2 * Sonitus - ResampleFilter.java - Copyright © 2013 David Roden
4 * This program is free software: you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation, either version 3 of the License, or
7 * (at your option) any later version.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with this program. If not, see <http://www.gnu.org/licenses/>.
18 package net.pterodactylus.sonitus.data.filter;
20 import static com.google.common.base.Preconditions.checkArgument;
21 import static com.google.common.base.Preconditions.checkNotNull;
23 import java.io.IOException;
25 import net.pterodactylus.sonitus.data.Metadata;
27 import com.google.common.collect.ImmutableList;
30 * {@link net.pterodactylus.sonitus.data.Filter} implementation that uses {@code
31 * sox} to resample a PCM-encoded source.
33 * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
35 public class SoxResampleFilter extends ExternalFilter {
37 /** The location of the binary. */
38 private final String binary;
40 /** The final sampling rate. */
41 private final int rate;
44 * Creates a new resample filter.
47 * The location of the binary
50 public SoxResampleFilter(String binary, int rate) {
51 super(String.format("Resample to %s kHz", rate / 1000.0));
61 public Metadata metadata() {
62 return super.metadata().frequency(rate);
66 public void open(Metadata metadata) throws IOException {
67 checkNotNull(metadata, "metadata must not be null");
68 checkArgument(metadata.encoding().equalsIgnoreCase("PCM"), "source must be PCM-encoded");
74 // EXTERNALFILTER METHODS
78 protected String binary(Metadata metadata) {
83 protected Iterable<String> parameters(Metadata metadata) {
84 ImmutableList.Builder<String> parameters = ImmutableList.builder();
86 parameters.add("--bits").add("16");
87 parameters.add("--channels").add(String.valueOf(metadata.channels()));
88 parameters.add("--encoding").add("signed-integer");
89 parameters.add("--rate").add(String.valueOf(metadata.frequency()));
90 parameters.add("--type").add("raw");
91 parameters.add("--endian").add("little");
93 /* the output file. */
94 parameters.add("--bits").add("16");
95 parameters.add("--channels").add(String.valueOf(metadata.channels()));
96 parameters.add("--encoding").add("signed-integer");
97 parameters.add("--type").add("raw");
98 parameters.add("--endian").add("little");
101 parameters.add("rate").add("-h").add(String.valueOf(rate));
102 return parameters.build();