modules/core/producer_loader.c

/*
 * producer_loader.c -- auto-load producer by file name extension
 * Copyright (C) 2003-2021 Meltytech, LLC
 *
 * 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 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
 * Lesser General Public License for more details.
 *
 * 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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <fnmatch.h>
#include <assert.h>

#include <framework/mlt.h>

static mlt_properties dictionary = NULL;
static mlt_properties normalisers = NULL;

static mlt_producer create_from( mlt_profile profile, char *file, char *services )
{
	mlt_producer producer = NULL;
	char *temp = strdup( services );
	char *service = temp;
	do
	{
		char *p = strchr( service, ',' );
		if ( p != NULL )
			*p ++ = '\0';

		// If  the service name has a colon as field delimiter, then treat the
		// second field as a prefix for the file/url.
		char *prefix = strchr( service, ':' );
		if ( prefix )
		{
			*prefix ++ = '\0';
			char* prefix_file = calloc( 1, strlen( file ) + strlen( prefix ) + 1 );
			strcpy( prefix_file, prefix );
			strcat( prefix_file, file );
			producer = mlt_factory_producer( profile, service, prefix_file );
			free( prefix_file );
		}
		else
		{
			producer = mlt_factory_producer( profile, service, file );
		}
		service = p;
	}
	while ( producer == NULL && service != NULL );
	free( temp );
	return producer;
}

static mlt_producer create_producer( mlt_profile profile, char *file )
{
	mlt_producer result = NULL;

	// 1st Line - check for service:resource handling
	// And ignore drive letters on Win32 - no single char services supported.
	if ( strchr( file, ':' ) > file + 1 )
	{
		char *temp = strdup( file );
		char *service = temp;
		char *resource = strchr( temp, ':' );
		*resource ++ = '\0';
		result = mlt_factory_producer( profile, service, resource );
		free( temp );
	}

	// 2nd Line preferences
	if ( result == NULL )
	{
		int i = 0;
		char *lookup = strdup( file );
		char *p = lookup;

		// Make backup of profile for determining if we need to use 'consumer' producer.
		mlt_profile backup_profile = mlt_profile_clone( profile );

		// We only need to load the dictionary once
		if ( dictionary == NULL )
		{
			char temp[ 1024 ];
			sprintf( temp, "%s/core/loader.dict", mlt_environment( "MLT_DATA" ) );
			dictionary = mlt_properties_load( temp );
			mlt_factory_register_for_clean_up( dictionary, ( mlt_destructor )mlt_properties_close );
		}

		// Convert the lookup string to lower case
		while ( *p )
		{
			*p = tolower( *p );
			p ++;
		}

		// Chop off the query string
		p = strrchr( lookup, '?' );
		if ( p && p > lookup && p[-1] == '\\' )
			p[-1] = '\0';

		// Strip file:// prefix
		p = lookup;
		if ( strncmp( lookup, "file://", 7 ) == 0 )
			p += 7;

		// Iterate through the dictionary
		for ( i = 0; result == NULL && i < mlt_properties_count( dictionary ); i ++ )
		{
			char *name = mlt_properties_get_name( dictionary, i );
			if ( fnmatch( name, p, 0 ) == 0 )
				result = create_from( profile, file, mlt_properties_get_value( dictionary, i ) );
		}

		// Check if the producer changed the profile - xml does this.
		// The consumer producer does not handle frame rate differences.
		if ( result && backup_profile->is_explicit && (
		     profile->width != backup_profile->width ||
		     profile->height != backup_profile->height ||
		     profile->sample_aspect_num != backup_profile->sample_aspect_num ||
		     profile->sample_aspect_den != backup_profile->sample_aspect_den ||
		     profile->colorspace != backup_profile->colorspace ) )
		{
			// Restore the original profile attributes.
			profile->display_aspect_den = backup_profile->display_aspect_den;
			profile->display_aspect_num = backup_profile->display_aspect_num;
			profile->frame_rate_den = backup_profile->frame_rate_den;
			profile->frame_rate_num = backup_profile->frame_rate_num;
			profile->height = backup_profile->height;
			profile->progressive = backup_profile->progressive;
			profile->sample_aspect_den = backup_profile->sample_aspect_den;
			profile->sample_aspect_num = backup_profile->sample_aspect_num;
			profile->width = backup_profile->width;

			// Use the 'consumer' producer.
			mlt_producer_close( result );
			result = mlt_factory_producer( profile, "consumer", file );
		}

		mlt_profile_close( backup_profile );
		free( lookup );
	}

	// Finally, try just loading as service
	if ( result == NULL )
		result = mlt_factory_producer( profile, file, NULL );

	return result;
}

static void create_filter( mlt_profile profile, mlt_producer producer, char *effect, int *created )
{
	mlt_filter filter;
	char *id = strdup( effect );
	char *arg = strchr( id, ':' );
	if ( arg != NULL )
		*arg ++ = '\0';

	filter = mlt_factory_filter( profile, id, arg );
	if ( filter )
	{
		mlt_properties_set_int( MLT_FILTER_PROPERTIES( filter ), "_loader", 1 );
		mlt_producer_attach( producer, filter );
		mlt_filter_close( filter );
		*created = 1;
	}
	free( id );
}

static void attach_normalisers( mlt_profile profile, mlt_producer producer )
{
	// Loop variable
	int i;

	// Tokeniser
	mlt_tokeniser tokeniser = mlt_tokeniser_init( );

	// We only need to load the normalising properties once
	if ( normalisers == NULL )
	{
		char temp[ 1024 ];
		sprintf( temp, "%s/core/loader.ini", mlt_environment( "MLT_DATA" ) );
		normalisers = mlt_properties_load( temp );
		mlt_factory_register_for_clean_up( normalisers, ( mlt_destructor )mlt_properties_close );
	}

	// Apply normalisers
	for ( i = 0; i < mlt_properties_count( normalisers ); i ++ )
	{
		int j = 0;
		int created = 0;
		char *value = mlt_properties_get_value( normalisers, i );
		mlt_tokeniser_parse_new( tokeniser, value, "," );
		for ( j = 0; !created && j < mlt_tokeniser_count( tokeniser ); j ++ )
			create_filter( profile, producer, mlt_tokeniser_get_string( tokeniser, j ), &created );
	}

	// Close the tokeniser
	mlt_tokeniser_close( tokeniser );
}

mlt_producer producer_loader_init( mlt_profile profile, mlt_service_type type, const char *id, char *arg )
{
	// Create the producer
	mlt_producer producer = NULL;
	mlt_properties properties = NULL;

	if ( arg != NULL )
		producer = create_producer( profile, arg );

	if ( producer != NULL )
		properties = MLT_PRODUCER_PROPERTIES( producer );

	// Attach filters if we have a producer and it isn't already xml'd :-)
	if ( producer && strcmp( id, "abnormal" ) &&
		strncmp( arg, "abnormal:", 9 ) &&
		mlt_properties_get( properties, "xml" ) == NULL &&
		mlt_properties_get( properties, "_xml" ) == NULL &&
		mlt_properties_get( properties, "loader_normalised" ) == NULL )
		attach_normalisers( profile, producer );

	if ( producer && mlt_service_identify( MLT_PRODUCER_SERVICE( producer ) ) != mlt_service_chain_type )
	{
		// Always let the image and audio be converted
		int created = 0;
		// movit.convert skips setting the frame->convert_image pointer if GLSL cannot be used.
		create_filter( profile, producer, "movit.convert", &created );
		// avcolor_space and imageconvert only set frame->convert_image if it has not been set.
		create_filter( profile, producer, "avcolor_space", &created );
		if ( !created )
			create_filter( profile, producer, "imageconvert", &created );
		create_filter( profile, producer, "audioconvert", &created );
	}

	// Now make sure we don't lose our identity
	if ( properties != NULL )
		mlt_properties_set_int( properties, "_mlt_service_hidden", 1 );

	// Return the producer
	return producer;
}