mirror of
https://github.com/cookiengineer/audacity
synced 2025-05-05 14:18:53 +02:00
64 lines
1.8 KiB
Plaintext
64 lines
1.8 KiB
Plaintext
(CONVOLVE-ALG
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(NAME "convolve")
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(SUPPORT-FUNCTIONS "
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void h_reverse(sample_type *h, long len)
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{
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sample_type temp;
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int i;
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for (i = 0; i < len; i++) {
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temp = h[i];
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h[i] = h[len - 1];
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h[len - 1] = temp;
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len--;
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}
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}
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")
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(ARGUMENTS ("sound_type" "x_snd") ("sound_type" "h_snd") )
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(TABLE "h_snd")
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(START (MIN x_snd))
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(NOT-IN-INNER-LOOP "h_snd")
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(STATE
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("table_type" "table" "sound_to_table(h_snd)")
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("sample_type *" "h_buf" "susp->table->samples")
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("double" "length_of_h" "susp->table->length")
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("long" "h_len" "(long) susp->length_of_h;
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h_reverse(susp->h_buf, susp->h_len)")
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("long" "x_buf_len" "2 * susp->h_len")
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("sample_type *" "x_buffer_pointer"
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"calloc((2 * (susp->h_len)), sizeof(float))")
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("sample_type *" "x_buffer_current" "susp->x_buffer_pointer") )
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(ALWAYS-SCALE x_snd)
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(TERMINATE (MIN x_snd))
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(LOGICAL-STOP (MIN x_snd))
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(INNER-LOOP-LOCALS
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"long i; double sum;")
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(INNER-LOOP "
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/* see if we've reached end of x_buffer */
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if ((x_buffer_pointer + x_buf_len) <= (x_buffer_current + h_len)) {
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/* shift x_buffer from current back to base */
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for (i = 1; i < h_len; i++) {
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x_buffer_pointer[i-1] = x_buffer_current[i];
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}
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/* this will be incremented back to x_buffer_pointer below */
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x_buffer_current = x_buffer_pointer - 1;
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}
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x_buffer_current++;
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x_buffer_current[h_len - 1] = x_snd;
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sum = 0.0;
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for (i = 0; i < h_len; i++) {
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sum += x_buffer_current[i] * h_buf[i];
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}
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output = (sample_type) sum;
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")
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(CONSTANT "h_buf" "h_len" "x_buf_len" "table")
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(SAMPLE-RATE "x_snd->sr")
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(FINALIZATION " table_unref(susp->table);
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free(susp->x_buffer_pointer);")
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)
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