0
- Video track bitrate (Kbps): 4262
- Frame rate (fps): 25.00
- Bitrate mode: Constant
- Encoding profile: Main@Main
- Resolution: Undefined
- Video width (Pixel number): 720
- Video height (Pixel number): 576
- Pixel Aspect Ratio: 16:15
- Display aspect ratio: 4:3
- Chroma subsampling format: YUV420p
- TV standard: PAL
- Interlacing: Interlaced - Top Field First
- Video encoding library: Undefined
- Additional Parameters:
Matrix: Standard
Bits/(Pixel*Frame) ratio: 0.945

*** Audio Track Parameters ***
- Audio track format: AC3-A52
- Audio stream size: Undefined
- Audio FourCC: 0x2000
- Language(s):
128: Undefined
- Audio details: -
- Audio Profile: Undefined
- Audio bitrate (Kbps): 224
- Audio bitrate mode: Constant
- Audio resolution: Undefined
- Audio rate (KHz): 48.0
- Audio channel(s): 2 (stereo)
- Position: Left Right
- Audio Encoding Library: Undefined

So, if I just leave ffmpegX on the default setting, "AVI DivX", it says it will encode to "mencoder mpeg4, 640x352, 1265kbps, 25 fps, no crop" and that file will not play in my standalone player.

One obvious thing there is that the output size is somewhat random. 720x576 => 640x352?

[Case]

What is the filesize of the VOB file? What is the duration? Can you play in in a software player? Which player(s)?
What is the filesize of the DivX AVI? What is the duration? Can you play in in a software player? Which player(s)?

I've got some VOB files

Are these extracted from a DVD? Do all VOBs from that source have this problem? Some DVD items, like stills, menus and some message type video are stored in VOB files, but not in the same way as a regular DVD title. Those are often in the VTS_xx_0.VOB (the Zero VOB) and can be tough to convert.

I have a standalone player (CONIA brand) which plays any DivX AVI I've ever downloaded: TV shows, movies, etc., never had a problem.

1. Try to convert some other (short) clip with the same preset. That should tell you if the settings or the source is causing trouble here. It would be a waste of time if you tried to tweak the target settings, if in fact it were the source file that is causing headache.

One obvious thing there is that the output size is somewhat random. 720x576 => 640x352?

True, starting with the first incarnation of v0.0.9, the program should detect the source aspect ratio and apply that to the target video settings. It seems stuck on 16:9 now, unfortunately. I don't now when this ability was lost, but it didn't function in 0.0.9x either. So, you'll have to 'manually' adjust the video parameters (auto size aspect ratio) to get the desired result. Unrelated to non-playback, tho'.

[jman98]

I don't make Divx a lot, but I NEVER use ffmpegX. It could be that by default it uses one of those options that are known to be problematic for DVD players that support the format. This sticky lists options that might be a problem:
https://forum.videohelp.com/topic352457.html

QPel, Packed Bitstream and GMC are the ones that usually cause playback problems. Your bit rate and resolution should be fine. Including the VideoSpec info on your source VOB isn't really helpful. Including the details on your problem Divx videos would be helpful.

[tomlee59]

Like jman98, I don't use ffmpegx for divx from DVD. It's not that I have anything against it; it's just that I have a preference for the way D-Vision3 works. I started using it before discovering ffmpegx, and since it always "just worked" I had zero motivation to try something else.

Jman98 gave you great things to watch out for. Qpel is a particularly troublesome issue; you get potentially higher quality at the expense of greatly increasing the probability of playback issues. For most folks, the improvement isn't worth the tradeoff in hassle factor.

If you use D-Vision3, you'll find that it selects default parameters that are very widely acceptable to software and hardware players alike. You might want to consider that as another option, in addition to continuing your debug of ffmpegx.

[ambrosechapel]

Thanks for all the help so far.

In the end I tried twelve different settings (4 presets x 3 output sizes) and I found one which worked reliably, which was AVI DivX, mencoder xvid, 640x512, 1265, 25fps.

So I'm using that. When all the VOBs are out of the Progress queue I'll take a look at exactly what the problem presets did.

[jman98]

I suppose I could clarify and state that when I said that "I NEVER use ffmpegX" that this is not because I think it sucks but because I have other tools that I prefer to use for this, usually Dr. Divx. I have no experience with ffmpegX. That means that I have no idea what sorts of things it does in encoding to Divx and by default it may use some options that are problematic.

Rather than try 12 different options you could have just posted a screen capture of what GSpot said about your problematic encodes and we could have looked at it and told you what the problem was, but it's your time to waste.