[melted] / src / framework / mlt_playlist.c

/*
 * mlt_playlist.c -- playlist 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_playlist.h"
#include "mlt_frame.h"

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

/** Virtual playlist entry.
*/

typedef struct
{
        mlt_producer producer;
        mlt_timecode in;
        mlt_timecode playtime;
}
playlist_entry;

/** Private definition.
*/

struct mlt_playlist_s
{
        struct mlt_producer_s parent;
        struct mlt_producer_s blank;

        int size;
        int count;
        playlist_entry **list;
};

/** Forward declarations
*/

static int producer_get_frame( mlt_producer producer, mlt_frame_ptr frame, int index );

/** Constructor.
*/

mlt_playlist mlt_playlist_init( )
{
        mlt_playlist this = calloc( sizeof( struct mlt_playlist_s ), 1 );
        if ( this != NULL )
        {
                mlt_producer producer = &this->parent;

                // Construct the producer
                mlt_producer_init( producer, this );

                // Override the producer get_frame
                producer->get_frame = producer_get_frame;

                // Initialise blank
                mlt_producer_init( &this->blank, NULL );

                // Indicate that this producer is a playlist
                mlt_properties_set_data( mlt_playlist_properties( this ), "playlist", this, 0, NULL, NULL );
        }
        
        return this;
}

/** Get the producer associated to this playlist.
*/

mlt_producer mlt_playlist_producer( mlt_playlist this )
{
        return &this->parent;
}

/** Get the service associated to this playlist.
*/

mlt_service mlt_playlist_service( mlt_playlist this )
{
        return mlt_producer_service( &this->parent );
}

/** Get the propertues associated to this playlist.
*/

mlt_properties mlt_playlist_properties( mlt_playlist this )
{
        return mlt_producer_properties( &this->parent );
}

/** Append to the virtual playlist.
*/

static int mlt_playlist_virtual_append( mlt_playlist this, mlt_producer producer, mlt_timecode in, mlt_timecode out )
{
        // Get the fps of the first producer
        double fps = mlt_properties_get_double( mlt_playlist_properties( this ), "first_fps" );

        mlt_timecode playtime = mlt_producer_get_playtime( mlt_playlist_producer( this ) ) + out - in;

        // If fps is 0
        if ( fps == 0 )
        {
                // Inherit it from the producer
                fps = mlt_producer_get_fps( producer );
        }
        else if ( fps != mlt_properties_get_double( mlt_producer_properties( producer ), "fps" ) )
        {
                // Generate a warning for now - the following attempt to fix may fail
                fprintf( stderr, "Warning: fps mismatch on playlist producer %d\n", this->count );

                // It should be safe to impose fps on an image producer, but not necessarily safe for video
                mlt_properties_set_double( mlt_producer_properties( producer ), "fps", fps );
        }

        // Check that we have room
        if ( this->count >= this->size )
        {
                int i;
                this->list = realloc( this->list, ( this->size + 10 ) * sizeof( playlist_entry * ) );
                for ( i = this->size; i < this->size + 10; i ++ )
                        this->list[ i ] = NULL;
                this->size += 10;
        }

        this->list[ this->count ] = calloc( sizeof( playlist_entry ), 1 );
        this->list[ this->count ]->producer = producer;
        this->list[ this->count ]->in = in;
        this->list[ this->count ]->playtime = out - in;

        this->count ++;

        mlt_properties_set_double( mlt_playlist_properties( this ), "first_fps", fps );
        mlt_properties_set_double( mlt_playlist_properties( this ), "fps", fps );
        mlt_properties_set_timecode( mlt_playlist_properties( this ), "length", playtime );
        mlt_properties_set_timecode( mlt_playlist_properties( this ), "out", playtime );

        return 0;
}

/** Seek in the virtual playlist.
*/

static mlt_producer mlt_playlist_virtual_seek( mlt_playlist this )
{
        // Default producer to blank
        mlt_producer producer = &this->blank;

        // Map playlist position to real producer in virtual playlist
        mlt_timecode position = mlt_producer_position( &this->parent );

        // Loop through the virtual playlist
        int i = 0;

        for ( i = 0; i < this->count; i ++ )
        {
                if ( position < this->list[ i ]->playtime )
                {
                        // Found it, now break
                        producer = this->list[ i ]->producer;
                        position += this->list[ i ]->in;
                        break;
                }
                else
                {
                        // Decrement position by length of this entry
                        position -= this->list[ i ]->playtime;
                }
        }

        // Seek in real producer to relative position
        mlt_producer_seek( producer, position );

        return producer;
}

static mlt_producer mlt_playlist_virtual_set_out( mlt_playlist this )
{
        // Default producer to blank
        mlt_producer producer = &this->blank;

        // Map playlist position to real producer in virtual playlist
        mlt_timecode position = mlt_producer_position( &this->parent );

        // Loop through the virtual playlist
        int i = 0;

        for ( i = 0; i < this->count; i ++ )
        {
                if ( position < this->list[ i ]->playtime )
                {
                        // Found it, now break
                        producer = this->list[ i ]->producer;
                        position += this->list[ i ]->in;
                        break;
                }
                else
                {
                        // Decrement position by length of this entry
                        position -= this->list[ i ]->playtime;
                }
        }

        // Seek in real producer to relative position
        if ( i < this->count )
        {
                fprintf( stderr, "END OF CLIP %d AT %e\n", i, position );
                this->list[ i ]->playtime = position - this->list[ i ]->in;
        }

        return producer;
}

static int mlt_playlist_current_clip( mlt_playlist this )
{
        // Map playlist position to real producer in virtual playlist
        mlt_timecode position = mlt_producer_position( &this->parent );

        // Loop through the virtual playlist
        int i = 0;

        for ( i = 0; i < this->count; i ++ )
        {
                if ( position < this->list[ i ]->playtime )
                {
                        // Found it, now break
                        break;
                }
                else
                {
                        // Decrement position by length of this entry
                        position -= this->list[ i ]->playtime;
                }
        }

        return i;
}

/** Get the timecode which corresponds to the start of the next clip.
*/

mlt_timecode mlt_playlist_clip( mlt_playlist this, mlt_whence whence, int index )
{
        mlt_timecode position = 0;
        int absolute_clip = index;
        int i = 0;

        // Determine the absolute clip
        switch ( whence )
        {
                case mlt_whence_relative_start:
                        absolute_clip = index;
                        break;

                case mlt_whence_relative_current:
                        absolute_clip = mlt_playlist_current_clip( this ) + index;
                        break;

                case mlt_whence_relative_end:
                        absolute_clip = this->count - index;
                        break;
        }

        // Check that we're in a valid range
        if ( absolute_clip < 0 )
                absolute_clip = 0;
        else if ( absolute_clip > this->count )
                absolute_clip = this->count;

        // Now determine the timecode
        for ( i = 0; i < absolute_clip; i ++ )
                position += this->list[ i ]->playtime;

        return position;
}

/** Append a producer to the playlist.
*/

int mlt_playlist_append( mlt_playlist this, mlt_producer producer )
{
        // Append to virtual list
        return mlt_playlist_virtual_append( this, producer, 0, mlt_producer_get_playtime( producer ) );
}

/** Append a blank to the playlist of a given length.
*/

int mlt_playlist_blank( mlt_playlist this, mlt_timecode length )
{
        // Append to the virtual list
        return mlt_playlist_virtual_append( this, &this->blank, 0, length );
}

/** Get the current frame.
*/

static int producer_get_frame( mlt_producer producer, mlt_frame_ptr frame, int index )
{
        // Get this mlt_playlist
        mlt_playlist this = producer->child;

        // Get the real producer
        mlt_producer real = mlt_playlist_virtual_seek( this );

        // Get the frame
        mlt_service_get_frame( mlt_producer_service( real ), frame, index );

        // Check if we're at the end of the clip
        mlt_properties properties = mlt_frame_properties( *frame );
        if ( mlt_properties_get_int( properties, "end_of_clip" ) )
                mlt_playlist_virtual_set_out( this );

        // Update timecode on the frame we're creating
        mlt_frame_set_timecode( *frame, mlt_producer_position( producer ) );

        // Position ourselves on the next frame
        mlt_producer_prepare_next( producer );

        return 0;
}

/** Close the playlist.
*/

void mlt_playlist_close( mlt_playlist this )
{
        mlt_producer_close( &this->parent );
        mlt_producer_close( &this->blank );
        free( this );
}