Make your Movies, your Way

The video format you need depends upon the application you’re

going to put it to. So if you want a video with all the data for editing, AVI is

the best option. If you need to save space and yet retain the quality, opt for

formats that use some sort of compression, like MPEG, DivX or even MPEG 4. As it’s

not possible to discuss all of them, we’ll talk about the most-popular ones

here.

Whenever you convert a video from one format to another,

there will be some irretrievable loss in video quality. That’s why for most

video editing work and conversions, AVI is used as the base format. To get the

best AVI file, you’ll need a good quality video capture card or Webcam that

doesn’t drop too many frames during video capture. With these base guidelines

in mind, let’s proceed with the various conversions. Also, keep in mind that

different video formats use their own codecs for compression and decompression.

AVI to MPEG-1

When you record from a source, say a TV card, a video capture

card, a digital video camera or even from a Beta-cam, the associated software

records the video in raw, uncompressed AVI format most of the time (though

sometimes a simple codec may be used). An AVI file takes up a lot of hard disk

space and is not always feasible if you want to put it on a CD. For that, it’s

better to store the video on a VCD. For this you need to convert it to MPEG-1

format. Simple programs like ‘avi2vcd’ are available to help you do this.

Just select the file to be encoded and the output path and hit Encode. You have

the option of selecting the output standard viz PAL, NTSC or Film. The MPEG file

thus created can be burnt on a CD using any of the commonly available CD burning

software like Adaptec or Nero.

AVI to MPEG-2

MPEG-2 is more popular than MPEG-1 for storing digital video

as it gives higher data rate and hence better quality. For encoding to this

format ‘bbMPEG’ is a good software. Apart from encoding, the software lets

you do basic editing, like cropping image frames and changing the final movie’s

resolution in terms of its height and width. The output video will not be as

smooth and detailed as the original because of compression, so don’t choose a

higher resolution than the original. Otherwise, you’ll get a ‘blocky’

video. bbMPEG can also be used to convert MPEG-1 streams to MPEG-2.

MPEG to AVI and ASF

Why would you want to convert MPEG to AVI? One reason could

be if you want to stream your video, for which MPEG can’t be used. For that,

the MPEG has to be converted to an ASF (Advanced Streaming Format) file. Since

there aren’t too many utilities that let you convert from MPEG to ASF, you’ll

first have to convert it to AVI. For this, a utility called ‘VirtualDub’ is

available. The process is time consuming. After converting to AVI, use Microsoft’s

Windows On-Demand Producer for converting the AVI to ASF format. The utility is

part of Windows 2000. Microsoft NetShow Tools has the NetShow Encoder, that can

do the same, but we found the former a lot easier and better.

VCD to MPEG

As already discussed, video on VCD (file extension DAT) is

MPEG-1 by nature, stored as DAT files. A host of software is available for

ripping video CDs. VCDGear is one package that lets you convert your DAT tracks

on the VCD to MPEG directly. Just load the DAT file and select the appropriate

extraction/conversion option. It also lets you convert the other way round, that

is, MPEG to DAT. Alternatively you can use VirtualDub, which does a lot of

things apart from just ripping CDs. You can use this to rip the video track off

the CD and save it as an uncompressed AVI. This AVI can then be encoded into

MPEG as already explained. Please keep in mind that a VCD holds around 600 MB of

compressed video that’ll balloon up to a large size when converted to AVI. So

you’d better have plenty of free hard



disk space.

Video tape to VCD

This is a big time business even for small time

professionals. Video tapes are the primary storage for video from live events,

parties and marriages and since video tapes are a hassle to maintain or use,

users want to convert their videos to the easier to use VCDs. You need a video

capture card for this purpose and of course a compression/encoding software. The

quality and frame rates of the final video depend on the kind of capture card

you use. High-end cards allow higher frame rates during capture, but they’re

very expensive. The accompanying software for capturing usually allows you to

specify the capture size, resolution, and colors. They normally save the video

as uncompressed AVI. You can use any of the earlier discussed schemes to convert

this video to VCD-compliant MPEG-1 and burn it on to VCDs. For details read the

story ‘Working with Video’, page 80, in the January 2000 issue. You can also

check out our Website–www.pcquest.com–if

you don’t have a copy of the issue.

VCD to DivX

DivX is making waves in video similar to what MP3 did in

audio. What’s the advantage? DivX is a format that achieves a high level of

compression, even more than conventional MPEG files. You’ll find many movies

in DivX format on the Internet for download. The advantage is that DivX gives

you good picture quality despite the compression. It’s sometimes confused with

MPEG-4, but the two are actually different formats and use different codecs. If

you have a VCD and want to put up a movie server in the near future (when the

bandwidth situations improve), you can readily convert your VCD movies to DivX

for download. To do this, VirtualDub is an easy-to-use software. It rips the

video data track (along with the sound) from the VCD, and its data stream can

then be processed to give you a DivX movie. The beauty of the software is the

amount of experimentation you can do it. You can select the video codec to be

used for compression; the audio codec can be specified separately and could be

DivX audio or even MP3.

DivX to VCD

Now why the other way round? DivX playback requires a lot of

CPU power. So if your PC is slow, the playback is jerky. On the other hand, VCDs

can be played back even on an ordinary PC with a decent video card or even on

your home theatre. For this, you’ll first have to strip the audio from the

DivX file using VirtualDub. Load the file and then click on ‘Save WAV’.

Though this WAV file can be played back normally, it’s not an ordinary WAV

file, but a Windows Media Audio V2 file for DivX audio. You have to convert it

to a PCM WAV file for your use. Our good old Winamp did the job with its output

plugin set to NullSoft Disk Writer. For the final encoding, the audio and video

have to be merged. You can use either Xing MPEG Encoder or Panasonic MPEG for

the purpose. Load the DivX AVI in the video box and the normal WAV in the audio

(after unchecking ‘Use identical files’). Start encoding and you get the

MPEG that can be burned into a VCD using either Nero or Adaptec Easy CD Creator.

Video tapes to Streaming video

So you videotaped your daughter’s birthday and want the

whole world to see it. What do you do? Put it on your Website. And for that you

need to convert it to Real video. Though video can be streamed in other formats

also (like ASF), Real media is popular because it is easy to encode, distribute

and play back on client machines. This is a two-stage process–the first

involves capturing the video as an AVI and then encoding it to RM depending upon

your bandwidth considerations. For the first part, any graphics capture card

would do. For the second part, RealNetworks’ Real Producer again comes handy.

The software encodes AVI, MOV, and even QT files. It can also take input

directly from a media device like a camera or a VCR and publish it as streaming

media. The data rate of the encoded file is determined on the basis of target

bandwidth say 28.8 kbps, DSL or intranet LANs.

DVD to VCD

Why do you need to convert a DVD movie to a VCD? Well,

suppose you have a standalone VCD player at home, and a DVD drive on your PC.

You can convert all DVDs you have to VCD for viewing on your larger TV screen.

The process can be divided into four steps:

1. Rip the data
   
   tracks (VOB files) off the DVD

2. Strip the video
   
   from the VOB file

3. Strip the audio
   
   and convert it to stereo or mono, and

4. Combine the video
   
   and audio to generate a VCD compliant MPEG file.

Though you can see the VOB files if you explore the DVD, you

may not always be able to copy them directly because DVDs are copy protected.

VOBDec is a command-line software that rips the VOB files and stores them on the

hard disk. It also has a GUI, which makes it easier to use for a novice. Other

tools like CladDVD or SmartRipper also do the same job. Then you need to extract

the video and also the Dolby AC3 sound from the file. Use DVD2AVI, a utility

that creates a project file storing the two.

The next step is to convert the sound to stereo from Dolby

AC3 5.01 format to simple stereo format for putting on to the VCD. Any good

sound-editing package like Sonic Foundry’s Soft Encode lets you do that and

gives the output as a PCM WAV file. Now we use an encoder to merge the audio and

video. TMPGEnc is one such software. Load TMPGEnc, select the project file that

you made earlier as the video and the WAV file as the audio and hit ‘Start’.

It takes a while to generate the MPEG output, which can then be used to make a

VCD. You might have to use a MPEG splitter to split the MPEG into two files so

as to fit on CDs.

This list of conversions is in no way comprehensive. There

are a lot of other things you can do with your videos. For this, you need to

keep experimenting and updating yourself.