apps/plugins/vbrfix.c

   1 /***************************************************************************
   2  *             __________               __   ___.
   3  *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   4  *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   5  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   6  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7  *                     \/            \/     \/    \/            \/
   8  * $Id$
   9  *
  10  * Copyright (C) 2004 Linus Nielsen Feltzing
  11  *
  12  * This program is free software; you can redistribute it and/or
  13  * modify it under the terms of the GNU General Public License
  14  * as published by the Free Software Foundation; either version 2
  15  * of the License, or (at your option) any later version.
  16  *
  17  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  18  * KIND, either express or implied.
  19  *
  20  ****************************************************************************/
  21 #include "plugin.h"
  22
  23 PLUGIN_HEADER
  24
  25 static char   *audiobuf;
  26 static size_t audiobuflen;
  27 unsigned char xingbuf[1500];
  28 char tmpname[MAX_PATH];
  29
  30 static void xingupdate(int percent)
  31 {
  32     char buf[32];
  33
  34     rb->snprintf(buf, 32, "%d%%", percent);
  35     rb->lcd_puts(0, 1, buf);
  36     rb->lcd_update();
  37 }
  38
  39 static int insert_data_in_file(const char *fname, int fpos, char *buf, int num_bytes)
  40 {
  41     int readlen;
  42     int rc;
  43     int orig_fd, fd;
  44
  45     rb->snprintf(tmpname, MAX_PATH, "%s.tmp", fname);
  46
  47     orig_fd = rb->open(fname, O_RDONLY);
  48     if(orig_fd < 0) {
  49         return 10*orig_fd - 1;
  50     }
  51
  52     fd = rb->creat(tmpname, 0666);
  53     if(fd < 0) {
  54         rb->close(orig_fd);
  55         return 10*fd - 2;
  56     }
  57
  58     /* First, copy the initial portion (the ID3 tag) */
  59     if(fpos) {
  60         readlen = rb->read(orig_fd, audiobuf, fpos);
  61         if(readlen < 0) {
  62             rb->close(fd);
  63             rb->close(orig_fd);
  64             return 10*readlen - 3;
  65         }
  66
  67         rc = rb->write(fd, audiobuf, readlen);
  68         if(rc < 0) {
  69             rb->close(fd);
  70             rb->close(orig_fd);
  71             return 10*rc - 4;
  72         }
  73     }
  74
  75     /* Now insert the data into the file */
  76     rc = rb->write(fd, buf, num_bytes);
  77     if(rc < 0) {
  78         rb->close(orig_fd);
  79         rb->close(fd);
  80         return 10*rc - 5;
  81     }
  82
  83     /* Copy the file */
  84     do {
  85         readlen = rb->read(orig_fd, audiobuf, audiobuflen);
  86         if(readlen < 0) {
  87             rb->close(fd);
  88             rb->close(orig_fd);
  89             return 10*readlen - 7;
  90         }
  91
  92         rc = rb->write(fd, audiobuf, readlen);
  93         if(rc < 0) {
  94             rb->close(fd);
  95             rb->close(orig_fd);
  96             return 10*rc - 8;
  97         }
  98     } while(readlen > 0);
  99
 100     rb->close(fd);
 101     rb->close(orig_fd);
 102
 103     /* Remove the old file */
 104     rc = rb->remove(fname);
 105     if(rc < 0) {
 106         return 10*rc - 9;
 107     }
 108
 109     /* Replace the old file with the new */
 110     rc = rb->rename(tmpname, fname);
 111     if(rc < 0) {
 112         return 10*rc - 9;
 113     }
 114
 115     return 0;
 116 }
 117
 118 static void fileerror(int rc)
 119 {
 120     rb->splashf(HZ*2, "File error: %d", rc);
 121 }
 122
 123 static const unsigned char empty_id3_header[] =
 124 {
 125     'I', 'D', '3', 0x04, 0x00, 0x00,
 126     0x00, 0x00, 0x1f, 0x76 /* Size is 4096 minus 10 bytes for the header */
 127 };
 128
 129 static bool vbr_fix(const char *selected_file)
 130 {
 131     struct mp3entry entry;
 132     int fd;
 133     int rc;
 134     int flen;
 135     int num_frames;
 136     int numbytes;
 137     int framelen;
 138     int unused_space;
 139
 140     rb->lcd_clear_display();
 141     rb->lcd_puts_scroll(0, 0, selected_file);
 142     rb->lcd_update();
 143
 144     xingupdate(0);
 145
 146     rc = rb->mp3info(&entry, selected_file);
 147     if(rc < 0) {
 148         fileerror(rc);
 149         return true;
 150     }
 151
 152     fd = rb->open(selected_file, O_RDWR);
 153     if(fd < 0) {
 154         fileerror(fd);
 155         return true;
 156     }
 157
 158     flen = rb->lseek(fd, 0, SEEK_END);
 159
 160     xingupdate(0);
 161
 162     num_frames = rb->count_mp3_frames(fd, entry.first_frame_offset,
 163                                       flen, xingupdate);
 164
 165     if(num_frames) {
 166         /* Note: We don't need to pass a template header because it will be
 167            taken from the mpeg stream */
 168         framelen = rb->create_xing_header(fd, entry.first_frame_offset,
 169                                           flen, xingbuf, num_frames, 0,
 170                                           0, xingupdate, true);
 171
 172         /* Try to fit the Xing header first in the stream. Replace the existing
 173            VBR header if there is one, else see if there is room between the
 174            ID3 tag and the first MP3 frame. */
 175         if(entry.first_frame_offset - entry.id3v2len >=
 176            (unsigned int)framelen) {
 177             DEBUGF("Using existing space between ID3 and first frame\n");
 178
 179             /* Seek to the beginning of the unused space */
 180             rc = rb->lseek(fd, entry.id3v2len, SEEK_SET);
 181             if(rc < 0) {
 182                 rb->close(fd);
 183                 fileerror(rc);
 184                 return true;
 185             }
 186
 187             unused_space =
 188                 entry.first_frame_offset - entry.id3v2len - framelen;
 189
 190             /* Fill the unused space with 0's (using the MP3 buffer)
 191                and write it to the file */
 192             if(unused_space)
 193             {
 194                 rb->memset(audiobuf, 0, unused_space);
 195                 rc = rb->write(fd, audiobuf, unused_space);
 196                 if(rc < 0) {
 197                     rb->close(fd);
 198                     fileerror(rc);
 199                     return true;
 200                 }
 201             }
 202
 203             /* Then write the Xing header */
 204             rc = rb->write(fd, xingbuf, framelen);
 205             if(rc < 0) {
 206                 rb->close(fd);
 207                 fileerror(rc);
 208                 return true;
 209             }
 210
 211             rb->close(fd);
 212         } else {
 213             /* If not, insert some space. If there is an ID3 tag in the
 214                file we only insert just enough to squeeze the Xing header
 215                in. If not, we insert an additional empty ID3 tag of 4K. */
 216
 217             rb->close(fd);
 218
 219             /* Nasty trick alert! The insert_data_in_file() function
 220                uses the MP3 buffer when copying the data. We assume
 221                that the ID3 tag isn't longer than 1MB so the xing
 222                buffer won't be overwritten. */
 223
 224             if(entry.first_frame_offset) {
 225                 DEBUGF("Inserting %d bytes\n", framelen);
 226                 numbytes = framelen;
 227             } else {
 228                 DEBUGF("Inserting 4096+%d bytes\n", framelen);
 229                 numbytes = 4096 + framelen;
 230
 231                 rb->memset(audiobuf + 0x100000, 0, numbytes);
 232
 233                 /* Insert the ID3 header */
 234                 rb->memcpy(audiobuf + 0x100000, empty_id3_header,
 235                            sizeof(empty_id3_header));
 236             }
 237
 238             /* Copy the Xing header */
 239             rb->memcpy(audiobuf + 0x100000 + numbytes - framelen,
 240                        xingbuf, framelen);
 241
 242             rc = insert_data_in_file(selected_file,
 243                                      entry.first_frame_offset,
 244                                      audiobuf + 0x100000, numbytes);
 245
 246             if(rc < 0) {
 247                 fileerror(rc);
 248                 return true;
 249             }
 250         }
 251
 252         xingupdate(100);
 253     }
 254     else
 255     {
 256         /* Not a VBR file */
 257         DEBUGF("Not a VBR file\n");
 258         rb->splash(HZ*2, "Not a VBR file");
 259     }
 260
 261     return false;
 262 }
 263
 264 enum plugin_status plugin_start(const void *parameter)
 265 {
 266
 267     if (!parameter)
 268         return PLUGIN_ERROR;
 269
 270     audiobuf = rb->plugin_get_audio_buffer(&audiobuflen);
 271
 272 #ifdef HAVE_ADJUSTABLE_CPU_FREQ
 273     rb->cpu_boost(true);
 274 #endif
 275
 276     vbr_fix(parameter);
 277
 278 #ifdef HAVE_ADJUSTABLE_CPU_FREQ
 279     rb->cpu_boost(false);
 280 #endif
 281     return PLUGIN_OK;
 282 }