Waveform analysis/Top and tail: Difference between revisions
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→{{header|Wren}}: Minor tidy
(julia example) |
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Setting the squelch level to 2 or 3 per cent of the maximum sample value worked reasonably well in my tests.
<
import (
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err = os.Remove(tmp2)
check(err)
}</
=={{header|Julia}}==
Implemented as a Gtk GUI app.
<
function dB(buf, i, channels, cutoff=0.001)
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silencecropperapp()
</syntaxhighlight>
=={{header|Nim}}==
{{trans|Go}}
<syntaxhighlight lang="nim">import os, osproc, strutils
const Sec = "00:00:01"
proc getString(prompt: string): string =
while true:
stdout.write prompt
stdout.flushFile()
try:
result = stdin.readLine().strip()
if result.len != 0: break
except EOFError:
quit "\nEOF encountered. Quitting.", QuitFailure
proc getFloatValue(prompt: string; minval, maxval: float): float =
while true:
stdout.write prompt
stdout.flushFile()
try:
result = stdin.readLine.strip().parseFloat()
if result notin minval..maxval:
echo "Invalid value"
else:
return
except ValueError:
echo "Error: invalid value."
except EOFError:
quit "\nEOF encountered. Quitting.", QuitFailure
let infile = getString("Enter name of audio file to be trimmed: ")
let outfile = getString("Enter name of output file: ")
let squelch = getFloatValue("Enter squelch level % max (1 to 10): ", 1, 10)
let squelchS = squelch.formatFloat(ffDecimal, precision = -1) & '%'
let tmp1 = "tmp1_" & infile
let tmp2 = "tmp2_" & infile
# Trim audio below squelch level from start and output to tmp1.
var args = @[infile, tmp1, "silence", "1", Sec, squelchS]
discard execProcess("sox", args = args, options = {poStdErrToStdOut, poUsePath})
# Reverse tmp1 to tmp2.
args = @[tmp1, tmp2, "reverse"]
discard execProcess("sox", args = args, options = {poStdErrToStdOut, poUsePath})
# Trim audio below squelch level from tmp2 and output to tmp1.
args = @[tmp2, tmp1, "silence", "1", Sec, squelchS]
discard execProcess("sox", args = args, options = {poStdErrToStdOut, poUsePath})
# Reverse tmp1 to the output file.
args = @[tmp1, outfile, "reverse"]
discard execProcess("sox", args = args, options = {poStdErrToStdOut, poUsePath})
# Remove the temporary files.
removeFile(tmp1)
removeFile(tmp2)</syntaxhighlight>
=={{header|Phix}}==
The first part is a copy of [[Musical_scale#version_2]] but with first and last 2s written out as silence.<br>
I referred to http://soundfile.sapp.org/doc/WaveFormat/ when writing this.<br>
You may want to check for average volume over some period, rather than just all-0.<br>
This is clearly just a starting point and not a practical/useful/finished product!
<!--<syntaxhighlight lang="phix">(phixonline)-->
<span style="color: #008080;">without</span> <span style="color: #008080;">js</span> <span style="color: #000080;font-style:italic;">-- (file i/o)</span>
<span style="color: #008080;">constant</span> <span style="color: #000000;">sample_rate</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">44100</span><span style="color: #0000FF;">,</span>
<span style="color: #000000;">duration</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">8</span><span style="color: #0000FF;">,</span>
<span style="color: #000000;">dataLength</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">sample_rate</span> <span style="color: #0000FF;">*</span> <span style="color: #000000;">duration</span><span style="color: #0000FF;">,</span>
<span style="color: #000000;">hdrSize</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">44</span><span style="color: #0000FF;">,</span>
<span style="color: #000000;">fileLen</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">dataLength</span> <span style="color: #0000FF;">+</span> <span style="color: #000000;">hdrSize</span> <span style="color: #0000FF;">-</span> <span style="color: #000000;">8</span><span style="color: #0000FF;">,</span>
<span style="color: #000000;">freqs</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{</span> <span style="color: #000000;">261.6</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">293.6</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">329.6</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">349.2</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">392.0</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">440.0</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">493.9</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">523.3</span> <span style="color: #0000FF;">},</span>
<span style="color: #000000;">wavhdr</span> <span style="color: #0000FF;">=</span> <span style="color: #008000;">"RIFF"</span><span style="color: #0000FF;">&</span>
<span style="color: #7060A8;">int_to_bytes</span><span style="color: #0000FF;">(</span><span style="color: #000000;">fileLen</span><span style="color: #0000FF;">,</span><span style="color: #000000;">4</span><span style="color: #0000FF;">)&</span>
<span style="color: #008000;">"WAVE"</span><span style="color: #0000FF;">&</span>
<span style="color: #008000;">"fmt "</span><span style="color: #0000FF;">&</span>
<span style="color: #7060A8;">int_to_bytes</span><span style="color: #0000FF;">(</span><span style="color: #000000;">16</span><span style="color: #0000FF;">,</span><span style="color: #000000;">4</span><span style="color: #0000FF;">)&</span> <span style="color: #000080;font-style:italic;">-- length of format data (= 16)</span>
<span style="color: #7060A8;">int_to_bytes</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #000000;">2</span><span style="color: #0000FF;">)&</span> <span style="color: #000080;font-style:italic;">-- type of format (= 1 (PCM))</span>
<span style="color: #7060A8;">int_to_bytes</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #000000;">2</span><span style="color: #0000FF;">)&</span> <span style="color: #000080;font-style:italic;">-- number of channels (= 1)</span>
<span style="color: #7060A8;">int_to_bytes</span><span style="color: #0000FF;">(</span><span style="color: #000000;">sample_rate</span><span style="color: #0000FF;">,</span><span style="color: #000000;">4</span><span style="color: #0000FF;">)&</span> <span style="color: #000080;font-style:italic;">-- sample rate</span>
<span style="color: #7060A8;">int_to_bytes</span><span style="color: #0000FF;">(</span><span style="color: #000000;">sample_rate</span><span style="color: #0000FF;">,</span><span style="color: #000000;">4</span><span style="color: #0000FF;">)&</span> <span style="color: #000080;font-style:italic;">-- sample rate * bps(8) * channels(1) / 8 (= sample rate)</span>
<span style="color: #7060A8;">int_to_bytes</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #000000;">2</span><span style="color: #0000FF;">)&</span> <span style="color: #000080;font-style:italic;">-- bps(8) * channels(1) / 8 (= 1)</span>
<span style="color: #7060A8;">int_to_bytes</span><span style="color: #0000FF;">(</span><span style="color: #000000;">8</span><span style="color: #0000FF;">,</span><span style="color: #000000;">2</span><span style="color: #0000FF;">)&</span> <span style="color: #000080;font-style:italic;">-- bits per sample (bps) (= 8)</span>
<span style="color: #008000;">"data"</span><span style="color: #0000FF;">&</span>
<span style="color: #7060A8;">int_to_bytes</span><span style="color: #0000FF;">(</span><span style="color: #000000;">dataLength</span><span style="color: #0000FF;">,</span><span style="color: #000000;">4</span><span style="color: #0000FF;">)</span> <span style="color: #000080;font-style:italic;">-- size of data section</span>
<span style="color: #008080;">if</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">wavhdr</span><span style="color: #0000FF;">)!=</span><span style="color: #000000;">hdrSize</span> <span style="color: #008080;">then</span> <span style="color: #0000FF;">?</span><span style="color: #000000;">9</span><span style="color: #0000FF;">/</span><span style="color: #000000;">0</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span> <span style="color: #000080;font-style:italic;">-- sanity check</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">fn</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">open</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"notes.wav"</span><span style="color: #0000FF;">,</span> <span style="color: #008000;">"wb"</span><span style="color: #0000FF;">)</span>
<span style="color: #7060A8;">puts</span><span style="color: #0000FF;">(</span><span style="color: #000000;">fn</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">wavhdr</span><span style="color: #0000FF;">)</span>
<span style="color: #008080;">for</span> <span style="color: #000000;">j</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span> <span style="color: #008080;">to</span> <span style="color: #000000;">duration</span> <span style="color: #008080;">do</span>
<span style="color: #004080;">atom</span> <span style="color: #000000;">omega</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">2</span> <span style="color: #0000FF;">*</span> <span style="color: #004600;">PI</span> <span style="color: #0000FF;">*</span> <span style="color: #000000;">freqs</span><span style="color: #0000FF;">[</span><span style="color: #000000;">j</span><span style="color: #0000FF;">]</span>
<span style="color: #008080;">for</span> <span style="color: #000000;">i</span><span style="color: #0000FF;">=</span><span style="color: #000000;">0</span> <span style="color: #008080;">to</span> <span style="color: #000000;">dataLength</span><span style="color: #0000FF;">/</span><span style="color: #000000;">duration</span><span style="color: #0000FF;">-</span><span style="color: #000000;">1</span> <span style="color: #008080;">do</span>
<span style="color: #004080;">atom</span> <span style="color: #000000;">y</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">32</span> <span style="color: #0000FF;">*</span> <span style="color: #7060A8;">sin</span><span style="color: #0000FF;">(</span><span style="color: #000000;">omega</span> <span style="color: #0000FF;">*</span> <span style="color: #000000;">i</span> <span style="color: #0000FF;">/</span> <span style="color: #000000;">sample_rate</span><span style="color: #0000FF;">)</span>
<span style="color: #000080;font-style:italic;">-- integer byte = and_bits(y,#FF) -- (makes for no cropping)</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">byte</span> <span style="color: #0000FF;">=</span> <span style="color: #008080;">iff</span><span style="color: #0000FF;">(</span><span style="color: #000000;">j</span><span style="color: #0000FF;"><=</span><span style="color: #000000;">2</span> <span style="color: #008080;">or</span> <span style="color: #000000;">j</span><span style="color: #0000FF;">>=</span><span style="color: #000000;">7</span><span style="color: #0000FF;">?</span><span style="color: #000000;">0</span><span style="color: #0000FF;">:</span><span style="color: #7060A8;">and_bits</span><span style="color: #0000FF;">(</span><span style="color: #000000;">y</span><span style="color: #0000FF;">,</span><span style="color: #000000;">#FF</span><span style="color: #0000FF;">))</span>
<span style="color: #7060A8;">puts</span><span style="color: #0000FF;">(</span><span style="color: #000000;">fn</span><span style="color: #0000FF;">,</span><span style="color: #000000;">byte</span><span style="color: #0000FF;">)</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
<span style="color: #7060A8;">close</span><span style="color: #0000FF;">(</span><span style="color: #000000;">fn</span><span style="color: #0000FF;">)</span> <span style="color: #000080;font-style:italic;">-- </copy of Musical_scale></span>
<span style="color: #004080;">string</span> <span style="color: #000000;">raw</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">get_text</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"notes.wav"</span><span style="color: #0000FF;">)</span>
<span style="color: #008080;">if</span> <span style="color: #000000;">raw</span><span style="color: #0000FF;">[</span><span style="color: #000000;">1</span><span style="color: #0000FF;">..</span><span style="color: #000000;">4</span><span style="color: #0000FF;">]!=</span><span style="color: #008000;">"RIFF"</span> <span style="color: #008080;">then</span> <span style="color: #0000FF;">?</span><span style="color: #000000;">9</span><span style="color: #0000FF;">/</span><span style="color: #000000;">0</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">rawlen</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">bytes_to_int</span><span style="color: #0000FF;">(</span><span style="color: #000000;">raw</span><span style="color: #0000FF;">[</span><span style="color: #000000;">5</span><span style="color: #0000FF;">..</span><span style="color: #000000;">8</span><span style="color: #0000FF;">])</span>
<span style="color: #008080;">if</span> <span style="color: #000000;">rawlen</span><span style="color: #0000FF;">!=</span><span style="color: #000000;">fileLen</span> <span style="color: #008080;">then</span> <span style="color: #0000FF;">?</span><span style="color: #000000;">9</span><span style="color: #0000FF;">/</span><span style="color: #000000;">0</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
<span style="color: #008080;">if</span> <span style="color: #000000;">raw</span><span style="color: #0000FF;">[</span><span style="color: #000000;">9</span><span style="color: #0000FF;">..</span><span style="color: #000000;">12</span><span style="color: #0000FF;">]!=</span><span style="color: #008000;">"WAVE"</span> <span style="color: #008080;">then</span> <span style="color: #0000FF;">?</span><span style="color: #000000;">9</span><span style="color: #0000FF;">/</span><span style="color: #000000;">0</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
<span style="color: #008080;">if</span> <span style="color: #000000;">raw</span><span style="color: #0000FF;">[</span><span style="color: #000000;">13</span><span style="color: #0000FF;">..</span><span style="color: #000000;">16</span><span style="color: #0000FF;">]!=</span><span style="color: #008000;">"fmt "</span> <span style="color: #008080;">then</span> <span style="color: #0000FF;">?</span><span style="color: #000000;">9</span><span style="color: #0000FF;">/</span><span style="color: #000000;">0</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
<span style="color: #008080;">if</span> <span style="color: #7060A8;">bytes_to_int</span><span style="color: #0000FF;">(</span><span style="color: #000000;">raw</span><span style="color: #0000FF;">[</span><span style="color: #000000;">17</span><span style="color: #0000FF;">..</span><span style="color: #000000;">20</span><span style="color: #0000FF;">])!=</span><span style="color: #000000;">16</span> <span style="color: #008080;">then</span> <span style="color: #0000FF;">?</span><span style="color: #000000;">9</span><span style="color: #0000FF;">/</span><span style="color: #000000;">0</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span> <span style="color: #000080;font-style:italic;">-- 2 bytes per sample</span>
<span style="color: #008080;">if</span> <span style="color: #7060A8;">bytes_to_int</span><span style="color: #0000FF;">(</span><span style="color: #000000;">raw</span><span style="color: #0000FF;">[</span><span style="color: #000000;">21</span><span style="color: #0000FF;">..</span><span style="color: #000000;">22</span><span style="color: #0000FF;">])!=</span><span style="color: #000000;">1</span> <span style="color: #008080;">then</span> <span style="color: #0000FF;">?</span><span style="color: #000000;">9</span><span style="color: #0000FF;">/</span><span style="color: #000000;">0</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span> <span style="color: #000080;font-style:italic;">-- must be PCM</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">channels</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">bytes_to_int</span><span style="color: #0000FF;">(</span><span style="color: #000000;">raw</span><span style="color: #0000FF;">[</span><span style="color: #000000;">23</span><span style="color: #0000FF;">..</span><span style="color: #000000;">24</span><span style="color: #0000FF;">])</span>
<span style="color: #008080;">if</span> <span style="color: #000000;">channels</span><span style="color: #0000FF;">!=</span><span style="color: #000000;">1</span> <span style="color: #008080;">and</span> <span style="color: #000000;">channels</span><span style="color: #0000FF;">!=</span><span style="color: #000000;">2</span> <span style="color: #008080;">then</span> <span style="color: #0000FF;">?</span><span style="color: #000000;">9</span><span style="color: #0000FF;">/</span><span style="color: #000000;">0</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span> <span style="color: #000080;font-style:italic;">-- mono or stereo (else??)</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">bps</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">bytes_to_int</span><span style="color: #0000FF;">(</span><span style="color: #000000;">raw</span><span style="color: #0000FF;">[</span><span style="color: #000000;">35</span><span style="color: #0000FF;">..</span><span style="color: #000000;">36</span><span style="color: #0000FF;">])</span>
<span style="color: #008080;">if</span> <span style="color: #000000;">bps</span><span style="color: #0000FF;">!=</span><span style="color: #000000;">8</span> <span style="color: #008080;">and</span> <span style="color: #000000;">bps</span><span style="color: #0000FF;">!=</span><span style="color: #000000;">16</span> <span style="color: #008080;">then</span> <span style="color: #0000FF;">?</span><span style="color: #000000;">9</span><span style="color: #0000FF;">/</span><span style="color: #000000;">0</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span> <span style="color: #000080;font-style:italic;">-- 8 or 16 bits per sample?</span>
<span style="color: #000000;">bps</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">bps</span><span style="color: #0000FF;">/</span><span style="color: #000000;">8</span><span style="color: #0000FF;">*</span><span style="color: #000000;">channels</span><span style="color: #0000FF;">*</span><span style="color: #000000;">2</span> <span style="color: #000080;font-style:italic;">-- ===> bytes per sample (pair(s)(s))</span>
<span style="color: #008080;">if</span> <span style="color: #000000;">raw</span><span style="color: #0000FF;">[</span><span style="color: #000000;">37</span><span style="color: #0000FF;">..</span><span style="color: #000000;">40</span><span style="color: #0000FF;">]!=</span><span style="color: #008000;">"data"</span> <span style="color: #008080;">then</span> <span style="color: #0000FF;">?</span><span style="color: #000000;">9</span><span style="color: #0000FF;">/</span><span style="color: #000000;">0</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">rawdata</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">bytes_to_int</span><span style="color: #0000FF;">(</span><span style="color: #000000;">raw</span><span style="color: #0000FF;">[</span><span style="color: #000000;">41</span><span style="color: #0000FF;">..</span><span style="color: #000000;">44</span><span style="color: #0000FF;">])</span>
<span style="color: #008080;">if</span> <span style="color: #000000;">rawdata</span><span style="color: #0000FF;">!=</span><span style="color: #000000;">dataLength</span> <span style="color: #008080;">then</span> <span style="color: #0000FF;">?</span><span style="color: #000000;">9</span><span style="color: #0000FF;">/</span><span style="color: #000000;">0</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">bs</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">be</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">crop</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">0</span>
<span style="color: #008080;">for</span> <span style="color: #000000;">bs</span><span style="color: #0000FF;">=</span><span style="color: #000000;">45</span> <span style="color: #008080;">to</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">raw</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">by</span> <span style="color: #000000;">bps</span> <span style="color: #008080;">do</span>
<span style="color: #000080;font-style:italic;">-- some volume threshold...</span>
<span style="color: #008080;">if</span> <span style="color: #7060A8;">sum</span><span style="color: #0000FF;">(</span><span style="color: #000000;">raw</span><span style="color: #0000FF;">[</span><span style="color: #000000;">bs</span><span style="color: #0000FF;">..</span><span style="color: #000000;">bs</span><span style="color: #0000FF;">+</span><span style="color: #000000;">bps</span><span style="color: #0000FF;">-</span><span style="color: #000000;">1</span><span style="color: #0000FF;">])></span><span style="color: #000000;">0</span> <span style="color: #008080;">then</span> <span style="color: #008080;">exit</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span> <span style="color: #000080;font-style:italic;">-- (assumes unsigned)</span>
<span style="color: #000000;">crop</span> <span style="color: #0000FF;">+=</span> <span style="color: #000000;">bps</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
<span style="color: #008080;">for</span> <span style="color: #000000;">be</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">raw</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">to</span> <span style="color: #000000;">bs</span> <span style="color: #008080;">by</span> <span style="color: #0000FF;">-</span><span style="color: #000000;">bps</span> <span style="color: #008080;">do</span>
<span style="color: #008080;">if</span> <span style="color: #7060A8;">sum</span><span style="color: #0000FF;">(</span><span style="color: #000000;">raw</span><span style="color: #0000FF;">[</span><span style="color: #000000;">be</span><span style="color: #0000FF;">-</span><span style="color: #000000;">bps</span><span style="color: #0000FF;">+</span><span style="color: #000000;">1</span><span style="color: #0000FF;">..</span><span style="color: #000000;">be</span><span style="color: #0000FF;">])></span><span style="color: #000000;">0</span> <span style="color: #008080;">then</span> <span style="color: #008080;">exit</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
<span style="color: #000000;">crop</span> <span style="color: #0000FF;">+=</span> <span style="color: #000000;">bps</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
<span style="color: #008080;">if</span> <span style="color: #000000;">crop</span><span style="color: #0000FF;">=</span><span style="color: #000000;">0</span> <span style="color: #008080;">then</span>
<span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"nothing to crop\n"</span><span style="color: #0000FF;">)</span>
<span style="color: #008080;">else</span>
<span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"cropping %d bytes\n"</span><span style="color: #0000FF;">,</span><span style="color: #000000;">crop</span><span style="color: #0000FF;">)</span>
<span style="color: #000000;">rawlen</span> <span style="color: #0000FF;">-=</span> <span style="color: #000000;">crop</span>
<span style="color: #000000;">rawdata</span> <span style="color: #0000FF;">-=</span> <span style="color: #000000;">crop</span>
<span style="color: #000000;">raw</span><span style="color: #0000FF;">[</span><span style="color: #000000;">5</span><span style="color: #0000FF;">..</span><span style="color: #000000;">8</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">int_to_bytes</span><span style="color: #0000FF;">(</span><span style="color: #000000;">rawlen</span><span style="color: #0000FF;">,</span><span style="color: #000000;">4</span><span style="color: #0000FF;">)</span>
<span style="color: #000000;">raw</span><span style="color: #0000FF;">[</span><span style="color: #000000;">41</span><span style="color: #0000FF;">..</span><span style="color: #000000;">44</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">int_to_bytes</span><span style="color: #0000FF;">(</span><span style="color: #000000;">rawdata</span><span style="color: #0000FF;">,</span><span style="color: #000000;">4</span><span style="color: #0000FF;">)</span>
<span style="color: #000000;">raw</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">raw</span><span style="color: #0000FF;">[</span><span style="color: #000000;">1</span><span style="color: #0000FF;">..</span><span style="color: #000000;">be</span><span style="color: #0000FF;">]</span>
<span style="color: #000000;">raw</span><span style="color: #0000FF;">[</span><span style="color: #000000;">46</span><span style="color: #0000FF;">..</span><span style="color: #000000;">bs</span><span style="color: #0000FF;">-</span><span style="color: #000000;">1</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{}</span>
<span style="color: #000000;">fn</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">open</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"notes.wav"</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"wb"</span><span style="color: #0000FF;">)</span>
<span style="color: #7060A8;">puts</span><span style="color: #0000FF;">(</span><span style="color: #000000;">fn</span><span style="color: #0000FF;">,</span><span style="color: #000000;">raw</span><span style="color: #0000FF;">)</span>
<span style="color: #7060A8;">close</span><span style="color: #0000FF;">(</span><span style="color: #000000;">fn</span><span style="color: #0000FF;">)</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
<span style="color: #000080;font-style:italic;">-- without cropping 8s, with 4s</span>
<span style="color: #008080;">if</span> <span style="color: #7060A8;">platform</span><span style="color: #0000FF;">()=</span><span style="color: #004600;">WINDOWS</span> <span style="color: #008080;">then</span>
<span style="color: #000000;">system</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"notes.wav"</span><span style="color: #0000FF;">)</span>
<span style="color: #008080;">elsif</span> <span style="color: #7060A8;">platform</span><span style="color: #0000FF;">()=</span><span style="color: #004600;">LINUX</span> <span style="color: #008080;">then</span>
<span style="color: #000000;">system</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"aplay notes.wav"</span><span style="color: #0000FF;">)</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
<!--</syntaxhighlight>-->
=={{header|Wren}}==
{{trans|Go}}
The ability to call external processes such as ''SoX'' is expected to be added to Wren-cli in the next release. In the meantime, we embed the following Wren script in a C host to complete this task.
<syntaxhighlight lang="wren">/* Waveform_analysis_Top_and_tail.wren */
class C {
foreign static getInput(maxSize)
foreign static sox(args)
foreign static removeFile(name)
}
var sec = "00:00:01"
var name = ""
while (name == "") {
System.write("Enter name of audio file to be trimmed : ")
name = C.getInput(80)
}
var name2 = ""
while (name2 == "") {
System.write("Enter name of output file : ")
name2 = C.getInput(80)
}
var squelch = 0
while (!squelch || squelch < 1 || squelch > 10) {
System.write("Enter squelch level \% max (1 to 10) : ")
squelch = Num.fromString(C.getInput(5))
}
var squelchS = squelch.toString + "\%"
var tmp1 = "tmp1_" + name
var tmp2 = "tmp2_" + name
// Trim audio below squelch level from start and output to tmp1.
var args = [name, tmp1, "silence", "1", sec, squelchS]
C.sox(args.join(" "))
// Reverse tmp1 to tmp2.
args = [tmp1, tmp2, "reverse"]
C.sox(args.join(" "))
// Trim audio below squelch level from tmp2 and output to tmp1.
args = [tmp2, tmp1, "silence", "1", sec, squelchS]
C.sox(args.join(" "))
// Reverse tmp1 to the output file.
args = [tmp1, name2, "reverse"]
C.sox(args.join(" "))
// Remove the temporary files.
C.removeFile(tmp1)
C.removeFile(tmp2)</syntaxhighlight>
<br>
We now embed this in the following C program, compile and run it.
<syntaxhighlight lang="c">/* gcc Waveform_analysis_Top_and_tail.c -o Waveform_analysis_Top_and_tail -lwren -lm */
#include <stdio.h>
#include <stdio_ext.h>
#include <stdlib.h>
#include <string.h>
#include "wren.h"
void C_getInput(WrenVM* vm) {
int maxSize = (int)wrenGetSlotDouble(vm, 1) + 2;
char input[maxSize];
fgets(input, maxSize, stdin);
__fpurge(stdin);
input[strcspn(input, "\n")] = 0;
wrenSetSlotString(vm, 0, (const char*)input);
}
void C_sox(WrenVM* vm) {
const char *args = wrenGetSlotString(vm, 1);
char command[strlen(args) + 4];
strcpy(command, "sox ");
strcat(command, args);
system(command);
}
void C_removeFile(WrenVM* vm) {
const char *name = wrenGetSlotString(vm, 1);
if (remove(name) != 0) perror("Error deleting file.");
}
WrenForeignMethodFn bindForeignMethod(
WrenVM* vm,
const char* module,
const char* className,
bool isStatic,
const char* signature) {
if (strcmp(module, "main") == 0) {
if (strcmp(className, "C") == 0) {
if (isStatic && strcmp(signature, "getInput(_)") == 0) return C_getInput;
if (isStatic && strcmp(signature, "sox(_)") == 0) return C_sox;
if (isStatic && strcmp(signature, "removeFile(_)") == 0) return C_removeFile;
}
}
return NULL;
}
static void writeFn(WrenVM* vm, const char* text) {
printf("%s", text);
}
void errorFn(WrenVM* vm, WrenErrorType errorType, const char* module, const int line, const char* msg) {
switch (errorType) {
case WREN_ERROR_COMPILE:
printf("[%s line %d] [Error] %s\n", module, line, msg);
break;
case WREN_ERROR_STACK_TRACE:
printf("[%s line %d] in %s\n", module, line, msg);
break;
case WREN_ERROR_RUNTIME:
printf("[Runtime Error] %s\n", msg);
break;
}
}
char *readFile(const char *fileName) {
FILE *f = fopen(fileName, "r");
fseek(f, 0, SEEK_END);
long fsize = ftell(f);
rewind(f);
char *script = malloc(fsize + 1);
fread(script, 1, fsize, f);
fclose(f);
script[fsize] = 0;
return script;
}
int main(int argc, char **argv) {
WrenConfiguration config;
wrenInitConfiguration(&config);
config.writeFn = &writeFn;
config.errorFn = &errorFn;
config.bindForeignMethodFn = &bindForeignMethod;
WrenVM* vm = wrenNewVM(&config);
const char* module = "main";
const char* fileName = "Waveform_analysis_Top_and_tail.wren";
char *script = readFile(fileName);
WrenInterpretResult result = wrenInterpret(vm, module, script);
switch (result) {
case WREN_RESULT_COMPILE_ERROR:
printf("Compile Error!\n");
break;
case WREN_RESULT_RUNTIME_ERROR:
printf("Runtime Error!\n");
break;
case WREN_RESULT_SUCCESS:
break;
}
wrenFreeVM(vm);
free(script);
return 0;
}</syntaxhighlight>
{{omit from|AWK}}
| |||