diff --git a/manual/configure_rockbox/recording_settings.tex b/manual/configure_rockbox/recording_settings.tex index ed2c234e77..113508b2e5 100644 --- a/manual/configure_rockbox/recording_settings.tex +++ b/manual/configure_rockbox/recording_settings.tex @@ -36,7 +36,7 @@ Choose which format to save your recording in. The available choices are the two uncompressed formats \setting{PCM Wave} and \setting{AIFF}, the losslessly compressed \setting{WavPack} and the lossy - \setting{MPEG Layer 3}. + \setting{MPEG Layer 3}. \section{Encoder Settings} This sets the bitrate when using the \setting{MPEG Layer 3} format. And has @@ -133,9 +133,96 @@ Options: \setting{Off}, \setting{Main unit only}, \setting{Main and remote unit}, \setting{Remote unit only}. } - \section{Trigger} - \fixme{Add description of triggered recording.} - +\section{Trigger} + When you record a source you often are only interested in the sound and not + the silence in between. The recording trigger provides you with a + tool to automatically distinguish between sound and silence and record the + sound only. Unfortunately it is not very easy to make this distinction between + silence and sound because you hardly ever encounter real silence. There always + are background noises. What is considered as background noise depends on the + situation. For example during a lecture the very low noise of rustling paper + might be considered as background noise. During a rock concert the murmur of + the audience might be concidered background noise which is much louder compared + to rustling paper. Also the duration of the signal matters. When you record + speech you want to record every syllable. When you record live music you may + not be interested in that chord the guitarist strokes for two minutes before + the show to verify his amp is turned on. The trigger features numerous + parameters to adapt its behaviour to the desired situation. + \begin{description} + \item[Trigger] + This parameter specifies the trigger mode. When set to \setting{Off} + the recording must be started manually and apart from the Prerecord time no + other parameter has any effect. \setting{Once} will have the trigger start + one recording only; after the recording has finished the input signal will + not start another recording. \setting{Repeat} will have the trigger start + multiple recordings. + + \item[Trigtype] + \fixme{Add description of Trigtype} + Options: \setting{Stop}, \setting{Pause}, \setting{New File}. + + \item[Prerecord Time] + This specifies the time that is included into the recording before the + trigger event occurs. This is very useful if you record a signal that fades + in. Usually you want to set the prerecord time >= start duration. That + ensures that you record the entire sound. Strictly speaking the prerecord + time is not a special parameter of the trigger. It is available during normal + recordings too. + + \item[Start Above] + The start threshold defines the minimal volume a sound must have to start the + recording. It is displayed numerically in the line "Start Above". Note that + the unit of the threshold depends on the settings of the peakmeter. (i.e. + When the peakmeter displays db you can adjust the level in db and when the + peakmeter is set to linear the threshold is displayed as percentage.) In the + peakmeter at the bottom of the screen the start threshold is displayed + graphically by a little triangle pointing to the right. There are two special + values. The value \setting{Off} turns the start condition off. With this + setting you have to start the recording manually and the trigger only stops + the recording according to the stop condition. The setting \setting{-inf} + sets the trigger to the absolute minimum. This setting only makes sense when + you record via a digital input as even the noise of the device itself would + exceed this threshold immediately. + + \item[for at least] + The start duration defines the minimal duration that a signal must exceed the + start threshold to start the recording. Depending on your situation you may + want to set this setting to 0 (e.g. when copying a song from a commercial + medium) or to quite big values. Because sound is not continuous by nature + (think of percussion) neglectable dropouts are tolerated during this start + duration. + + \item[Stop Below] + When the sound level drops below the stop threshold the recording is stopped. + It is displayed numerically in the line "Stop Below". Just like the start + threshold the unit of the stop threshold depends on the settings of the peak + meter. There's also a small triangular marker in the peak meter at the bottom + of the screen. In contrast to the start threshold marker it points to the + left. The value \setting{Off} turns the stop condition off. With this setting you + have to stop the recording manually. + + \item[for at least] + This time specifies the duration the signal must drop below the stop + threshold to stop the recording. By selecting high values you can ensure + that, for example, trailing fade-outs are recorded entirely. + + \item[Presplit Gap] + When the signal drops below the stop threshold for the time specified by the + presplit gap a new recording may be started when the signal raises above the + start threshold. Thus the value of the presplit gap should be smaller than + the stop hold time. Otherwise the recording would stop anyway and the + presplit gap has no effect. For most uses I recommend to set this parameter + equal to the stop hold time. Sometimes you may encounter a sound source (e.g. + a CD) where the songs have fade outs and hardly any gaps between the tracks. + Here you can set the stop hold time to long values to ensure that all fade + outs are recorded completely. By specifying a short presplit gap you still + can split the recording into seperate tracks whenever the trigger start + condition is met. + + \end{description} + +More information can be found at \wikilink{VolumeTriggeredRecording}. + \opt{h1xx,h300}{% \section{Automatic Gain Control} The \setting{Automatic Gain Control} has five different presets for @@ -168,3 +255,5 @@ This setting controls how long the level is too loud or soft before the \setting{Automatic Gain Control} kicks in. }% + +