vgritsenko 01/12/13 10:40:55 Added: src/org/apache/cocoon/generation MP3DirectoryGenerator.java Log: I wonder why i'm first to implement this... VBR guru (if any) might want to check how bitrate is calculated for variable-bitrate files. Revision Changes Path 1.1 xml-cocoon2/src/org/apache/cocoon/generation/MP3DirectoryGenerator.java Index: MP3DirectoryGenerator.java =================================================================== /***************************************************************************** * Copyright (C) The Apache Software Foundation. All rights reserved. * * ------------------------------------------------------------------------- * * This software is published under the terms of the Apache Software License * * version 1.1, a copy of which has been included with this distribution in * * the LICENSE file. * *****************************************************************************/ package org.apache.cocoon.generation; import java.io.File; import java.io.FileInputStream; import java.io.IOException; import java.io.RandomAccessFile; import org.xml.sax.SAXException; /** * An extension of DirectoryGenerators that adds extra attributes for MP3 * files. * <p> * Following extra attributes added to valid MP3 files: * <blockquote> * <dl> * <dt> frequency * <dd> the frequency of the MP3 file in KHz (most common: 44.1) * <dt> bitrate * <dd> the bitrate of the MP3 file in Kbit, from 8 to 448. * <dt> mode * <dd> the mode of the MP3 file, one of the following: Stereo, Joint stereo, * Dual channel, Single channel. * <dt> variable-rate (optional) * <dd> value is "yes" if VBR header is detected * <dt> title, artitst, album, year, comment, track, genre (all optional) * <dd> values obtained from MP3 ID3 tag * </dl> * </blockquote> * * @author <a href="mailto:[EMAIL PROTECTED]";>Vadim Gritsenko</a> * @version CVS $Revision: 1.1 $ $Date: 2001/12/13 18:40:55 $ */ public class MP3DirectoryGenerator extends DirectoryGenerator { // MP3 Constants private static final int VERSION_MPEG1 = 3; private static final int VERSION_MPEG2 = 2; private static final int MODE_DUAL_CHANNEL = 2; private static final int MODE_JOINT_STEREO = 1; private static final int MODE_SINGLE_CHANNEL = 3; private static final int MODE_STEREO = 0; private static final int BITRATE_441 = 0; private static final int BITRATE_48 = 1; private static final int BITRATE_32 = 2; private static final int VBR_FRAMES_FLAG = 1; private static final int VBR_BYTES_FLAG = 2; private static final int VBR_TOC_FLAG = 4; private static final int VBR_SCALE_FLAG = 8; // Attributes protected static String MP3_FREQUENCY_ATTR_NAME = "frequency"; protected static String MP3_BITRATE_ATTR_NAME = "bitrate"; protected static String MP3_MODE_ATTR_NAME = "mode"; protected static String MP3_VBR_ATTR_NAME = "variable-rate"; protected static String MP3_TITLE_ATTR_NAME = "title"; protected static String MP3_ARTITST_ATTR_NAME = "artist"; protected static String MP3_ALBUM_ATTR_NAME = "album"; protected static String MP3_YEAR_ATTR_NAME = "year"; protected static String MP3_COMMENT_ATTR_NAME = "comment"; protected static String MP3_TRACK_ATTR_NAME = "track"; protected static String MP3_GENRE_ATTR_NAME = "genre"; /** * Extends the <code>setNodeAttributes</code> method from the * <code>DirectoryGenerator</code> by adding MP3 tag attributes * if the path is a MP3 file with valid tag. */ protected void setNodeAttributes(File path) throws SAXException { super.setNodeAttributes(path); if (path.isDirectory()) { return; } RandomAccessFile in = null; try { in = new RandomAccessFile(path, "r"); setID3HeaderAttributes(in); setID3TagAttributes(in); } catch (IOException e) { getLogger().debug("Could not set attributes for " + path, e); } finally { if(in != null) try{ in.close(); }catch(IOException ignored){} } } /** * Read ID3 Tag */ private void setID3TagAttributes(RandomAccessFile in) throws IOException { String s; // TAG takes 128 bytes if (in.length() < 128) return; in.seek(in.length() - 128); byte [] buf = new byte[128]; // Read TAG if (in.read(buf,0, 128) != 128) return; // Check TAG presence if(buf[0] != 'T' || buf[1] != 'A' || buf[2] != 'G') return; s = new String(buf, 3, 30).trim(); if(s.length() > 0) attributes.addAttribute("", MP3_TITLE_ATTR_NAME, MP3_TITLE_ATTR_NAME, "CDATA", s); s = new String(buf, 33,30).trim(); if(s.length() > 0) attributes.addAttribute("", MP3_ARTITST_ATTR_NAME, MP3_ARTITST_ATTR_NAME, "CDATA", s); s = new String(buf, 63,30).trim(); if(s.length() > 0) attributes.addAttribute("", MP3_ALBUM_ATTR_NAME, MP3_ALBUM_ATTR_NAME, "CDATA", s); s = new String(buf, 93, 4).trim(); if(s.length() > 0) attributes.addAttribute("", MP3_YEAR_ATTR_NAME, MP3_YEAR_ATTR_NAME, "CDATA", s); s = new String(buf, 97,29).trim(); if(s.length() > 0) attributes.addAttribute("", MP3_COMMENT_ATTR_NAME, MP3_COMMENT_ATTR_NAME, "CDATA", s); if(buf[126] > 0) attributes.addAttribute("", MP3_TRACK_ATTR_NAME, MP3_TRACK_ATTR_NAME, "CDATA", Byte.toString(buf[126])); if(buf[127] > 0) attributes.addAttribute("", MP3_GENRE_ATTR_NAME, MP3_GENRE_ATTR_NAME, "CDATA", Byte.toString(buf[127])); } private void setID3HeaderAttributes(RandomAccessFile in) throws IOException { byte[] buffer = new byte[4]; // http://floach.pimpin.net/grd/mp3info/frmheader/index.html if (in.read(buffer, 0, 3) != 3) { return; } int header = ((buffer[0] << 16) & 0x00FF0000) | ((buffer[1] << 8) & 0x0000FF00) | ((buffer[2] << 0) & 0x000000FF); do { header <<= 8; if (in.read(buffer, 3, 1) != 1) { return; } header |= (buffer[3] & 0x000000FF); } while (!isSyncMark(header)); int version = (header >>> 19) & 3; int layer = 4 - (header >>> 17) & 3; int protection = (header >>> 16) & 1; int bitrate = (header >>> 12) & 0xF; int frequency = (header >>> 10) & 3; // Value 3 is reserved if (frequency == 3) return; int padding = (header >>> 9) & 1; int mode = ((header >>> 6) & 3); attributes.addAttribute("", MP3_FREQUENCY_ATTR_NAME, MP3_FREQUENCY_ATTR_NAME, "CDATA", frequencyString(version, frequency)); attributes.addAttribute("", MP3_MODE_ATTR_NAME, MP3_MODE_ATTR_NAME, "CDATA", mode(mode)); int frames = getVBRHeaderFrames(in, version, mode); if (frames != -1) { // get average frame size by deviding fileSize by the number of frames float medFrameSize = (float)in.length() / frames; // This does not work properly: (version == VERSION_MPEG1? 12000.0:144000.0) bitrate = (int)(medFrameSize * frequency(version, frequency) / 144000.0); attributes.addAttribute("", MP3_BITRATE_ATTR_NAME, MP3_BITRATE_ATTR_NAME, "CDATA", Integer.toString(bitrate)); } else { attributes.addAttribute("", MP3_BITRATE_ATTR_NAME, MP3_BITRATE_ATTR_NAME, "CDATA", bitrate(version, layer, bitrate)); } } private static boolean isSyncMark(int header) { boolean sync = ((header & 0xFFF00000) == 0xFFF00000); // filter out invalid sample rate if (sync) sync = ((header >>> 10) & 3) != 3; // filter out invalid layer if (sync) sync = ((header >>> 17) & 3) != 0; // filter out invalid version if (sync) sync = ((header >>> 19) & 3) != 1; return sync; } private int getVBRHeaderFrames(RandomAccessFile in, int version, int mode) throws IOException { byte[] buffer = new byte[12]; // Try to detect VBR header int skip; if (version == VERSION_MPEG1) { if (mode == MODE_SINGLE_CHANNEL) skip = 17; else skip = 32; } else { // mpeg version 2 or 2.5 if (mode == MODE_SINGLE_CHANNEL) skip = 9; else skip = 17; } while (skip > 0) { if (in.read() == -1) return -1; skip --; } if (in.read(buffer, 0, 12) != 12) { return -1; } if (buffer[0] != 'X' || buffer[1] != 'i' || buffer[2] != 'n' || buffer[3] != 'g'){ return -1; } attributes.addAttribute("", MP3_VBR_ATTR_NAME, MP3_VBR_ATTR_NAME, "CDATA", "yes"); int flags = ((buffer[4] & 0xFF) << 24) | ((buffer[5] & 0xFF) << 16) | ((buffer[6] & 0xFF) << 8) | (buffer[7] & 0xFF); if ((flags & VBR_FRAMES_FLAG) == VBR_FRAMES_FLAG){ int frames = ((buffer[ 8] & 0xFF) << 24) | ((buffer[ 9] & 0xFF) << 16) | ((buffer[10] & 0xFF) << 8) | (buffer[11] & 0xFF); return frames; } else { return -1; } } // version - layer - bitrate index private static final String bitrates[][][] = { { // MPEG2 - layer 1 {"free format", "32", "48", "56", "64", "80", "96", "112", "128", "144", "160", "176", "192", "224", "256", "forbidden"}, // MPEG2 - layer 2 {"free format", "8", "16", "24", "32", "40", "48", "56", "64", "80", "96", "112", "128", "144", "160", "forbidden"}, // MPEG2 - layer 3 {"free format", "8", "16", "24", "32", "40", "48", "56", "64", "80", "96", "112", "128", "144", "160", "forbidden"} }, { // MPEG1 - layer 1 {"free format", "32", "64", "96", "128", "160", "192", "224", "256", "288", "320", "352", "384", "416", "448", "forbidden"}, // MPEG1 - layer 2 {"free format", "32", "48", "56", "64", "80", "96", "112", "128", "160", "192", "224", "256", "320", "384", "forbidden"}, // MPEG1 - layer 3 {"free format", "32", "40", "48", "56", "64", "80" , "96", "112", "128", "160", "192", "224", "256", "320", "forbidden"} } }; private static String bitrate(int version, int layer, int bitrate_index) { return bitrates[version & 1][layer - 1][bitrate_index]; } private static String mode(int mode) { switch(mode) { case MODE_STEREO: return "Stereo"; case MODE_JOINT_STEREO: return "Joint stereo"; case MODE_DUAL_CHANNEL: return "Dual channel"; case MODE_SINGLE_CHANNEL: return "Single channel"; } return null; } private static final int frequencies[][] = { {32000, 16000, 8000}, //MPEG 2.5 { 0, 0, 0}, //reserved {22050, 24000, 16000}, //MPEG 2 {44100, 48000, 32000} //MPEG 1 }; private static int frequency(int version, int frequency) { return frequencies[version][frequency]; } private static String frequencyString(int version, int frequency) { return String.valueOf((float)frequency(version, frequency)/1000); } }
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