I've recently been investigating creating .FLV files, a format that sadly Vegas can't yet render to on its own.

As I'm purely an amateur and do this stuff only for my own amusement I was looking for a way to do it for free if possible, or for very little money if not. I found that although it is easy to create the earlier Flash6/Spark/FLV1 format files using a number of free utilities (SUPER, a friendly front end for FFMPEG, is the example most often suggested hereabouts) it did not seem to be possible to create the much superior Flash8/On2VP6 format files without spending some money. I've not been very impressed with the quality of the Spark FLV files I've seen (this is the format used by YouTube) so I was keen to be able to create On2VP6 FLV files if at all possible. The cheapest way to create On2VP6 FLV files seemed to be with On2's Flix software, but annoyingly the affordable version restricts you to only creating files using one-pass rendering - two-pass rendering is only available in the much more expensive versions which are way out of my price range for amateur dabbling.

But after a bit of hunting around the WWW I have discovered that it is possible to create two-pass-encoded On2VP6 FLV files without spending any money at all (so long as it is for private use only). What follows is a description of how to do it, in case anyone else is interested in creating FLV files from their Vegas videos. (I don't make any claims to have invented any of this myself - all the information has come from Klaus Post's webpage here and the pages he links to - I've merely simplified the procedure to do as much of the work as possible in Vegas.)

Creating the FLV is a two-stage process. The first stage uses Vegas to render the video to a On2VP6-encoded .AVI file and the second stage uses a modified version of FFMPEG to extract the audio and video streams from the AVI and put them into a FLV wrapper.

0 - Preparation:

First you need to install the On2VP6 VFW codec which can be downloaded from here (free for personal use.) Then you need to download the modified version of FFMPEG which can be obtained from here and unzip it into a convenient directory somewhere on your PC.

1 - Creating the VP6 AVI

For some reason the FLV format seems to have a different idea of which way is up than the AVI format does. This means that unless you take steps to correct it your video will play back upside down once it has been converted to FLV. To compensate for this you need to render your VP6 AVI upside down. You could do this using Track Motion in Vegas, but it's much quicker to use the free Adam's Flip plugin which can be downloaded from here

When you've finished editing and are ready to render, add the "Adam's Flip Vertical Only" effect to the Video Output FX (you'll see the Video Preview will now turn upside down) and then click on File|Render As... Then choose "Video for Windows (.avi)" and click on the Custom button.

Under "Video Format" choose "VP62 Heightened Sharpness Profile" and choose suitable values for Frame Size, Pixel Aspect Ratio, etc - in testing I've used 320x240, PAR 1.000, Progressive, 25fps. Then click the Configure button and on the Settings tab choose Two Pass - First Pass. You can go to the General tab and vary some of the setttings if you like, but I have just left things as they are preset - 300kbps VBR. Then click OK. Now on the Audio tab choose MPeg Layer 3 and choose a suitable bitrate. All FLV files I've ever seen have used MP3 audio but I'm not sure if there are any restrictions on bitrates, etc. In testing I've used 56kbps, 22.050kHz, Stereo which seems to work OK. Now click on OK, choose a suitable filename, and finally click on Save to start the first pass of the render. (After the render is completed you will have an .avi file and a pair of files called firstpass.fpf and firstpass.fpf.sst which presumably contain the details that will guide allocation of bits in the second pass.)

Now click on File|Render As... again and make the same setting changes under Custom as you did the first pass, except this time choose "Two Pass - Second Pass - Local File Playback" on the Settings tab in the VP6 Configuration page. (To save time you could save these combinations of settings as templates, of course.) Now click OK, then OK again, and finally click on Save to start the second pass of the render (choose to overwrite the avi file that was created by the first pass). Eventually you should end up with a two-pass On2VP6-encoded .avi file. If you play this file using a file player you will find that it is upside down but otherwise plays OK (though it will probably only play on machines that have had the On2VP6 codec installed on them).

2 - Wrapping the Audio and Video streams in an FLV wrapper.

Copy the modified version of the FFMPEG .exe file to the directory where the VP6 .avi is located and then open a command prompt window and browse to the appropriate directory and issue the following command (this assumes the .avi is called test.avi):

ffmpeg -vcodec copy -i "test.avi" -acodec copy -i "test.avi" "test.flv"

Now play the .flv file in your favourite Flash video file player and you should find that it works OK (right side up now, of course).

(The "-vcodec copy" and "-acodec copy" bits tell FFMPEG to use the streams as is, i.e. without recoding, so it just takes the audio and video data and wraps them up in a FLV wrapper and saves it as test.flv.)

Hopefully Vegas 8 will be able to render to Flash so all this will be unnecessary but I thought I'd post the details here in case anyone was interested.

Mark