xvid okay for progressive avi downloads?

[vlogger]

Hi All,

I have some xvid avi files that are sitting on a web site. Using Windows, I tried viewing the file as a progressive download using windows media player (wmp), vlc, and mplayer. Results:

wmp: complained that it couldn't find a decompressor
vld: audio, no video
mplayer: perfect

The problem is that I am building an app around video and I need the average, non-technical person to be able to use it. So I can only really rely on wmp for Windows users. I spent a few hours trying to find information about the why this doesn't seem to work and I found a few people pointing the finger at xvid and few others pointing the finger at the avi container. (I realize avi isn't an ideal progressive download format, but based on what I read, it should work.)

Anyone have any ideas what the problem might be or how I could resolve it?

Thanks,
David

[chilledinsanity]

Nah, as much as I love Xvid, I'd say you're better of sticking with DivX for the masses, since most people have that. If you want the ultimate compatibility, use MPG, although you have to make even more sacrifices in quality.

[unskinnyboy]

There have been countless discussions in this forum as to the most appropriate format which is universally playable by everyone without having to install anything extraneous and the answer is always MPEG-1. Forget everything else.

To get the discussion threads on the above subjects, :search: and please don't open threads on already-much-discussed topics.

[vlogger]

There have been countless discussions in this forum as to the most appropriate format which is universally playable by everyone without having to install anything extraneous and the answer is always MPEG-1. Forget everything else.

To get the discussion threads on the above subjects :search: , and please don't open threads on already-much-discussed topics.

I am NOT asking about compatibility - a word that never popped up in my initial post; besides it is well documented that avi enjoys support across platforms. I have searched rather extensively on this forum and others about my question. In any case, MPEG-1 files are completely unviable to distribute via the Internet because file sizes would be prohibitively large. Please read the question before you criticize and tell people to look elsewhere. As for the earlier response, users of xvid can generally decode divx files and vice versa.

Let me try rephrasing my question:

Is there anything inherent in either the avi container format or the xvid codec that prevents a file with those two attributes from being played by Windows Media Player during a progressive download?

Thanks,
David

[stephanV]

For progressive download there isnt (as long as you dont want to seek), although AVI is probably not the best choice either. If you want it to work on WMP i would look into asf if i were you.

[unskinnyboy]

@vlogger, From what you said "I need the average, non-technical person to be able to use it", suggested compatibility to me. I am sorry if you meant otherwise. I am not sure about why WMP is giving that error (assuming you do have the codec installed), but why not try and stream the AVI files? I found this (http://dmrl.usc.edu/pubs/sac2003-web.pdf) paper on it. Looks like a lot of work, but maybe it will help.

Also, as Stephan said, I would also look into ASF and WMV formats to see if they would work for progressive downloads. AVI are not suitable for progressive downloads or streaming, because of seeking issues. But it can be circumvented as explained in that^^ paper.

[vlogger]

@unskinnyboy -- thanks for the link. The paper is interesting. When I suggested the "average, non-technical person," I meant a Windows user with WMP as the only media player.
@stephanV -- hmmm, so theoretically, it should work. Seeking is not particularly important to me right now.

I think it will help if I put what I'm doing into context. Users of the service can upload their own videos. If they upload wmv, progressive downloads should work. However, it seems that the vast majority of video files are avi. Digital cameras and camcorders generate them. I'm considering writing a Windows Media Encoder app that transcodes avi to wmv, but the transcoding process is long and complex for my userbase.

As for streaming, I have a custom-built backed distribution platform. It doesn't (and can't easily be modified) to support streaming, but I figured that would be less important with progressive downloads over broadband. So I am still confused why my xvid-encoded avis can't be viewed until they have been completely downloaded.

Cheers,
David

[stephanV]

So I am still confused why my xvid-encoded avis can't be viewed until they have been completely downloaded.

My guess is that WMP is waiting for the index to be downloaded (and the index is placed at the end). While an index is not mandatory for AVI, I do not know if MS AVI splitter supports files without index. Or files that are supposed to have an index but don't. (replacing the idx1 chunk with JUNK certainly doesn't keep a file playable in WMP)

Question: Why do you keep emphasizing XviD? Is it only not working with XviD?

[vlogger]

My guess is that WMP is waiting for the index to be downloaded (and the index is placed at the end). While an index is not mandatory for AVI, I do not know if MS AVI splitter supports files without index. Or files that are supposed to have an index but don't. (replacing the idx1 chunk with JUNK certainly doesn't keep a file playable in WMP)

Question: Why do you keep emphasizing XviD? Is it only not working with XviD?

Hmmm, I think you might be onto something.... From what I understand, mplayer can create an index on the fly and it may well be impossible for MS AVI splitter to handle a file without an index. If that is the case, I wonder if there is a way around it with XviD. To your question, why XviD? Intel's Indeo codec has supported progressive download of AVI files since 1998. (http://groups.google.com/group/intel.other_products.indeo/browse_thread/thread/1ccd465a9536980f/1f7323f487f4482a?lnk=st&q=index+avi+progressive+download&rnum=3&hl=en#1f7323f487f4482a)

XviD is a newer, better codec and I'd much rather use it than Indeo. So if there is a way to get AVIs encoded with XviD to progressively download in WMP, I'd be a happy guy.

-David

[stephanV]

Hmmm, I think you might be onto something.... From what I understand, mplayer can create an index on the fly and it may well be impossible for MS AVI splitter to handle a file without an index. If that is the case, I wonder if there is a way around it with XviD.
No, XviD does not handle the container format. WMP/DirectShow is doing that. This is codec independant.

To your question, why XviD? Intel's Indeo codec has supported progressive download of AVI files since 1998. (http://groups.google.com/group/intel.other_products.indeo/browse_thread/thread/1ccd465a9536980f/1f7323f487f4482a?lnk=st&q=index+avi+progressive+download&rnum=3&hl=en#1f7323f487f4482a)

XviD is a newer, better codec and I'd much rather use it than Indeo. So if there is a way to get AVIs encoded with XviD to progressively download in WMP, I'd be a happy guy.
You misunderstood my question a little. Have you verified this works using other codecs? (DivX, VP7, Cinepack, whatever)

[Isochroma]

Since the index is at the end of AVIs as mentioned previously, they will never play until completely downloaded, or if they do play they will not be seekable.

ASF/WMV was designed from the start to be streamable, and will play as soon as sufficient data is buffered. Make sure to have WMP10 installed, then install Windows Media Encoder 9, and use Advanced Profile.

WMP and the IE plugin will auto-download the WMV9 codec if necessary directly from Microsoft's ActiveX plugin gallery. WMV is the most supported streaming format in the world (the player is built into every Windows installation).

[vlogger]

@StephanV
No, XviD does not handle the container format. WMP/DirectShow is doing that. This is codec independant.
Yep, I'm clear on that -- it's the big plus (and big minus) of DirectShow. :-)


You misunderstood my question a little. Have you verified this works using other codecs? (DivX, VP7, Cinepack, whatever)
I had similar problems with those, but I remembered that I had seen streaming avis at some point. I think it must have been an older version of WMP, which as I understand, could handle avis without indices.

@Isochroma
Since the index is at the end of AVIs as mentioned previously, they will never play until completely downloaded, or if they do play they will not be seekable.


Yeah, it appears that WMP is unhappy unless there is an index. Mplayer and VLC (and the old WMP) are a little less particular.

WMV is the most supported streaming format in the world (the player is built into every Windows installation).
The problem is that I'm dealing with user generated content and avi is the most popular container format in the world. I guess my options are to stick with WMP and transcode the avis to WMV or to install a player like mplayer on user machines.

I appreciate all of the help. I don't know what I'm going to do yet, but I'm glad to be clear on the problem and options to resolve it.

Best,
David