AutoRec Instructions


The time based automatic recorder - player for radio broadcast.


version 1.2  January, 2002, Copyright Chris Scott


NOTE: The schedule files included in the download are just samples and not demo files - you must customize these to fit your needs prior to your use. I recommend that you print this page for reference prior to use.  








Auto Recorder will record or play wav audio files, and execute batch or other executable application programs at scheduled times.  It operates sequentially, processing jobs in strict chronological order, accurate within one-tenth of a second for audio operations, and one second for .exe and .bat file operations.  The primary use for Auto Recorder is automatic, unattended recording and playback of network or other satellite-delivered radio station program material, sometimes termed time shifting; airing a program at a time other than when the syndicator feeds it.  The .exe or .bat file execution feature allows renaming, copying, or other file handling operations, providing greater flexibility in practical radio station applications.


The Auto Recorder software is free, entirely unwarranted and unsupported.  You accept sole responsibility for all liability whatsoever.  If you're uncomfortable with this, don't install or use it. You may not redistribute it without permission, but may publish the web page url:   Autorec has been tested and found robust on recent 32 bit Windows, with several different sound cards - but your results may vary. Please note that upon installation you must manually create a c:\wav folder and place your audio files there, or else edit the AutoRec.ini setup file to reflect the path of your audio files.  The ini is located in the same folder that AutoRec.exe is installed.






---- OPERATION ----


Auto Recorder uses written instructions contained in a text (.txt) file, of which there are seven, named appropriately for each day of the week. Up to 99 events per day can be scheduled, with each day's operations independent of every other day's.  These .txt "event" instruction files can be created and edited with the internal schedule editor, which also provides a basic syntax checking utility to help identify typographical errors prior to attempted execution. Note that events cannot span the midnight boundary, and must be strictly sequential - no overlapping times.  An event must complete before the next event starts. Recordings make permanent their .wav file at stop time, and this process can last anywhere from several seconds to several minutes. The time required for saving varies greatly depending upon disk i/o speed, but can be determined experimentally by checking in the AutoRec log file for the difference between the stop time and the saved time.  This saving io action can take several minutes for long (hour) programs recorded in stereo at 44.a khz. Saving to a network drive can also slow things down.  So, be careful about how close you schedule consecutive events. 



Auto Recorder works with normal windows compatible soundcards, which the audio quality is completely dependant upon.  11.025, 22.050, 32 and 44.1 khz sample rates, mono or stereo are supported. All recordings are 16 bits (since 8 bits is inferior.) Prior to using Auto Recorder, make sure your soundcard and mixer levels are configured correctly.  AutoRec does not do this for you.  Use another audio application like sound recorder or CoolEdit to configure the Windows mixer before deciding that Auto Recorder doesn't work.  Your levels are between you and your soundcard mixer. Again: Autorec does not set or control levels.


Shown below is a schedule file.  Every separate line contains instructions for one event.  Anything after an apostrophe (') is considered an optional comment, and is ignored by AutoRec. Here are two sample events:



Afternoon News ,R,13:00:00,00:05:00,AftNews1,22,M 'Record AP newscast for later play


AftNews Playback,P,17:00:00,0,Aftnews1,0,0 ' Play AP newscast



These two event instruction lines define the recording and later playback of a five minute newscast.  The general format for a line is as follows:


Label,Rec or Play or Bat or Exe,Start Time,Length,Filename prefix, 22 or 32 or 44 ,Mono or Stereo  'Comment


All parameters for an instruction line must be separated by commas.  In fact, every valid instruction line must have exactly six commas. This is a useful syntax check - every valid instruction line must have exactly six commas.





A record instruction line contains the following, in order:


1. Label for internal use, up to 16 characters long.  This does not affect operation, but is simply a plain-language description of the event.


2. R or Rec for record.


3. The start time in 24 hour format:  ##:##:##


4. The length (duration) of the recording in 24 hour format: ##:##:##


5. The prefix of the actual .wav filename to be recorded, up to eight characters or numbers without punctuation or spaces, i.e. Aftnews1


6. Two digits representing the sample rate of the recording: 11 or 22 or 32 or 44. This is interpreted as 11.025, 22.05 32, or 44.1 khz.


7. M or S specifying mono or stereo


After that, on the same line, optional comments can be used following an apostrophe.  If blank lines are used between instructions to improve readability, it's best to have an apostrophe first.


For the purposes of playback, the format becomes simpler:


1. Label


2. P or play


3. Playback start time ##:##:##


4. (Not applicable) use dummy number 0


5. The prefix of the actual .wav file to be played; don't include ".wav".


6. (Not applicable)  0


7. (Not applicable)  0





---- INI FILE ----


The program initialization file is located in the same folder as the AutoRec.exe file, usually c:\Program Files\AutoRec, customizes the configuration to suit user preferences.  Here is the default autorec.ini file:




Auto Recorder configuration file

must be in same folder as .exe file.









Edit this file if required using wordpad, notepad, or other ASCII text editor.


WAVPLAY= 1 designates playback using the first soundcard device. Edit this entry to 0, 1,2 or other if you get no playback, a system error, or playback from the wrong soundcard.  See known bug below.


WAVPATH= C:\wav    ... this is folder / path where all play and record .wav files will be.  Mapped network drives can be used, but be aware that the save operation which is automatically performed immediately after a record event can take significantly longer than when local drives are used. 


OFF-SET= 0  sets the number, in tenths of one second that record and play events actually occur, relative to the system clock.  This number can range from -20 (two seconds early) to 20 (two seconds late).  This feature is allows sub second accuracy.  Often due to satellite delays, network times may be slightly offset from real time, and this setting allows fine tuning. Start with 0 and adjust according to experience with up-cutting or clipping start and end times.  Note that AutoRec can only be as accurate as your computer's clock; time sync software is available to maintain agreement with national standards, and more accurate techniques using GPS sync or network "relay closures" are available but are beyond the scope of this help.


KILLDAY= SUNDAY    this refers to the AutoRec.log file which can be viewed using the schedule editor.  Each week the log file is renamed to Lastweek.log, and a new week's log is created.  This occurs at the beginning of the killday.  The log is very useful for determining if something actually occurred as planned, and for debugging an event line if things go awry.  The log can be viewed with the internal schedule editor.



Note that when using a PC for broadcast use, it's a good idea to disable user feedback system sounds that the operating system generates to prevent them from being broadcast.  Normally this will be in the control panel under sounds - select the "no sounds" scheme.





---- WAV FORMAT ----


Because the WAV format is so universal, so editable, and without distortion artifacts introduced by lossy compression systems like Mpeg, apt-x, etc, it delivers superior audio quality, limited only by your soundcard.  About 7.7 megabytes per minute are required for stereo, half that for mono. Current hard drive storage capacities now make this uncompressed and very clean audio storage very practical. 16 bit audio is far superior to 8 bit, and is most suitable for broadcast. To achieve the maximum quality deliverable over FM broadcast use a 32 khz sample rate setting during recording (or ripping). A 44 khz sample rate will deliver additional frequency response to achieve true CD quality, but will use 25% more data and provides no additional quality benefit for broadcast purposes. Sample rate limits only frequency response, not distortion or noise.  All three of these are key quality ingredients - sample rate is not the only factor affecting quality. FM broadcast frequency response is 15 khz, which the 32 khz sample rate provides. For AM station or news use, 22 khz may be optimum.  WAV file editors and recorders are widely available. CoolEdit ( is inexpensive and highly recommended.





---- ADVANCED ----


It was mentioned that .exe (executable programs)or .bat ("dos command line") batch files can also be scheduled in addition to audio record or play events. Using autorec this way is quite similar to the "scheduler" in windows, but keeps audio operations integrated in one package.  If you're comfortable working with these files they can add great utility to autorec operations. Here is sample event syntax:



Overnite Backup,B,00:10:00,0,C:\Batch\Backit.bat,0,0 ' copy all wav files to network drive - backit.bat required



For the purposes of .bat or .exe execution, the format is very simple, with one key item different from audio use:


1. Label


2. B (bat) or E (exe)


3. Execution time ##:##:##


4. (Not applicable) use dummy number 0


5. The complete path and filename of the exe or bat file

[Note that this is different - for audio applications, only the prefix is used.]


6. (Not applicable)  0


7. (Not applicable)  0


' comment



Of course, it's up to you to write the Backit.bat file located in the C:\Batch folder.  This is a sample only and as a practical matter you will need to dream up your own.  This requires an understanding of "dos" command-line syntax.  As a simple example, here are the contents of Backit.bat allowing nightly backup of all audio files to a network drive:


COPY C:\wav\*.wav H:\backup


This would assume that H: is a valid drive and \backup is a valid folder on H:  Depending upon how much .wav file material you're moving with this operation and network file transfer speed, this could take seconds or hours.  Although Auto Recorder can process audio events just seconds after executing a batch or executable file, if your execution is preoccupying, the CPU or disk I/O, dropouts or pauses may occur.



---- KNOWN BUGS ----


There are no known bugs that affect operation or reliability.  But:


1. Users have reported errors during the install process.  These have to date been false alarms, not causing any problems, but appear mighty unpromising when you see them.  Please report these but let me know specifically if any operational issues are seen.


2. It is a bad idea to edit a schedule file while an event is recording or playing - do this at your own risk.  If Auto Recorder thinks its close to an event time when you enter the schedule editor, it will warn you about this, but will allow it if you insist.  The time shown may or may not be correct.


3. It is very important to check the schedule file for errors after editing - a button is provided to do this.  For this to work correctly, you must first SAVE the changes, which will exit the schedule editor, then re-enter the schedule editor, select the just-changed file, and press the check errors button.


4. Some report that they are unable to record long programs - at 44 khz stereo, about one hour is all that will be recorded, even though the log reports the recording continued longer.  This is an issue with some 9x versions of windows - due to an OS maximum file size. It may also be related to which format your hard drive is using (fat16, fat32, or NTFS) The fix is to either use a combination which reduces file size like switching to mono or lowering the sample rate, or else upgrade to w2000.  Using 2000, Autorec has had no file size issues and regularly records 2 hour programs.





---- Revision History ----


V 1.2 Fixed failure to load new day's schedule under certain conditions.





I welcome bug reports, but PLEASE provide enough detail so that I may have a chance to recreate the problem.


The current version can be found at:

I can be reached by clicking the "Send Email " on that page.


Chris Scott

January, 2002