1 /* EasyTAG - tag editor for audio files
2 * Copyright (C) 2014 David King <amigadave@amigadave.com>
3 * Copyright (C) 2002 Artur Polaczynski (Ar't) <artii@o2.pl>
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License as published by the Free
7 * Software Foundation; either version 2 of the License, or (at your option)
8 * any later version.
9 *
10 * This program is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
13 * more details.
14 *
15 * You should have received a copy of the GNU General Public License along with
16 * this program; if not, write to the Free Software Foundation, Inc., 51
17 * Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
18 */
19
20 #include <errno.h>
21 #include <glib/gstdio.h>
22 #include <stdio.h>
23 #include <stdlib.h>
24 #include <string.h>
25 #include "info_mac.h"
26 #include "is_tag.h"
27
28 #define MAC_FORMAT_FLAG_8_BIT 1 // 8-bit wave
29 #define MAC_FORMAT_FLAG_CRC 2 // new CRC32 error detection
30 #define MAC_FORMAT_FLAG_HAS_PEAK_LEVEL 4 // u-long Peak_Level after the header
31 #define MAC_FORMAT_FLAG_24_BIT 8 // 24-bit wave
32 #define MAC_FORMAT_FLAG_HAS_SEEK_ELEMENTS 16 // number of seek elements after the peak level
33 #define MAC_FORMAT_FLAG_CREATE_WAV_HEADER 32 // wave header not stored
34
35 #define MAC_FORMAT_HEADER_LENGTH 16
36
37 struct macHeader {
38 char id[4]; // should equal 'MAC '
39 unsigned short ver; // version number * 1000 (3.81 = 3810)
40 unsigned short compLevel; // the compression level
41 unsigned short formatFlags; // any format flags (for future use)
42 unsigned short channels; // the number of channels (1 or 2)
43 unsigned long sampleRate; // the sample rate (typically 44100)
44 unsigned long headerBytesWAV; // the bytes after the MAC header that compose the WAV header
45 unsigned long terminatingBytesWAV; // the bytes after that raw data (for extended info)
46 unsigned long totalFrames; // the number of frames in the file
47 unsigned long finalFrameBlocks; // the number of samples in the final frame
48 unsigned long peakLevel;
49 unsigned short seekElements;
50 };
51
52
53 // local prototypes
54 static int
55 monkey_samples_per_frame(unsigned int versionid, unsigned int compressionlevel);
56 static const char *
57 monkey_stringify(unsigned int profile);
58
59 static const char *
monkey_stringify(unsigned int profile)60 monkey_stringify(unsigned int profile)
61 {
62 static const char na[] = "unknown";
63 static const char *Names[] = {
64 na, "Fast", "Normal", "High", "Extra-High", "Insane"
65 };
66 unsigned int profile2 = profile/1000;
67
68 return (profile2 >= sizeof (Names) / sizeof (*Names)) ? na : Names[(profile2)];
69 }
70
71
72 static int
monkey_samples_per_frame(unsigned int versionid,unsigned int compressionlevel)73 monkey_samples_per_frame(unsigned int versionid, unsigned int compressionlevel)
74 {
75 if (versionid >= 3950) {
76 return 294912; // 73728 * 4
77 } else if (versionid >= 3900) {
78 return 73728;
79 } else if ((versionid >= 3800) && (compressionlevel == COMPRESSION_LEVEL_EXTRA_HIGH)) {
80 return 73728;
81 } else {
82 return 9216;
83 }
84 }
85
86 /*
87 * info_mac_read:
88 * @file: file from which to read a header
89 * @stream_info: stream information to fill
90 * @error: a #GError, or NULL
91 *
92 * Read the header information from a Monkey's Audio file.
93 *
94 * Returns: %TRUE on success, or %FALSE and with @error set on failure
95 */
96 gboolean
info_mac_read(GFile * file,StreamInfoMac * stream_info,GError ** error)97 info_mac_read (GFile *file,
98 StreamInfoMac *stream_info,
99 GError **error)
100 {
101 GFileInfo *info;
102 GFileInputStream *istream;
103 guint8 header_buffer[MAC_FORMAT_HEADER_LENGTH];
104 gsize bytes_read;
105 gsize size_id3;
106 struct macHeader *header;
107
108 g_return_val_if_fail (error == NULL || *error == NULL, FALSE);
109
110 info = g_file_query_info (file, G_FILE_ATTRIBUTE_STANDARD_SIZE,
111 G_FILE_QUERY_INFO_NONE, NULL, error);
112
113 if (!info)
114 {
115 return FALSE;
116 }
117
118 stream_info->FileSize = g_file_info_get_size (info);
119 g_object_unref (info);
120
121 istream = g_file_read (file, NULL, error);
122
123 if (!istream)
124 {
125 return FALSE;
126 }
127
128 /* FIXME: is_id3v2() should accept an istream or a GFile. */
129 {
130 gchar *path;
131 FILE *fp;
132
133 path = g_file_get_path (file);
134 fp = g_fopen (path, "rb");
135
136 if (!fp)
137 {
138 /* TODO: Add specific error domain and message. */
139 g_set_error (error, G_FILE_ERROR, G_FILE_ERROR_INVAL, "%s",
140 g_strerror (EINVAL));
141 g_free (path);
142 return FALSE;
143 }
144
145 size_id3 = is_id3v2 (fp);
146 fclose (fp);
147 g_free (path);
148 }
149
150 if (!g_seekable_seek (G_SEEKABLE (istream), size_id3, G_SEEK_SET, NULL,
151 error))
152 {
153 return FALSE;
154 }
155
156 if (!g_input_stream_read_all (G_INPUT_STREAM (istream), header_buffer,
157 MAC_FORMAT_HEADER_LENGTH, &bytes_read, NULL,
158 error))
159 {
160 g_debug ("Only %" G_GSIZE_FORMAT " bytes out of 16 bytes of data were "
161 "read", bytes_read);
162 return FALSE;
163 }
164
165 if (memcmp (header_buffer, "MAC", 3) != 0)
166 {
167 /* TODO: Add specific error domain and message. */
168 g_set_error (error, G_FILE_ERROR, G_FILE_ERROR_INVAL, "%s",
169 g_strerror (EINVAL));
170 return FALSE; // no monkeyAudio file
171 }
172
173 header = (struct macHeader *) header_buffer;
174
175 stream_info->Version = stream_info->EncoderVersion = header->ver;
176 stream_info->Channels = header->channels;
177 stream_info->SampleFreq = header->sampleRate;
178 stream_info->Flags = header->formatFlags;
179 stream_info->SamplesPerFrame = monkey_samples_per_frame(header->ver, header->compLevel);
180 stream_info->BitsPerSample = (header->formatFlags & MAC_FORMAT_FLAG_8_BIT)
181 ? 8 : ((header->formatFlags & MAC_FORMAT_FLAG_24_BIT) ? 24 : 16);
182
183 stream_info->PeakLevel = header->peakLevel;
184 // Info->PeakRatio = Info->PakLevel / pow(2, Info->bitsPerSample - 1);
185 stream_info->Frames = header->totalFrames;
186 stream_info->Samples = (stream_info->Frames - 1)
187 * stream_info->SamplesPerFrame
188 + header->finalFrameBlocks;
189
190 stream_info->Duration = stream_info -> SampleFreq > 0 ?
191 ((float)stream_info->Samples
192 / stream_info->SampleFreq) * 1000 : 0;
193
194 stream_info->Compresion = header->compLevel;
195 stream_info->CompresionName = monkey_stringify (stream_info->Compresion);
196
197 stream_info->UncompresedSize = stream_info->Samples
198 * stream_info->Channels
199 * (stream_info->BitsPerSample / 8);
200
201 stream_info->CompresionRatio = (stream_info->UncompresedSize
202 + header->headerBytesWAV) > 0
203 ? stream_info->FileSize
204 / (float) (stream_info->UncompresedSize
205 + header->headerBytesWAV) : 0.;
206
207 stream_info->Bitrate = stream_info->Duration > 0
208 ? (((stream_info->Samples * stream_info->Channels
209 * stream_info->BitsPerSample)
210 / (float) stream_info->Duration)
211 * stream_info->CompresionRatio) * 1000 : 0;
212
213 stream_info->PeakRatio = stream_info->ByteLength = 0;
214
215 return TRUE;
216 }
217