mlt/src/modules/fezzik/producer_hold.c

/*
 * producer_hold.c -- frame holding producer
 * Copyright (C) 2003-2004 Ushodaya Enterprises Limited
 * Author: Charles Yates <charles.yates@pandora.be>
 *
 * 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 "producer_hold.h"

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <framework/mlt.h>

// Forward references
static int producer_get_frame( mlt_producer this, mlt_frame_ptr frame, int index );
static void producer_close( mlt_producer this );

/** Constructor for the frame holding producer. Basically, all this producer does is
	provide a producer wrapper for the requested producer, allows the specifcation of
	the frame required and will then repeatedly obtain that frame for each get_frame
	and get_image requested.
*/

mlt_producer producer_hold_init( char *arg )
{
	// Construct a new holding producer
	mlt_producer this = mlt_producer_new( );

	// Construct the requested producer via fezzik
	mlt_producer producer = mlt_factory_producer( "fezzik", arg );

	// Initialise the frame holding capabilities
	if ( this != NULL && producer != NULL )
	{
		// Get the properties of this producer
		mlt_properties properties = MLT_PRODUCER_PROPERTIES( this );

		// Store the producer
		mlt_properties_set_data( properties, "producer", producer, 0, ( mlt_destructor )mlt_producer_close, NULL );

		// Set frame, in, out and length for this producer
		mlt_properties_set_position( properties, "frame", 0 );
		mlt_properties_set_position( properties, "in", 0 );
		mlt_properties_set_position( properties, "out", 25 );
		mlt_properties_set_position( properties, "length", 15000 );
		mlt_properties_set( properties, "resource", arg );
		mlt_properties_set( properties, "method", "onefield" );

		// Override the get_frame method
		this->get_frame = producer_get_frame;
		this->close = ( mlt_destructor )producer_close;
	}
	else
	{
		// Clean up (not sure which one failed, can't be bothered to find out, so close both)
		if ( this )
			mlt_producer_close( this );
		if ( producer )
			mlt_producer_close( producer );

		// Make sure we return NULL
		this = NULL;
	}

	// Return this producer
	return this;
}

static int producer_get_image( mlt_frame frame, uint8_t **buffer, mlt_image_format *format, int *width, int *height, int writable )
{
	// Get the properties of the frame
	mlt_properties properties = MLT_FRAME_PROPERTIES( frame );

	// Obtain the real frame
	mlt_frame real_frame = mlt_frame_pop_service( frame );

	// Get the image from the real frame
	int size = 0;
	*buffer = mlt_properties_get_data( MLT_FRAME_PROPERTIES( real_frame ), "image", &size );
	*width = mlt_properties_get_int( MLT_FRAME_PROPERTIES( real_frame ), "width" );
	*height = mlt_properties_get_int( MLT_FRAME_PROPERTIES( real_frame ), "height" );

	// If this is the first time, get it from the producer
	if ( *buffer == NULL )
	{
		mlt_properties_pass( MLT_FRAME_PROPERTIES( real_frame ), properties, "" );

		// We'll deinterlace on the downstream deinterlacer
		mlt_properties_set_int( MLT_FRAME_PROPERTIES( real_frame ), "consumer_deinterlace", 1 );

		// We want distorted to ensure we don't hit the resize filter twice
		mlt_properties_set_int( MLT_FRAME_PROPERTIES( real_frame ), "distort", 1 );

		// Get the image
		mlt_frame_get_image( real_frame, buffer, format, width, height, writable );
	
		// Make sure we get the size
		*buffer = mlt_properties_get_data( MLT_FRAME_PROPERTIES( real_frame ), "image", &size );
	}

	mlt_properties_pass( properties, MLT_FRAME_PROPERTIES( real_frame ), "" );

	// Set the values obtained on the frame
	if ( *buffer != NULL )
	{
		uint8_t *image = mlt_pool_alloc( size );
		memcpy( image, *buffer, size );
		*buffer = image;
		mlt_properties_set_data( properties, "image", *buffer, size, mlt_pool_release, NULL );
	}
	else
	{
		// Pass the current image as is
		mlt_properties_set_data( properties, "image", *buffer, size, NULL, NULL );
	}

	// Make sure that no further scaling is done
	mlt_properties_set( properties, "rescale.interps", "none" );
	mlt_properties_set( properties, "scale", "off" );

	// All done
	return 0;
}

static int producer_get_frame( mlt_producer this, mlt_frame_ptr frame, int index )
{
	// Get the properties of this producer
	mlt_properties properties = MLT_PRODUCER_PROPERTIES( this );

	// Construct a new frame
	*frame = mlt_frame_init( );

	// If we have a frame, then stack the producer itself and the get_image method
	if ( *frame != NULL )
	{
		// Define the real frame
		mlt_frame real_frame = mlt_properties_get_data( properties, "real_frame", NULL );

		// Obtain real frame if we don't have it
		if ( real_frame == NULL )
		{
			// Get the producer
			mlt_producer producer = mlt_properties_get_data( properties, "producer", NULL );

			// Get the frame position requested
			mlt_position position = mlt_properties_get_position( properties, "frame" );

			// Seek the producer to the correct place
			mlt_producer_seek( producer, position );

			// Get the real frame
			mlt_service_get_frame( MLT_PRODUCER_SERVICE( producer ), &real_frame, index );

			// Ensure that the real frame gets wiped eventually
			mlt_properties_set_data( properties, "real_frame", real_frame, 0, ( mlt_destructor )mlt_frame_close, NULL );
		}
		else
		{
			// Temporary fix - ensure that we aren't seen as a test frame
			int8_t *image = mlt_properties_get_data( MLT_FRAME_PROPERTIES( real_frame ), "image", NULL );
			mlt_properties_set_data( MLT_FRAME_PROPERTIES( *frame ), "image", image, 0, NULL, NULL );
			mlt_properties_set_int( MLT_FRAME_PROPERTIES( *frame ), "test_image", 0 );
		}

		// Stack the real frame and method
		mlt_frame_push_service( *frame, real_frame );
		mlt_frame_push_service( *frame, producer_get_image );

		// Ensure that the consumer sees what the real frame has
		mlt_properties_pass( MLT_FRAME_PROPERTIES( *frame ), MLT_FRAME_PROPERTIES( real_frame ), "" );

		mlt_properties_set( MLT_FRAME_PROPERTIES( real_frame ), "deinterlace_method",
			mlt_properties_get( properties, "method" ) );
	}

	// Move to the next position
	mlt_producer_prepare_next( this );

	return 0;
}

static void producer_close( mlt_producer this )
{
	this->close = NULL;
	mlt_producer_close( this );
	free( this );
}