av/exp/pcm/resample/resample.go

89 lines
2.3 KiB
Go

/*
NAME
resample.go
AUTHOR
Trek Hopton <trek@ausocean.org>
LICENSE
resample.go is Copyright (C) 2018 the Australian Ocean Lab (AusOcean)
It is free software: you can redistribute it and/or modify them
under the terms of the GNU General Public License as published by the
Free Software Foundation, either version 3 of the License, or (at your
option) any later version.
It is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
for more details.
You should have received a copy of the GNU General Public License in gpl.txt.
If not, see [GNU licenses](http://www.gnu.org/licenses).
*/
// resample is a command-line program for resampling a pcm file.
package main
import (
"flag"
"fmt"
"io/ioutil"
"log"
"bitbucket.org/ausocean/av/codec/pcm"
)
// This program accepts an input pcm file and outputs a resampled pcm file.
// Input and output file names, to and from sample rates, channels and sample format can be specified as arguments.
func main() {
var inPath = *flag.String("in", "data.pcm", "file path of input data")
var outPath = *flag.String("out", "resampled.pcm", "file path of output")
var from = *flag.Int("from", 48000, "sample rate of input file")
var to = *flag.Int("to", 8000, "sample rate of output file")
var channels = *flag.Int("ch", 1, "number of channels in input file")
var SFString = *flag.String("sf", "S16_LE", "sample format of input audio, eg. S16_LE")
flag.Parse()
// Read pcm.
inPcm, err := ioutil.ReadFile(inPath)
if err != nil {
log.Fatal(err)
}
fmt.Println("Read", len(inPcm), "bytes from file", inPath)
var sf pcm.SampleFormat
switch SFString {
case "S32_LE":
sf = pcm.S32_LE
case "S16_LE":
sf = pcm.S16_LE
default:
log.Fatalf("Unhandled ALSA format: %v", SFString)
}
format := pcm.ClipFormat{
Channels: channels,
Rate: from,
SFormat: sf,
}
clip := pcm.Clip{
Format: format,
Data: inPcm,
}
// Resample audio.
resampled, err := pcm.Resample(clip, to)
if err != nil {
log.Fatal(err)
}
// Save resampled to file.
err = ioutil.WriteFile(outPath, resampled.Data, 0644)
if err != nil {
log.Fatal(err)
}
fmt.Println("Encoded and wrote", len(resampled.Data), "bytes to file", outPath)
}