Wave file (7): Create an empty wave file (three methods)

Unit unit1; interfaceuses windows, messages, sysutils, variants, classes, graphics, controls, forms, dialogs; Type tform1 = Class (tform) Procedure formcreate (Sender: tobject); end; vaR form1: tform1; implementation {$ R *. DFM} uses mmsystem; // Chan: 1 single channel, 2 stereo; // freq: frequency, value: 11025,220 50, 44100 // bit: the size of each sample, value: 8 and 16 function createwav1 (Chan, freq, bit: word; const filepath: string): Boolean; var H: hmmio; ckiriff, ckifmt, ckidata: tmmckinfo; FMT: tpcmwaveformat; begin // This function uses the mmiocreatechunk function to create each block of the wave file separately. {preliminary knowledge-related structure} zeromemory (@ ckiriff, sizeof (tmmckinfo); ckiriff. cksize: = 36; {The mmiocreatechunk function automatically writes the ckid, but the cksize must be manually assigned to} ckiriff. fcctype: = mmiostringtofourcc ('wave ', 0); zeromemory (@ ckifmt, sizeof (tmmckinfo); ckifmt. ckid: = mmiostringtofourcc ('fmt', 0); zeromemory (@ ckidata, sizeof (tmmckinfo); ckidata. ckid: = mmiostringtofourcc ('data', 0); {specify the wave format} FMT. WF. wformattag: = wave_format_pcm; FMT. WF. nchannels: = Chan; FMT. WF. nsamplespersec: = freq; FMT. WF. navgbytespersec: = freq * chan * bit Div 8; FMT. WF. nblockalign: = chan * bit Div 8; FMT. wbitspersample: = bit; H: = mmioopen (pchar (filepath), nil, mmio_create or mmio_write); If H = 0 Then exit (false ); {create riff, FMT, data blocks respectively} If (mmiocreatechunk (H, @ ckiriff, blocks) = mmsyserr_noerror) and (mmiocreatechunk (H, @ ckifmt, 0) = mmsyserr_noerror) and (mmiowrite (H, pansichar (@ FMT), sizeof (tpcmwaveformat) = sizeof (tpcmwaveformat) and (mmioascend (H, @ ckifmt, 0) = mmsyserr_noerror) and (mmiocreatechunk (H, @ ckidata, 0) = mmsyserr_noerror) then result: = true; mmioclose (H, 0); end; // regard the first 44 bytes of the PCM-encoded wave file as a structure for Operation: function createwav2 (Chan, freq, bit: word; const filepath: string): Boolean; type twaveheader = record failed: DWORD; riff_cksize: DWORD; rule: DWORD; fmt_cksize: DWORD; wformattag: word; nchannels: word; nsamplespersec: DWORD; rule: DWORD; nblockalign: word; wbitspersample: word; data_ckid: DWORD; data_cksize: DWORD; end; var wh: twaveheader; hfile: integer; begin Wh. riff_ckid: = fourcc_riff; Wh. riff_cksize: = 36; Wh. riff_fcctype: = mmiostringtofourcc ('wave ', 0); Wh. fmt_ckid: = mmiostringtofourcc ('fmt', 0); Wh. fmt_cksize: = 16; Wh. wformattag: = wave_format_pcm; Wh. nchannels: = Chan; Wh. nsamplespersec: = freq; Wh. navgbytespersec: = freq * chan * bit Div 8; Wh. nblockalign: = chan * bit Div 8; Wh. wbitspersample: = bit; Wh. data_ckid: = mmiostringtofourcc ('data', 0); Wh. data_cksize: = 0; hfile: = filecreate (filepath); Result: = (filewrite (hfile, wh, sizeof (twaveheader)-1); fileclose (hfile); end; // same as above, only use stream to Write File function createwav3 (Chan, freq, bit: word; const filepath: string): Boolean; Type twaveheader = record riff_ckid: DWORD; riff_cksize: DWORD; rule: DWORD; fmt_cksize: DWORD; wformattag: word; nchannels: word; nsamplespersec: DWORD; rule: DWORD; nblockalign: word; wbitspersample: word; data_ckid: DWORD; data_cksize: DWORD; end; var wh: twaveheader; begin Wh. riff_ckid: = fourcc_riff; Wh. riff_cksize: = 36; Wh. riff_fcctype: = mmiostringtofourcc ('wave ', 0); Wh. fmt_ckid: = mmiostringtofourcc ('fmt', 0); Wh. fmt_cksize: = 16; Wh. wformattag: = wave_format_pcm; Wh. nchannels: = Chan; Wh. nsamplespersec: = freq; Wh. navgbytespersec: = freq * chan * bit Div 8; Wh. nblockalign: = chan * bit Div 8; Wh. wbitspersample: = bit; Wh. data_ckid: = mmiostringtofourcc ('data', 0); Wh. data_cksize: = 0; with tfilestream. create (filepath, fmcreate) Do begin result: = (write (Wh, sizeof (twaveheader) = sizeof (twaveheader); free; end; Procedure tform1.formcreate (Sender: tobject); begin createwav1 (1, 11025, 8, 'c: \ temp \ x1.wav '); createwav2 (2, 22050, 16, 'c: \ temp \ x2.wav '); createwav3 (2, 44100, 16, 'c: \ temp \ x3.wav '); end.