add FLAC__metadata_get_tags(), FLAC::Metadata::get_tags()

doc/html/changelog.html

@@ -168,6 +168,7 @@
 				<LI>
 					libFLAC:
 					<UL>
+						<LI><B>Added</B> FLAC__metadata_get_tags()</LI>
 						<LI><B>Added</B> callback-based versions of metadata editing functions:
 							<UL>
 								<LI>FLAC__metadata_chain_read_with_callbacks()</LI>
@@ -198,6 +199,7 @@
 				<LI>
 					libFLAC++:
 					<UL>
+						<LI><B>Added</B> FLAC::Metadata::get_tags()</LI>
 						<LI><B>Added</B> decoder functions for skipping single frames, also useful for quickly finding frame boundaries:
 							<UL>
 								<LI>FLAC::Decoder::Stream::skip_single_frame()</LI>

include/FLAC++/metadata.h

@@ -787,7 +787,7 @@ namespace FLAC {
 		 *  \ingroup flacpp_metadata
 		 *
 		 *  \brief
-		 *  Level 0 metadata iterator.
+		 *  Level 0 metadata iterators.
 		 *
 		 *  See the \link flac_metadata_level0 C layer equivalent \endlink
 		 *  for more.
@@ -797,6 +797,9 @@ namespace FLAC {
 
 	 	//! See FLAC__metadata_get_streaminfo().
 		FLACPP_API bool get_streaminfo(const char *filename, StreamInfo &streaminfo);
+		//
+	 	//! See FLAC__metadata_get_tags().
+		FLACPP_API bool get_tags(const char *filename, VorbisComment *&tags);
 
 		/* \} */
 

include/FLAC/metadata.h

@@ -64,7 +64,7 @@
  *  There are three metadata interfaces of increasing complexity:
  *
  *  Level 0:
- *  Read-only access to the STREAMINFO block.
+ *  Read-only access to the STREAMINFO and VORBIS_COMMENT blocks.
  *
  *  Level 1:
  *  Read-write access to all metadata blocks.  This level is write-
@@ -123,8 +123,8 @@ extern "C" {
  *  \ingroup flac_metadata
  *
  *  \brief
- *  The level 0 interface consists of a single routine to read the
- *  STREAMINFO block.
+ *  The level 0 interface consists of individual routines to read the
+ *  STREAMINFO and VORBIS_COMMENT blocks, requiring only a filename.
  *
  *  It skips any ID3v2 tag at the head of the file.
  *
@@ -135,17 +135,40 @@ extern "C" {
  *  will skip any ID3v2 tag at the head of the file.
  *
  * \param filename    The path to the FLAC file to read.
- * \param streaminfo  A pointer to space for the STREAMINFO block.
+ * \param streaminfo  A pointer to space for the STREAMINFO block.  Since
+ *                    FLAC__StreamMetadata is a simple structure with no
+ *                    memory allocation involved, you pass the address of
+ *                    an existing structure.  It need not be initialized.
  * \assert
  *    \code filename != NULL \endcode
  *    \code streaminfo != NULL \endcode
  * \retval FLAC__bool
  *    \c true if a valid STREAMINFO block was read from \a filename.  Returns
  *    \c false if there was a memory allocation error, a file decoder error,
- *    or the file contained no STREAMINFO block.
+ *    or the file contained no STREAMINFO block.  (A memory allocation error
+ *    is possible because this function must set up a file decoder.)
  */
 FLAC_API FLAC__bool FLAC__metadata_get_streaminfo(const char *filename, FLAC__StreamMetadata *streaminfo);
 
+/** Read the VORBIS_COMMENT metadata block of the given FLAC file.  This
+ *  function will skip any ID3v2 tag at the head of the file.
+ *
+ * \param filename    The path to the FLAC file to read.
+ * \param tags        The address where the returned pointer will be
+ *                    stored.  The \a tags object must be deleted by
+ *                    the caller using FLAC__metadata_object_delete().
+ * \assert
+ *    \code filename != NULL \endcode
+ *    \code streaminfo != NULL \endcode
+ * \retval FLAC__bool
+ *    \c true if a valid VORBIS_COMMENT block was read from \a filename,
+ *    and \a *tags will be set to the address of the tag structure.
+ *    Returns \c false if there was a memory allocation error, a file
+ *    decoder error, or the file contained no VORBIS_COMMENT block, and
+ *    \a *tags will be set to \c NULL.
+ */
+FLAC_API FLAC__bool FLAC__metadata_get_tags(const char *filename, FLAC__StreamMetadata **tags);
+
 /* \} */
 
 

src/libFLAC++/metadata.cpp

@@ -985,10 +985,26 @@ namespace FLAC {
 		{
 			FLAC__ASSERT(0 != filename);
 
-			::FLAC__StreamMetadata s;
+			::FLAC__StreamMetadata object;
 
-			if(::FLAC__metadata_get_streaminfo(filename, &s)) {
-				streaminfo = s;
+			if(::FLAC__metadata_get_streaminfo(filename, &object)) {
+				streaminfo = object;
+				return true;
+			}
+			else
+				return false;
+		}
+
+		FLACPP_API bool get_tags(const char *filename, VorbisComment *&tags)
+		{
+			FLAC__ASSERT(0 != filename);
+
+			::FLAC__StreamMetadata *object;
+
+			tags = 0;
+
+			if(::FLAC__metadata_get_tags(filename, &object)) {
+				tags = new VorbisComment(object, /*copy=*/false);
 				return true;
 			}
 			else

src/libFLAC/metadata_iterators.c

@@ -153,8 +153,8 @@ static void error_callback_(const FLAC__FileDecoder *decoder, FLAC__StreamDecode
 
 typedef struct {
 	FLAC__bool got_error;
-	FLAC__bool got_streaminfo;
-	FLAC__StreamMetadata *streaminfo;
+	FLAC__bool got_object;
+	FLAC__StreamMetadata *object;
 } level0_client_data;
 
 FLAC_API FLAC__bool FLAC__metadata_get_streaminfo(const char *filename, FLAC__StreamMetadata *streaminfo)
@@ -171,8 +171,8 @@ FLAC_API FLAC__bool FLAC__metadata_get_streaminfo(const char *filename, FLAC__St
 		return false;
 
 	cd.got_error = false;
-	cd.got_streaminfo = false;
-	cd.streaminfo = streaminfo;
+	cd.got_object = false;
+	cd.object = 0;
 
 	FLAC__file_decoder_set_md5_checking(decoder, false);
 	FLAC__file_decoder_set_filename(decoder, filename);
@@ -189,17 +189,77 @@ FLAC_API FLAC__bool FLAC__metadata_get_streaminfo(const char *filename, FLAC__St
 		return false;
 	}
 
-	/* the first thing decoded must be the STREAMINFO block: */
 	if(!FLAC__file_decoder_process_until_end_of_metadata(decoder) || cd.got_error) {
 		FLAC__file_decoder_finish(decoder);
 		FLAC__file_decoder_delete(decoder);
+		if(0 != cd.object)
+			FLAC__metadata_object_delete(cd.object);
 		return false;
 	}
 
 	FLAC__file_decoder_finish(decoder);
 	FLAC__file_decoder_delete(decoder);
 
-	return !cd.got_error && cd.got_streaminfo;
+	if(cd.got_object) {
+		/* can just copy the contents since STREAMINFO has no internal structure */
+		*streaminfo = *(cd.object);
+	}
+
+	if(0 != cd.object)
+		FLAC__metadata_object_delete(cd.object);
+
+	return cd.got_object;
+}
+
+FLAC_API FLAC__bool FLAC__metadata_get_tags(const char *filename, FLAC__StreamMetadata **tags)
+{
+	level0_client_data cd;
+	FLAC__FileDecoder *decoder;
+
+	FLAC__ASSERT(0 != filename);
+	FLAC__ASSERT(0 != tags);
+
+	decoder = FLAC__file_decoder_new();
+
+	if(0 == decoder)
+		return false;
+
+	*tags = 0;
+
+	cd.got_error = false;
+	cd.got_object = false;
+	cd.object = 0;
+
+	FLAC__file_decoder_set_md5_checking(decoder, false);
+	FLAC__file_decoder_set_filename(decoder, filename);
+	FLAC__file_decoder_set_metadata_ignore_all(decoder);
+	FLAC__file_decoder_set_metadata_respond(decoder, FLAC__METADATA_TYPE_VORBIS_COMMENT);
+	FLAC__file_decoder_set_write_callback(decoder, write_callback_);
+	FLAC__file_decoder_set_metadata_callback(decoder, metadata_callback_);
+	FLAC__file_decoder_set_error_callback(decoder, error_callback_);
+	FLAC__file_decoder_set_client_data(decoder, &cd);
+
+	if(FLAC__file_decoder_init(decoder) != FLAC__FILE_DECODER_OK || cd.got_error) {
+		FLAC__file_decoder_finish(decoder);
+		FLAC__file_decoder_delete(decoder);
+		return false;
+	}
+
+	if(!FLAC__file_decoder_process_until_end_of_metadata(decoder) || cd.got_error) {
+		FLAC__file_decoder_finish(decoder);
+		FLAC__file_decoder_delete(decoder);
+		if(0 != cd.object)
+			FLAC__metadata_object_delete(cd.object);
+		return false;
+	}
+
+	FLAC__file_decoder_finish(decoder);
+	FLAC__file_decoder_delete(decoder);
+
+	if(cd.got_object)
+		*tags = cd.object;
+
+	return cd.got_object;
 }
 
 FLAC__StreamDecoderWriteStatus write_callback_(const FLAC__FileDecoder *decoder, const FLAC__Frame *frame, const FLAC__int32 * const buffer[], void *client_data)
@@ -214,9 +274,15 @@ void metadata_callback_(const FLAC__FileDecoder *decoder, const FLAC__StreamMeta
 	level0_client_data *cd = (level0_client_data *)client_data;
 	(void)decoder;
 
-	if(metadata->type == FLAC__METADATA_TYPE_STREAMINFO && 0 != cd->streaminfo) {
-		*(cd->streaminfo) = *metadata;
-		cd->got_streaminfo = true;
+	/*
+	 * we assume we only get here when the one metadata block we were
+	 * looking for was passed to us
+	 */
+	if(!cd->got_object) {
+		if(0 == (cd->object = FLAC__metadata_object_clone(metadata)))
+			cd->got_error = true;
+		else
+			cd->got_object = true;
 	}
 }
 

src/test_libFLAC++/metadata_manip.cpp

@@ -591,6 +591,7 @@ static bool remove_file_(const char *filename)
 static bool test_level_0_()
 {
 	FLAC::Metadata::StreamInfo streaminfo;
+	FLAC::Metadata::VorbisComment *tags = 0;
 
 	printf("\n\n++++++ testing level 0 interface\n");
 
@@ -600,6 +601,8 @@ static bool test_level_0_()
 	if(!test_file_(flacfile_, /*ignore_metadata=*/true))
 		return false;
 
+	printf("testing FLAC::Metadata::get_streaminfo()... ");
+
 	if(!FLAC::Metadata::get_streaminfo(flacfile_, streaminfo))
 		return die_("during FLAC::Metadata::get_streaminfo()");
 
@@ -615,6 +618,21 @@ static bool test_level_0_()
 	if(streaminfo.get_max_blocksize() != 576)
 		return die_("mismatch in streaminfo.get_max_blocksize()");
 
+	printf("OK\n");
+
+	printf("testing FLAC::Metadata::get_tags()... ");
+
+	if(!FLAC::Metadata::get_tags(flacfile_, tags))
+		return die_("during FLAC::Metadata::get_tags()");
+
+	/* check to see if some basic data matches (c.f. generate_file_()) */
+	if(tags->get_num_comments() != 0)
+		return die_("mismatch in tags->get_num_comments()");
+
+	printf("OK\n");
+
+	delete tags;
+
 	if(!remove_file_(flacfile_))
 		return false;
 

src/test_libFLAC/metadata_manip.c

@@ -604,6 +604,7 @@ static FLAC__bool remove_file_(const char *filename)
 static FLAC__bool test_level_0_()
 {
 	FLAC__StreamMetadata streaminfo;
+	FLAC__StreamMetadata *tags = 0;
 
 	printf("\n\n++++++ testing level 0 interface\n");
 
@@ -613,6 +614,8 @@ static FLAC__bool test_level_0_()
 	if(!test_file_(flacfile_, decoder_metadata_callback_null_))
 		return false;
 
+	printf("testing FLAC__metadata_get_streaminfo()... ");
+
 	if(!FLAC__metadata_get_streaminfo(flacfile_, &streaminfo))
 		return die_("during FLAC__metadata_get_streaminfo()");
 
@@ -628,6 +631,21 @@ static FLAC__bool test_level_0_()
 	if(streaminfo.data.stream_info.max_blocksize != 576)
 		return die_("mismatch in streaminfo.data.stream_info.max_blocksize");
 
+	printf("OK\n");
+
+	printf("testing FLAC__metadata_get_tags()... ");
+
+	if(!FLAC__metadata_get_tags(flacfile_, &tags))
+		return die_("during FLAC__metadata_get_tags()");
+
+	/* check to see if some basic data matches (c.f. generate_file_()) */
+	if(tags->data.vorbis_comment.num_comments != 0)
+		return die_("mismatch in tags->data.vorbis_comment.num_comments");
+
+	printf("OK\n");
+
+	FLAC__metadata_object_delete(tags);
+
 	if(!remove_file_(flacfile_))
 		return false;