2 * producer_noise.c -- noise generating producer
3 * Copyright (C) 2003-2004 Ushodaya Enterprises Limited
4 * Author: Charles Yates <charles.yates@pandora.be>
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software Foundation,
18 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
21 #include "producer_noise.h"
22 #include <framework/mlt_frame.h>
23 #include <framework/mlt_pool.h>
29 /** Random number generator
32 static unsigned int seed_x
= 521288629;
33 static unsigned int seed_y
= 362436069;
35 static unsigned inline int fast_rand( )
37 static unsigned int a
= 18000, b
= 30903;
38 seed_x
= a
* ( seed_x
& 65535 ) + ( seed_x
>> 16 );
39 seed_y
= b
* ( seed_y
& 65535 ) + ( seed_y
>> 16 );
40 return ( ( seed_x
<< 16 ) + ( seed_y
& 65535 ) );
43 // Foward declarations
44 static int producer_get_frame( mlt_producer
this, mlt_frame_ptr frame
, int index
);
45 static void producer_close( mlt_producer
this );
50 mlt_producer
producer_noise_init( void *arg
)
52 // Create a new producer object
53 mlt_producer
this = mlt_producer_new( );
55 // Initialise the producer
58 int is_pal
= mlt_properties_get_int( MLT_PRODUCER_PROPERTIES( this ), "normalised_height" ) == 576;
60 // Synthetic - aspect ratio of 1
61 mlt_properties_set_double( MLT_PRODUCER_PROPERTIES( this ), "aspect_ratio", is_pal ?
59.0/54.0 : 10.0/11.0 );
63 // Callback registration
64 this->get_frame
= producer_get_frame
;
65 this->close
= ( mlt_destructor
)producer_close
;
71 static int producer_get_image( mlt_frame frame
, uint8_t **buffer
, mlt_image_format
*format
, int *width
, int *height
, int writable
)
73 // Obtain properties of frame
74 mlt_properties properties
= MLT_FRAME_PROPERTIES( frame
);
76 // Calculate the size of the image
77 int size
= *width
* *height
* 2;
79 // Set the format being returned
80 *format
= mlt_image_yuv422
;
83 *buffer
= mlt_pool_alloc( size
);
86 mlt_properties_set_data( properties
, "image", *buffer
, size
, mlt_pool_release
, NULL
);
87 mlt_properties_set_int( properties
, "width", *width
);
88 mlt_properties_set_int( properties
, "height", *height
);
90 // Before we write to the image, make sure we have one
91 if ( *buffer
!= NULL
)
93 // Calculate the end of the buffer
94 uint8_t *p
= *buffer
+ *width
* *height
* 2;
96 // Value to hold a random number
99 // Generate random noise
100 while ( p
!= *buffer
)
102 value
= fast_rand( ) & 0xff;
104 *( -- p
) = value
< 16 ?
16 : value
> 240 ?
240 : value
;
111 static int producer_get_audio( mlt_frame frame
, int16_t **buffer
, mlt_audio_format
*format
, int *frequency
, int *channels
, int *samples
)
113 // Get the frame properties
114 mlt_properties properties
= MLT_FRAME_PROPERTIES( frame
);
118 // Correct the returns if necessary
119 *samples
= *samples
<= 0 ?
1920 : *samples
;
120 *channels
= *channels
<= 0 ?
2 : *channels
;
121 *frequency
= *frequency
<= 0 ?
48000 : *frequency
;
123 // Calculate the size of the buffer
124 size
= *samples
* *channels
* sizeof( int16_t );
126 // Allocate the buffer
127 *buffer
= mlt_pool_alloc( size
);
129 // Make sure we got one and fill it
130 if ( *buffer
!= NULL
)
132 int16_t *p
= *buffer
+ size
/ 2;
133 while ( p
!= *buffer
)
134 *( -- p
) = fast_rand( ) & 0x0f00;
137 // Set the buffer for destruction
138 mlt_properties_set_data( properties
, "audio", *buffer
, size
, ( mlt_destructor
)mlt_pool_release
, NULL
);
143 static int producer_get_frame( mlt_producer
this, mlt_frame_ptr frame
, int index
)
146 *frame
= mlt_frame_init( );
148 // Check that we created a frame and initialise it
149 if ( *frame
!= NULL
)
151 // Obtain properties of frame
152 mlt_properties properties
= MLT_FRAME_PROPERTIES( *frame
);
154 // Obtain properties of producer
155 mlt_properties producer_props
= MLT_PRODUCER_PROPERTIES( this );
157 // Determine if we're producing PAL or NTSC
158 int is_pal
= mlt_properties_get_double( producer_props
, "fps" ) == 25.0;
160 // Aspect ratio is 1?
161 mlt_properties_set_double( properties
, "aspect_ratio", is_pal ?
59.0/54.0 : 10.0/11.0 );
163 // Set producer-specific frame properties
164 mlt_properties_set_int( properties
, "progressive", 1 );
166 // Update timecode on the frame we're creating
167 mlt_frame_set_position( *frame
, mlt_producer_position( this ) );
169 // Push the get_image method
170 mlt_frame_push_get_image( *frame
, producer_get_image
);
173 mlt_frame_push_audio( *frame
, producer_get_audio
);
176 // Calculate the next timecode
177 mlt_producer_prepare_next( this );
182 static void producer_close( mlt_producer
this )
185 mlt_producer_close( this );