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

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/* 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__ */