Best AVI audio codec for universal compatibility?

DSinOR · Post by **DSinOR** » Sat May 03, 2008 5:27 am

Hi, I'm making a 720x480 14-minute AVI video for distribution on cd-rom. It's intended for playback on desktop computers in office environments, frequently in multiple international locations (for example USA, Mexico, Philippines, Thailand, Taiwan, Costa Rica, Colombia, Chile, Spain, to name a few).

My goal is maximum compatibilty (PC or Mac) without requiring the viewer to download and install any codecs.

My research suggests that Cinepak is the clear best choice for the video codec.

But I'm not sure which audio codec to use.

In their respective "standard" configurations, WMP and QT both support the following audio codecs:
- ALAW
- ULAW
- MS ADPCM

QT also supports 24-bit integer, 32-bit FP, 32-bit integer, and 64-bit FP audio codecs. I don't know what these are. Are they varying forms of PCM? If so..., does the PCM audio option in VS11 "match up" to one them?

Bottom line, Cinepak is a great "universal" video codec. I need to choose an audio codec to go with it that provides decent sound and doesn't have a huge impact on the overall data rate.

Thanks!

Devil · Post by **Devil** » Sat May 03, 2008 8:22 am

I'm sorry, but AVI is not designed as a distribution format. It would mean that each computer it is viewed on would need special codecs. Is there any reason why you cannot use MPEG-2, for example, which is a distribution format and can be configured to whatever quality you need?

Post by **Ken Berry** » Sat May 03, 2008 8:37 am

... And the great universal high quality audio codec is in fact (L)PCM...

You also don't tell us which variety of AVI you are proposing to use. There is a huge variety of video formats out there which use the .avi extension. That is just a carrier format. There is raw .AVI which is huge at around 65 GB per hour of video. Then there is DV/AVI from mini DV digital video cameras, still large at 13 GB per hour. At the other end of the spectrum are high quality but highly compressed mpeg-4 type formats such as DivX and XVid. But as Devil has already said, just about all of these require that the person playing back your video has the relevant codecs on his/her computer -- and that's without even beginning to think of the audio codecs!

skier-hughes · Post by **skier-hughes** » Sat May 03, 2008 10:00 am

Ken Berry wrote: You also don't tell us which variety of AVI you are proposing to use. There is a huge variety of video formats out there which use the .avi extension. That is just a carrier format. There is raw .AVI which is huge at around 65 GB per hour of video. Then there is DV/AVI from mini DV digital video cameras, still large at 13 GB per hour.

There are in fact over 800 file types that can be wrapped into an avi.

DSinOR · Post by **DSinOR** » Sun May 04, 2008 1:06 am

Hey guys, thanks for the replies!

MPEG2 really is the ideal format, but it won't play on QT on a Mac without the user purchasing a $20 add-on which must be downloaded and installed.

A primary objective for this movie is that the user doesn't have to do anything to his computer to get the movie to play. My target audience is impatient, busy, not frequently tech savvy, and often in possession of 5-year-old desktops.

My movie is 14 minutes of raw AVI ("OpenDML"), 720x480, 29.97fps.

Yes, the file is enormous. It will be between 600 and 700MB.

But the data rate will be easily less than 1200kbps, and if I tweak the "percent level" on the Cinepak compression AND use 24fps instead of 29.97, then I may be able to get the data rate down to 600kbps, which as you know will play on an old 4X CD_ROM.

Raw AVI - if the vid codec is Cinepak and the Audio codec is ALaw or ULaw or ADPCM, then I'm pretty sure that the movie will play on any machine with any version of WMP, RMP, or QT published in the last 8 years, because those players and many others like them have supported raw AVI with that combination of codecs since forever. Please correct me if I'm wrong about this.

In short test clips I've made, I perceive better audio from the Cinepak-PCM clip than than the Cinepak / *LAW or ADPCM clips, hence my interest in PCM.

I'm happy with 22050kHz 8bit mono sound. The movie contains only voice, no music or background sound or 2nd audio track.

I need to know if a VS11+ raw AVI movie made with PCM audio codec will play on QT.

The Apple website list of audio codecs supported by QT 7.4.5 includes "24-bit integer, 32-bit integer, 32-bit FP, and 64-bit FP". Further research indicates that QT has supported those "codecs" for many product generations. Unfortunately, I don't know what those codecs are. I suspect they may refer to uncompressed audio. I'm wondering if they are apple-speak for various versions of PCM? If so, does the VS11+ PCM audio option relate in any way to one of those "integer or floating point" codecs described by Apple? If so, which one?

If i'm way off base on the PCM thing please say so. I'll revert back to a LAW or ADPCM codec, and would be grateful for advice in choosing one of those.

If PCM is a viable option, will it have a significantly greater impact on overall bitrate than *LAW or ADPCM?

Ken - What is (L)PCM? Does it differ from the PCM codec option available on VS11+?

Other things I'm not sure about:

1 - all my titles were shifted offcenter to the left during "square pixel" rendering. My target playback machine is a desktop computer to a monitor, so I don't need to use non-square pixel rendering. But the only way to fix the title problem was to check the box for non-square pixel rendering. Now my movie has the slightly "fattened" look. It's tolerable, but if you know of another way to eliminate the offcenter title problem, show me how so I can uncheck the non-square pixeling option.

2 - What key frame rate should I select for 29.97fps? For 24fps?

The next three questions assume a raw AVI movie delivered on cd-rom using Cinepak and a "best choice" audio codec. On the Advanced Options window, there are three choices I need to make:

1 - Recompress? Should I use this?

2 - Interleave audio and video? Should I use this?
2a - Pack audio for every X frames. What value should I use for X?

3 - Pad for CD-ROM? Is this necessary for my avi movie?

WOW! Big post!

My goal is the best video and audio quality i can milk from a raw avi delivered via cd, keeping the file size to 700MB and the bitrate to less than 1200 (maybe less than 600 if that step can be made without killing quality).

I'm really grateful for any help you can provide. My timeline is short, so thank you for your help!

DSinOR · Post by **DSinOR** » Sun May 04, 2008 1:31 am

I posted all of the above assuming that raw avi is "universally playable", therefore NOT requiring special codecs.

I hope that assumption is correct. If not, it's back to square-one.

If you need more info on the raw video:

Filmed on a Sony DCR-TRV330. Captured via firewire.

Specs: AVI - OpenDML, 29.97fps
Video: DV Video Encoder - Type 1, 24bit, 720x480, 4:3
Audio: DV Audio - NTSC, 32000kHz 12bit Stereo

Thx!

Devil · Post by **Devil** » Sun May 04, 2008 7:01 am

AVI is to Windows as MOV is to Mac. Are you sure QT will play AVI and with what codecs that come as standard? I can't answer as I've never owned a Mac. And do any of your users have Linux?

Post by **Ken Berry** » Sun May 04, 2008 10:20 am

The basic problem, apart from all your musings about the various options, is that you don't have raw AVI. Raw AVI is huge -- as I said it is 65 GB per hour of video, so if you have 14 minutes of video which only take 600 or 700 MB then it is neither huge nor, more to the point, raw AVI. That would be 15 GB or more!!!

Then you say that instead of raw AVI, it is DV/AVI which in fact is five times compressed at 13 GB per hour of video. So again the math suggests that whatever you have, it is not DV either since 14 minutes of DV would be over 3 GB and not 600 - 700 MB.

So I am stumped.

Even if it were DV/AVI, then for it to play on a Mac, it would need to have the .dv extension, not the .avi extension, and that has to go through a QT Pro converter -- believe me, I know, since I have had to do it the other way (starting with Mac .dv format and getting it, through QT, into DV/AVI format for PC).

In other words, my basic message is that if you are after something which is truly cross platform automatically without extra codecs or plug-ins involved, I suspect that true raw .AVI is needed, but that is so huge you will not be able to burn a 14 minute file to anything except Blu-Ray, and you certainly will not be able to send it via any email service I am aware of simply for size reasons...

Or else you burn it to a DVD which is standard for both Macs and PCs...

Devil · Post by **Devil** » Sun May 04, 2008 10:57 am

I agree, Ken. The only reasonable option is mpeg-2, as I already stated, burnt into a DVD, not as a CD or, better, as a SVCD. The latter is a standard format MPEG-2 at 480 x 480 (or 576 for PAL) at 2500 kbit/s max with 224 kbit/s audio MP2 and you get ~30 mins max on a CD. The quality is actually astoundingly good and I've burnt many such for short projects. This can be done in VS without problems. I suggest you try it instead of looking for all kinds of difficulties.

skier-hughes · Post by **skier-hughes** » Sun May 04, 2008 11:02 am

I'd go with flash, as more computers and Macs have Flash installed than anything else for playing media files.

DSinOR · Post by **DSinOR** » Sun May 04, 2008 6:17 pm

Edit - never mind.

I'm just gonna make avi movies and send them to Mac people and see if it works.

If it works, I'll post back.

FYI:
> QT support for Cinepak AVI dates from at least QT Version 3 (1998) to present.
> Windows player support for Cinepak AVI dates from Cinepak inception to present.

ALAW, ULAW, ADPCM audio codec support goes at least 10 years back too, I think.

Okay - my clips are in DV/AVI, not raw AVI. Thanks for helping me understand that.

The clips that make up the movie are 3.9GB in total size. The Cinepak compressed avi version is ~650KB.

In my 2nd post, I asked 11 questions.

I would pretty much pay money to have any or all of them answered. They don't necessarily hinge on the avi issue.

Can you guys answer any of those questions?

THANKS!

DSinOR · Post by **DSinOR** » Sun May 04, 2008 6:26 pm

Devil wrote:I agree, Ken. The only reasonable option is mpeg-2, I suggest you try it instead of looking for all kinds of difficulties.

I did try it. It is the reason my project is behind schedule.

We absolutely knew that an MPEG2 SVCD would play anywhere, and were absolutely wrong.

To play on QT (Mac or windows version), you have to pay more money and download add-ons.

DSinOR · Post by **DSinOR** » Sun May 04, 2008 6:35 pm

skier-hughes wrote:I'd go with flash, as more computers and Macs have Flash installed than anything else for playing media files.

Using the latest flash capability, it's possible to import the movie, convert it to an swf, and then wrap it in a Projector file for either Windows or Mac. Both can be burned onto one CD, and MacImage can be used to make image files that will autorun in either Windows or Mac.

Cool!

We don't have the $700 or the three weeks it will take to implement that new capability.

The quality won't be better than AVI.

AVI will do what we want now.

Just need a bit of info about PCM, non-square pixel rendering, recompress, interleave, and pad.

THANKS!

skier-hughes · Post by **skier-hughes** » Sun May 04, 2008 9:05 pm

DSinOR wrote:
Devil wrote:I agree, Ken. The only reasonable option is mpeg-2, I suggest you try it instead of looking for all kinds of difficulties.
I did try it. It is the reason my project is behind schedule.

We absolutely knew that an MPEG2 SVCD would play anywhere, and were absolutely wrong.

To play on QT (Mac or windows version), you have to pay more money and download add-ons.

Not all windows pc's come with an mpeg2 codec either, even the latest vista comes in mpeg and mpegless versions.