The Audio Diver Options tab looks like this:
Use Software Mixer(s): If ticked then the audio driver will not use hardware mixing. This is the default setting, but only because some sound cards/chips produce irregular audio output. If you have a good or even a reasonably good sound card then by clearing this checkbox the audio driver will use hardware mixing where available, freeing up processing resources for other tasks.*
Do NOT use floating point for audio channels: This may seem a bit of a mystery but you should only need to tick this checkbox if you find that speaker selection is not working. Typically this seems to occur on Sound Blaster and Audigy cards. The symptoms are varied - sometimes sound in front channels but nowhere else; sometimes very low levels. If you have any of these problems then tick this checkbox. If you don't have any such problems then leave this checkbox clear.*
Force enabling of speaker assignments: With some devices/drivers, the number of speakers the audio driver detects may be 2 when the device in fact supports more than 2 speakers. This flag forces the enabling of assignment to 8 possible speakers. This flag has no effect with non-WDM drivers. This option is set by default but must be cleared for Creative Labs Sound Blaster cards (as shown below).*
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Creative Labs Sound Blaster and Audigy Cards If you have one of these cards and you wish to use speaker assignments then SCS needs the following option settings:  To save you having to specifically set these options, SCS sets them internally if the sound card appears to be a Creative Labs card (based on the device name published by the driver). |
One of the changes made when SCS 10 was released was the use of a mixer component of the audio library used by SCS. Although this mixer is a component of the audio library, it is referred to in this Help file as the SCS Internal Mixer, or just as the Internal Mixer.
The internal mixer was added to enable certain features to be implemented that were not available in SCS 9. The major drawback in using the internal mixer is that it is necessary to use a much smaller playback buffer. In SCS 9 the default playback buffer size was set to 5000ms (5 seconds) to ensure that cues played smoothly even if the computer has been idle for a while. However, when using the internal mixer, level and pan changes are applied pre-mixer as the internal mixer may need to mix several channels, each with specific level and pan settings. This mixing is performed in the playback buffer, so using a playback buffer size of 5000ms can delay level and pan changes being heard by up to 5 seconds. To counter this issue, the default playback buffer size in SCS 10 has been reduced to 200ms (0.2 second), which is a far more acceptable 'delay'.
Unfortunately some users have reported glitches in audio playback, and this is due to using the short playback buffer. What happens is what is referred to as 'buffer underrun', where feeding data into the playback buffer has not been fast enough and the audio playback temporarily runs out of data to play.
If you have issues with audio glitches then you can now choose not to use the internal mixer.
Use SCS internal mixer: This is the default setting and provides the full SCS 10 functionality available for your license level. The default sizes for pre-buffering and playback buffering are set to 200ms (0.2 second), and the default update period is set to 50ms.
Do NOT use SCS internal mixer: Choose this option if you experience glitches during audio playback. The default sizes for pre-buffering and playback buffering are set to 5000ms (5 seconds), and the default update period is set to 100ms. If you choose this option it is strongly recommended that you also use default settings for pre-buffering, playback buffering and update period.
The following features are NOT available when you choose not to use the SCS internal mixer:
Ignore ASIO: A few users (very few) have reported a conflict between the SCS ASIO module and some other software on the computer. The simplest solution to this is to prevent SCS from using ASIO. There are now two ways you can do this. ASIO is only available when using the SCS Internal Mixer, so the first way to ignore ASIO is to to select 'Do NOT use SCS internal mixer'. However, if you do want to use the SCS Internal Mixer then mark the checkbox Ignore ASIO.
Changing the SCS Internal Mixer option takes effect the next time you start SCS.
Pre-buffering enables the audio driver to start decoding the audio file as soon as it is opened instead of waiting until it is played. Without pre-buffering there would be a small delay while the initial data is decoded for playback. The delay may not be noticeable, but to start playback instantly you should enable pre-buffering. SCS pre-buffers 200ms (0.2 seconds) of the file by default (or 5000ms if you are not using the internal mixer), and you have the option here to alternatively turn off pre-buffering or to nominate your own pre-buffer length in milliseconds.*
If you nominate a short pre-buffer length then you may find that audio cues 'stutter' at the start if the machine has been idle for a while (eg 10 minutes). This only seems to occur on some machines, most notably laptops, and seems to be caused by a delay when the audio driver tries to resume reading from the file resulting in a buffer underrun. In some testing it was apparently at least partially due to ZoneAlarm, as the problem stopped when ZoneAlarm was disabled.
SCS default pre-buffer length: This option sets the pre-buffer length to 200ms (or 5000ms if you are not using the internal mixer).
Disable pre-buffering: This may be your safest choice if you have 'stutter' problems, provided you do not have linked cues. The downside is that there may be a small delay in starting each audio cue. However, be prepared to try this option as you may find the delay acceptable. If you have linked cues then it is recommended that you do not disable pre-buffering as this may cause the linked cues to drift out of sync.
Set pre-buffer length to ... milliseconds: This option enables you to specify your own value for the pre-buffer length, up to 5000ms. If you leave this field blank, or set the value to 0 (zero), then the default will be used. The pre-buffer length cannot be greater than the playback buffer length. It is not advisable to set a non-zero pre-buffer length less than 100ms.
A Playback Buffer is used for each audio cue as it is being played and is used to buffer the data read from disk. The default playback buffer length is 200 milliseconds (0.2 seconds), or 5000ms if you are not using the internal mixer. Increasing the length decreases the chance of the sound possibly breaking-up on slower computers, but increases the latency. For example, if you increase the playback buffer length to 3000ms (3 seconds) then it may take up to 3 seconds for a level change to be heard if you ARE using the internal mixer. You have the option here to select the default length or to nominate your own playback buffer length in milliseconds.*
SCS default playback buffer length: This option sets the playback buffer length to 200ms (or 5000ms if you are not using the internal mixer).
Set playback buffer length to ... milliseconds: This option enables you to specify your own value for the playback buffer length. The minimum length is the Update Period + 1ms and the maximum length is 5000ms.
The Update Period is the amount of time between updates of the playback buffers. Each update cycle has a certain amount of overhead (besides the actual decoding), so lower update periods (ie more frequent updates) mean the overhead becoms a higher proportion of the processing. At the other end of the scale, you don't want an update period that's too high to keep the playback buffers fairly full (or cause CPU usage spikes). In general, it is recommended that you do not go below 10ms or above a third of the playback buffer length. The default update period in SCS is 50ms if you are using the internal mixer, or 100ms if you are not.
SCS default update period: This option sets the update period to 50ms (or 100ms if you are not using the internal mixer).
Set update period to ... milliseconds: This option enables you to specify your own value for the update period. This must be between 5 and 100ms. If you leave this field blank then the default will be used (50ms).
Sample Rate: The sample rate is only used by some sound card drivers - in fact, AFAIK only RME drivers use the field. With other WDM drivers the sample rate is automatically set depending on the format of the channels that are played and what the device supports. In Vista the sample rate is determined by the user's choice in the control panel. RME cards may require the sample rate to be set to 48000, but other common sample rates are also included in the drop-down list.
ASIO Control Panel: Click this button to open the ASIO Control Panel for your ASIO driver. Note that the ASIO control panel is not a part of SCS.
Link Sync Point: The syncing of linked cues and files can sometimes be a bit loose. It has been observed that on repositioning the primary cue, then syncing becomes much tighter. In the Link Sync Point field you can set the number of milliseconds after which SCS will automatically resync linked files. If you leave the field blank (or set it to 0), the resync will not occur. A suggested value for resyncing is 50 (milliseconds).
* Changes to Audio Driver options may not be effected on currently open audio files. You may need to re-open your cue file, or close and restart SCS, for your changes to take effect.
The audio driver used by SCS is the BASS Audio Library, copyright © un4seen developments.