decoder/wavpack: convert to C++

src/decoder/WavpackDecoderPlugin.cxx

@@ -0,0 +1,601 @@
+/*
+ * 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"
+#include "WavpackDecoderPlugin.hxx"
+#include "decoder_api.h"
+
+extern "C" {
+#include "audio_check.h"
+}
+
+#include "tag_handler.h"
+#include "tag_ape.h"
+
+#include <wavpack/wavpack.h>
+#include <glib.h>
+
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#undef G_LOG_DOMAIN
+#define G_LOG_DOMAIN "wavpack"
+
+#define ERRORLEN 80
+
+/** A pointer type for format converter function. */
+typedef void (*format_samples_t)(
+	int bytes_per_sample,
+	void *buffer, uint32_t count
+);
+
+/*
+ * This function has been borrowed from the tiny player found on
+ * wavpack.com. Modifications were required because mpd only handles
+ * max 24-bit samples.
+ */
+static void
+format_samples_int(int bytes_per_sample, void *buffer, uint32_t count)
+{
+	int32_t *src = (int32_t *)buffer;
+
+	switch (bytes_per_sample) {
+	case 1: {
+		int8_t *dst = (int8_t *)buffer;
+		/*
+		 * The asserts like the following one are because we do the
+		 * formatting of samples within a single buffer. The size
+		 * of the output samples never can be greater than the size
+		 * of the input ones. Otherwise we would have an overflow.
+		 */
+		static_assert(sizeof(*dst) <= sizeof(*src), "Wrong size");
+
+		/* pass through and align 8-bit samples */
+		while (count--) {
+			*dst++ = *src++;
+		}
+		break;
+	}
+	case 2: {
+		uint16_t *dst = (uint16_t *)buffer;
+		static_assert(sizeof(*dst) <= sizeof(*src), "Wrong size");
+
+		/* pass through and align 16-bit samples */
+		while (count--) {
+			*dst++ = *src++;
+		}
+		break;
+	}
+
+	case 3:
+	case 4:
+		/* do nothing */
+		break;
+	}
+}
+
+/*
+ * This function converts floating point sample data to 24-bit integer.
+ */
+static void
+format_samples_float(G_GNUC_UNUSED int bytes_per_sample, void *buffer,
+		     uint32_t count)
+{
+	float *p = (float *)buffer;
+
+	while (count--) {
+		*p /= (1 << 23);
+		++p;
+	}
+}
+
+/**
+ * Choose a MPD sample format from libwavpacks' number of bits.
+ */
+static enum sample_format
+wavpack_bits_to_sample_format(bool is_float, int bytes_per_sample)
+{
+	if (is_float)
+		return SAMPLE_FORMAT_FLOAT;
+
+	switch (bytes_per_sample) {
+	case 1:
+		return SAMPLE_FORMAT_S8;
+
+	case 2:
+		return SAMPLE_FORMAT_S16;
+
+	case 3:
+		return SAMPLE_FORMAT_S24_P32;
+
+	case 4:
+		return SAMPLE_FORMAT_S32;
+
+	default:
+		return SAMPLE_FORMAT_UNDEFINED;
+	}
+}
+
+/*
+ * This does the main decoding thing.
+ * Requires an already opened WavpackContext.
+ */
+static void
+wavpack_decode(struct decoder *decoder, WavpackContext *wpc, bool can_seek)
+{
+	GError *error = NULL;
+	bool is_float;
+	enum sample_format sample_format;
+	struct audio_format audio_format;
+	format_samples_t format_samples;
+	float total_time;
+	int bytes_per_sample, output_sample_size;
+
+	is_float = (WavpackGetMode(wpc) & MODE_FLOAT) != 0;
+	sample_format =
+		wavpack_bits_to_sample_format(is_float,
+					      WavpackGetBytesPerSample(wpc));
+
+	if (!audio_format_init_checked(&audio_format,
+				       WavpackGetSampleRate(wpc),
+				       sample_format,
+				       WavpackGetNumChannels(wpc), &error)) {
+		g_warning("%s", error->message);
+		g_error_free(error);
+		return;
+	}
+
+	if (is_float) {
+		format_samples = format_samples_float;
+	} else {
+		format_samples = format_samples_int;
+	}
+
+	total_time = WavpackGetNumSamples(wpc);
+	total_time /= audio_format.sample_rate;
+	bytes_per_sample = WavpackGetBytesPerSample(wpc);
+	output_sample_size = audio_format_frame_size(&audio_format);
+
+	/* wavpack gives us all kind of samples in a 32-bit space */
+	int32_t chunk[1024];
+	const uint32_t samples_requested = G_N_ELEMENTS(chunk) /
+		audio_format.channels;
+
+	decoder_initialized(decoder, &audio_format, can_seek, total_time);
+
+	enum decoder_command cmd = decoder_get_command(decoder);
+	while (cmd != DECODE_COMMAND_STOP) {
+		if (cmd == DECODE_COMMAND_SEEK) {
+			if (can_seek) {
+				unsigned where = decoder_seek_where(decoder) *
+					audio_format.sample_rate;
+
+				if (WavpackSeekSample(wpc, where)) {
+					decoder_command_finished(decoder);
+				} else {
+					decoder_seek_error(decoder);
+				}
+			} else {
+				decoder_seek_error(decoder);
+			}
+		}
+
+		uint32_t samples_got = WavpackUnpackSamples(wpc, chunk,
+							    samples_requested);
+		if (samples_got == 0)
+			break;
+
+		int bitrate = (int)(WavpackGetInstantBitrate(wpc) / 1000 +
+				    0.5);
+		format_samples(bytes_per_sample, chunk,
+			       samples_got * audio_format.channels);
+
+		cmd = decoder_data(decoder, NULL, chunk,
+				   samples_got * output_sample_size,
+				   bitrate);
+	}
+}
+
+/**
+ * Locate and parse a floating point tag.  Returns true if it was
+ * found.
+ */
+static bool
+wavpack_tag_float(WavpackContext *wpc, const char *key, float *value_r)
+{
+	char buffer[64];
+	int ret;
+
+	ret = WavpackGetTagItem(wpc, key, buffer, sizeof(buffer));
+	if (ret <= 0)
+		return false;
+
+	*value_r = atof(buffer);
+	return true;
+}
+
+static bool
+wavpack_replaygain(struct replay_gain_info *replay_gain_info,
+		   WavpackContext *wpc)
+{
+	bool found = false;
+
+	replay_gain_info_init(replay_gain_info);
+
+	found |= wavpack_tag_float(
+		wpc, "replaygain_track_gain",
+		&replay_gain_info->tuples[REPLAY_GAIN_TRACK].gain
+	);
+	found |= wavpack_tag_float(
+		wpc, "replaygain_track_peak",
+		&replay_gain_info->tuples[REPLAY_GAIN_TRACK].peak
+	);
+	found |= wavpack_tag_float(
+		wpc, "replaygain_album_gain",
+		&replay_gain_info->tuples[REPLAY_GAIN_ALBUM].gain
+	);
+	found |= wavpack_tag_float(
+		wpc, "replaygain_album_peak",
+		&replay_gain_info->tuples[REPLAY_GAIN_ALBUM].peak
+	);
+
+	return found;
+}
+
+static void
+wavpack_scan_tag_item(WavpackContext *wpc, const char *name,
+		      enum tag_type type,
+		      const struct tag_handler *handler, void *handler_ctx)
+{
+	char buffer[1024];
+	int len = WavpackGetTagItem(wpc, name, buffer, sizeof(buffer));
+	if (len <= 0 || (unsigned)len >= sizeof(buffer))
+		return;
+
+	tag_handler_invoke_tag(handler, handler_ctx, type, buffer);
+
+}
+
+static void
+wavpack_scan_pair(WavpackContext *wpc, const char *name,
+		  const struct tag_handler *handler, void *handler_ctx)
+{
+	char buffer[8192];
+	int len = WavpackGetTagItem(wpc, name, buffer, sizeof(buffer));
+	if (len <= 0 || (unsigned)len >= sizeof(buffer))
+		return;
+
+	tag_handler_invoke_pair(handler, handler_ctx, name, buffer);
+}
+
+/*
+ * Reads metainfo from the specified file.
+ */
+static bool
+wavpack_scan_file(const char *fname,
+		  const struct tag_handler *handler, void *handler_ctx)
+{
+	WavpackContext *wpc;
+	char error[ERRORLEN];
+
+	wpc = WavpackOpenFileInput(fname, error, OPEN_TAGS, 0);
+	if (wpc == NULL) {
+		g_warning(
+			"failed to open WavPack file \"%s\": %s\n",
+			fname, error
+		);
+		return false;
+	}
+
+	tag_handler_invoke_duration(handler, handler_ctx,
+				    WavpackGetNumSamples(wpc) /
+				    WavpackGetSampleRate(wpc));
+
+	/* the WavPack format implies APEv2 tags, which means we can
+	   reuse the mapping from tag_ape.c */
+
+	for (unsigned i = 0; i < TAG_NUM_OF_ITEM_TYPES; ++i) {
+		const char *name = tag_item_names[i];
+		if (name != NULL)
+			wavpack_scan_tag_item(wpc, name, (enum tag_type)i,
+					      handler, handler_ctx);
+	}
+
+	for (const struct tag_table *i = ape_tags; i->name != NULL; ++i)
+		wavpack_scan_tag_item(wpc, i->name, i->type,
+				      handler, handler_ctx);
+
+	if (handler->pair != NULL) {
+		char name[64];
+
+		for (int i = 0, n = WavpackGetNumTagItems(wpc);
+		     i < n; ++i) {
+			int len = WavpackGetTagItemIndexed(wpc, i, name,
+							   sizeof(name));
+			if (len <= 0 || (unsigned)len >= sizeof(name))
+				continue;
+
+			wavpack_scan_pair(wpc, name, handler, handler_ctx);
+		}
+	}
+
+	WavpackCloseFile(wpc);
+
+	return true;
+}
+
+/*
+ * mpd input_stream <=> WavpackStreamReader wrapper callbacks
+ */
+
+/* This struct is needed for per-stream last_byte storage. */
+struct wavpack_input {
+	struct decoder *decoder;
+	struct input_stream *is;
+	/* Needed for push_back_byte() */
+	int last_byte;
+};
+
+/**
+ * Little wrapper for struct wavpack_input to cast from void *.
+ */
+static struct wavpack_input *
+wpin(void *id)
+{
+	assert(id);
+	return (struct wavpack_input *)id;
+}
+
+static int32_t
+wavpack_input_read_bytes(void *id, void *data, int32_t bcount)
+{
+	uint8_t *buf = (uint8_t *)data;
+	int32_t i = 0;
+
+	if (wpin(id)->last_byte != EOF) {
+		*buf++ = wpin(id)->last_byte;
+		wpin(id)->last_byte = EOF;
+		--bcount;
+		++i;
+	}
+
+	/* wavpack fails if we return a partial read, so we just wait
+	   until the buffer is full */
+	while (bcount > 0) {
+		size_t nbytes = decoder_read(
+			wpin(id)->decoder, wpin(id)->is, buf, bcount
+		);
+		if (nbytes == 0) {
+			/* EOF, error or a decoder command */
+			break;
+		}
+
+		i += nbytes;
+		bcount -= nbytes;
+		buf += nbytes;
+	}
+
+	return i;
+}
+
+static uint32_t
+wavpack_input_get_pos(void *id)
+{
+	return wpin(id)->is->offset;
+}
+
+static int
+wavpack_input_set_pos_abs(void *id, uint32_t pos)
+{
+	return input_stream_lock_seek(wpin(id)->is, pos, SEEK_SET, NULL)
+		? 0 : -1;
+}
+
+static int
+wavpack_input_set_pos_rel(void *id, int32_t delta, int mode)
+{
+	return input_stream_lock_seek(wpin(id)->is, delta, mode, NULL)
+		? 0 : -1;
+}
+
+static int
+wavpack_input_push_back_byte(void *id, int c)
+{
+	if (wpin(id)->last_byte == EOF) {
+		wpin(id)->last_byte = c;
+		return c;
+	} else {
+		return EOF;
+	}
+}
+
+static uint32_t
+wavpack_input_get_length(void *id)
+{
+	if (wpin(id)->is->size < 0)
+		return 0;
+
+	return wpin(id)->is->size;
+}
+
+static int
+wavpack_input_can_seek(void *id)
+{
+	return wpin(id)->is->seekable;
+}
+
+static WavpackStreamReader mpd_is_reader = {
+	wavpack_input_read_bytes,
+	wavpack_input_get_pos,
+	wavpack_input_set_pos_abs,
+	wavpack_input_set_pos_rel,
+	wavpack_input_push_back_byte,
+	wavpack_input_get_length,
+	wavpack_input_can_seek,
+	nullptr /* no need to write edited tags */
+};
+
+static void
+wavpack_input_init(struct wavpack_input *isp, struct decoder *decoder,
+		   struct input_stream *is)
+{
+	isp->decoder = decoder;
+	isp->is = is;
+	isp->last_byte = EOF;
+}
+
+static struct input_stream *
+wavpack_open_wvc(struct decoder *decoder, const char *uri,
+		 GMutex *mutex, GCond *cond,
+		 struct wavpack_input *wpi)
+{
+	struct input_stream *is_wvc;
+	char *wvc_url = NULL;
+	char first_byte;
+	size_t nbytes;
+
+	/*
+	 * As we use dc->utf8url, this function will be bad for
+	 * single files. utf8url is not absolute file path :/
+	 */
+	if (uri == NULL)
+		return nullptr;
+
+	wvc_url = g_strconcat(uri, "c", NULL);
+	is_wvc = input_stream_open(wvc_url, mutex, cond, NULL);
+	g_free(wvc_url);
+
+	if (is_wvc == NULL)
+		return NULL;
+
+	/*
+	 * And we try to buffer in order to get know
+	 * about a possible 404 error.
+	 */
+	nbytes = decoder_read(
+		decoder, is_wvc, &first_byte, sizeof(first_byte)
+	);
+	if (nbytes == 0) {
+		input_stream_close(is_wvc);
+		return NULL;
+	}
+
+	/* push it back */
+	wavpack_input_init(wpi, decoder, is_wvc);
+	wpi->last_byte = first_byte;
+	return is_wvc;
+}
+
+/*
+ * Decodes a stream.
+ */
+static void
+wavpack_streamdecode(struct decoder * decoder, struct input_stream *is)
+{
+	char error[ERRORLEN];
+	WavpackContext *wpc;
+	struct input_stream *is_wvc;
+	int open_flags = OPEN_NORMALIZE;
+	struct wavpack_input isp, isp_wvc;
+	bool can_seek = is->seekable;
+
+	is_wvc = wavpack_open_wvc(decoder, is->uri, is->mutex, is->cond,
+				  &isp_wvc);
+	if (is_wvc != NULL) {
+		open_flags |= OPEN_WVC;
+		can_seek &= is_wvc->seekable;
+	}
+
+	if (!can_seek) {
+		open_flags |= OPEN_STREAMING;
+	}
+
+	wavpack_input_init(&isp, decoder, is);
+	wpc = WavpackOpenFileInputEx(
+		&mpd_is_reader, &isp,
+		open_flags & OPEN_WVC ? &isp_wvc : NULL,
+		error, open_flags, 23
+	);
+
+	if (wpc == NULL) {
+		g_warning("failed to open WavPack stream: %s\n", error);
+		return;
+	}
+
+	wavpack_decode(decoder, wpc, can_seek);
+
+	WavpackCloseFile(wpc);
+	if (open_flags & OPEN_WVC) {
+		input_stream_close(is_wvc);
+	}
+}
+
+/*
+ * Decodes a file.
+ */
+static void
+wavpack_filedecode(struct decoder *decoder, const char *fname)
+{
+	char error[ERRORLEN];
+	WavpackContext *wpc;
+
+	wpc = WavpackOpenFileInput(
+		fname, error,
+		OPEN_TAGS | OPEN_WVC | OPEN_NORMALIZE, 23
+	);
+	if (wpc == NULL) {
+		g_warning(
+			"failed to open WavPack file \"%s\": %s\n",
+			fname, error
+		);
+		return;
+	}
+
+	struct replay_gain_info replay_gain_info;
+	if (wavpack_replaygain(&replay_gain_info, wpc))
+		decoder_replay_gain(decoder, &replay_gain_info);
+
+	wavpack_decode(decoder, wpc, true);
+
+	WavpackCloseFile(wpc);
+}
+
+static char const *const wavpack_suffixes[] = {
+	"wv",
+	NULL
+};
+
+static char const *const wavpack_mime_types[] = {
+	"audio/x-wavpack",
+	NULL
+};
+
+const struct decoder_plugin wavpack_decoder_plugin = {
+	"wavpack",
+	nullptr,
+	nullptr,
+	wavpack_streamdecode,
+	wavpack_filedecode,
+	wavpack_scan_file,
+	nullptr,
+	nullptr,
+	wavpack_suffixes,
+	wavpack_mime_types
+};