v1.0.14

Author: RaspberryFpc

source/alsa_volume.pas

@@ -0,0 +1,168 @@
+unit alsa_volume;
+
+{$mode objfpc}{$H+}
+
+interface
+
+uses
+  Classes, SysUtils, ctypes, dynlibs;
+
+function SetVolume(CardIndex: Integer; Percent: Integer): Boolean;
+function GetVolume(CardIndex: Integer; out Percent: Integer): Boolean;
+
+implementation
+
+type
+  Psnd_mixer_t = Pointer;
+  Psnd_mixer_elem_t = Pointer;
+  Psnd_mixer_selem_id_t = Pointer;
+
+var
+  asound: TLibHandle;
+
+  snd_mixer_open: function(mixer: PPointer; mode: cint): cint; cdecl;
+  snd_mixer_attach: function(mixer: Pointer; name: PChar): cint; cdecl;
+  snd_mixer_selem_register: function(mixer: Pointer; options: Pointer; classp: PPointer): cint; cdecl;
+  snd_mixer_load: function(mixer: Pointer): cint; cdecl;
+  snd_mixer_first_elem: function(mixer: Pointer): Pointer; cdecl;
+  snd_mixer_elem_next: function(elem: Pointer): Pointer; cdecl;
+  snd_mixer_selem_is_active: function(elem: Pointer): cint; cdecl;
+  snd_mixer_selem_get_name: function(elem: Pointer): PChar; cdecl;
+
+  snd_mixer_selem_has_playback_volume: function(elem: Pointer): cint; cdecl;
+  snd_mixer_selem_get_playback_volume_range: function(elem: Pointer; min, max: Plongint): cint; cdecl;
+  snd_mixer_selem_set_playback_volume_all: function(elem: Pointer; value: clong): cint; cdecl;
+  snd_mixer_selem_get_playback_volume: function(elem: Pointer; channel: cint; value: Plongint): cint; cdecl;
+
+  snd_mixer_close: function(mixer: Pointer): cint; cdecl;
+
+const
+  SND_MIXER_SCHN_FRONT_LEFT = 0;
+
+function LoadALSA: Boolean;
+begin
+  if asound <> 0 then exit(True);
+
+  asound := LoadLibrary('libasound.so');
+  if asound = 0 then exit(False);
+
+  Pointer(snd_mixer_open) := GetProcAddress(asound, 'snd_mixer_open');
+  Pointer(snd_mixer_attach) := GetProcAddress(asound, 'snd_mixer_attach');
+  Pointer(snd_mixer_selem_register) := GetProcAddress(asound, 'snd_mixer_selem_register');
+  Pointer(snd_mixer_load) := GetProcAddress(asound, 'snd_mixer_load');
+  Pointer(snd_mixer_first_elem) := GetProcAddress(asound, 'snd_mixer_first_elem');
+  Pointer(snd_mixer_elem_next) := GetProcAddress(asound, 'snd_mixer_elem_next');
+  Pointer(snd_mixer_selem_is_active) := GetProcAddress(asound, 'snd_mixer_selem_is_active');
+  Pointer(snd_mixer_selem_get_name) := GetProcAddress(asound, 'snd_mixer_selem_get_name');
+
+  Pointer(snd_mixer_selem_has_playback_volume) := GetProcAddress(asound, 'snd_mixer_selem_has_playback_volume');
+  Pointer(snd_mixer_selem_get_playback_volume_range) := GetProcAddress(asound, 'snd_mixer_selem_get_playback_volume_range');
+  Pointer(snd_mixer_selem_set_playback_volume_all) := GetProcAddress(asound, 'snd_mixer_selem_set_playback_volume_all');
+  Pointer(snd_mixer_selem_get_playback_volume) := GetProcAddress(asound, 'snd_mixer_selem_get_playback_volume');
+
+  Pointer(snd_mixer_close) := GetProcAddress(asound, 'snd_mixer_close');
+
+  Result := True;
+end;
+
+function OpenMixer(CardIndex: Integer; out Mixer: Pointer): Boolean;
+var
+  name: String;
+begin
+  Result := False;
+
+  if snd_mixer_open(@Mixer, 0) < 0 then exit;
+
+  name := 'hw:' + IntToStr(CardIndex);
+
+  if snd_mixer_attach(Mixer, PChar(name)) < 0 then exit;
+  if snd_mixer_selem_register(Mixer, nil, nil) < 0 then exit;
+  if snd_mixer_load(Mixer) < 0 then exit;
+
+  Result := True;
+end;
+
+function FindVolumeElem(Mixer: Pointer): Pointer;
+var
+  elem: Pointer;
+begin
+  Result := nil;
+
+  elem := snd_mixer_first_elem(Mixer);
+  while elem <> nil do
+  begin
+    if (snd_mixer_selem_is_active(elem) <> 0) and
+       (snd_mixer_selem_has_playback_volume(elem) <> 0) then
+    begin
+      Result := elem;
+      exit;
+    end;
+
+    elem := snd_mixer_elem_next(elem);
+  end;
+end;
+
+function SetVolume(CardIndex: Integer; Percent: Integer): Boolean;
+var
+  mixer, elem: Pointer;
+  minv, maxv: clong;
+  value: clong;
+begin
+  Result := False;
+
+  if not LoadALSA then exit;
+  if not OpenMixer(CardIndex, mixer) then exit;
+
+  elem := FindVolumeElem(mixer);
+  if elem = nil then
+  begin
+    snd_mixer_close(mixer);
+    exit;
+  end;
+
+  snd_mixer_selem_get_playback_volume_range(elem, @minv, @maxv);
+
+  value := minv + (Percent * (maxv - minv) div 100);
+
+  snd_mixer_selem_set_playback_volume_all(elem, value);
+
+  snd_mixer_close(mixer);
+  Result := True;
+end;
+
+function GetVolume(CardIndex: Integer; out Percent: Integer): Boolean;
+var
+  mixer, elem: Pointer;
+  minv, maxv, value: clong;
+begin
+  Result := False;
+  Percent := 0;
+
+  if not LoadALSA then exit;
+  if not OpenMixer(CardIndex, mixer) then exit;
+
+  elem := FindVolumeElem(mixer);
+  if elem = nil then
+  begin
+    snd_mixer_close(mixer);
+    exit;
+  end;
+
+  snd_mixer_selem_get_playback_volume_range(elem, @minv, @maxv);
+  snd_mixer_selem_get_playback_volume(elem, SND_MIXER_SCHN_FRONT_LEFT, @value);
+
+  if maxv > minv then
+    Percent := (value - minv) * 100 div (maxv - minv);
+
+  snd_mixer_close(mixer);
+  Result := True;
+end;
+
+initialization
+  asound := 0;
+
+finalization
+  if asound <> 0 then
+    FreeLibrary(asound);
+
+end.

source/udp_player

@@ -122,6 +122,11 @@
         <ResourceBaseClass Value="Form"/>
         <UnitName Value="Unit2"/>
       </Unit>
+      <Unit>
+        <Filename Value="alsa_volume.pas"/>
+        <FRMtype Value="0"/>
+        <IsPartOfProject Value="True"/>
+      </Unit>
     </Units>
   </ProjectOptions>
   <CompilerOptions>