AC3Filter – AC3 and DTS Audio Decoding

With a large percentage of new camcorders using MPEG-2 video combined with AC3 audio as a common storage format, it’s become much more complicated to work with camcorder video. If you have one of these camcorders and use free tools like Windows Movie Maker for video editing, you simply shouldn’t be without the free DirectShow filter AC3Filter. The app runs in the background as an audio decoder and processor filter for AC3 and DTS audio tracks. AC3Filter supports playback of AC3 and DTS audio tracks in software like Windows Media Player, in addition to enabling editing features in things like Windows Movie Maker. Audio processing supports an up-mixing any audio source to 6 channels or down-mixing to stereo from surround sound. Both analog multi-channel and digital (SPDIF) output are supported. AC3Filter encodes any audio source to AC3 on-the-fly and send it over SPDIF to your receiver. [Windows 2k/XP/Vista $0.00]

Split MP3s into Multiple Files

Adam writes, “Is there a way I can manipulate the length of MP3 files, as I’ve been converting videos of live bands into MP3s but I’m getting the whole set as one file and Id rather have individual songs.”
Virtually any audio editing app will allow you to chop up an MP3 file. The problem is, most of them also re-encode the file, which adds additional compression and often makes the file sound worse. There are a number of apps that support trimming MP3 files up into smaller segments. One of my favorites is mpTrim, which allows you to split MP3 files, without needing to re-encode the file. In some cases, you might need the pay version for trimming large files, but the free version works for many applications.

Recording Voice Audio with a M-Audio Microtrack

Beverly writes, I need to record voice to CD, efficiently, and have the cd play in any normal CD player. I have an M-Audio Microtrack recorder with 1gb compact flash, but it seems that I have a high quality recording but it takes up a lot of space. In a work day I need to make 6 recordings. Does it make sense to consider a 30gb iPod to record voice to, and then burn to CD?
You don’t mention how long your six recordings per day are, but if you want good quality sound for recording, don’t use the iPod or any other portable media player. The Microtrack recorder is a good tool for what you are doing. If you want to use less space per file change your record settings. Under the Record Settings on the Menu make the following changes: Set Encoder to WAV. Set Sample Rate to 44.1. Set Bits to 16 (not 24). Using these settings, you will get about 90 minutes on a 1GB Compact Flash card and won’t notice any quality difference. A much cheaper solution than buying an iPod would be to get several 1GB or 2GB compact flash cards and then swapping the card when it gets full. This also gives you the flexibility of using the Microtrack all day long. Keep in mind that an audio CD only holds as much as 74 minutes of audio, so a single 1GB card recording 90 minutes of voice audio is more audio than you can fit on a single audio CD.

Creating Small Audio Files

Jonathan asks, “How can someone create an Audible sound file from an mp3 or wma? Is there another reduced size file format available?”
Audible’s file format is proprietary. To create an Audible file, you need to work directly with Audible. Depending on what type of audio content you are working with, you might not get any real advantage from their format anyway. Audible files are optimized for voice only audio content. While they can make music files noticeably smaller, the way the Audible codec works, it would also make a music file sound noticeably awful. If you happen to have voice audio and want the advantages of smaller files sizes with no noticeable quality loss, there are two ways you can achieve optimal sound at small file sizes.

Audio Tagging Tools

Audio Tagging Tools is one of the more complete audio tag editors I’ve seen, with a number of batch and single file editing features to make managing tags on large audio file collections a snap. Clean audio file names to conform to your naming convention (not the convention assigned by your download source. Tag and rename files en masse. Modify ID3v1, ID3v2 or both when changing audio file details. Audio Tagging Tools also includes a handy duplicate file finder, making it easy to eliminate wasted space consumed by extra files. The app supports mp3, ogg, wma, flac, ape, asf and the standard playlist formats like m3u, wpl and pls. A scripting engine supports a ton of features not directly exposed through the UI. A few of the features could be more intuitive, but if you have a large audio collection, you’ll catch on to the workflow process very quickly. [Windows 9x/2k/XP $0.00]