From 070ccac33d65c651c972dfab9c6148e43d8d5d8e Mon Sep 17 00:00:00 2001 From: fulup Date: Thu, 3 Aug 2017 12:00:41 +0200 Subject: Initial Working Version on Alsa Policy-Policy-Hook --- HAL-afb/HAL-plugin/README.md | 44 -------------------------------------------- 1 file changed, 44 deletions(-) delete mode 100644 HAL-afb/HAL-plugin/README.md (limited to 'HAL-afb/HAL-plugin/README.md') diff --git a/HAL-afb/HAL-plugin/README.md b/HAL-afb/HAL-plugin/README.md deleted file mode 100644 index 1c1e7a2..0000000 --- a/HAL-afb/HAL-plugin/README.md +++ /dev/null @@ -1,44 +0,0 @@ -Hal-Plugin - -Object: provide an ALSA a HAL (Hardware Abstraction Layer) to automotive sound cards -Status: Current version is proof of concept and not a usable product -Author: Fulup Ar Foll -Date : June-2017 - -HAL-plugin allows: - - to expose any existing NUMID under a customized label name, this is order to abstract sound card config. - - to add non alsa NUMID supported through a callback mechanism (eg: volume rampdown, power off, ...) - -installation - - Plugin should be placed where ever alsaplugins are located (typically: /usr/share/alsa-lib) - - Callback sharelib directory should be declare in $LD_LIBRARY_PATH - -Config -``` -cat ~/.asoundrc - ctl.agl_hal { - type afbhal - devid "hw:4" - cblib "afbhal_cb_sample.so" - ctls { - # ctlLabel {numid integer name "Alsa Ctl Name"} - MasterSwitch { numid 4 name "My_First_Control" } - MasterVol { numid 5 name "My_Second_Control" } - CB_sample { ctlcb @AfbHalSampleCB name "My_Sample_Callback"} - } - pcm.agl_hal { - type copy # Copy PCM - slave "hw:4" # Slave name - } -``` - -With such a config file - - numid=4 from sndcard=hw:4 is renamed "My_First_Control" - - numid=4 from sndcard=hw:4 is renamed "My_Second_Control" - - numid=4 will call AfbHalSampleCB from afbhal_cb_sample.so - -Note: to really implement a usable HAL at minimum every ALSA call should be implemented and read/write of values should be normalised from 0 to 100% with a step of 1. - -Conclusion: This demonstrate that implementing a HAL that both abstract ALSA get/set and enable non ALSA support is possible at an acceptable cost -without having to hack ALSA source code. The beauty of the model is than it is fully transparent to any ALSA application. The limit is that the plugin is loaded -within every application context, thus interaction with an external event loop remains complete as well as conflict management in case of share resources. -- cgit 1.2.3-korg