+++ /dev/null
-/*
- * transition_mix.c -- mix two audio streams
- * Copyright (C) 2003-2004 Ushodaya Enterprises Limited
- * Author: Dan Dennedy <dan@dennedy.org>
- *
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; either
- * version 2.1 of the License, or (at your option) any later version.
- *
- * This library 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
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
- */
-
-#include <framework/mlt_transition.h>
-#include <framework/mlt_frame.h>
-
-#include <stdio.h>
-#include <stdlib.h>
-
-
-/** Get the audio.
-*/
-
-static int transition_get_audio( mlt_frame frame, int16_t **buffer, mlt_audio_format *format, int *frequency, int *channels, int *samples )
-{
- // Get the b frame from the stack
- mlt_frame b_frame = mlt_frame_pop_audio( frame );
-
- // Get the effect
- mlt_transition effect = mlt_frame_pop_audio( frame );
-
- // Get the properties of the b frame
- mlt_properties b_props = MLT_FRAME_PROPERTIES( b_frame );
-
- if ( mlt_properties_get_int( MLT_TRANSITION_PROPERTIES( effect ), "combine" ) == 0 )
- {
- double mix_start = 0.5, mix_end = 0.5;
- if ( mlt_properties_get( b_props, "audio.previous_mix" ) != NULL )
- mix_start = mlt_properties_get_double( b_props, "audio.previous_mix" );
- if ( mlt_properties_get( b_props, "audio.mix" ) != NULL )
- mix_end = mlt_properties_get_double( b_props, "audio.mix" );
- if ( mlt_properties_get_int( b_props, "audio.reverse" ) )
- {
- mix_start = 1 - mix_start;
- mix_end = 1 - mix_end;
- }
-
- mlt_frame_mix_audio( frame, b_frame, mix_start, mix_end, buffer, format, frequency, channels, samples );
- }
- else
- {
- mlt_frame_combine_audio( frame, b_frame, buffer, format, frequency, channels, samples );
- }
-
- return 0;
-}
-
-
-/** Mix transition processing.
-*/
-
-static mlt_frame transition_process( mlt_transition this, mlt_frame a_frame, mlt_frame b_frame )
-{
- mlt_properties properties = MLT_TRANSITION_PROPERTIES( this );
- mlt_properties b_props = MLT_FRAME_PROPERTIES( b_frame );
-
- // Only if mix is specified, otherwise a producer may set the mix
- if ( mlt_properties_get( properties, "start" ) != NULL )
- {
- // Determine the time position of this frame in the transition duration
- mlt_properties props = mlt_properties_get_data( MLT_FRAME_PROPERTIES( b_frame ), "_producer", NULL );
- int always_active = mlt_properties_get_int( MLT_TRANSITION_PROPERTIES( this ), "always_active" );
- mlt_position in = !always_active ? mlt_transition_get_in( this ) : mlt_properties_get_int( props, "in" );
- mlt_position out = !always_active ? mlt_transition_get_out( this ) : mlt_properties_get_int( props, "out" );
- int length = mlt_properties_get_int( MLT_TRANSITION_PROPERTIES( this ), "length" );
- mlt_position time = !always_active ? mlt_frame_get_position( b_frame ) : mlt_properties_get_int( props, "_frame" );
- double mix = ( double )( time - in ) / ( double )( out - in + 1 );
-
- // TODO: Check the logic here - shouldn't we be computing current and next mixing levels in all cases?
- if ( length == 0 )
- {
- // If there is an end mix level adjust mix to the range
- if ( mlt_properties_get( properties, "end" ) != NULL )
- {
- double start = mlt_properties_get_double( properties, "start" );
- double end = mlt_properties_get_double( properties, "end" );
- mix = start + ( end - start ) * mix;
- }
- // A negative means total crossfade (uses position)
- else if ( mlt_properties_get_double( properties, "start" ) >= 0 )
- {
- // Otherwise, start/constructor is a constant mix level
- mix = mlt_properties_get_double( properties, "start" );
- }
-
- // Finally, set the mix property on the frame
- mlt_properties_set_double( b_props, "audio.mix", mix );
-
- // Initialise transition previous mix value to prevent an inadvertant jump from 0
- mlt_position last_position = mlt_properties_get_position( properties, "_last_position" );
- mlt_position current_position = mlt_frame_get_position( b_frame );
- if ( mlt_properties_get( properties, "_previous_mix" ) == NULL
- || current_position != last_position + 1 )
- mlt_properties_set_double( properties, "_previous_mix", mix );
-
- // Tell b frame what the previous mix level was
- mlt_properties_set_double( b_props, "audio.previous_mix", mlt_properties_get_double( properties, "_previous_mix" ) );
-
- // Save the current mix level for the next iteration
- mlt_properties_set_double( properties, "_previous_mix", mlt_properties_get_double( b_props, "audio.mix" ) );
-
- mlt_properties_set_double( b_props, "audio.reverse", mlt_properties_get_double( properties, "reverse" ) );
- }
- else
- {
- double level = mlt_properties_get_double( properties, "start" );
- double mix_start = level;
- double mix_end = mix_start;
- double mix_increment = 1.0 / length;
- if ( time - in < length )
- {
- mix_start = mix_start * ( ( double )( time - in ) / length );
- mix_end = mix_start + mix_increment;
- }
- else if ( time > out - length )
- {
- mix_end = mix_start * ( ( double )( out - time - in ) / length );
- mix_start = mix_end - mix_increment;
- }
-
- mix_start = mix_start < 0 ? 0 : mix_start > level ? level : mix_start;
- mix_end = mix_end < 0 ? 0 : mix_end > level ? level : mix_end;
- mlt_properties_set_double( b_props, "audio.previous_mix", mix_start );
- mlt_properties_set_double( b_props, "audio.mix", mix_end );
- }
- }
-
- // Override the get_audio method
- mlt_frame_push_audio( a_frame, this );
- mlt_frame_push_audio( a_frame, b_frame );
- mlt_frame_push_audio( a_frame, transition_get_audio );
-
- return a_frame;
-}
-
-/** Constructor for the transition.
-*/
-
-mlt_transition transition_mix_init( mlt_profile profile, mlt_service_type type, const char *id, char *arg )
-{
- mlt_transition this = calloc( sizeof( struct mlt_transition_s ), 1 );
- if ( this != NULL && mlt_transition_init( this, NULL ) == 0 )
- {
- this->process = transition_process;
- if ( arg != NULL )
- mlt_properties_set_double( MLT_TRANSITION_PROPERTIES( this ), "start", atof( arg ) );
- // Inform apps and framework that this is an audio only transition
- mlt_properties_set_int( MLT_TRANSITION_PROPERTIES( this ), "_transition_type", 2 );
- }
- return this;
-}
-
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