decoder/mpg123: new decoder plugin based on libmpg123

Still missing:
- seeking
- tags
- streaming
- encodings other than MPG123_ENC_SIGNED_16

2 files changed, 214 insertions, 0 deletions

diff --git a/src/decoder/mpg123_decoder_plugin.c b/src/decoder/mpg123_decoder_plugin.c
new file mode 100644
index 000000000..7ffeb1155
--- /dev/null
+++ b/src/decoder/mpg123_decoder_plugin.c
@@ -0,0 +1,210 @@
+/*
+ * Copyright (C) 2003-2009 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 "decoder_api.h"
+
+#include <glib.h>
+
+#include <mpg123.h>
+
+#undef G_LOG_DOMAIN
+#define G_LOG_DOMAIN "mpg123"
+
+static bool
+mpd_mpg123_init(G_GNUC_UNUSED const struct 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,
+		struct audio_format *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;
+	}
+
+	audio_format_init(audio_format, rate, 16, channels);
+	if (!audio_format_valid(audio_format)) {
+		g_warning("invalid audio format");
+		return false;
+	}
+
+	return true;
+}
+
+static void
+mpd_mpg123_file_decode(struct decoder *decoder, const char *path_fs)
+{
+	struct audio_format audio_format;
+	mpg123_handle *handle;
+	int error;
+	off_t num_samples, position;
+	enum decoder_command cmd;
+
+	/* open the file */
+
+	handle = mpg123_new(NULL, &error);
+	if (handle == NULL) {
+		g_warning("mpg123_new() failed: %s",
+			  mpg123_plain_strerror(error));
+		return;
+	}
+
+	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, false,
+			    (float)num_samples /
+			    (float)audio_format.sample_rate);
+
+	/* the decoder main loop */
+
+	do {
+		unsigned char buffer[8192];
+		size_t nbytes;
+
+		position = mpg123_tell(handle);
+
+		/* 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;
+		}
+
+		/* send to MPD */
+
+		cmd = decoder_data(decoder, NULL, buffer, nbytes,
+				   (float)position /
+				   (float)audio_format.sample_rate,
+				   0, NULL);
+
+		/* seeking not yet implemented */
+	} while (cmd == DECODE_COMMAND_NONE);
+
+	/* cleanup */
+
+	mpg123_delete(handle);
+}
+
+static struct tag *
+mpd_mpg123_tag_dup(const char *path_fs)
+{
+	struct audio_format audio_format;
+	mpg123_handle *handle;
+	int error;
+	off_t num_samples;
+	struct tag *tag;
+
+	handle = mpg123_new(NULL, &error);
+	if (handle == NULL) {
+		g_warning("mpg123_new() failed: %s",
+			  mpg123_plain_strerror(error));
+		return NULL;
+	}
+
+	if (!mpd_mpg123_open(handle, path_fs, &audio_format)) {
+		mpg123_delete(handle);
+		return NULL;
+	}
+
+	num_samples = mpg123_length(handle);
+	if (num_samples <= 0) {
+		mpg123_delete(handle);
+		return NULL;
+	}
+
+	tag = tag_new();
+
+	tag->time = num_samples / audio_format.sample_rate;
+
+	/* ID3 tag support not yet implemented */
+
+	mpg123_delete(handle);
+	return tag;
+}
+
+static const char *const mpg123_suffixes[] = {
+	"mp3",
+	NULL
+};
+
+const struct decoder_plugin mpg123_decoder_plugin = {
+	.name = "mpg123",
+	.init = mpd_mpg123_init,
+	.finish = mpd_mpg123_finish,
+	.file_decode = mpd_mpg123_file_decode,
+	/* streaming not yet implemented */
+	.tag_dup = mpd_mpg123_tag_dup,
+	.suffixes = mpg123_suffixes,
+};
diff --git a/src/decoder_list.c b/src/decoder_list.c
index 177ac46e4..d30611e1b 100644
--- a/src/decoder_list.c
+++ b/src/decoder_list.c
@@ -28,6 +28,7 @@
 #include <string.h>
 
 extern const struct decoder_plugin mad_decoder_plugin;
+extern const struct decoder_plugin mpg123_decoder_plugin;
 extern const struct decoder_plugin vorbis_decoder_plugin;
 extern const struct decoder_plugin flac_decoder_plugin;
 extern const struct decoder_plugin oggflac_decoder_plugin;
@@ -48,6 +49,9 @@ static const struct decoder_plugin *const decoder_plugins[] = {
 #ifdef HAVE_MAD
 	&mad_decoder_plugin,
 #endif
+#ifdef HAVE_MPG123
+	&mpg123_decoder_plugin,
+#endif
 #ifdef ENABLE_VORBIS_DECODER
 	&vorbis_decoder_plugin,
 #endif