decoder/mpg123: convert to C++

1 files changed, 250 insertions, 0 deletions

diff --git a/src/decoder/Mpg123DecoderPlugin.cxx b/src/decoder/Mpg123DecoderPlugin.cxx
new file mode 100644
index 000000000..f43aa5dea
--- /dev/null
+++ b/src/decoder/Mpg123DecoderPlugin.cxx
@@ -0,0 +1,250 @@
+/*
+ * 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 "decoder_api.h"
+#include "audio_check.h"
+#include "tag_handler.h"
+
+#include <glib.h>
+
+#include <mpg123.h>
+#include <stdio.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)
+{
+	GError *gerror = nullptr;
+	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;
+	}
+
+	if (!audio_format_init_checked(audio_format, rate, SAMPLE_FORMAT_S16,
+				       channels, &gerror)) {
+		g_warning("%s", gerror->message);
+		g_error_free(gerror);
+		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;
+	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;
+	}
+
+	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)
+{
+	struct audio_format audio_format;
+	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;
+	}
+
+	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,
+};