[melted] / src / framework / mlt_tractor.c

/*
 * mlt_tractor.c -- tractor service class
 * Copyright (C) 2003-2004 Ushodaya Enterprises Limited
 * Author: Charles Yates <charles.yates@pandora.be>
 *
 * 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

#include "config.h"

#include "mlt_tractor.h"
#include "mlt_frame.h"
#include "mlt_multitrack.h"
#include "mlt_field.h"

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

/** Private structure.
*/

struct mlt_tractor_s
{
        struct mlt_producer_s parent;
        mlt_service producer;
};

/** Forward references to static methods.
*/

static int producer_get_frame( mlt_producer this, mlt_frame_ptr frame, int track );
static void mlt_tractor_listener( mlt_multitrack tracks, mlt_tractor this );

/** Constructor for the tractor.
*/

mlt_tractor mlt_tractor_init( )
{
        mlt_tractor this = calloc( sizeof( struct mlt_tractor_s ), 1 );
        if ( this != NULL )
        {
                mlt_producer producer = &this->parent;
                if ( mlt_producer_init( producer, this ) == 0 )
                {
                        mlt_properties_set( mlt_producer_properties( producer ), "resource", "<tractor>" );
                        mlt_properties_set( mlt_producer_properties( producer ), "mlt_type", "mlt_producer" );
                        mlt_properties_set( mlt_producer_properties( producer ), "mlt_service", "tractor" );

                        producer->get_frame = producer_get_frame;
                        producer->close = ( mlt_destructor )mlt_tractor_close;
                        producer->close_object = this;
                }
                else
                {
                        free( this );
                        this = NULL;
                }
        }
        return this;
}

mlt_tractor mlt_tractor_new( )
{
        mlt_tractor this = calloc( sizeof( struct mlt_tractor_s ), 1 );
        if ( this != NULL )
        {
                mlt_producer producer = &this->parent;
                if ( mlt_producer_init( producer, this ) == 0 )
                {
                        mlt_multitrack multitrack = mlt_multitrack_init( );
                        mlt_field field = mlt_field_new( multitrack, this );
                        mlt_properties props = mlt_producer_properties( producer );

                        mlt_properties_set( props, "resource", "<tractor>" );
                        mlt_properties_set( props, "mlt_type", "mlt_producer" );
                        mlt_properties_set( props, "mlt_service", "tractor" );
                        mlt_properties_set_position( props, "in", 0 );
                        mlt_properties_set_position( props, "out", 0 );
                        mlt_properties_set_position( props, "length", 0 );
                        mlt_properties_set_data( props, "multitrack", multitrack, 0, ( mlt_destructor )mlt_multitrack_close, NULL );
                        mlt_properties_set_data( props, "field", field, 0, ( mlt_destructor )mlt_field_close, NULL );

                        mlt_events_listen( mlt_multitrack_properties( multitrack ), this, "producer-changed", ( mlt_listener )mlt_tractor_listener );

                        producer->get_frame = producer_get_frame;
                        producer->close = ( mlt_destructor )mlt_tractor_close;
                        producer->close_object = this;
                }
                else
                {
                        free( this );
                        this = NULL;
                }
        }
        return this;
}

/** Get the service object associated to the tractor.
*/

mlt_service mlt_tractor_service( mlt_tractor this )
{
        return mlt_producer_service( &this->parent );
}

/** Get the producer object associated to the tractor.
*/

mlt_producer mlt_tractor_producer( mlt_tractor this )
{
        return this != NULL ? &this->parent : NULL;
}

/** Get the properties object associated to the tractor.
*/

mlt_properties mlt_tractor_properties( mlt_tractor this )
{
        return mlt_producer_properties( &this->parent );
}

/** Get the field this tractor is harvesting.
*/

mlt_field mlt_tractor_field( mlt_tractor this )
{
        return mlt_properties_get_data( mlt_tractor_properties( this ), "field", NULL );
}

/** Get the multitrack this tractor is pulling.
*/

mlt_multitrack mlt_tractor_multitrack( mlt_tractor this )
{
        return mlt_properties_get_data( mlt_tractor_properties( this ), "multitrack", NULL );
}

/** Ensure the tractors in/out points match the multitrack.
*/

void mlt_tractor_refresh( mlt_tractor this )
{
        mlt_multitrack multitrack = mlt_tractor_multitrack( this );
        mlt_properties properties = mlt_multitrack_properties( multitrack );
        mlt_properties self = mlt_tractor_properties( this );
        mlt_events_block( properties, self );
        mlt_events_block( self, self );
        mlt_multitrack_refresh( multitrack );
        mlt_properties_set_position( self, "in", 0 );
        mlt_properties_set_position( self, "out", mlt_properties_get_position( properties, "out" ) );
        mlt_events_unblock( self, self );
        mlt_events_unblock( properties, self );
        mlt_properties_set_position( self, "length", mlt_properties_get_position( properties, "length" ) );
}

static void mlt_tractor_listener( mlt_multitrack tracks, mlt_tractor this )
{
        mlt_tractor_refresh( this );
}

/** Connect the tractor.
*/

int mlt_tractor_connect( mlt_tractor this, mlt_service producer )
{
        int ret = mlt_service_connect_producer( mlt_tractor_service( this ), producer, 0 );

        // This is the producer we're going to connect to
        if ( ret == 0 )
                this->producer = producer;

        return ret;
}

/** Set the producer for a specific track.
*/

int mlt_tractor_set_track( mlt_tractor this, mlt_producer producer, int index )
{
        return mlt_multitrack_connect( mlt_tractor_multitrack( this ), producer, index );
}

/** Get the producer for a specific track.
*/

mlt_producer mlt_tractor_get_track( mlt_tractor this, int index )
{
        return mlt_multitrack_track( mlt_tractor_multitrack( this ), index );
}

static int producer_get_image( mlt_frame this, uint8_t **buffer, mlt_image_format *format, int *width, int *height, int writable )
{
        mlt_properties properties = mlt_frame_properties( this );
        mlt_frame frame = mlt_frame_pop_service( this );
        mlt_properties_inherit( mlt_frame_properties( frame ), properties );
        mlt_frame_get_image( frame, buffer, format, width, height, writable );
        mlt_properties_set_data( properties, "image", *buffer, *width * *height * 2, NULL, NULL );
        mlt_properties_set_int( properties, "width", *width );
        mlt_properties_set_int( properties, "height", *height );
        return 0;
}

static int producer_get_audio( mlt_frame this, int16_t **buffer, mlt_audio_format *format, int *frequency, int *channels, int *samples )
{
        mlt_properties properties = mlt_frame_properties( this );
        mlt_frame frame = mlt_frame_pop_audio( this );
        mlt_properties_inherit( mlt_frame_properties( frame ), properties );
        mlt_frame_get_audio( frame, buffer, format, frequency, channels, samples );
        mlt_properties_set_data( properties, "audio", *buffer, 0, NULL, NULL );
        mlt_properties_set_int( properties, "frequency", *frequency );
        mlt_properties_set_int( properties, "channels", *channels );
        return 0;
}

/** Get the next frame.
*/

static int producer_get_frame( mlt_producer parent, mlt_frame_ptr frame, int track )
{
        mlt_tractor this = parent->child;

        // We only respond to the first track requests
        if ( track == 0 && this->producer != NULL )
        {
                int i = 0;
                int done = 0;
                mlt_frame temp = NULL;
                int count = 0;

                // Get the properties of the parent producer
                mlt_properties properties = mlt_producer_properties( parent );

                // Try to obtain the multitrack associated to the tractor
                mlt_multitrack multitrack = mlt_properties_get_data( properties, "multitrack", NULL );

                // Or a specific producer
                mlt_producer producer = mlt_properties_get_data( properties, "producer", NULL );

                // If we don't have one, we're in trouble... 
                if ( multitrack != NULL )
                {
                        // Used to garbage collect all frames
                        char label[ 30 ];

                        // Get the id of the tractor
                        char *id = mlt_properties_get( properties, "_unique_id" );

                        // Will be used to store the frame properties object
                        mlt_properties frame_properties = NULL;

                        // We'll store audio and video frames to use here
                        mlt_frame audio = NULL;
                        mlt_frame video = NULL;

                        // Get the multitrack's producer
                        mlt_producer target = mlt_multitrack_producer( multitrack );
                        mlt_producer_seek( target, mlt_producer_frame( parent ) );
                        mlt_producer_set_speed( target, mlt_producer_get_speed( parent ) );

                        // We will create one frame and attach everything to it
                        *frame = mlt_frame_init( );

                        // Get the properties of the frame
                        frame_properties = mlt_frame_properties( *frame );

                        // Loop through each of the tracks we're harvesting
                        for ( i = 0; !done; i ++ )
                        {
                                // Get a frame from the producer
                                mlt_service_get_frame( this->producer, &temp, i );

                                // Check for last track
                                done = mlt_properties_get_int( mlt_frame_properties( temp ), "last_track" );

                                // We store all frames with a destructor on the output frame
                                sprintf( label, "_%s_%d", id, count ++ );
                                mlt_properties_set_data( frame_properties, label, temp, 0, ( mlt_destructor )mlt_frame_close, NULL );

                                // Pick up first video and audio frames
                                if ( !done && !mlt_frame_is_test_audio( temp ) && !( mlt_properties_get_int( mlt_frame_properties( temp ), "hide" ) & 2 ) )
                                        audio = temp;
                                if ( !done && !mlt_frame_is_test_card( temp ) && !( mlt_properties_get_int( mlt_frame_properties( temp ), "hide" ) & 1 ) )
                                        video = temp;
                        }
        
                        // Now stack callbacks
                        if ( audio != NULL )
                        {
                                mlt_frame_push_audio( *frame, audio );
                                ( *frame )->get_audio = producer_get_audio;
                                mlt_properties_inherit( mlt_frame_properties( *frame ), mlt_frame_properties( audio ) );
                        }

                        if ( video != NULL )
                        {
                                mlt_frame_push_service( *frame, video );
                                mlt_frame_push_service( *frame, producer_get_image );
                                mlt_properties_inherit( mlt_frame_properties( *frame ), mlt_frame_properties( video ) );
                        }

                        mlt_properties_set_int( mlt_frame_properties( *frame ), "test_audio", audio == NULL );
                        mlt_properties_set_int( mlt_frame_properties( *frame ), "test_image", video == NULL );
                }
                else if ( producer != NULL )
                {
                        mlt_producer_seek( producer, mlt_producer_frame( parent ) );
                        mlt_producer_set_speed( producer, mlt_producer_get_speed( parent ) );
                        mlt_service_get_frame( this->producer, frame, track );
                }
                else
                {
                        fprintf( stderr, "tractor without a multitrack!!\n" );
                        mlt_service_get_frame( this->producer, frame, track );
                }

                // Prepare the next frame
                mlt_producer_prepare_next( parent );

                // Indicate our found status
                return 0;
        }
        else
        {
                // Generate a test card
                *frame = mlt_frame_init( );
                return 0;
        }
}

/** Close the tractor.
*/

void mlt_tractor_close( mlt_tractor this )
{
        if ( this != NULL && mlt_properties_dec_ref( mlt_tractor_properties( this ) ) <= 0 )
        {
                this->parent.close = NULL;
                mlt_producer_close( &this->parent );
                free( this );
        }
}