Minor fixes to westley and mlt_consumer; first draft westley docs

[melted] / src / framework / mlt_consumer.c

/*
 * mlt_consumer.c -- abstraction for all consumer services
 * 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_consumer.h"
#include "mlt_factory.h"
#include "mlt_producer.h"
#include "mlt_frame.h"
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <sys/time.h>

/** Public final methods
*/

int mlt_consumer_init( mlt_consumer this, void *child )
{
        int error = 0;
        memset( this, 0, sizeof( struct mlt_consumer_s ) );
        this->child = child;
        error = mlt_service_init( &this->parent, this );
        if ( error == 0 )
        {
                // Get the properties from the service
                mlt_properties properties = mlt_service_properties( &this->parent );

                // Get the normalisation preference
                char *normalisation = mlt_environment( "MLT_NORMALISATION" );

                // Deal with normalisation
                if ( normalisation == NULL || strcmp( normalisation, "NTSC" ) )
                {
                        mlt_properties_set( properties, "normalisation", "PAL" );
                        mlt_properties_set_double( properties, "fps", 25.0 );
                        mlt_properties_set_int( properties, "width", 720 );
                        mlt_properties_set_int( properties, "height", 576 );
                        mlt_properties_set_int( properties, "progressive", 0 );
                        mlt_properties_set_double( properties, "aspect_ratio", 128.0 / 117.0 );
                }
                else
                {
                        mlt_properties_set( properties, "normalisation", "NTSC" );
                        mlt_properties_set_double( properties, "fps", 30000.0 / 1001.0 );
                        mlt_properties_set_int( properties, "width", 720 );
                        mlt_properties_set_int( properties, "height", 480 );
                        mlt_properties_set_int( properties, "progressive", 0 );
                        mlt_properties_set_double( properties, "aspect_ratio", 72.0 / 79.0 );
                }

                // Default rescaler for all consumers
                mlt_properties_set( properties, "rescale", "bilinear" );

                // Default read ahead buffer size
                mlt_properties_set_int( properties, "buffer", 25 );

                // Hmm - default all consumers to yuv422 :-/
                this->format = mlt_image_yuv422;
        }
        return error;
}

/** Get the parent service object.
*/

mlt_service mlt_consumer_service( mlt_consumer this )
{
        return &this->parent;
}

/** Get the consumer properties.
*/

mlt_properties mlt_consumer_properties( mlt_consumer this )
{
        return mlt_service_properties( &this->parent );
}

/** Connect the consumer to the producer.
*/

int mlt_consumer_connect( mlt_consumer this, mlt_service producer )
{
        return mlt_service_connect_producer( &this->parent, producer, 0 );
}

/** Start the consumer.
*/

int mlt_consumer_start( mlt_consumer this )
{
        // Get the properies
        mlt_properties properties = mlt_consumer_properties( this );

        // Determine if there's a test card producer
        char *test_card = mlt_properties_get( properties, "test_card" );

        // Deal with it now.
        if ( test_card != NULL )
        {
                if ( mlt_properties_get_data( properties, "test_card_producer", NULL ) == NULL )
                {
                        // Create a test card producer
                        // TODO: do we want to use fezzik here?
                        mlt_producer producer = mlt_factory_producer( "fezzik", test_card );

                        // Do we have a producer
                        if ( producer != NULL )
                        {
                                // Test card should loop I guess...
                                mlt_properties_set( mlt_producer_properties( producer ), "eof", "loop" );

                                // Set the test card on the consumer
                                mlt_properties_set_data( properties, "test_card_producer", producer, 0, ( mlt_destructor )mlt_producer_close, NULL );
                        }

                        // Check and run an ante command
                        if ( mlt_properties_get( properties, "ante" ) )
                                system( mlt_properties_get( properties, "ante" ) );
                }
        }
        else
        {
                // Allow the hash table to speed things up
                mlt_properties_set_data( properties, "test_card_producer", NULL, 0, NULL, NULL );
        }

        // Start the service
        if ( this->start != NULL )
                return this->start( this );

        return 0;
}

/** Protected method :-/ for consumer to get frames from connected service
*/

mlt_frame mlt_consumer_get_frame( mlt_consumer this )
{
        // Frame to return
        mlt_frame frame = NULL;

        // Get the service assoicated to the consumer
        mlt_service service = mlt_consumer_service( this );

        // Get the frame
        if ( mlt_service_get_frame( service, &frame, 0 ) == 0 )
        {
                // Get the consumer properties
                mlt_properties properties = mlt_consumer_properties( this );

                // Get the frame properties
                mlt_properties frame_properties = mlt_frame_properties( frame );

                // Get the test card producer
                mlt_producer test_card = mlt_properties_get_data( properties, "test_card_producer", NULL );

                // Attach the test frame producer to it.
                if ( test_card != NULL )
                        mlt_properties_set_data( frame_properties, "test_card_producer", test_card, 0, NULL, NULL );

                // Attach the rescale property
                mlt_properties_set( frame_properties, "rescale.interp", mlt_properties_get( properties, "rescale" ) );

                // Aspect ratio and other jiggery pokery
                mlt_properties_set_double( frame_properties, "consumer_aspect_ratio", mlt_properties_get_double( properties, "aspect_ratio" ) );
                mlt_properties_set_int( frame_properties, "consumer_progressive", mlt_properties_get_int( properties, "progressive" ) );
                mlt_properties_set_int( frame_properties, "consumer_deinterlace", mlt_properties_get_int( properties, "deinterlace" ) );
        }

        // Return the frame
        return frame;
}

static inline long time_difference( struct timeval *time1 )
{
        struct timeval time2;
        time2.tv_sec = time1->tv_sec;
        time2.tv_usec = time1->tv_usec;
        gettimeofday( time1, NULL );
        return time1->tv_sec * 1000000 + time1->tv_usec - time2.tv_sec * 1000000 - time2.tv_usec;
}

static void *consumer_read_ahead_thread( void *arg )
{
        // The argument is the consumer
        mlt_consumer this = arg;

        // Get the properties of the consumer
        mlt_properties properties = mlt_consumer_properties( this );

        // Get the width and height
        int width = mlt_properties_get_int( properties, "width" );
        int height = mlt_properties_get_int( properties, "height" );

        // Get the maximum size of the buffer
        int buffer = mlt_properties_get_int( properties, "buffer" );

        // General frame variable
        mlt_frame frame = NULL;
        uint8_t *image = NULL;

        // Time structures
        struct timeval ante;

        // Average time for get_frame and get_image
        int count = 1;
        int skipped = 0;
        int64_t time_wait = 0;
        int64_t time_frame = 0;
        int64_t time_image = 0;

        // Get the first frame
        frame = mlt_consumer_get_frame( this );

        // Get the image of the first frame
        mlt_frame_get_image( frame, &image, &this->format, &width, &height, 0 );
        mlt_properties_set_int( mlt_frame_properties( frame ), "rendered", 1 );

        // Get the starting time (can ignore the times above)
        gettimeofday( &ante, NULL );

        // Continue to read ahead
        while ( this->ahead )
        {
                // Put the current frame into the queue
                pthread_mutex_lock( &this->mutex );
                while( this->ahead && mlt_deque_count( this->queue ) >= buffer )
                        pthread_cond_wait( &this->cond, &this->mutex );
                mlt_deque_push_back( this->queue, frame );
                pthread_cond_broadcast( &this->cond );
                pthread_mutex_unlock( &this->mutex );
                time_wait += time_difference( &ante );

                // Get the next frame
                frame = mlt_consumer_get_frame( this );
                time_frame += time_difference( &ante );

                // Increment the count
                count ++;

                // Get the image
                if ( ( time_frame + time_image ) / count < ( 40000 - ( time_wait / count ) ) )
                {
                        // Get the image, mark as rendered and time it
                        mlt_frame_get_image( frame, &image, &this->format, &width, &height, 0 );
                        mlt_properties_set_int( mlt_frame_properties( frame ), "rendered", 1 );
                        time_image += time_difference( &ante );

                        // Reset the skipped count
                        skipped = 0;
                }
                else
                {
                        // Increment the number of sequentially skipped frames
                        skipped ++;

                        // If we've reached an unacceptable level, reset everything
                        if ( skipped > 10 )
                        {
                                skipped = 0;
                                time_frame = 0;
                                time_image = 0;
                        }
                }
        }

        // Remove the last frame
        mlt_frame_close( frame );

        return NULL;
}

static void consumer_read_ahead_start( mlt_consumer this )
{
        // We're running now
        this->ahead = 1;

        // Create the frame queue
        this->queue = mlt_deque_init( );

        // Create the mutex
        pthread_mutex_init( &this->mutex, NULL );

        // Create the condition
        pthread_cond_init( &this->cond, NULL );

        // Create the read ahead 
        pthread_create( &this->ahead_thread, NULL, consumer_read_ahead_thread, this );

}

static void consumer_read_ahead_stop( mlt_consumer this )
{
        // Make sure we're running
        if ( this->ahead )
        {
                // Inform thread to stop
                this->ahead = 0;

                // Broadcast to the condition in case it's waiting
                pthread_mutex_lock( &this->mutex );
                pthread_cond_broadcast( &this->cond );
                pthread_mutex_unlock( &this->mutex );

                // Join the thread
                pthread_join( this->ahead_thread, NULL );

                // Destroy the mutex
                pthread_mutex_destroy( &this->mutex );

                // Destroy the condition
                pthread_cond_destroy( &this->cond );

                // Wipe the queue
                while ( mlt_deque_count( this->queue ) )
                        mlt_frame_close( mlt_deque_pop_back( this->queue ) );
        }
}

mlt_frame mlt_consumer_rt_frame( mlt_consumer this )
{
        // Frame to return
        mlt_frame frame = NULL;
        int size = 1;

        // Is the read ahead running?
        if ( this->ahead == 0 )
        {
                int buffer = mlt_properties_get_int( mlt_consumer_properties( this ), "buffer" );
                consumer_read_ahead_start( this );
                if ( buffer > 1 )
                        size = buffer / 2;
        }

        // Get frame from queue
        pthread_mutex_lock( &this->mutex );
        while( this->ahead && mlt_deque_count( this->queue ) < size )
                pthread_cond_wait( &this->cond, &this->mutex );
        frame = mlt_deque_pop_front( this->queue );
        pthread_cond_broadcast( &this->cond );
        pthread_mutex_unlock( &this->mutex );

        return frame;
}

/** Stop the consumer.
*/

int mlt_consumer_stop( mlt_consumer this )
{
        // Get the properies
        mlt_properties properties = mlt_consumer_properties( this );

        // Stop the consumer
        if ( this->stop != NULL )
                this->stop( this );

        // Kill the read ahead
        consumer_read_ahead_stop( this );

        // Kill the test card
        mlt_properties_set_data( properties, "test_card_producer", NULL, 0, NULL, NULL );

        // Check and run a post command
        if ( mlt_properties_get( properties, "post" ) )
                system( mlt_properties_get( properties, "post" ) );

        return 0;
}

/** Determine if the consumer is stopped.
*/

int mlt_consumer_is_stopped( mlt_consumer this )
{
        // Check if the consumer is stopped
        if ( this->is_stopped != NULL )
                return this->is_stopped( this );

        return 0;
}

/** Close the consumer.
*/

void mlt_consumer_close( mlt_consumer this )
{
        // Get the childs close function
        void ( *consumer_close )( ) = this->close;

        // Make sure it only gets called once
        this->close = NULL;

        // Call the childs close if available
        if ( consumer_close != NULL )
                consumer_close( this );
        else
                mlt_service_close( &this->parent );
}