decoder/{opus,vorbis}: support embedded pictures (METADATA_BLOCK_PICTURE)

More for https://github.com/MusicPlayerDaemon/MPD/issues/42

src/decoder/plugins/OpusTags.cxx

@@ -19,6 +19,7 @@
 
 #include "OpusTags.hxx"
 #include "OpusReader.hxx"
+#include "lib/xiph/VorbisPicture.hxx"
 #include "lib/xiph/XiphTags.hxx"
 #include "tag/Handler.hxx"
 #include "tag/ParseName.hxx"
@@ -45,6 +46,10 @@ ScanOneOpusTag(StringView name, StringView value,
 	       ReplayGainInfo *rgi,
 	       TagHandler &handler) noexcept
 {
+	if (handler.WantPicture() &&
+	    name.EqualsIgnoreCase("METADATA_BLOCK_PICTURE"))
+		return ScanVorbisPicture(value, handler);
+
 	if (value.size >= 4096)
 		/* ignore large values */
 		return;

src/decoder/plugins/meson.build

@@ -192,6 +192,7 @@ decoder_plugins = static_library(
 decoder_plugins_dep = declare_dependency(
   link_with: decoder_plugins,
   dependencies: [
+    crypto_base64_dep,
     decoder_api_dep,
     pcm_dep,
   ],

src/lib/xiph/VorbisComments.cxx

@@ -18,6 +18,7 @@
  */
 
 #include "VorbisComments.hxx"
+#include "VorbisPicture.hxx"
 #include "XiphTags.hxx"
 #include "tag/Table.hxx"
 #include "tag/Handler.hxx"
@@ -84,6 +85,12 @@ vorbis_copy_comment(StringView comment,
 static void
 vorbis_scan_comment(StringView comment, TagHandler &handler) noexcept
 {
+	const auto picture_b64 = handler.WantPicture()
+		? GetVorbisCommentValue(comment, "METADATA_BLOCK_PICTURE")
+		: nullptr;
+	if (!picture_b64.IsNull())
+		return ScanVorbisPicture(picture_b64, handler);
+
 	if (handler.WantPair()) {
 		const auto split = comment.Split('=');
 		if (!split.first.empty() && !split.second.IsNull())

src/lib/xiph/VorbisPicture.cxx

@@ -0,0 +1,56 @@
+/*
+ * Copyright 2003-2019 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 "VorbisPicture.hxx"
+#include "lib/crypto/Base64.hxx"
+#include "tag/Id3Picture.hxx"
+#include "tag/Handler.hxx"
+#include "util/StringView.hxx"
+#include "util/WritableBuffer.hxx"
+#include "config.h"
+
+#include <memory>
+
+void
+ScanVorbisPicture(StringView value, TagHandler &handler) noexcept
+{
+#ifdef HAVE_BASE64
+	if (value.size > 1024 * 1024)
+		/* ignore image files which are too huge */
+		return;
+
+	size_t debase64_size = CalculateBase64OutputSize(value.size);
+	std::unique_ptr<uint8_t[]> debase64_buffer;
+	debase64_buffer.reset(new uint8_t[debase64_size]);
+
+	try {
+		debase64_size =
+			DecodeBase64({debase64_buffer.get(), debase64_size},
+				     value);
+	} catch (...) {
+		// TODO: log?
+		return;
+	}
+
+	return ScanId3Apic({debase64_buffer.get(), debase64_size}, handler);
+#else
+	(void)value;
+	(void)handler;
+#endif
+}

src/lib/xiph/VorbisPicture.hxx

@@ -0,0 +1,29 @@
+/*
+ * Copyright 2003-2019 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.
+ */
+
+#ifndef MPD_VORBIS_PICTURE_HXX
+#define MPD_VORBIS_PICTURE_HXX
+
+struct StringView;
+class TagHandler;
+
+void
+ScanVorbisPicture(StringView value, TagHandler &handler) noexcept;
+
+#endif

src/lib/xiph/meson.build

@@ -47,6 +47,7 @@ endif
 xiph = static_library(
   'xiph',
   'VorbisComments.cxx',
+  'VorbisPicture.cxx',
   'XiphTags.cxx',
   include_directories: inc,
 )

src/tag/Id3Picture.cxx

@@ -0,0 +1,80 @@
+/*
+ * Copyright 2003-2019 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 "Id3Picture.hxx"
+#include "Handler.hxx"
+#include "util/ByteOrder.hxx"
+#include "util/ConstBuffer.hxx"
+#include "util/StringView.hxx"
+
+#include <string>
+
+#include <stdint.h>
+
+static StringView
+ReadString(ConstBuffer<uint8_t> &src) noexcept
+{
+	if (src.size < 4)
+		return nullptr;
+
+	const size_t length = FromBE32(*(const uint32_t *)src.data);
+	src.skip_front(4);
+
+	if (src.size < length)
+		return nullptr;
+
+	StringView result((const char *)src.data, length);
+	src.skip_front(length);
+	return result;
+}
+
+void
+ScanId3Apic(ConstBuffer<void> _buffer, TagHandler &handler) noexcept
+{
+	auto buffer = ConstBuffer<uint8_t>::FromVoid(_buffer);
+	if (buffer.size < 4)
+		return;
+
+	buffer.skip_front(4); /* picture type */
+
+	const auto mime_type = ReadString(buffer);
+	if (mime_type.IsNull())
+		return;
+
+	/* description */
+	if (ReadString(buffer).IsNull())
+		return;
+
+	if (buffer.size < 20)
+		return;
+
+	buffer.skip_front(16);
+
+	const size_t image_size = FromBE32(*(const uint32_t *)buffer.data);
+	buffer.skip_front(4);
+
+	if (buffer.size < image_size)
+		return;
+
+	ConstBuffer<void> image(buffer.data, image_size);
+
+	// TODO: don't copy MIME type, pass StringView to TagHandler::OnPicture()
+	handler.OnPicture(std::string(mime_type.data, mime_type.size).c_str(),
+			  image);
+}

src/tag/Id3Picture.hxx

@@ -0,0 +1,32 @@
+/*
+ * Copyright 2003-2019 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.
+ */
+
+#ifndef MPD_TAG_ID3_PICTURE_HXX
+#define MPD_TAG_ID3_PICTURE_HXX
+
+template<typename T> struct ConstBuffer;
+class TagHandler;
+
+/**
+ * Scan an "APIC" value and call TagHandler::OnPicture().
+ */
+void
+ScanId3Apic(ConstBuffer<void> buffer, TagHandler &handler) noexcept;
+
+#endif

src/tag/meson.build

@@ -15,6 +15,7 @@ tag_sources = [
   'MixRamp.cxx',
   'Generic.cxx',
   'Id3MusicBrainz.cxx',
+  'Id3Picture.cxx',
   'ApeLoader.cxx',
   'ApeReplayGain.cxx',
   'ApeTag.cxx',