+/*
+ * producer_noise.c -- noise generating producer
+ * 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 "producer_noise.h"
+#include <framework/mlt_frame.h>
+#include <framework/mlt_pool.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+/** Random number generator
+*/
+
+static unsigned int seed_x = 521288629;
+static unsigned int seed_y = 362436069;
+
+static unsigned inline int fast_rand( )
+{
+ static unsigned int a = 18000, b = 30903;
+ seed_x = a * ( seed_x & 65535 ) + ( seed_x >> 16 );
+ seed_y = b * ( seed_y & 65535 ) + ( seed_y >> 16 );
+ return ( ( seed_x << 16 ) + ( seed_y & 65535 ) );
+}
+
+// Foward declarations
+static int producer_get_frame( mlt_producer this, mlt_frame_ptr frame, int index );
+
+/** Initialise.
+*/
+
+mlt_producer producer_noise_init( void *arg )
+{
+ // Create a new producer object
+ mlt_producer this = mlt_producer_new( );
+
+ // Initialise the producer
+ if ( this != NULL )
+ {
+ // Callback registration
+ this->get_frame = producer_get_frame;
+ }
+
+ return this;
+}
+
+static int producer_get_image( mlt_frame frame, uint8_t **buffer, mlt_image_format *format, int *width, int *height, int writable )
+{
+ // Obtain properties of frame
+ mlt_properties properties = mlt_frame_properties( frame );
+
+ // Calculate the size of the image
+ int size = *width * *height * 2;
+
+ // Set the format being returned
+ *format = mlt_image_yuv422;
+
+ // Allocate the image
+ *buffer = mlt_pool_alloc( size );
+
+ // Update the frame
+ mlt_properties_set_data( properties, "image", *buffer, size, mlt_pool_release, NULL );
+ mlt_properties_set_int( properties, "width", *width );
+ mlt_properties_set_int( properties, "height", *height );
+
+ // Before we write to the image, make sure we have one
+ if ( *buffer != NULL )
+ {
+ // Calculate the end of the buffer
+ uint8_t *p = *buffer + *width * *height * 2;
+
+ // Value to hold a random number
+ uint32_t value;
+
+ // Generate random noise
+ while ( p != *buffer )
+ {
+ value = fast_rand( );
+ *( -- p ) = 128;
+ *( -- p ) = value & 0xff;
+ *( -- p ) = 128;
+ *( -- p ) = ( ( value & 0xff00 ) >> 8 ) & 0xf0;
+ }
+ }
+
+ return 0;
+}
+
+static int producer_get_audio( mlt_frame frame, int16_t **buffer, mlt_audio_format *format, int *frequency, int *channels, int *samples )
+{
+ // Get the frame properties
+ mlt_properties properties = mlt_frame_properties( frame );
+
+ int size = 0;
+
+ // Correct the returns if necessary
+ *samples = *samples <= 0 ? 1920 : *samples;
+ *channels = *channels <= 0 ? 2 : *channels;
+ *frequency = *frequency <= 0 ? 48000 : *frequency;
+
+ // Calculate the size of the buffer
+ size = *samples * *channels * sizeof( int16_t );
+
+ // Allocate the buffer
+ *buffer = mlt_pool_alloc( size );
+
+ // Make sure we got one and fill it
+ if ( *buffer != NULL )
+ {
+ int16_t *p = *buffer + size / 2;
+ while ( p != *buffer )
+ *( -- p ) = fast_rand( ) & 0xff;
+ }
+
+ // Set the buffer for destruction
+ mlt_properties_set_data( properties, "audio", *buffer, size, ( mlt_destructor )mlt_pool_release, NULL );
+
+ return 0;
+}
+
+static int producer_get_frame( mlt_producer this, mlt_frame_ptr frame, int index )
+{
+ // Generate a frame
+ *frame = mlt_frame_init( );
+
+ // Check that we created a frame and initialise it
+ if ( *frame != NULL )
+ {
+ // Obtain properties of frame
+ mlt_properties properties = mlt_frame_properties( *frame );
+
+ // Aspect ratio is 1?
+ mlt_properties_set_double( properties, "aspect_ratio", 1.0 );
+
+ // Set producer-specific frame properties
+ mlt_properties_set_int( properties, "progressive", 1 );
+
+ // Update timecode on the frame we're creating
+ mlt_frame_set_position( *frame, mlt_producer_position( this ) );
+
+ // Push the get_image method
+ mlt_frame_push_get_image( *frame, producer_get_image );
+
+ // Specify the audio
+ ( *frame )->get_audio = producer_get_audio;
+ }
+
+ // Calculate the next timecode
+ mlt_producer_prepare_next( this );
+
+ return 0;
+}
+
+
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