Use the multi-media library bass. DLL to play MP3 [8]-display the peak value of the left and right audio channels in real time

In this example:

Code File:

Unit unit1; interfaceuses windows, messages, sysutils, variants, classes, graphics, controls, forms, dialogs, classes, extctrls, comctrls; Type tform1 = Class (tform) opendialog1: topendialog; timer1: ttimer; button1: tbutton; button2: tbutton; button3: tbutton; weight: weight; Procedure alert (Sender: tobject); Procedure button1click (Sender: tobject ); proc Edure button2click (Sender: tobject); Procedure button3click (Sender: tobject); Procedure formdestroy (Sender: tobject); Procedure destroy (Sender: tobject); end; var form1: tform1; implementation {$ R *. DFM} uses bass; var HS: hstream; {stream handle} procedure handle (Sender: tobject); begin timer1.interval: = 100; timer1.enabled: = false; progressbar1.align: = alleft; progressbar2.align: = alright; Pro Direction: = pbvertical; direction: = pbvertical; progressbar1.width: = 20; progressbar2.width: = 20; progressbar1.max: = maxword Div 2; progressbar2.max: = maxword Div 2; If hiword (bass_getversion) bassversion then MessageBox (0, '"Bass. the DLL file version is not suitable! ', Nil, mb_iconerror); if not bass_init (-1, 44100, 0, 0, nil) Then showmessage ('initialization error'); end; {open} procedure tform1.button1click (Sender: tobject); var mp3path: ansistring; begin bass_streamfree (HS); timer1.enabled: = false; opendialog1.filter: = 'mp3 file (*. MP3) | *. MP3 | WAV file (*. wav) | * WAV '; If opendialog1.execute then mp3path: = ansistring (opendialog1.filename); HS: = bass_streamcreatefile (false, pansichar (mp3path), 0, 0, 0); if hs

Form file:

Object form1: tform1 left = 222 Top = 114 caption = 'form1' clientheight = 113 clientwidth = 243 color = clbtnface font. charset = default_charset font. color = clwindowtext font. height =-11 font. name = 'tahoma 'font. style = [] oldcreateorder = false position = podesigned oncreate = formcreate ondestroy = formdestroy pixelsperinch = 96 textheight = 13 object button1: tbutton left = 83 Top = 17 width = 75 Height = 25 caption = #25171 #24320 taborder = 0 onclick = button1click end object button2: tbutton left = 83 Top = 48 width = 75 Height = 25 caption = #25773 #25918 taborder = 1 onclick = button2click end object button3: tbutton left = 83 Top = 79 width = 75 Height = 25 caption = #26242 #20572 taborder = 2 onclick = button3click end object progressbar1: tprogressbar left = 8 Top = 74 width = 69 Height = 17 taborder = 3 end object progressbar2: tprogressbar left = 164 Top = 74 width = 77 Height = 17 taborder = 4 end object opendialog1: topendialog left = 192 Top = 8 end object timer1: ttimer ontimer = timer1timer left = 40 top = 8 endend