gstreamer/gst-libs/gst/audio/gstaudiometa.h

/* GStreamer
 * Copyright (C) <2011> Wim Taymans <wim.taymans@gmail.com>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 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
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library 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.
 */

#ifndef __GST_AUDIO_META_H__
#define __GST_AUDIO_META_H__

#include <gst/gst.h>

#include <gst/audio/audio.h>

G_BEGIN_DECLS

#define GST_AUDIO_DOWNMIX_META_API   "GstAudioDownmixMeta"
#define GST_AUDIO_DOWNMIX_META_INFO  (gst_audio_downmix_meta_get_info())
typedef struct _GstAudioDownmixMeta GstAudioDownmixMeta;

/**
 * GstAudioDownmixMeta:
 * @meta: parent #GstMeta
 * @from_position: the channel positions of the source
 * @to_position: the channel positions of the destination
 * @from_channels: the number of channels of the source
 * @to_channels: the number of channels of the destination
 * @matrix: the matrix coefficients.
 *
 * Extra buffer metadata describing audio downmixing matrix. This metadata is
 * attached to audio buffers and contains a matrix to downmix the buffer number
 * of channels to @channels.
 *
 * @matrix is an two-dimensional array of @to_channels times @from_channels
 * coefficients, i.e. the i-th output channels is constructed by multiplicating
 * the input channels with the coefficients in @matrix[i] and taking the sum
 * of the results.
 */
struct _GstAudioDownmixMeta {
  GstMeta      meta;

  GstAudioChannelPosition *from_position;
  GstAudioChannelPosition *to_position;
  gint        from_channels, to_channels;
  gfloat       **matrix;
};

const GstMetaInfo * gst_audio_downmix_meta_get_info (void);

#define gst_buffer_get_audio_downmix_meta(b) ((GstAudioDownmixMeta*)gst_buffer_get_meta((b),GST_AUDIO_DOWNMIX_META_INFO))
GstAudioDownmixMeta * gst_buffer_get_audio_downmix_meta_for_channels    (GstBuffer *buffer,
                                                                         const GstAudioChannelPosition *to_position,
                                                                         gint                           to_channels);

GstAudioDownmixMeta * gst_buffer_add_audio_downmix_meta (GstBuffer    *buffer,
                                                         const GstAudioChannelPosition *from_position,
                                                         gint                           from_channels,
                                                         const GstAudioChannelPosition *to_position,
                                                         gint                           to_channels,
                                                         const gfloat                 **matrix);

G_END_DECLS

#endif /* __GST_AUDIO_META_H__ */