mp3TrueEdit™ 3.0 (Touch)
A lossless MP3 and AAC audio editor*
TABLE OF CONTENTS
mp3TrueEdit™ 3.0 (Touch) is the latest release of our audio editing family of applications with the user interface completely rewritten for mobile devices. It is a simple to use and affordable MP3 and AAC audio editor which was specifically written for quick and easy editing of audio files, without losing any of the original quality! This can be done because mp3TrueEdit knows about the internal structure of MP3 and AAC files and does not need to decompress and recompress the audio to make its edits. mp3TrueEdit features also include: opening very large audio files quickly • easily viewing and finding sections of audio • cut, copy, paste, delete and crop operations • exporting audio files or generating audio tracks • adding effects such as fade in/out • normalization and silencing audio • and finally recording of audio files from within mp3TrueEdit or using an internal audio recording app or if preferred by using your favorite external recording app.
*Supported formats are MPEG-1/2/2.5 Audio Layer III (MP3) and Advanced Audio Coding - Low-Complexity profile (AAC-LC). ‘MP3 Pro’ or ‘MP3 free format’ files are not currently supported. AAC profiles other than LC are also not currently supported. Supported container file formats are MP3 (.mp3), AAC MPEG-4 (.m4a, .m4b, .mp4) and AAC ADTS (.aac). AAC audio files that are protected using Digital rights management (DRM) or other means are not supported.
Getting started with mp3TrueEdit - This manual will introduce you to the basic concepts of editing audio using mp3TrueEdit and it also contains useful tips and tricks which will help you to perform your editing effortlessly.
Practical applications – if you prefer to dive into a practical example, then visit out YouTube page (http://www.youtube.com/user/ithinkapps) to see some real world examples of what can be done.
Don’t forget when you purchased mp3TrueEdit you will also enjoy the full benefits that come with it – free online support and free priority e-mail support for the next 18 months.
We will do our best to answer all support queries within 1-2 business days, but do please check this manual first or go to the online FAQ at: http://www.ithinkapps.com/faq to check if your question has already been asked first.
To purchase a copy of mp3TrueEdit go to http://www.ithinkapps.com/purchase. We hope you enjoy using our product and any feedback from you using our contact form: http://www.ithinkapps.com/support would be very welcome as we strive to continually improve our software and support service.
To see a list of the latest features added to mp3TrueEdit and any additional release notes since this manual was produced, please see our FAQ topic: http://www.ithinkapps.com/tutorials/#releases.
mp3TrueEdit 3.0 (Touch) now joins our Desktop family of products and leads the way in fast lossless MP3 and AAC audio editing and is currently available on Android tablet and phone devices running Android 4.1 Jelly Bean and above.
mp3TrueEdit is currently available for Android phone and tablet devices on Google Play store using the following link: http://play.google.com/store/apps/details?id=com.ithinkapps.mp3trueedit
You may also be interested to know that there are other Desktop based version of mp3TrueEdit available for Windows and Apple OS X computers. Please see out website www.ithinkapps.com for more details.
In most cases upgraded versions of mp3TrueEdit will be offered free of charge. However, we do reserve the right to charge for extra functionality introduced in new versions of our applications should we feel that any new functionality warrants an additional payment.
We also reserve the right to charge for a new major version of any of our software applications and cease to offer free maintenance upgrades for previous versions should this be deemed appropriate by us.
To uninstall the software:
On Android devices Run the ‘Settings’ app and select ‘Apps’ then press on the mp3TrueEdit entry and select ‘Uninstall’ and follow the instructions.
When you first start mp3TrueEdit you will encounter a number of popup guides that will introduce you to some of the basic features of mp3TrueEdit. These guides will display themselves at appropriate points while editing an audio project but can be cancelled at any time.
The various features, menus and commands within mp3TrueEdit can be activated from three icons in three corners of the app.
To navigate the Menu commands press on the three vertical dots in the top right corner of the screen.
To switch between the various feature screens such as Edit, Record, Tags and Settings, press on the three horizontal lines or the mp3TrueEdit logo in the top left of the screen.
When editing an audio file or project various commands and effects can be done using the popup menu box which is launched by pressing the plus sign inside a green circle on the bottom right of the screen. When a popup command is used it can easily be repeated using the last command icon next to the plus sign. Additional effects are located in an Effects overflow menu.
There are also two toolbars located at the top and bottom of the screen that contain commands that are useful when editing audio and are always shown. The top toolbar contains commands for selecting, playing and looping audio. The bottom toolbar contains commands for zooming in and out, undo and redo and the last used command.
To open a supported audio file or group of files you can use the File | Open menu command and select a file or an adjacent group of files before pressing the Open button. One or more files can be selected by pressing a single file name or by dragging over a group of adjacent file names.
When an MP3 or AAC file is opened, it will be displayed on the audio display screen as a section or window into the audio file and also on a map view showing the entire content of the audio project. These views show a graphical representation of the audio volume over time in addition to an audio time ruler and a map ruler to aid in navigating through the loaded audio project. The current play position is indicated by the red vertical line and shows where the audio will start playing when audio playback is started.
You will notice that the audio display screen shows the audio as a series of dark blue vertical bars. Each vertical bar represents a compressed frame of audio in the MP3 or AAC file format with a typical duration of around 25 milliseconds. It is these frames that mp3TrueEdit is able to manipulate directly by cutting, coping or pasting them as a group or by changing the individual volume levels of a section of frames. This allows mp3TrueEdit to do its magic of editing audio files without losing any quality!
You also have the ability to Append Files to an existing editing project and this is explained in more detail in section 5.12.
Use the following commands on the top toolbar to play, pause or loop audio in an mp3TrueEdit project.
Press the Play button to play from the Current play position in the audio file or project. The current play position is indicated by a red vertical line in the audio display screen. When audio is playing the Play button will turn into the Pause button.
Press the Pause button to pause or stop playback. When playback is paused the Pause button changes back to the Play button.
Press the Play Sel (play selection) button to play the currently selected audio. When the audio selection is playing the Play Sel button turns into the Pause Sel (pause selection) button. NB: please see section 5.6 on how to select a section of audio.
Press the Pause Sel button to pause or stop playing back the current selection. When playback is paused or stopped the Pause Sel button changes back to the Play Sel button.
You can also loop the playback of the selected audio or loop the playback of the entire audio project. To do this, simply press the Loop button before the current playback ends. The Loop button then turns into the Looping button which can be turned off by pressing it again.
You can use the + and – volume buttons on your device to changes the playback volume. mp3TrueEdit responds to the Media system volume level.
NB: To adjust the volume of the exported audio you must use the Normalize command described in section 5.13.1 or one of the other commands in section 5.13 that affect the exported audio such as Fade in or out and volume increase or decrease.
For larger audio files or projects the audio display screen will not show the entire length of the audio but rather a window into the audio file. In this case the map view will show a condensed view of the entire audio being edited. The map view will indicate the audio sections outside of the windowed audio by coloring them in a grayed out style. This map view can be pressed in order to jump to the same location in the windowed audio display screen. In addition the audio display screen can be pressed and dragged to make finer adjustments to the current play position of the audio. If you require a finer adjustment of the current play position then you can zoom in or out using the Zoom-in and Zoom-out buttons on the bottom toolbar before dragging the audio time ruler. You will also notice that the scale of the audio time ruler will adjust automatically when zoomed in or out.
There is also a Navigate Controls popup menu that enables navigation through the audio project in other ways which are explained later is section 5.15.
Most audio editing commands will operate on a selected area of audio so to enable these editing commands you must first select a section of audio to edit from within your audio file or project. There are two ways to select audio:
1. Press on the map view and/or press and drag on the audio display screen to adjust the current play position to the desired start position.
2. Then press the Set Start button. You will see a green vertical line appearing at the start position.
3. Then press on the map view and/or drag on the audio display screen to adjust the current play position to the desired end position of the selection.
4. Then press the Set End button.
5. The selected audio is then highlighted in green.
6. If necessary the selection start point or selection end point can also be adjusted by moving the play position to the desired new start or new end point and re-pressing Set Start or Set End respectively.
Important Note: When you see a dotted green line – this shows the selection start and end are at the same time position. In this case there is nothing selected – so nothing can be copied or any editing effect applied. If you see an alternate dotted red and green line, this indicates that the current play position and the current ‘zero-width’ selection are both at the same location.
1. If you wish to select the entire audio in a file or project then you can use the Select All popup menu command
Any operation or command in mp3TrueEdit can be undone and redone using the unlimited Undo and Redo commands to restore your edits to any previous state since the file was opened. This feature makes it much easier and safer to perform any editing of your audio files since if you make a mistake or you want do adjust and improve on any editing command then you can simply undo any number of commands and repeat the editing operations.
NB: If the mp3TrueEdit app is suspended or closed down then the undo history since the file was opened will be lost.
The Undo and Redo commands in addition to undoing and redoing the actual audio edits can also be used to undo and redo the audio selections (as highlighted in green). This is to make it easier to adjust selections of the exact audio to be edited.
If you want to move a section of your MP3 or AAC audio from one location to another along the audio timeline or even to another loaded mp3TrueEdit project, you can use the Cut and Paste functions.
1. First, make a selection of the audio (see section 5.6 above on how to select audio)
2. Then, press on the popup menu command followed by the Cut command to remove the section of audio and put it onto the clipboard.
3. You can then select a ‘zero-width’ section of audio by navigating to where you wish to paste the audio as described in section 5.5 and then pressing the Set Start button followed by the Set End button without scrolling the current play position
4. The ‘zero-width’ selection point will be displayed as a dotted line. Then you can press the Paste button to paste the previously ‘cut’ section into the new location specified by the dotted ‘zero-width’ selection line.
1. Cut a section of audio as described in the first part of Method 1 above.
2. If you then wish to paste the ‘cut’ audio over another section of audio, replacing the selected audio with the ‘cut’ audio, then simply select the audio that you want to replace and the press the Paste button to paste the previously ‘cut’ section over the new selection.
Note: You may notice that where audio has been cut and pasted there is a change in color at the edit points to a light blue frame color. This is to indicate where edits have been made and we call them ‘cellotape markers’, analogous to the old way of cutting magnetic audio tape and sticking the tape back together using cellotape.
To copy a section of your MP3 or AAC audio and paste to another position along the audio timeline in the file or to another file, use the Copy and Paste commands as described below.
1. To copy a section of audio from one part of your MP3 or AAC file to another, first select the audio that you wish to copy (see section 5.6). Then press the Copy button.
2. Second, select a ‘zero-width’ section of audio by navigating to where you wish to paste the audio as described in section 5.5 and then pressing the Set Start button followed by the Set End button without scrolling the current play position
3. The ‘zero-width’ selection point will be displayed as a dotted line. Then you can press the Paste button to paste the previously ‘copied’ section into the location specified by the dotted ‘zero-width’ selection line.
1. Copy a section of audio as described in the first part of Method 1 above.
2. If you then wish to paste the ‘copied’ audio over another section of audio, replacing the selection with the ‘copied’ audio, then simply select the audio that you want to replace and the press the Paste button to paste the previously ‘copied’ section over the new selection.
Important Note: You can copy from different files only if the MP3 or AAC compression format is compatible, for example, sampling frequency (expressed in Hz) must be same and mono and stereo formats cannot be mixed. If the bit rate is different, it is still compatible but the exported MP3 or AAC file will be converted to a variable bit rate file format.
1. First, select the section of the audio to be deleted as described in section 5.6.
2. Then press on the Delete button to delete the selected section.
Note: The selection either side of the deleted audio are joined together, leaving no gaps. The section you have deleted is indicated by a vertical light blue line or cellotape marker on the first frame of a new ‘non-contiguous’ part in the audio.
Note: Unlike many other ‘direct’ MP3 audio editors mp3TrueEdit will preserve the continuity of audio when joining MP3 frames after delete, copy or paste operations have been applied.
1. First, select the section of the audio you wish to keep (see section 5.6 on how to do this).
2. Then, press on the popup menu command followed by the Crop command and the audio before and after the selected audio will be deleted.
There are two ways to combine a number of audio files.
Method 1 – Using the Open command
1. Use the File | Open menu command to launch the open dialog where you can select one or more files that you want to combine. Multiple files can be selected by dragging over a number of adjacent files.
2. Press the Open button and the group of files will be loaded into your project.
3. If there are additional files in the open dialog that you want to combine or you want to combine files in a different order then you must add them using the Append command below.
Method 2 – Using the Append command
1. Use the File | Append menu command to launch the append dialog where you can select the file or files that you wish to append to an existing project. If later you decide to append other files to the combined files in the project, you can use the File | Append menu command again.
Note: When you have combined all the files that you need in a project you may wish to use the File |Save Project… menu command to save the list of combined files as a project file for further editing later. When you are happy with the edited project you can use the Export |Export All As… menu command to save the combined files as a single audio file.
The Effects functions currently include easy to use normalize, fade-in, fade-out, volume adjustment commands and special functions to silence or remove previously applied silencing to selected audio. In addition you can insert a length of silent audio into any location within an editing project.
1. To increase the volume to the maximum level without distorting the audio quality, first select the audio section you wish to adjust.
2. Then, press on the popup menu command followed by the Normalize command to display normalize dialog.
3. When the audio has been analyzed the Peak (dB): value shows the maximum volume in decibels that was found in the selected audio.
4. You are then able to select the Target (dB): level in decibels that you wish to normalize to. The slider and Change by steps: value will then automatically be set so that the selected audio will be adjusted to your desired target value in decibels.
Note: A value of 0 dB (0 decibels) represents the maximum volume that can be played back without distortion and the more negative the value the quieter the sound will be played back.
5. If desired the horizontal volume slider or the Change by steps: value can be adjusted manually and the resulting maximum volume can be seen in the New (dB): field.
6. If you have changed the volume level manually you can also reset the volume level to the automatically calculated value by pressing the Reset button.
The volume of a selected range of audio may be faded in by gradually reducing the volume to the beginning or faded out be gradually reducing it to the end.
1. First, select the section of audio to adjust.
2. Then, press the popup menu command followed by the Fade In button so that the volume is gradually increased over time or alternatively you can use the Fade Out button to gradually decrease the volume over time.
Tip: You can subsequently increase the Fade In and Fade Out effect by repeatedly pressing the Fade In and Fade Out buttons until the desired fade level is reached. You can also press the Play Sel (play selection) button to listen to the faded audio level at any time.
Tip: If you not happy with what you are hearing, press on the Undo button to undo the faded in or out steps.
Tip: If you wish to change the amount of fade in or out that is performed when a Fade In or Fade Out button is pressed then you can press the top left logo and then select the Settings function to set the Fade Volume By value for the fade-in or fade-out volume change that will be applied each time a fade command is performed.
The volume level of the selected audio can also be increased or decreased to your desired level.
1. First, select the section of audio to adjust.
2. Then, press either the Vol inc (volume increase) or Vol Dec volume decrease buttons to increase or decrease the volume of the selected audio.
Tip: If you wish to change the amount that the volume is increased or decreased by when a Vol Inc or Vol Dec button is pressed then you can press the top left logo and then select the Settings function to set the Change Volume By value for the volume increase or decrease value that will be applied each time a change volume command is performed.
To make the currently selected audio completely silent without affecting the total length of the audio file or project,
1. First select the audio you wish to make silent using any of the selection methods.
2. Then use the effects overflow command Effects | Silence to make that selected audio completely silent. You will notice that silenced audio is shown in the audio display screen as a light grey-blue color.
3. To remove any previously applied silencing of a section of audio, any part of a silenced section of can be restored to its previous volume level by selecting that portion and using the effects overflow command Effects | Remove Silencing to remove the previously applied silence effect. Again this is done without affecting the total length of a project.
Note: Silence mode only suppresses the volume in a project it is not lost until the audio in a project is exported to MP3 or AAC format. When finally exported it will then be completely removed or redacted and will not be recoverable from the exported audio.
The Insert Silence command allows you to insert a section of silent audio at the current play position marker. To insert silence,
1. Navigate through the project so that the current play position is at the start of where you want to insert the silence.
2. Press the Ins Silence button. A dialog box will appear. Enter the number of seconds of silence to insert and press the OK button. You will notice the silenced audio inserted at the current play position in the audio display screen.
Sometimes you may want to split an audio file into multiple tracks and save each track into a separate file. The steps involved are as follows:
1. To mark the start position of the track, press and drag the audio display screen to move the current play position to the desired start position of the track.
2. Then press on the Track Start button to mark the start position. A green colored track bar will appear at the bottom of the audio display screen and by default, it will mark the end of the audio project as the track end position.
3. To mark the end position of the track, drag the audio display screen to move the current play position to the desired end position of the track.
4. Then press on the Track End button to mark the end position. The new track end position will be updated to the current play position.
5. You can also use the Split Track command to divide an existing track into two adjacent tracks. Additionally if this command is used on a section of audio that is not within a track two new adjacent tracks will be created.
6. To delete a previously created track the Del Track (delete track) command can be used by navigating the current play position to within the track you with to delete and then pressing the Del Track button.
7. You can also use the Track Start and Track End buttons to adjust the track start or end positions of any existing track. Pressing on the Track Start button will move the start position of the current or next track to the current play position and pressing on the Track End button will move the end position of the current or previous track to the current play position.
When creating tracks in this way they will be displayed as green bars with beveled edges with a track name and number at the bottom of the audio display screen as shown above. The track names and other tagging information for each track can set using the tagging facility of mp3TrueEdit. This tagging facility is accessed by pressing the top left logo and selecting the Tags screen. Once a project is split into tracks these individual tracks can be exported as separate files as outlined in section 5.18.
Use the File | Navigate Controls menu command to show the popup Navigate Controls toolbar. This will show you a number of command buttons that will enable you to navigate through the open project more easily. Use the blue left and right pointing arrows at the ends of the Navigate Controls popup to scroll to reveal any extra navigate controls to the left or right.
The Step Back toolbar command will scroll the audio display screen one audio frame backwards and the Step Forwards command will scroll one audio frame forwards.
If you have split your project into one or more tracks then the Prev Track (previous track) command will scroll to the start or end of any previous tracks before the current play position. Similarly the Next Track command will scroll to the start or end of any following tracks after the current play position.
The Rewind command will scroll the audio to the start of the project and the Forward command will scroll to the end of the project.
Use the Sel Start (selection start) command to scroll to the start of the current selection and use the Sel End (selection end) command to scroll to the end of the selection.
To further aid navigation you are able to scroll forwards or backwards a set time interval using the -N Secs (back N seconds) command and the +N Secs (forward N seconds) command. The number of seconds scrolled forwards or backwards is determined by the Navigate Step Seconds value in the Settings screen.
If your project has been edited so that it contains removed or moved sections of audio or you have combined two or more audio files into a project then your project will contain non-contiguous sections of audio that are marked with the light blue cellotape frame marks described earlier. You can navigate to these non-contiguous sections of audio using the Prev Edit (previous edit) and Next Edit commands.
Finally uncheck the File | Navigate Controls menu command to dismiss the Navigate Controls popup.
Use the File | Playback Controls menu command to show the popup Playback Controls toolbar. This will show two controls, one for changing the playback pitch without affecting the tempo and one for changing the tempo without affecting the pitch. You can use these controls, for example, to change the pitch of a song to match your singing range or to speed up or slow down a recording of a meeting to easily review the content or make notes.
The ‘–1 semitone’ button will reduce the playback pitch by 1 semitone.
The ‘+1 semitone’ button will increase the playback pitch by 1 semitone.
The slider can also be used and the change the pitch and the value is displayed above it.
The ‘slower’ and ‘faster’ buttons or the associated slider can also be used to adjust the playback tempo without adjusting the pitch. The percentage change in speed is shown above the slider.
Finally, use the associated ‘reset’ buttons to reset the pitch or tempo to normal playback settings.
You can uncheck the File | Playback Controls menu command to dismiss the Playback Controls popup.
We recommend that you save your work as a project file that contains a list of all the edits you have made to your source audio files. This will enable you to re-load the project at a later date and modify any edits you have done to your project.
To save your work as a project you can use the File | Save Project... or File | Save Project As... menu commands to launch the project save dialog.
Important Note: When you save an mp3TrueEdit project file (.mteproj) what you are saving is just a list of commands that you applied to your source audio files, it does not contain any actual audio it’s self but merely links to your original source audio files. It is very important you do not move, delete or modify these source audio files for your project or you will no longer be able to open your associated projects or export them.
When you have finished editing audio in an mp3TrueEdit project you can then export audio in your original audio format without any loss in quality at all.
Use the Export | Export All As... menu command once you are happy with all the editing you have done in a project, this command will save the entire audio in your project to a single audio file.
Use the Export Selection As... menu command if you wish only to export the currently selected audio to a new audio file.
Use the Save Tracks As... menu command if you have split your audio project into multiple tracks (see section 5.14). This then allows you to save each track as a series of separate files, one for each track into the folder selected in the track save dialog.
Note: In order to create Ringtones, Notifications and Alarms that can be used to set system sounds on your device you must export your completed edits to one of the designated system sounds folders. The Ringtones, Notifications and Alarms folders can be seen and navigated to by selecting one of these folders in the left hand pane of any of the Export dialogs.
Note: Exported audio files using any of these methods can contain tagging information such as the title and artist for a track. This tagging information can be configured for projects with or without separate tracks using the Tags screen which can be navigated to by pressing the top left mp3TrueEdit logo.
Note: When saving tracks into a folder the track name and track number in the tagging information is used to name the file. This can also be customized as described in section 7.
mp3TrueEdit has a built-in recording facility for recording audio using the AAC file format. We do not currently have a built-in MP3 recording facility due to patent restrictions but you may wish to connect to an external recording app for recording either MP3 or AAC audio if you have one installed. To use a pre-installed external recording app with mp3TrueEdit you can check the Use External Recording App feature in the Settings screen. However, if you do use an external recording app you must configure it to record using either the MP3 (.mp3) or AAC (.m4a) file format.
To use the internal recording function press the top left mp3TrueEdit logo and select the Record screen.
Then simply press the microphone record button and it will turn red when recording. To stop recording just press the record button again. Each time you press the record button a recording will be made into a new file. Press the Done button when you have finished your recording session to load all the recordings into a new mp3TrueEdit project while switching to the Edit screen. Alternatively you can cancel and delete the recordings by pressing the Cancel button.
mp3TrueEdit projects can be edited to contain MP3 or AAC tagging information. This tagging information will be saved to the exported audio files when any of the File | Export ... commands are used. The track titles entered into the Tags screen will also be used with the track number to display the track names shown in the Edit screen. You can also use the Track Naming String macro in the Settings screen to customize track names that are shown in the Edit screen. This can be done using any combination of track title, track artist or track number to generate a track name which is displayed in the Edit screen and which is also used to generate individual filenames when exporting tracks.
To start editing tagging information for the current project press on the top left mp3TrueEdit logo and select Tags. You can then use the << and >> buttons to switch between displaying and editing tags from either the first file loaded in a project (‘File’) or any of the tracks added to a project as shown in section 5.14 (‘Track: N’). When using the Export All As... menu command or the Export Selection As... menu command the tagging information in the ‘File’ page will be used for the single file exported. However, when using the Export Tracks... menu command the tagging information for each track number (‘Track: N’) will be used for each respective exported track.
When you have finished editing the tag information for the ‘File’ or any individual track then pressing the >> or << buttons will save that track information and then start editing the next or previous track respectively.
You can also use the top right menu commands Copy All or Paste All to copy all the track fields to the clipboard and paste into another track. Alternatively, if you have copied all of the tracks fields using the Copy All command then you can also use the individual ‘paste’ buttons next to each field of a track to individually paste the various fields copied to the clipboard into a new track’s field.
NB: Some fields in the Tags screen are not enabled for AAC (.m4a) files due to different tagging standards.
There are various settings available to customize the appearance and function of mp3TrueEdit which can be changed in the Settings screen. To access the Settings screen simply press the top left mp3TrueEdit logo and select Settings. When you have finished changing your settings pressing the Done button will then return you to the Edit screen.
24bit Recording – normally 16 bits are used to record audio to CD quality however if your audio interface supports 24 bit recording then these extra bits can improve the quality of quieter sections of audio especially when the volume is increased later using mp3TrueEdit or other audio editors.
Audio display screen- It shows a graphical representation of the audio volume over time. Each vertical bar is a frame of compressed audio. The height of the blue bar is an indication of the volume level for that small section of audio. However, this frame volume indicator is only a visual guide to the actual volume of the decompressed audio that you hear during playback.
Bit rate - a measure of is how much the file is being compressed. The lower the bitrate, the more the file has been compressed and the smaller the resulting file size, this will also result in a lower quality when playing back the audio.
Compressed audio frame – MP3 and AAC format files compress audio into discrete packets of information which are called frames. Each frame is of a fixed length and mp3TrueEdit allows you to edit audio down to individual frame boundaries and also change the volume of these frames. These frames are shown as blue bars in the audio display screen. Editing audio files with mp3TrueEdit will allow you to cut/copy/paste or delete any number of frames represented by the blue vertical bars and also allow you to change the volume levels of any individual or group of frames. This is done in a way that does not lose any of the quality of the original AAC or MP3 recording so you won’t degrade the quality of your final audio file by de-compressing and re-compressing the audio.
Decibels (dB) – a way of showing the loudness of a sound using a logarithmic scale which is closer to how we perceive the volume of sound. A volume of 1dB is at the limit of what the human ear can hear and volume of 80dB or higher is considered loud. However, in software applications where the volume of your speakers is not known the highest volume is defined a 0 and the more negative the decibel reading the quieter the sound.
Encoder – the software that is used to convert audio from a sound card input device into the compressed audio file format. Converting to the MP3 or AAC file format will cause some loss of quality from the original uncompressed audio but will substantially reduce the file size required to store the audio. Also any subsequent decompression and recompression will also cause additional loss in quality. Note: mp3TrueEdit will not decompress and recompress audio when editing MP3 or AAC files and so will not cause a further loss of quality from the originally encoded audio file.
Mono or stereo - Mono sound uses only a single channel while stereo sound uses two channels for the left and right ears. Stereo sound gives you a more natural listening experience compared to mono.
Sampling frequency - the number of times per second audio is sampled and stored as a number. The more samples taken per second, the more accurate the digital representation of the sound can be. For example, the current sample rate for CD-quality audio is 44.1 KHz (44,100 samples per second).
Time ruler – A time ruler has now been added to the audio display screen and the map view. This is to aid in seeing how long the audio sequences and edits are.
VU meter – located below the audio map view is a volume indicator that displays the loudness of an audio signal. For playback and recording, the optimum level is between the green and yellow bars but try avoiding the red bars for long periods.