Use the multi-media library bass. DLL to play MP3 [15]-set and obtain the playback speed

In this example:

Code File:

Unit unit1; interfaceuses windows, messages, sysutils, variants, classes, graphics, controls, forms, dialogs, classes, comctrls; Type tform1 = Class (tform) opendialog1: topendialog; button1: tbutton; button2: tbutton; button3: tbutton; trackbar1: ttrackbar; label1: tlabel; button4: tbutton; Procedure alert (Sender: tobject ); procedure button2click (Sender: Tobject); Procedure button3click (Sender: tobject); Procedure trackbar1change (Sender: tobject); Procedure future (Sender: tobject); end; var form1: tform1; implementation {$ R *. DFM} uses bass; var HS: hstream; {stream handle} procedure tform1.formcreate (Sender: tobject); begin trackbar1.showselrange: = false; trackbar1.height: = 23; trackbar1.max: = 100000; trackbar1.mi N: = 100; trackbar1.position: = 44100; If hiword (bass_getversion) bassversion then MessageBox (0, '"Bass. 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); 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 = 205 Top = 107 caption = 'form1' clientheight = 119 clientwidth = 286 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 label1: tlabel left = 32 top = 59 width = 31 Height = 13 caption = 'label1' end object button1: tbutton left = 24 Top = 17 width = 75 Height = 25 caption = #25171 #24320 taborder = 0 onclick = button1click end object button2: tbutton left = 105 Top = 17 width = 75 Height = 25 caption = #25773 #25918 taborder = 1 onclick = button2click end object button3: tbutton left = 186 Top = 17 width = 75 Height = 25 caption = #26242 #20572 taborder = 2 onclick = button3click end object trackbar1: ttrackbar left = 24 Top = 78 width = 237 Height = 32 taborder = 3 onchange = trackbar1change end object button4: tbutton left = 186 Top = 48 width = 75 Height = 25 caption = #21407 #36895 taborder = 4 onclick = button4click end object opendialog1: topendialog left = 256 endend