Audio Switch 1.4.4
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http://SOLAIR.EUnet.yu/~zvezdand

Author of the program: B. Sc. Mech. Eng. Zvezdan Dimitrijevic


PURPOSE OF THE PROGRAM
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Program Audio Switch serves for overlapping between various audio sources on PC computer, i.e. it can alternatively toggle on/off audibility of two or more audio sources. As it allows hearing of only one sound at a time, the program can best serve for audible comparison of different recordings of the same song. For example:

1. comparison of grabbing quality from audio CDs (CD Copy, Easy CD Extractor, ...) as it can simultaneously play the reproduction from CD and the very same song previously grabbed in Wav format;

2. comparison of the noise removal quality from gramophone records performed by various programs (Cool Edit Pro, Sound Forge, ...), at the same time the songs can be reproduced in Wav format obtained by those programs;

3. comparison of compression quality of different compressors (Xing, Fraunhofer, ...), various types of compression (Layer III, Twin VQ, AAC, ...), various bit-rates (128 kb/s, 192 kb/s, ...), ...

Program Audio Switch can operate in two ways: 1) by overlapping between Wave Out and Aux (CD Audio, Line In, ...) sound source, and 2) by overlapping between more (up to 9) instances of WinAMP program.

Overlapping of various audio sources by Audio Switch program can be performed manually by pressing one button or letting the computer perform automatic periodical overlapping with set time interval. The order of switching of certain audio sources can be sequential or random.

Audio Switch program can also serve for audio testing with statistic representation of results, especially in combination with automatic overlapping and random sequence.


USE OF PROGRAM: TYPE OF OVERLAPPING
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At the top of the window of the Audio Switch, beneath the title bar, there is a Manual Switch button by which you can manually overlap between various audio sources. If the program window is maximised, this button shall cover almost the complete surface of the screen, which is useful if you do not want to be particularly careful where to click. If the program operates in Switch Mode and if the window is maximized, the current sound source shall be written on this button, and if the program operates in Test Mode the test results shall be written on this button.

Beneath the above mention button, there is a group of options for tuning the type of overlapping. With Automatic Switch option it can be selected operation with automatic periodical overlapping of audio sources. The Option Interval can be used for time interval setting of automatic switching. The random sequence of overlapping of audio sources is determined by option Random and it can be switched on only if automatic switching has been selected first.

If automatic switching has been selected, and if the option Switch between 9x WinAMP is on, it is possible to select option 1st alternate. This option is meaningful only if 3 or more audio sources are played at the same time, as it enables listening of the first song successively with the remaining songs from the list. This means, if this option is switched off, the sequence of overlapping of sources 1, 2, 3, 4, shall be 1234 1234 12..., while if this option is on, the sequence of sources overlapping shall be 12 13 14 12 13... This option can be practically used for example, when we would like to hear the original recording, which is played back by the first source, after every other modified recording.

If both options 1st alternate and Random are on, the first song from the list shall be heard after every second overlapping, while all other songs from the list shall be heard randomly.


USE OF PROGRAM: SELECTING AUDIO SOURCE
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At the bottom of the window there is a group of options Switch Between which are intended for selecting the mode of operation and tuning various audio sources. Program Audio Switch can operate in two ways: 1) by overlapping between Wave and Aux sound source, and 2) by overlapping between more (up to 9) instances of WinAMP program.

Overlapping between Wave and Aux source can be used in combination with any program for digital wave reproduction (Media Player, many MP3 players, Yamaha SoundVQ, Liquid Audio, Audio Library PAC, ...). If the computer has more than one sound card, the selection of certain Wave output is performed by combo box Wave, while the selection of certain Aux source is performed from combo box Aux. For Aux source, the most practical solution is selecting CD Audio (or CD-Digital if CD-ROM and the sound card have S/PDIF ports), in combination with certain audio CD player program.

If Wave-Aux operation mode is used, starting of the reproduction in programs which shall be heard on Wave and Aux channels, as well as tuning of the position from which the reproduction is started (if the reproduction from the beginning is not desired) has to be performed manually in each program separately. It is up to user to perform this tuning precisely, as otherwise overlapping between Wave and Aux source shall be audible and very noticeable. However, this operation mode is necessary if an audio format not supported in WinAMP has to be auditively compared.

The other mode requires for it operation the use of program WinAMP, but thus it has important advantages. In the first place, if the sound card has an option for simultaneous reproduction of several Wave sources, or if it has DirectSound output plug-in for WinAMP which enables the same, than it is possible to auditively compare several files which are all reproduced through Wave output (not only Wave-Aux comparison). Second, starting of the reproduction as well as tuning the position is performed only in one instance of the program WinAMP or in Audio Switch itself, and thus the reproduction is synchronous in all instances (at least as much as the computer is fast and if too many WinAMPs do not run at the same time). Because of this second advantage it is justified to use this mode of operation even in comparing audio CDs with files which are reproduced through Wave output, as the overlapping between them shall be imperceptible (of course, if the same song is played).

The choice between instances of WinAMP which shall be heard can be performed, besides by pressing keys 1 to 9 in Switch program mode, can be done in the two following ways: clicking the corresponding row of list with active WinAMPs, i.e. the list of songs, as well as by direct activating certain instance of WinAMP window.


USE OF PROGRAM: AUDITIVE TEST
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The function of keys 1-9 in Audio Switch program depends on the mode in which the program operates: Switch or Test. If Switch program mode is activated, pressing those keys shall cause turning on of the corresponding audio source.

If the Test mode is activated, by pressing keys 1-9 we denote which of the possible nine audio sources is audible at the time, and if the choice is correct, the percent in the result shall be increased. The current result is written on the button for manual overlapping in the form: number_of_correct_attempts / number_of_total_attempts = percent. Pressing the key 0 in the test mode resets the test result to zero.

If the option Switch between Wave-Aux is on, only two choices are possible: by pressing 1, Wave is selected, while key 2 selects Aux source. If option 9x WinAMP is selected it is possible to choose one of the available WinAMPs (up to 9 possibly available).


WINAMP TIPS FOR USING WITH AUDIO SWITCH
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- Don't use any sound format that is not seekable, VQF plugin 0.1 may be used only with fast CPU.
- Turn off option "Scroll song title in the Windows taskbar".
- Turn off option "Autoscroll Songname".
- Turn off any visualization.


REQUIREMENTS AND LIMITATIONS OF THE PROGRAM
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Audio Switch program is PC 32-bit Windows application that can run under MS Windows 95, 98, NT 4.0 or Win2000 operating system. For its work it requires file Msvbvm50.dll included in Win98, Win2000 and NT 4.0 service pack >5. This file is also included with some applications like MS Internet Explorer 4.x, but not included in Win95 or NT 4.0 release. It can be downloaded from: http://support.microsoft.com/download/support/mslfiles/MSVBVM50.EXE.

For simultaneous reproduction of several compressed songs the PC computer should have the fastest possible CPU (approx.: Pentium 100 MHz for one compressed song, Pentium 233 MMX for 2-3 compressed songs, ...). For program operation, a sound card is necessary, if possible one of those enabling simultaneous reproduction of several Wave sources.

If program option Switch between 9x WinAMP is going to be implemented, the corresponding program WinAMP should be installed, its version 2.0 or later. Program Audio Switch has been tested conclusively with WinAMP version 2.6, and if the authors of WinAMP subsequently change the way of operation of their program it might happen that the program Audio Switch could not work with that version, or that it does not work as it should.


INSTALLATION
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There is no installation program, just unzip package to an empty directory.


DISCLAIMER
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Audio Switch is distributed 'as is' with no warranty of any kind. The author is not to be held responsible for any use or missuse of this product.


COPYRIGHT AND DISTRIBUTION
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Program Audio Switch is in a short ZIP file, about 60 kB long. Audio Switch is a freeware and you may give copies of this ZIP package to other people as long as no file is changed, added or removed. You may not sell, rent of lease the software to others without written permission of the author.

All brand and product names are trademarks and/or registered trademarks of their respective owners.


E-MAIL
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The author of the program would be grateful to program users if they would inform him about observed deficiencies, unforeseen behaviour and for possible suggestions in connection with the program.

mailto:zvezdand@EUnet.yu
