research.m1stereo.tv/gitweb/ - melted/blob - mlt/src/modules/ffmpeg/filter_ffmpeg_dub.c

   1 /*
   2  * filter_ffmpeg_dub.c -- simple ffmpeg dub test case
   3  * Copyright (C) 2003-2004 Ushodaya Enterprises Limited
   4  * Author: Charles Yates <charles.yates@pandora.be>
   5  *
   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.
  10  *
  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.
  15  *
  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.
  19  */
  20
  21 #include "filter_ffmpeg_dub.h"
  22 #include <stdio.h>
  23 #include <stdlib.h>
  24 #include <framework/mlt.h>
  25
  26 /** Do it.
  27 */
  28
  29 static int filter_get_audio( mlt_frame frame, int16_t **buffer, mlt_audio_format *format, int *frequency, int *channels, int *samples )
  30 {
  31         // Obtain the frame properties
  32         mlt_properties frame_properties = mlt_frame_properties( frame );
  33
  34         // Get the producer used.
  35         mlt_producer producer = mlt_properties_get_data( frame_properties, "producer", NULL );
  36
  37         // Get the producer properties
  38         mlt_properties producer_properties = mlt_producer_properties( producer );
  39
  40         // Get the original get_audio
  41         int ( *get_audio )( mlt_frame, int16_t **, mlt_audio_format *, int *, int *, int * ) = mlt_properties_get_data( frame_properties, "get_audio", NULL );
  42
  43         // Call the original get_audio
  44         get_audio( frame, buffer, format, frequency, channels, samples );
  45
  46         // Now if our producer is still producing, override the audio
  47         if ( !mlt_properties_get_int( producer_properties, "end_of_clip" ) )
  48         {
  49                 // Get the position
  50                 double position = mlt_properties_get_double( producer_properties, "dub_position" );
  51
  52                 // We need a frame from the producer
  53                 mlt_frame producer_frame;
  54
  55                 // Seek to the position
  56                 mlt_producer_seek_frame( producer, ( int64_t )position );
  57
  58                 // Get the next frame
  59                 producer->get_frame( producer, &producer_frame, 0 );
  60
  61                 if ( !mlt_properties_get_int( producer_properties, "end_of_clip" ) )
  62                 {
  63                         // Now get the audio from this frame
  64                         producer_frame->get_audio( producer_frame, buffer, format, frequency, channels, samples );
  65
  66                         // This producer frame will be destroyed automatically when frame is destroyed
  67                         mlt_properties_set_data( frame_properties, "ffmpeg_dub_frame", producer_frame, 0, ( mlt_destructor )mlt_frame_close, NULL );
  68
  69                         // Incrment the position
  70                         mlt_properties_set_double( producer_properties, "dub_position", position + 1 );
  71                 }
  72         }
  73
  74         return 0;
  75 }
  76
  77 /** Filter processing.
  78 */
  79
  80 static mlt_frame filter_process( mlt_filter this, mlt_frame frame )
  81 {
  82         // Obtain the filter properties
  83         mlt_properties filter_properties = mlt_filter_properties( this );
  84
  85         // Get the producer used.
  86         mlt_producer producer = mlt_properties_get_data( filter_properties, "producer", NULL );
  87
  88         // Obtain the frame properties
  89         mlt_properties frame_properties = mlt_frame_properties( frame );
  90
  91         // Backup the original get_audio (it's still needed)
  92         mlt_properties_set_data( frame_properties, "get_audio", frame->get_audio, 0, NULL, NULL );
  93
  94         // Pass the producer on the frame
  95         mlt_properties_set_data( frame_properties, "producer", producer, 0, NULL, NULL );
  96
  97         // Override the get_audio method
  98         frame->get_audio = filter_get_audio;
  99
 100         return frame;
 101 }
 102
 103 /** Constructor for the filter.
 104 */
 105
 106 mlt_filter filter_ffmpeg_dub_init( char *file )
 107 {
 108         // Create the filter object
 109         mlt_filter this = calloc( sizeof( struct mlt_filter_s ), 1 );
 110
 111         // Initialise it
 112         mlt_filter_init( this, NULL );
 113
 114         // Overide the filter process method
 115         this->process = filter_process;
 116
 117         // Obtain the properties
 118         mlt_properties properties = mlt_filter_properties( this );
 119
 120         // Create an ffmpeg producer
 121         mlt_producer producer = mlt_factory_producer( "ffmpeg", file );
 122
 123         // Pass the producer
 124         mlt_properties_set_data( properties, "producer", producer, 0, ( mlt_destructor )mlt_producer_close, NULL );
 125
 126         // Initialise the audio frame position
 127         mlt_properties_set_double( properties, "dub_position", 0 );
 128
 129         return this;
 130 }
 131