X-Git-Url: http://shamusworld.gotdns.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=_manual%2F19_synchronization%2F02_latency-and-latency-compensation.html;h=9954e0da1f4be2e717ce6007c9982a5361753b10;hb=1321d4a5f39bf9163b6776dddc24d8ce151fd4d3;hp=2ce04981ecd724b7ce25af5a86856ca418aeaf39;hpb=876124925eb2b43064a58dcc118e685ac876514c;p=ardour-manual diff --git a/_manual/19_synchronization/02_latency-and-latency-compensation.html b/_manual/19_synchronization/02_latency-and-latency-compensation.html index 2ce0498..9954e0d 100644 --- a/_manual/19_synchronization/02_latency-and-latency-compensation.html +++ b/_manual/19_synchronization/02_latency-and-latency-compensation.html @@ -7,9 +7,9 @@ menu_title: About Latency
-When speaking about synchronization, there is no way around also mentioning Latency: -Latency is how you call the reaction time of a system to a certain stimulus. There are many factors that contribute to the total latency of a given system. -In order to achieve exact time synchronization all sources of latency need to be take into account and compensated for. +When speaking about synchronization, it is also necessary to speak of latency. +Latency is a system's reaction time to a given stimulus. There are many factors that contribute to the total latency of a system. +In order to achieve exact time synchronization all sources of latency need to be taken into account and compensated for.
-Yet there are only few situations where a low-latency is really important, because they require very quick response from the computer. Some examples that come quickly to mind are: +Yet there are a few situations where a low-latency is really important, because they require very quick response from the computer.
-This is where latency-compensation comes into play. There are two possibilities to compensate for latency in a DAW: read-ahead the DAW actually starts playing a bit early (relative to the playhead), so that when the sound hits the speakers a short time later, it is exactly aligned with the material that is being recorded. -And write-behind since we know that the sound that is being played back has latency, the incoming audio can be delayed by the same amount to line things up again. +This is where latency-compensation comes into play. There are two possibilities to compensate for latency in a DAW: read-ahead the DAW starts playing a bit early (relative to the playhead), so that when the sound arrives at the speakers a short time later, it is exactly aligned with the material that is being recorded. +And write-behind; since we know that play-back has latency, the incoming audio can be delayed by the same amount to line things up again.
-As you may see the second approach has various issues implementation issues regarding timecode and transport synchronization. Ardour uses internal read-ahead to compensate for latency. The time displayed in the Ardour clock corresponds to the audio-signal that you hear on the speakers (and is not where ardour reads files from disk). +As you may see, the second approach is prone to various implementation issues regarding timecode and transport synchronization. Ardour uses read-ahead to compensate for latency. The time displayed in the Ardour clock corresponds to the audio-signal that you hear on the speakers (and is not where Ardour reads files from disk).
@@ -106,11 +106,11 @@ In order to compensate for Latency, JACK or JACK applications need to know exact
Figure: Jack Latency Compensation. This figure outlines the jack latency API. -- excerpt from http://jackaudio.org/files/jack-latency.png
-In above figure, clients A and B need to be able to answer the following two questions: +In the figure above, clients A and B need to be able to answer the following two questions: