[[PageOutline]]

= Ventana Audio
The Advanced Linux Sound Architecture (ALSA) system is the current audio driver subsystem in Linux. For details on detecting and configuring ALSA devices see [wiki:linux/audio linux/audio]

The audio hardware available on Ventana boards:
 * [http://cache.freescale.com/files/analog/doc/data_sheet/SGTL5000.pdf?pspll=1 Freescale SGTL5000] with line level input and output (standard board configuration) or (custom board configuration)
 headphone level output (custom board configuration) - 45mW max into 16ohme@3.3V load, and mic input
 * tda1997x (HDMI Audio in)
 * imxhdmisoc (HDMI Audio out)

For information regarding Audio / Video breakout adapters for Ventana see:
 * [wiki:ventana/breakoutadapters Audio / Video breakout Adapters]

Note that by default, Ventana family boards that have analog audio have a default strapping of [http://en.wikipedia.org/wiki/Line_level line level] audio (both input and output). However, there is an option to load Headphone level output/Mic level input on request. Please contact sales@gateworks.com if you would like a special built with these loadings.


[=#amixer-sgtl5000]
=== sgtl5000 (analog audio)
Note that by default, Ventana family boards that have analog audio have a default strapping of [http://en.wikipedia.org/wiki/Line_level line level] audio (both input and output).

However, there is an option to load Headphone level output and/or Mic level input on request. Please contact sales@gateworks.com if you would like a special built with these loadings.


[=#amixer-sgtl5000-lineout]
==== Line Level Audio Output
common {{{amixer}}} settings for Analog audio output (make sure to look at {{{/proc/asound/cards}}} to find the correct device number to use with the -c option below):
 * Output (Line out)
{{{#!bash
# unmute output
amixer -c 0 sset Lineout on
# set output level to max
amixer -c 0 sset PCM 100%
}}}
 * Input (Line in)
{{{#!bash
# set capture mux
amixer -c 0 sset "Capture Mux" LINE_IN
amixer -c 0 sset "Line In Function" on
# set capture gain
amixer -c 0 sset "Capture" 8
# enable it
amixer -c 0 sset "Capture" cap
}}}


[=#amixer-sgtl5000-hpout]
==== Headphone Level Audio Output ====
If you've ordered a board with HP level audio the following specifications apply:
 * sgtl5000 can drive 45mW max into a 16ohm load at 3.3V (53mA)

common {{{amixer}}} settings for headphone level audio:
{{{#!bash
# Set zero cross detect gain
amixer -c 0 sset Headphone Playback ZC 60%
# unmute output
amixer -c 0 sset Headphone on
# set output level to max
amixer -c 0 sset PCM 100%
}}}

In addition, you will also have to make a change to your device tree file in the kernel. Below is a sample patch of what you will have to do (filename depends on product you've ordered)
{{{
#!diff
diff --git a/arch/arm/boot/dts/imx6qdl-gw52xx.dtsi b/arch/arm/boot/dts/imx6qdl-gw52xx.dtsi
index ed71beb..1c0b229 100644
--- a/arch/arm/boot/dts/imx6qdl-gw52xx.dtsi
+++ b/arch/arm/boot/dts/imx6qdl-gw52xx.dtsi
@@ -109,7 +109,7 @@
                audio-codec = <&codec>;
                audio-routing =
                        "LINE_IN", "Line In Jack",
-                       "Line Out Jack", "LINE_OUT";
+                       "Headphone Jack", "HP_OUT";
                mux-int-port = <1>;
                mux-ext-port = <4>;
        };
}}}

The defaults for the analog audio (which are found by running 'amixer' with no args) are:
 * Output Level (PCM) (0 - 192)
  * Front Left: Playback 192 [100%]
  * Front Right: Playback 192 [100%]
  * disabled
 * Capture Mux (MIC_IN or LINE_IN)
  * MIC_IN
 * Capture Gain (0-15):
  * Front Left: Capture 5 [33%]
  * Front Right: Capture 6 [40%]
  * disabled



[=#amixer-hdmi-out]
=== HDMI (digital audio) ===

The '''imxhdmisoc''' audio (output only) device can be used to send digital audio to a connected (and unblanked) HDMI monitor that has speakers.

The '''tda1997xaudio''' audio (input only) device (on GW5400 models) can be used to capture digital audio from a connected (and unblanked) HDMI source that streams audio. Note that HDMI audio supports multiple sample-rates and the sample-rate available to capture depends on the incoming source stream. The source stream's audio sample rate can be found via sysfs /sys/bus/i2c/drivers/tda1997x/2-0048/audmode


[=#alsa-utils]
== ALSA utility (alsa-utils package) examples (arecord/aplay) ==
The alsa-utils package contains the arecord, aplay, amixer applications

aplay:
 * playback pre-recorded sound to analog audio device (GW54xx/GW53xx/GW52xx)
{{{
aplay -D sysdefault:CARD=sgtl5000audio /usr/share/sounds/alsa/Front_Center.wav
}}}
 * playback pre-recorded sound to HDMI audio output device
{{{
aplay -D sysdefault:CARD=imxhdmisoc /usr/share/sounds/alsa/Front_Center.wav
}}}

arecord:
 * record 10 seconds of CD quality audio (16bit, 44.1KHz, stereo) from analog audio device to /tmp/foo.wav
{{{
arecord -D sysdefault:CARD=sgtl5000audio -f cd -d 10 -t wav /tmp/foo.wav
}}}
  * make sure you have specified the capture gain and input device (see above)


== Codecs ==
For Codec support (Encoder / Decoder) details please see:
 * [wiki:ventana/codec Ventana Codecs]



[=#gstreamer]
== Gstreamer examples ==
For GStreamer information and examples please see:
 * [wiki:Yocto/gstreamer/audio GStreamer Audio Wiki Page]