100 lines
2.8 KiB
Racket
100 lines
2.8 KiB
Racket
(module flac-definitions racket/base
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(provide flac-stream-info
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make-flac-stream-info
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flac-stream-info->string
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flac-handle
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make-flac-handle
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flac-handle-ffi-decoder-handler
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flac-handle-stream-info
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set-flac-handle-stream-info!
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flac-handle-cb-stream-info
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set-flac-handle-cb-stream-info!
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flac-handle-cb-audio
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set-flac-handle-cb-audio!
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flac-handle->string
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flac-sample-rate
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flac-channels
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flac-bits-per-sample
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flac-total-samples
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flac-duration
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)
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(define-struct flac-stream-info
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(min-blocksize max-blocksize
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min-framesize max-framesize
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sample-rate
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channels
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bits-per-sample
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total-samples
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))
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(define (flac-stream-info->string si)
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(format "sample-rate: ~a, channels: ~a, bits-per-sample: ~a, total-samples: ~a"
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(flac-stream-info-sample-rate si)
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(flac-stream-info-channels si)
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(flac-stream-info-bits-per-sample si)
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(flac-stream-info-total-samples si)))
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(define (flac-sample-rate h)
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(let ((si (flac-handle-stream-info h)))
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(if (eq? si #f)
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#f
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(flac-stream-info-sample-rate si))))
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(define (flac-channels h)
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(let ((si (flac-handle-stream-info h)))
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(if (eq? si #f)
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#f
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(flac-stream-info-channels si))))
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(define (flac-bits-per-sample h)
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(let ((si (flac-handle-stream-info h)))
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(if (eq? si #f)
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#f
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(flac-stream-info-bits-per-sample si))))
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(define (flac-total-samples h)
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(let ((si (flac-handle-stream-info h)))
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(if (eq? si #f)
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#f
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(flac-stream-info-total-samples si))))
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(define (flac-handle->string h)
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(let* ((si (flac-handle-stream-info h))
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(ffi (flac-handle-ffi-decoder-handler h))
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(ff (ffi 'file)))
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(string-append
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(if (eq? ff #f)
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"no flac file available\n"
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(format "Flac File: ~a\n" ff))
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(if (eq? si #f)
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"no stream info available\n"
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(string-append
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(format "Stream Info: ~a\n" (flac-stream-info->string si))
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(format "Duration in seconds: ~a\n" (flac-duration h))))
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)))
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(define (flac-duration h)
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(let* ((si (flac-handle-stream-info h)))
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(if (eq? si #f)
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#f
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(let* ((total-samples (flac-stream-info-total-samples si))
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(sample-rate (flac-stream-info-sample-rate si)))
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(inexact->exact (round (/ total-samples sample-rate)))))))
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(define-struct flac-handle
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(
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ffi-decoder-handler
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[cb-stream-info #:auto #:mutable]
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[cb-audio #:auto #:mutable]
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[stream-info #:auto #:mutable]
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)
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#:auto-value #f
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)
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); end of module
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