72 lines
1.7 KiB
Plaintext
72 lines
1.7 KiB
Plaintext
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!
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! readwav - open and read the header of a WAV format file
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!
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! On successful exit the file is left positioned at the start of the
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! data.
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!
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! Example of usage:
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!
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! use readwav
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! integer*2 sample
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! type(wav_header) wav
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! call wav%read ('file.wav')
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! write (*,*) 'Sample rate is: ', wav%audio_format%sample_rate
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! do i=0,wav%data_size
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! read (unit=wav%lun) sample
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! ! process sample
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! end do
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!
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module readwav
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implicit none
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type format_chunk
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integer*2 audio_format
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integer*2 num_channels
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integer sample_rate
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integer byte_rate
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integer*2 block_align
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integer*2 bits_per_sample
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end type format_chunk
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type, public :: wav_header
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integer :: lun
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type(format_chunk) :: audio_format
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integer :: data_size
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contains
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procedure :: read
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end type wav_header
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private
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contains
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subroutine read (this, filename)
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implicit none
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type riff_descriptor
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character(len=4) :: id
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integer :: size
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end type riff_descriptor
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class(wav_header), intent(inout) :: this
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character(len=*), intent(in) :: filename
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integer :: filepos
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type(riff_descriptor) :: desc
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character(len=4) :: riff_type
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open (newunit=this%lun, file=filename, access='stream', form='unformatted', status='old')
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read (unit=this%lun) desc,riff_type
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inquire (unit=this%lun, pos=filepos)
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do
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read (unit=this%lun, pos=filepos) desc
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inquire (unit=this%lun, pos=filepos)
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if (desc%id .eq. 'fmt ') then
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read (unit=this%lun) this%audio_format
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else if (desc%id .eq. 'data') then
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this%data_size = desc%size
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exit
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end if
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filepos = filepos + (desc%size + 1) / 2 * 2 ! pad to even alignment
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end do
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end subroutine read
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end module readwav
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