aboutsummaryrefslogtreecommitdiffstats
path: root/src/decoder/Mpg123DecoderPlugin.cxx
blob: a44fc12410fb8b07babab4d2481c3f6f35eefdf2 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
/*
 * Copyright (C) 2003-2013 The Music Player Daemon Project
 * http://www.musicpd.org
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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 along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#include "config.h" /* must be first for large file support */
#include "Mpg123DecoderPlugin.hxx"
#include "DecoderAPI.hxx"
#include "CheckAudioFormat.hxx"
#include "tag/TagHandler.hxx"
#include "util/Error.hxx"

#include <glib.h>

#include <mpg123.h>
#include <stdio.h>

#undef G_LOG_DOMAIN
#define G_LOG_DOMAIN "mpg123"

static bool
mpd_mpg123_init(gcc_unused const config_param &param)
{
	mpg123_init();

	return true;
}

static void
mpd_mpg123_finish(void)
{
	mpg123_exit();
}

/**
 * Opens a file with an existing #mpg123_handle.
 *
 * @param handle a handle which was created before; on error, this
 * function will not free it
 * @param audio_format this parameter is filled after successful
 * return
 * @return true on success
 */
static bool
mpd_mpg123_open(mpg123_handle *handle, const char *path_fs,
		AudioFormat &audio_format)
{
	char *path_dup;
	int error;
	int channels, encoding;
	long rate;

	/* mpg123_open() wants a writable string :-( */
	path_dup = g_strdup(path_fs);

	error = mpg123_open(handle, path_dup);
	g_free(path_dup);
	if (error != MPG123_OK) {
		g_warning("libmpg123 failed to open %s: %s",
			  path_fs, mpg123_plain_strerror(error));
		return false;
	}

	/* obtain the audio format */

	error = mpg123_getformat(handle, &rate, &channels, &encoding);
	if (error != MPG123_OK) {
		g_warning("mpg123_getformat() failed: %s",
			  mpg123_plain_strerror(error));
		return false;
	}

	if (encoding != MPG123_ENC_SIGNED_16) {
		/* other formats not yet implemented */
		g_warning("expected MPG123_ENC_SIGNED_16, got %d", encoding);
		return false;
	}

	Error error2;
	if (!audio_format_init_checked(audio_format, rate, SampleFormat::S16,
				       channels, error2)) {
		g_warning("%s", error2.GetMessage());
		return false;
	}

	return true;
}

static void
mpd_mpg123_file_decode(struct decoder *decoder, const char *path_fs)
{
	mpg123_handle *handle;
	int error;
	off_t num_samples;
	enum decoder_command cmd;
	struct mpg123_frameinfo info;

	/* open the file */

	handle = mpg123_new(nullptr, &error);
	if (handle == nullptr) {
		g_warning("mpg123_new() failed: %s",
			  mpg123_plain_strerror(error));
		return;
	}

	AudioFormat audio_format;
	if (!mpd_mpg123_open(handle, path_fs, audio_format)) {
		mpg123_delete(handle);
		return;
	}

	num_samples = mpg123_length(handle);

	/* tell MPD core we're ready */

	decoder_initialized(decoder, audio_format, true,
			    (float)num_samples /
			    (float)audio_format.sample_rate);

	if (mpg123_info(handle, &info) != MPG123_OK) {
		info.vbr = MPG123_CBR;
		info.bitrate = 0;
	}

	switch (info.vbr) {
	case MPG123_ABR:
		info.bitrate = info.abr_rate;
		break;
	case MPG123_CBR:
		break;
	default:
		info.bitrate = 0;
	}

	/* the decoder main loop */

	do {
		unsigned char buffer[8192];
		size_t nbytes;

		/* decode */

		error = mpg123_read(handle, buffer, sizeof(buffer), &nbytes);
		if (error != MPG123_OK) {
			if (error != MPG123_DONE)
				g_warning("mpg123_read() failed: %s",
					  mpg123_plain_strerror(error));
			break;
		}

		/* update bitrate for ABR/VBR */
		if (info.vbr != MPG123_CBR) {
			/* FIXME: maybe skip, as too expensive? */
			/* FIXME: maybe, (info.vbr == MPG123_VBR) ? */
			if (mpg123_info (handle, &info) != MPG123_OK)
				info.bitrate = 0;
		}

		/* send to MPD */

		cmd = decoder_data(decoder, nullptr, buffer, nbytes, info.bitrate);

		if (cmd == DECODE_COMMAND_SEEK) {
			off_t c = decoder_seek_where(decoder)*audio_format.sample_rate;
			c = mpg123_seek(handle, c, SEEK_SET);
			if (c < 0)
				decoder_seek_error(decoder);
			else {
				decoder_command_finished(decoder);
				decoder_timestamp(decoder, c/(double)audio_format.sample_rate);
			}

			cmd = DECODE_COMMAND_NONE;
		}
	} while (cmd == DECODE_COMMAND_NONE);

	/* cleanup */

	mpg123_delete(handle);
}

static bool
mpd_mpg123_scan_file(const char *path_fs,
		     const struct tag_handler *handler, void *handler_ctx)
{
	mpg123_handle *handle;
	int error;
	off_t num_samples;

	handle = mpg123_new(nullptr, &error);
	if (handle == nullptr) {
		g_warning("mpg123_new() failed: %s",
			  mpg123_plain_strerror(error));
		return false;
	}

	AudioFormat audio_format;
	if (!mpd_mpg123_open(handle, path_fs, audio_format)) {
		mpg123_delete(handle);
		return false;
	}

	num_samples = mpg123_length(handle);
	if (num_samples <= 0) {
		mpg123_delete(handle);
		return false;
	}

	/* ID3 tag support not yet implemented */

	mpg123_delete(handle);

	tag_handler_invoke_duration(handler, handler_ctx,
				    num_samples / audio_format.sample_rate);
	return true;
}

static const char *const mpg123_suffixes[] = {
	"mp3",
	nullptr
};

const struct decoder_plugin mpg123_decoder_plugin = {
	"mpg123",
	mpd_mpg123_init,
	mpd_mpg123_finish,
	/* streaming not yet implemented */
	nullptr,
	mpd_mpg123_file_decode,
	mpd_mpg123_scan_file,
	nullptr,
	nullptr,
	mpg123_suffixes,
	nullptr,
};