X-Git-Url: http://research.m1stereo.tv/gitweb?a=blobdiff_plain;f=src%2Fframework%2Fmlt_properties.c;h=7e55da91c72d09a96025625c0b82d7c83f4d34ee;hb=5e12f8d2792991db7e4e7a86c1e3585a56b16e4e;hp=cf6c79293165ab9bceccbd11115a19e1465341fe;hpb=fa0d65478efe5d80e0affa58095109800a5cba71;p=melted

diff --git a/src/framework/mlt_properties.c b/src/framework/mlt_properties.c
index cf6c792..7e55da9 100644
--- a/src/framework/mlt_properties.c
+++ b/src/framework/mlt_properties.c
@@ -2,29 +2,35 @@
  * mlt_properties.c -- base properties class
  * Copyright (C) 2003-2004 Ushodaya Enterprises Limited
  * Author: Charles Yates <charles.yates@pandora.be>
+ * Contributor: Dan Dennedy <dan@dennedy.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 library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
  *
- * This program is distributed in the hope that it will be useful,
+ * This library 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.
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */
 
-#include "config.h"
 #include "mlt_properties.h"
 #include "mlt_property.h"
+#include "mlt_deque.h"
 
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <ctype.h>
+#include <stdarg.h>
+#include <pthread.h>
+#include <sys/types.h>
+#include <dirent.h>
 
 /* ---------------- // Private Implementation // ---------------- */
 
@@ -39,12 +45,16 @@ typedef struct
 	int count;
 	int size;
 	mlt_properties mirror;
+	int ref_count;
+	pthread_mutex_t mutex;
 }
 property_list;
 
 /** Memory leak checks.
 */
 
+//#define _MLT_PROPERTY_CHECKS_ 2
+
 #ifdef _MLT_PROPERTY_CHECKS_
 static int properties_created = 0;
 static int properties_destroyed = 0;
@@ -70,6 +80,10 @@ int mlt_properties_init( mlt_properties this, void *child )
 
 		// Allocate the local structure
 		this->local = calloc( sizeof( property_list ), 1 );
+
+		// Increment the ref count
+		( ( property_list * )this->local )->ref_count = 1;
+		pthread_mutex_init( &( ( property_list * )this->local )->mutex, NULL );;
 	}
 
 	// Check that initialisation was successful
@@ -91,10 +105,10 @@ mlt_properties mlt_properties_new( )
 	return this;
 }
 
-/** Load properties from a file.
+/** Load properties from a .properties file (DEPRECATED).
 */
 
-mlt_properties mlt_properties_load( char *filename )
+mlt_properties mlt_properties_load( const char *filename )
 {
 	// Construct a standalone properties object
 	mlt_properties this = mlt_properties_new( );
@@ -109,6 +123,7 @@ mlt_properties mlt_properties_load( char *filename )
 		{
 			// Temp string
 			char temp[ 1024 ];
+			char last[ 1024 ] = "";
 
 			// Read each string from the file
 			while( fgets( temp, 1024, file ) )
@@ -116,6 +131,19 @@ mlt_properties mlt_properties_load( char *filename )
 				// Chomp the string
 				temp[ strlen( temp ) - 1 ] = '\0';
 
+				// Check if the line starts with a .
+				if ( temp[ 0 ] == '.' )
+				{
+					char temp2[ 1024 ];
+					sprintf( temp2, "%s%s", last, temp );
+					strcpy( temp, temp2 );
+				}
+				else if ( strchr( temp, '=' ) )
+				{
+					strcpy( last, temp );
+					*( strchr( last, '=' ) ) = '\0';
+				}
+
 				// Parse and set the property
 				if ( strcmp( temp, "" ) && temp[ 0 ] != '#' )
 					mlt_properties_parse( this, temp );
@@ -130,7 +158,7 @@ mlt_properties mlt_properties_load( char *filename )
 	return this;
 }
 
-static inline int generate_hash( char *name )
+static inline int generate_hash( const char *name )
 {
 	int hash = 0;
 	int i = 1;
@@ -144,7 +172,7 @@ static inline int generate_hash( char *name )
 	real producer.
 */
 
-static inline void mlt_properties_do_mirror( mlt_properties this, char *name )
+static inline void mlt_properties_do_mirror( mlt_properties this, const char *name )
 {
 	property_list *list = this->local;
 	if ( list->mirror != NULL ) 
@@ -155,7 +183,52 @@ static inline void mlt_properties_do_mirror( mlt_properties this, char *name )
 	}
 }
 
-/** Allow the specification of a mirror.
+/** Maintain ref count to allow multiple uses of an mlt object.
+*/
+
+int mlt_properties_inc_ref( mlt_properties this )
+{
+	int result = 0;
+	if ( this != NULL )
+	{
+		property_list *list = this->local;
+		pthread_mutex_lock( &list->mutex );
+		result = ++ list->ref_count;
+		pthread_mutex_unlock( &list->mutex );
+	}
+	return result;
+}
+
+/** Maintain ref count to allow multiple uses of an mlt object.
+*/
+
+int mlt_properties_dec_ref( mlt_properties this )
+{
+	int result = 0;
+	if ( this != NULL )
+	{
+		property_list *list = this->local;
+		pthread_mutex_lock( &list->mutex );
+		result = -- list->ref_count;
+		pthread_mutex_unlock( &list->mutex );
+	}
+	return result;
+}
+
+/** Return the ref count of this object.
+*/
+
+int mlt_properties_ref_count( mlt_properties this )
+{
+	if ( this != NULL )
+	{
+		property_list *list = this->local;
+		return list->ref_count;
+	}
+	return 0;
+}
+
+/** Mirror properties set on 'this' to 'that'.
 */
 
 void mlt_properties_mirror( mlt_properties this, mlt_properties that )
@@ -186,7 +259,7 @@ int mlt_properties_inherit( mlt_properties this, mlt_properties that )
 /** Pass all properties from 'that' that match the prefix to 'this' (excluding the prefix).
 */
 
-int mlt_properties_pass( mlt_properties this, mlt_properties that, char *prefix )
+int mlt_properties_pass( mlt_properties this, mlt_properties that, const char *prefix )
 {
 	int count = mlt_properties_count( that );
 	int length = strlen( prefix );
@@ -207,7 +280,7 @@ int mlt_properties_pass( mlt_properties this, mlt_properties that, char *prefix
 /** Locate a property by name
 */
 
-static inline mlt_property mlt_properties_find( mlt_properties this, char *name )
+static inline mlt_property mlt_properties_find( mlt_properties this, const char *name )
 {
 	property_list *list = this->local;
 	mlt_property value = NULL;
@@ -234,7 +307,7 @@ static inline mlt_property mlt_properties_find( mlt_properties this, char *name
 /** Add a new property.
 */
 
-static mlt_property mlt_properties_add( mlt_properties this, char *name )
+static mlt_property mlt_properties_add( mlt_properties this, const char *name )
 {
 	property_list *list = this->local;
 	int key = generate_hash( name );
@@ -243,7 +316,7 @@ static mlt_property mlt_properties_add( mlt_properties this, char *name )
 	if ( list->count == list->size )
 	{
 		list->size += 50;
-		list->name = realloc( list->name, list->size * sizeof( char * ) );
+		list->name = realloc( list->name, list->size * sizeof( const char * ) );
 		list->value = realloc( list->value, list->size * sizeof( mlt_property ) );
 	}
 
@@ -262,7 +335,7 @@ static mlt_property mlt_properties_add( mlt_properties this, char *name )
 /** Fetch a property by name - this includes add if not found.
 */
 
-static mlt_property mlt_properties_fetch( mlt_properties this, char *name )
+static mlt_property mlt_properties_fetch( mlt_properties this, const char *name )
 {
 	// Try to find an existing property first
 	mlt_property property = mlt_properties_find( this, name );
@@ -275,10 +348,56 @@ static mlt_property mlt_properties_fetch( mlt_properties this, char *name )
 	return property;
 }
 
+/** Pass property 'name' from 'that' to 'this' 
+* Who to blame: Zach <zachary.drew@gmail.com>
+*/
+
+void mlt_properties_pass_property( mlt_properties this, mlt_properties that, const char *name )
+{
+	// Make sure the source property isn't null.
+	mlt_property that_prop = mlt_properties_find( that, name );
+	if( that_prop == NULL )
+		return;
+
+	mlt_property_pass( mlt_properties_fetch( this, name ), that_prop );
+}
+
+/** Pass all properties from 'that' to 'this' as found in comma seperated 'list'.
+* Who to blame: Zach <zachary.drew@gmail.com>
+*/
+
+int mlt_properties_pass_list( mlt_properties this, mlt_properties that, const char *list )
+{
+	char *props = strdup( list );
+	char *ptr = props;
+	char *delim = " ,\t\n";	// Any combination of spaces, commas, tabs, and newlines
+	int count, done = 0;
+
+	while( !done )
+	{
+		count = strcspn( ptr, delim );
+
+		if( ptr[count] == '\0' )
+			done = 1;
+		else
+			ptr[count] = '\0';	// Make it a real string
+
+		mlt_properties_pass_property( this, that, ptr );
+
+		ptr += count + 1;
+		ptr += strspn( ptr, delim );
+	}
+
+	free( props );
+
+	return 0;
+}
+
+
 /** Set the property.
 */
 
-int mlt_properties_set( mlt_properties this, char *name, char *value )
+int mlt_properties_set( mlt_properties this, const char *name, const char *value )
 {
 	int error = 1;
 
@@ -286,11 +405,70 @@ int mlt_properties_set( mlt_properties this, char *name, char *value )
 	mlt_property property = mlt_properties_fetch( this, name );
 
 	// Set it if not NULL
-	if ( property != NULL )
+	if ( property == NULL )
+	{
+		fprintf( stderr, "Whoops - %s not found (should never occur)\n", name );
+	}
+	else if ( value == NULL )
+	{
+		error = mlt_property_set_string( property, value );
+		mlt_properties_do_mirror( this, name );
+	}
+	else if ( *value != '@' )
 	{
 		error = mlt_property_set_string( property, value );
 		mlt_properties_do_mirror( this, name );
 	}
+	else if ( value[ 0 ] == '@' )
+	{
+		double total = 0;
+		double current = 0;
+		char id[ 255 ];
+		char op = '+';
+
+		value ++;
+
+		while ( *value != '\0' )
+		{
+			int length = strcspn( value, "+-*/" );
+
+			// Get the identifier
+			strncpy( id, value, length );
+			id[ length ] = '\0';
+			value += length;
+
+			// Determine the value
+			if ( isdigit( id[ 0 ] ) )
+				current = atof( id );
+			else
+				current = mlt_properties_get_double( this, id );
+
+			// Apply the operation
+			switch( op )
+			{
+				case '+':
+					total += current;
+					break;
+				case '-':
+					total -= current;
+					break;
+				case '*':
+					total *= current;
+					break;
+				case '/':
+					total = total / current;
+					break;
+			}
+
+			// Get the next op
+			op = *value != '\0' ? *value ++ : ' ';
+		}
+
+		error = mlt_property_set_double( property, total );
+		mlt_properties_do_mirror( this, name );
+	}
+
+	mlt_events_fire( this, "property-changed", name, NULL );
 
 	return error;
 }
@@ -298,7 +476,7 @@ int mlt_properties_set( mlt_properties this, char *name, char *value )
 /** Set or default the property.
 */
 
-int mlt_properties_set_or_default( mlt_properties this, char *name, char *value, char *def )
+int mlt_properties_set_or_default( mlt_properties this, const char *name, const char *value, const char *def )
 {
 	return mlt_properties_set( this, name, value == NULL ? def : value );
 }
@@ -306,7 +484,7 @@ int mlt_properties_set_or_default( mlt_properties this, char *name, char *value,
 /** Get a string value by name.
 */
 
-char *mlt_properties_get( mlt_properties this, char *name )
+char *mlt_properties_get( mlt_properties this, const char *name )
 {
 	mlt_property value = mlt_properties_find( this, name );
 	return value == NULL ? NULL : mlt_property_get_string( value );
@@ -357,7 +535,7 @@ int mlt_properties_count( mlt_properties this )
 /** Set a value by parsing a name=value string
 */
 
-int mlt_properties_parse( mlt_properties this, char *namevalue )
+int mlt_properties_parse( mlt_properties this, const char *namevalue )
 {
 	char *name = strdup( namevalue );
 	char *value = NULL;
@@ -396,7 +574,7 @@ int mlt_properties_parse( mlt_properties this, char *namevalue )
 /** Get a value associated to the name.
 */
 
-int mlt_properties_get_int( mlt_properties this, char *name )
+int mlt_properties_get_int( mlt_properties this, const char *name )
 {
 	mlt_property value = mlt_properties_find( this, name );
 	return value == NULL ? 0 : mlt_property_get_int( value );
@@ -405,7 +583,7 @@ int mlt_properties_get_int( mlt_properties this, char *name )
 /** Set a value associated to the name.
 */
 
-int mlt_properties_set_int( mlt_properties this, char *name, int value )
+int mlt_properties_set_int( mlt_properties this, const char *name, int value )
 {
 	int error = 1;
 
@@ -419,13 +597,46 @@ int mlt_properties_set_int( mlt_properties this, char *name, int value )
 		mlt_properties_do_mirror( this, name );
 	}
 
+	mlt_events_fire( this, "property-changed", name, NULL );
+
+	return error;
+}
+
+/** Get a value associated to the name.
+*/
+
+int64_t mlt_properties_get_int64( mlt_properties this, const char *name )
+{
+	mlt_property value = mlt_properties_find( this, name );
+	return value == NULL ? 0 : mlt_property_get_int64( value );
+}
+
+/** Set a value associated to the name.
+*/
+
+int mlt_properties_set_int64( mlt_properties this, const char *name, int64_t value )
+{
+	int error = 1;
+
+	// Fetch the property to work with
+	mlt_property property = mlt_properties_fetch( this, name );
+
+	// Set it if not NULL
+	if ( property != NULL )
+	{
+		error = mlt_property_set_int64( property, value );
+		mlt_properties_do_mirror( this, name );
+	}
+
+	mlt_events_fire( this, "property-changed", name, NULL );
+
 	return error;
 }
 
 /** Get a value associated to the name.
 */
 
-double mlt_properties_get_double( mlt_properties this, char *name )
+double mlt_properties_get_double( mlt_properties this, const char *name )
 {
 	mlt_property value = mlt_properties_find( this, name );
 	return value == NULL ? 0 : mlt_property_get_double( value );
@@ -434,7 +645,7 @@ double mlt_properties_get_double( mlt_properties this, char *name )
 /** Set a value associated to the name.
 */
 
-int mlt_properties_set_double( mlt_properties this, char *name, double value )
+int mlt_properties_set_double( mlt_properties this, const char *name, double value )
 {
 	int error = 1;
 
@@ -448,13 +659,15 @@ int mlt_properties_set_double( mlt_properties this, char *name, double value )
 		mlt_properties_do_mirror( this, name );
 	}
 
+	mlt_events_fire( this, "property-changed", name, NULL );
+
 	return error;
 }
 
 /** Get a value associated to the name.
 */
 
-mlt_position mlt_properties_get_position( mlt_properties this, char *name )
+mlt_position mlt_properties_get_position( mlt_properties this, const char *name )
 {
 	mlt_property value = mlt_properties_find( this, name );
 	return value == NULL ? 0 : mlt_property_get_position( value );
@@ -463,7 +676,7 @@ mlt_position mlt_properties_get_position( mlt_properties this, char *name )
 /** Set a value associated to the name.
 */
 
-int mlt_properties_set_position( mlt_properties this, char *name, mlt_position value )
+int mlt_properties_set_position( mlt_properties this, const char *name, mlt_position value )
 {
 	int error = 1;
 
@@ -477,13 +690,15 @@ int mlt_properties_set_position( mlt_properties this, char *name, mlt_position v
 		mlt_properties_do_mirror( this, name );
 	}
 
+	mlt_events_fire( this, "property-changed", name, NULL );
+
 	return error;
 }
 
 /** Get a value associated to the name.
 */
 
-void *mlt_properties_get_data( mlt_properties this, char *name, int *length )
+void *mlt_properties_get_data( mlt_properties this, const char *name, int *length )
 {
 	mlt_property value = mlt_properties_find( this, name );
 	return value == NULL ? NULL : mlt_property_get_data( value, length );
@@ -492,7 +707,7 @@ void *mlt_properties_get_data( mlt_properties this, char *name, int *length )
 /** Set a value associated to the name.
 */
 
-int mlt_properties_set_data( mlt_properties this, char *name, void *value, int length, mlt_destructor destroy, mlt_serialiser serialise )
+int mlt_properties_set_data( mlt_properties this, const char *name, void *value, int length, mlt_destructor destroy, mlt_serialiser serialise )
 {
 	int error = 1;
 
@@ -503,13 +718,15 @@ int mlt_properties_set_data( mlt_properties this, char *name, void *value, int l
 	if ( property != NULL )
 		error = mlt_property_set_data( property, value, length, destroy, serialise );
 
+	mlt_events_fire( this, "property-changed", name, NULL );
+
 	return error;
 }
 
 /** Rename a property.
 */
 
-int mlt_properties_rename( mlt_properties this, char *source, char *dest )
+int mlt_properties_rename( mlt_properties this, const char *source, const char *dest )
 {
 	mlt_property value = mlt_properties_find( this, dest );
 
@@ -546,39 +763,651 @@ void mlt_properties_dump( mlt_properties this, FILE *output )
 			fprintf( output, "%s=%s\n", list->name[ i ], mlt_properties_get( this, list->name[ i ] ) );
 }
 
-/** Close the list.
-*/
-
-void mlt_properties_close( mlt_properties this )
+void mlt_properties_debug( mlt_properties this, const char *title, FILE *output )
 {
+	if ( output == NULL ) output = stderr;
+	fprintf( output, "%s: ", title );
 	if ( this != NULL )
 	{
 		property_list *list = this->local;
-		int index = 0;
+		int i = 0;
+		fprintf( output, "[ ref=%d", list->ref_count );
+		for ( i = 0; i < list->count; i ++ )
+			if ( mlt_properties_get( this, list->name[ i ] ) != NULL )
+				fprintf( output, ", %s=%s", list->name[ i ], mlt_properties_get( this, list->name[ i ] ) );
+			else
+				fprintf( output, ", %s=%p", list->name[ i ], mlt_properties_get_data( this, list->name[ i ], NULL ) );
+		fprintf( output, " ]" );
+	}
+	fprintf( output, "\n" );
+}
+
+int mlt_properties_save( mlt_properties this, const char *filename )
+{
+	int error = 1;
+	FILE *f = fopen( filename, "w" );
+	if ( f != NULL )
+	{
+		mlt_properties_dump( this, f );
+		fclose( f );
+		error = 0;
+	}
+	return error;
+}
 
-		// Clean up names and values
-		for ( index = list->count - 1; index >= 0; index -- )
+/* This is a very basic cross platform fnmatch replacement - it will fail in
+** many cases, but for the basic *.XXX and YYY*.XXX, it will work ok.
+*/
+
+static int mlt_fnmatch( const char *wild, const char *file )
+{
+	int f = 0;
+	int w = 0;
+
+	while( f < strlen( file ) && w < strlen( wild ) )
+	{
+		if ( wild[ w ] == '*' )
+		{
+			w ++;
+			if ( w == strlen( wild ) )
+				f = strlen( file );
+			while ( f != strlen( file ) && tolower( file[ f ] ) != tolower( wild[ w ] ) )
+				f ++;
+		}
+		else if ( wild[ w ] == '?' || tolower( file[ f ] ) == tolower( wild[ w ] ) )
+		{
+			f ++;
+			w ++;
+		}
+		else if ( wild[ 0 ] == '*' )
+		{
+			w = 0;
+		}
+		else
+		{
+			return 0;
+		}
+	}
+
+	return strlen( file ) == f &&  strlen( wild ) == w;
+}
+
+static int mlt_compare( const void *this, const void *that )
+{
+	return strcmp( mlt_property_get_string( *( mlt_property * )this ), mlt_property_get_string( *( mlt_property * )that ) );
+}
+
+/* Obtains an optionally sorted list of the files found in a directory with a specific wild card.
+ * Entries in the list have a numeric name (running from 0 to count - 1). Only values change
+ * position if sort is enabled. Designed to be posix compatible (linux, os/x, mingw etc).
+ */
+
+int mlt_properties_dir_list( mlt_properties this, const char *dirname, const char *pattern, int sort )
+{
+	DIR *dir = opendir( dirname );
+
+	if ( dir )
+	{
+		char key[ 20 ];
+		struct dirent *de = readdir( dir );
+		char fullname[ 1024 ];
+		while( de != NULL )
 		{
-			free( list->name[ index ] );
-			mlt_property_close( list->value[ index ] );
+			sprintf( key, "%d", mlt_properties_count( this ) );
+			snprintf( fullname, 1024, "%s/%s", dirname, de->d_name );
+			if ( pattern == NULL )
+				mlt_properties_set( this, key, fullname );
+			else if ( de->d_name[ 0 ] != '.' && mlt_fnmatch( pattern, de->d_name ) )
+				mlt_properties_set( this, key, fullname );
+			de = readdir( dir );
 		}
 
-		// Clear up the list
-		free( list->name );
-		free( list->value );
-		free( list );
+		closedir( dir );
+	}
+
+	if ( sort && mlt_properties_count( this ) )
+	{
+		property_list *list = this->local;
+		qsort( list->value, mlt_properties_count( this ), sizeof( mlt_property ), mlt_compare );
+	}
+
+	return mlt_properties_count( this );
+}
 
-		// Free this now if this has no child
-		if ( this->child == NULL )
-			free( this );
+/** Close the list.
+*/
+
+void mlt_properties_close( mlt_properties this )
+{
+	if ( this != NULL && mlt_properties_dec_ref( this ) <= 0 )
+	{
+		if ( this->close != NULL )
+		{
+			this->close( this->close_object );
+		}
+		else
+		{
+			property_list *list = this->local;
+			int index = 0;
+
+#if _MLT_PROPERTY_CHECKS_ == 1
+			// Show debug info
+			mlt_properties_debug( this, "Closing", stderr );
+#endif
 
 #ifdef _MLT_PROPERTY_CHECKS_
-		// Increment destroyed count
-		properties_destroyed ++;
+			// Increment destroyed count
+			properties_destroyed ++;
 
-		// Show current stats - these should match when the app is closed
-		fprintf( stderr, "Created %d, destroyed %d\n", properties_created, properties_destroyed );
+			// Show current stats - these should match when the app is closed
+			fprintf( stderr, "Created %d, destroyed %d\n", properties_created, properties_destroyed );
 #endif
+
+			// Clean up names and values
+			for ( index = list->count - 1; index >= 0; index -- )
+			{
+				free( list->name[ index ] );
+				mlt_property_close( list->value[ index ] );
+			}
+	
+			// Clear up the list
+			pthread_mutex_destroy( &list->mutex );
+			free( list->name );
+			free( list->value );
+			free( list );
+	
+			// Free this now if this has no child
+			if ( this->child == NULL )
+				free( this );
+		}
 	}
 }
 
+/** Determine if the properties list is really just a sequence or ordered list.
+    Returns 0 if false or 1 if true.
+*/
+int mlt_properties_is_sequence( mlt_properties properties )
+{
+	int i;
+	int n = mlt_properties_count( properties );
+	for ( i = 0; i < n; i++ )
+		if ( ! isdigit( mlt_properties_get_name( properties, i )[0] ) )
+			return 0;
+	return 1;
+}
+
+/** YAML Tiny Parser
+ * YAML is a nifty text format popular in the Ruby world as a cleaner,
+ * less verbose alternative to XML. See this Wikipedia topic for an overview:
+ * http://en.wikipedia.org/wiki/YAML
+ * The YAML specification is at:
+ * http://yaml.org/
+ * YAML::Tiny is a Perl module that specifies a subset of YAML that we are
+ * using here (for the same reasons):
+ * http://search.cpan.org/~adamk/YAML-Tiny-1.25/lib/YAML/Tiny.pm
+ */
+
+struct yaml_parser_context
+{
+	mlt_deque stack;
+	unsigned int level;
+	unsigned int index;
+	char block;
+	char *block_name;
+	unsigned int block_indent;
+	
+};
+typedef struct yaml_parser_context *yaml_parser;
+
+static unsigned int ltrim( char **s )
+{
+	unsigned int i = 0;
+	char *c = *s;
+	int n = strlen( c );
+	for ( i = 0; i < n && *c == ' '; i++, c++ );
+	*s = c;
+	return i;
+}
+
+static unsigned int rtrim( char *s )
+{
+	int n = strlen( s );
+	int i;
+	for ( i = n; i > 0 && s[i - 1] == ' '; --i )
+		s[i - 1] = 0;
+	return n - i;
+}
+
+static int parse_yaml( yaml_parser context, const char *namevalue )
+{
+	char *name_ = strdup( namevalue );
+	char *name = name_;
+	char *value = NULL;
+	int error = 0;
+	char *ptr = strchr( name, ':' );
+	unsigned int indent = ltrim( &name );
+	mlt_properties properties = mlt_deque_peek_front( context->stack );
+	
+	// Ascending one more levels in the tree
+	if ( indent < context->level )
+	{
+		unsigned int i;
+		unsigned int n = ( context->level - indent ) / 2;
+		for ( i = 0; i < n; i++ )
+			mlt_deque_pop_front( context->stack );
+		properties = mlt_deque_peek_front( context->stack );
+		context->level = indent;
+	}
+	
+	// Descending a level in the tree
+	else if ( indent > context->level && context->block == 0 )
+	{
+		context->level = indent;
+	}
+	
+	// If there is a colon that is not part of a block
+	if ( ptr && ( indent == context->level ) )
+	{
+		// Reset block processing
+		if ( context->block_name )
+		{
+			free( context->block_name );
+			context->block_name = NULL;
+			context->block = 0;
+		}
+		
+		// Terminate the name and setup the value pointer
+		*( ptr ++ ) = 0;
+		
+		// Trim comment
+		char *comment = strchr( ptr, '#' );
+		if ( comment )
+		{
+			*comment = 0;
+		}
+		
+		// Trim leading and trailing spaces from bare value 
+		ltrim( &ptr );
+		rtrim( ptr );
+		
+		// No value means a child
+		if ( strcmp( ptr, "" ) == 0 )
+		{
+			mlt_properties child = mlt_properties_new();
+			mlt_properties_set_data( properties, name, child, 0, 
+				( mlt_destructor )mlt_properties_close, NULL );
+			mlt_deque_push_front( context->stack, child );
+			context->index = 0;
+			free( name_ );
+			return error;
+		}
+		
+		// A dash indicates a sequence item
+		if ( name[0] == '-' )
+		{
+			mlt_properties child = mlt_properties_new();
+			char key[20];
+			
+			snprintf( key, sizeof(key), "%d", context->index++ );
+			mlt_properties_set_data( properties, key, child, 0, 
+				( mlt_destructor )mlt_properties_close, NULL );
+			mlt_deque_push_front( context->stack, child );
+
+			name ++;
+			context->level += ltrim( &name ) + 1;
+			properties = child;
+		}
+		
+		// Value is quoted
+		if ( *ptr == '\"' )
+		{
+			ptr ++;
+			value = strdup( ptr );
+			if ( value && value[ strlen( value ) - 1 ] == '\"' )
+				value[ strlen( value ) - 1 ] = 0;
+		}
+		
+		// Value is folded or unfolded block
+		else if ( *ptr == '|' || *ptr == '>' )
+		{
+			context->block = *ptr;
+			context->block_name = strdup( name );
+			context->block_indent = 0;
+			value = strdup( "" );
+		}
+		
+		// Bare value
+		else
+		{
+			value = strdup( ptr );
+		}
+	}
+	
+	// A list of scalars
+	else if ( name[0] == '-' )
+	{
+		// Reset block processing
+		if ( context->block_name )
+		{
+			free( context->block_name );
+			context->block_name = NULL;
+			context->block = 0;
+		}
+		
+		char key[20];
+		
+		snprintf( key, sizeof(key), "%d", context->index++ );
+		ptr = name + 1;
+		
+		// Trim comment
+		char *comment = strchr( ptr, '#' );
+		if ( comment )
+			*comment = 0;
+		
+		// Trim leading and trailing spaces from bare value 
+		ltrim( &ptr );
+		rtrim( ptr );
+		
+		// Value is quoted
+		if ( *ptr == '\"' )
+		{
+			ptr ++;
+			value = strdup( ptr );
+			if ( value && value[ strlen( value ) - 1 ] == '\"' )
+				value[ strlen( value ) - 1 ] = 0;
+		}
+		
+		// Value is folded or unfolded block
+		else if ( *ptr == '|' || *ptr == '>' )
+		{
+			context->block = *ptr;
+			context->block_name = strdup( key );
+			context->block_indent = 0;
+			value = strdup( "" );
+		}
+		
+		// Bare value
+		else
+		{
+			value = strdup( ptr );
+		}
+		
+		free( name_ );
+		name = name_ = strdup( key );
+	}
+
+	// Non-folded block
+	else if ( context->block == '|' )
+	{
+		if ( context->block_indent == 0 )
+			context->block_indent = indent;
+		if ( indent > context->block_indent )
+			name = &name_[ context->block_indent ];
+		rtrim( name );
+		char *old_value = mlt_properties_get( properties, context->block_name );
+		value = calloc( 1, strlen( old_value ) + strlen( name ) + 2 );
+		strcpy( value, old_value );
+		if ( strcmp( old_value, "" ) )
+			strcat( value, "\n" );
+		strcat( value, name );
+		name = context->block_name;
+	}
+	
+	// Folded block
+	else if ( context->block == '>' )
+	{
+		ltrim( &name );
+		rtrim( name );
+		char *old_value = mlt_properties_get( properties, context->block_name );
+		
+		// Blank line (prepended with spaces) is new line
+		if ( strcmp( name, "" ) == 0 )
+		{
+			value = calloc( 1, strlen( old_value ) + 2 );
+			strcat( value, old_value );
+			strcat( value, "\n" );
+		}
+		// Concatenate with space
+		else
+		{
+			value = calloc( 1, strlen( old_value ) + strlen( name ) + 2 );
+			strcat( value, old_value );
+			if ( strcmp( old_value, "" ) && old_value[ strlen( old_value ) - 1 ] != '\n' )
+				strcat( value, " " );
+			strcat( value, name );
+		}
+		name = context->block_name;
+	}
+	
+	else
+	{
+		value = strdup( "" );
+	}
+
+	error = mlt_properties_set( properties, name, value );
+
+	free( name_ );
+	free( value );
+
+	return error;
+}
+
+mlt_properties mlt_properties_parse_yaml( const char *filename )
+{
+	// Construct a standalone properties object
+	mlt_properties this = mlt_properties_new( );
+
+	if ( this )
+	{
+		// Open the file
+		FILE *file = fopen( filename, "r" );
+
+		// Load contents of file
+		if ( file )
+		{
+			// Temp string
+			char temp[ 1024 ];
+			char *ptemp = &temp[ 0 ];
+			
+			// Parser context
+			yaml_parser context = calloc( 1, sizeof( struct yaml_parser_context ) );
+			context->stack = mlt_deque_init();
+			mlt_deque_push_front( context->stack, this );
+
+			// Read each string from the file
+			while( fgets( temp, 1024, file ) )
+			{
+				// Check for end-of-stream
+				if ( strncmp( ptemp, "...", 3 ) == 0 )
+					break;
+					
+				// Chomp the string
+				temp[ strlen( temp ) - 1 ] = '\0';
+
+				// Skip blank lines, comment lines, and document separator
+				if ( strcmp( ptemp, "" ) && ptemp[ 0 ] != '#' && strncmp( ptemp, "---", 3 ) 
+				     && strncmp( ptemp, "%YAML", 5 ) && strncmp( ptemp, "% YAML", 6 ) )
+					parse_yaml( context, temp );
+			}
+
+			// Close the file
+			fclose( file );
+			mlt_deque_close( context->stack );
+			if ( context->block_name )
+				free( context->block_name );
+			free( context );
+		}
+	}
+
+	// Return the pointer
+	return this;
+}
+
+/** YAML Tiny Serialiser
+*/
+
+/* strbuf is a self-growing string buffer */
+
+#define STRBUF_GROWTH (1024)
+
+struct strbuf_s
+{
+	size_t size;
+	char *string;
+};
+
+typedef struct strbuf_s *strbuf;
+
+static strbuf strbuf_new( )
+{
+	strbuf buffer = calloc( 1, sizeof( struct strbuf_s ) );
+	buffer->size = STRBUF_GROWTH;
+	buffer->string = calloc( 1, buffer->size );
+	return buffer;
+}
+
+static void strbuf_close( strbuf buffer )
+{
+	// We do not free buffer->string; strbuf user must save that pointer
+	// and free it.
+	if ( buffer )
+		free( buffer );
+}
+
+static char *strbuf_printf( strbuf buffer, const char *format, ... )
+{
+	while ( buffer->string )
+	{
+		va_list ap;
+		va_start( ap, format );
+		size_t len = strlen( buffer->string );
+		size_t remain = buffer->size - len - 1;
+		int need = vsnprintf( buffer->string + len, remain, format, ap );
+		va_end( ap );
+		if ( need > -1 && need < remain )
+			break;
+		buffer->string[ len ] = 0;
+		buffer->size += need + STRBUF_GROWTH;
+		buffer->string = realloc( buffer->string, buffer->size );
+	}
+	return buffer->string;
+}
+
+static inline void indent_yaml( strbuf output, int indent )
+{
+	int j;
+	for ( j = 0; j < indent; j++ )
+		strbuf_printf( output, " " );
+}
+
+static void output_yaml_block_literal( strbuf output, const char *value, int indent )
+{
+	char *v = strdup( value );
+	char *sol = v;
+	char *eol = strchr( sol, '\n' );
+	
+	while ( eol )
+	{
+		indent_yaml( output, indent );
+		*eol = '\0';
+		strbuf_printf( output, "%s\n", sol );
+		sol = eol + 1;
+		eol = strchr( sol, '\n' );
+	}	
+	indent_yaml( output, indent );
+	strbuf_printf( output, "%s\n", sol );
+}
+
+static void serialise_yaml( mlt_properties this, strbuf output, int indent, int is_parent_sequence )
+{
+	property_list *list = this->local;
+	int i = 0;
+	
+	for ( i = 0; i < list->count; i ++ )
+	{
+		// This implementation assumes that all data elements are property lists.
+		// Unfortunately, we do not have run time type identification.
+		mlt_properties child = mlt_property_get_data( list->value[ i ], NULL );
+		
+		if ( mlt_properties_is_sequence( this ) )
+		{
+			// Ignore hidden/non-serialisable items
+			if ( list->name[ i ][ 0 ] != '_' )
+			{
+				// Indicate a sequence item
+				indent_yaml( output, indent );
+				strbuf_printf( output, "- " );
+				
+				// If the value can be represented as a string
+				const char *value = mlt_properties_get( this, list->name[ i ] );
+				if ( value && strcmp( value, "" ) )
+				{
+					// Determine if this is an unfolded block literal
+					if ( strchr( value, '\n' ) )
+					{
+						strbuf_printf( output, "|\n" );
+						output_yaml_block_literal( output, value, indent + strlen( list->name[ i ] ) + strlen( "|" ) );
+					}
+					else
+					{
+						strbuf_printf( output, "%s\n", value );
+					}
+				}
+			}
+			// Recurse on child
+			if ( child )
+				serialise_yaml( child, output, indent + 2, 1 );
+		}
+		else 
+		{
+			// Assume this is a normal map-oriented properties list
+			const char *value = mlt_properties_get( this, list->name[ i ] );
+			
+			// Ignore hidden/non-serialisable items
+			// If the value can be represented as a string
+			if ( list->name[ i ][ 0 ] != '_' && value && strcmp( value, "" ) )
+			{
+				if ( is_parent_sequence == 0 )
+					indent_yaml( output, indent );
+				else
+					is_parent_sequence = 0;
+				
+				// Determine if this is an unfolded block literal
+				if ( strchr( value, '\n' ) )
+				{
+					strbuf_printf( output, "%s: |\n", list->name[ i ] );
+					output_yaml_block_literal( output, value, indent + strlen( list->name[ i ] ) + strlen( ": " ) );
+				}
+				else
+				{
+					strbuf_printf( output, "%s: %s\n", list->name[ i ], value );
+				}
+			}
+			
+			// Output a child as a map item
+			if ( child )
+			{
+				indent_yaml( output, indent );
+				strbuf_printf( output, "%s:\n", list->name[ i ] );
+
+				// Recurse on child
+				serialise_yaml( child, output, indent + 2, 0 );
+			}
+		}
+	}
+}
+
+/** Serialise the properties as a string of YAML Tiny.
+    The caller must free the returned string.
+*/
+
+char *mlt_properties_serialise_yaml( mlt_properties this )
+{
+	strbuf b = strbuf_new();
+	strbuf_printf( b, "---\n" );
+	serialise_yaml( this, b, 0, 0 );
+	strbuf_printf( b, "...\n" );
+	char *ret = b->string;
+	strbuf_close( b );
+	return ret;
+}