1 /* GStreamer
2  * Copyright (C) <2011> Wim Taymans <wim.taymans@gmail.com>
3  *
4  * This library is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU Library General Public
6  * License as published by the Free Software Foundation; either
7  * version 2 of the License, or (at your option) any later version.
8  *
9  * This library is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12  * Library General Public License for more details.
13  *
14  * You should have received a copy of the GNU Library General Public
15  * License along with this library; if not, write to the
16  * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
17  * Boston, MA 02110-1301, USA.
18  */
19 
20 #ifndef __GST_AUDIO_META_H__
21 #define __GST_AUDIO_META_H__
22 
23 #include <gst/audio/audio.h>
24 
25 G_BEGIN_DECLS
26 
27 #define GST_AUDIO_DOWNMIX_META_API_TYPE (gst_audio_downmix_meta_api_get_type())
28 #define GST_AUDIO_DOWNMIX_META_INFO  (gst_audio_downmix_meta_get_info())
29 
30 typedef struct _GstAudioDownmixMeta GstAudioDownmixMeta;
31 
32 /**
33  * GstAudioDownmixMeta:
34  * @meta: parent #GstMeta
35  * @from_position: the channel positions of the source
36  * @to_position: the channel positions of the destination
37  * @from_channels: the number of channels of the source
38  * @to_channels: the number of channels of the destination
39  * @matrix: the matrix coefficients.
40  *
41  * Extra buffer metadata describing audio downmixing matrix. This metadata is
42  * attached to audio buffers and contains a matrix to downmix the buffer number
43  * of channels to @channels.
44  *
45  * @matrix is an two-dimensional array of @to_channels times @from_channels
46  * coefficients, i.e. the i-th output channels is constructed by multiplicating
47  * the input channels with the coefficients in @matrix[i] and taking the sum
48  * of the results.
49  */
50 struct _GstAudioDownmixMeta {
51   GstMeta      meta;
52 
53   GstAudioChannelPosition *from_position;
54   GstAudioChannelPosition *to_position;
55   gint        from_channels, to_channels;
56   gfloat       **matrix;
57 };
58 
59 GST_AUDIO_API
60 GType gst_audio_downmix_meta_api_get_type (void);
61 
62 GST_AUDIO_API
63 const GstMetaInfo * gst_audio_downmix_meta_get_info (void);
64 
65 #define gst_buffer_get_audio_downmix_meta(b) ((GstAudioDownmixMeta*)gst_buffer_get_meta((b), GST_AUDIO_DOWNMIX_META_API_TYPE))
66 GST_AUDIO_API
67 GstAudioDownmixMeta * gst_buffer_get_audio_downmix_meta_for_channels    (GstBuffer *buffer,
68                                                                          const GstAudioChannelPosition *to_position,
69                                                                          gint                           to_channels);
70 
71 GST_AUDIO_API
72 GstAudioDownmixMeta * gst_buffer_add_audio_downmix_meta (GstBuffer    *buffer,
73                                                          const GstAudioChannelPosition *from_position,
74                                                          gint                           from_channels,
75                                                          const GstAudioChannelPosition *to_position,
76                                                          gint                           to_channels,
77                                                          const gfloat                 **matrix);
78 
79 
80 #define GST_AUDIO_CLIPPING_META_API_TYPE (gst_audio_clipping_meta_api_get_type())
81 #define GST_AUDIO_CLIPPING_META_INFO  (gst_audio_clipping_meta_get_info())
82 
83 typedef struct _GstAudioClippingMeta GstAudioClippingMeta;
84 
85 /**
86  * GstAudioClippingMeta:
87  * @meta: parent #GstMeta
88  * @format: GstFormat of @start and @stop, GST_FORMAT_DEFAULT is samples
89  * @start: Amount of audio to clip from start of buffer
90  * @end: Amount of  to clip from end of buffer
91  *
92  * Extra buffer metadata describing how much audio has to be clipped from
93  * the start or end of a buffer. This is used for compressed formats, where
94  * the first frame usually has some additional samples due to encoder and
95  * decoder delays, and the last frame usually has some additional samples to
96  * be able to fill the complete last frame.
97  *
98  * This is used to ensure that decoded data in the end has the same amount of
99  * samples, and multiply decoded streams can be gaplessly concatenated.
100  *
101  * Note: If clipping of the start is done by adjusting the segment, this meta
102  * has to be dropped from buffers as otherwise clipping could happen twice.
103  *
104  * Since: 1.8
105  */
106 struct _GstAudioClippingMeta {
107   GstMeta   meta;
108 
109   GstFormat format;
110   guint64   start;
111   guint64   end;
112 };
113 
114 GST_AUDIO_API
115 GType gst_audio_clipping_meta_api_get_type (void);
116 
117 GST_AUDIO_API
118 const GstMetaInfo * gst_audio_clipping_meta_get_info (void);
119 
120 #define gst_buffer_get_audio_clipping_meta(b) ((GstAudioClippingMeta*)gst_buffer_get_meta((b), GST_AUDIO_CLIPPING_META_API_TYPE))
121 
122 GST_AUDIO_API
123 GstAudioClippingMeta * gst_buffer_add_audio_clipping_meta (GstBuffer *buffer,
124                                                            GstFormat  format,
125                                                            guint64    start,
126                                                            guint64    end);
127 
128 
129 #define GST_AUDIO_META_API_TYPE (gst_audio_meta_api_get_type())
130 #define GST_AUDIO_META_INFO  (gst_audio_meta_get_info())
131 
132 typedef struct _GstAudioMeta GstAudioMeta;
133 
134 /**
135  * GstAudioMeta:
136  * @meta: parent #GstMeta
137  * @info: the audio properties of the buffer
138  * @samples: the number of valid samples in the buffer
139  * @offsets: the offsets (in bytes) where each channel plane starts in the
140  *   buffer or %NULL if the buffer has interleaved layout; if not %NULL, this
141  *   is guaranteed to be an array of @info.channels elements
142  *
143  * Buffer metadata describing how data is laid out inside the buffer. This
144  * is useful for non-interleaved (planar) buffers, where it is necessary to
145  * have a place to store where each plane starts and how long each plane is.
146  *
147  * It is a requirement for non-interleaved buffers to have this metadata
148  * attached and to be mapped with gst_audio_buffer_map() in order to ensure
149  * correct handling of clipping and channel reordering.
150  *
151  * The different channels in @offsets are always in the GStreamer channel order.
152  * Zero-copy channel reordering can be implemented by swapping the values in
153  * @offsets.
154  *
155  * It is not allowed for channels to overlap in memory,
156  * i.e. for each i in [0, channels), the range
157  * [@offsets[i], @offsets[i] + @samples * sample_stride) must not overlap
158  * with any other such range.
159  *
160  * It is, however, allowed to have parts of the buffer memory unused,
161  * by using @offsets and @samples in such a way that leave gaps on it.
162  * This is used to implement zero-copy clipping in non-interleaved buffers.
163  *
164  * Obviously, due to the above, it is not safe to infer the
165  * number of valid samples from the size of the buffer. You should always
166  * use the @samples variable of this metadata.
167  *
168  * Note that for interleaved audio it is not a requirement to have this
169  * metadata attached and at the moment of writing, there is actually no use
170  * case to do so. It is, however, allowed to attach it, for some potential
171  * future use case.
172  *
173  * Since: 1.16
174  */
175 struct _GstAudioMeta {
176   GstMeta      meta;
177 
178   GstAudioInfo info;
179   gsize        samples;
180   gsize        *offsets;
181 
182   /*< private >*/
183   gsize        priv_offsets_arr[8];
184   gpointer     _gst_reserved[GST_PADDING];
185 };
186 
187 GST_AUDIO_API
188 GType gst_audio_meta_api_get_type (void);
189 
190 GST_AUDIO_API
191 const GstMetaInfo * gst_audio_meta_get_info (void);
192 
193 #define gst_buffer_get_audio_meta(b) \
194     ((GstAudioMeta*)gst_buffer_get_meta((b), GST_AUDIO_META_API_TYPE))
195 
196 GST_AUDIO_API
197 GstAudioMeta * gst_buffer_add_audio_meta (GstBuffer *buffer,
198                                           const GstAudioInfo *info,
199                                           gsize samples, gsize offsets[]);
200 
201 G_END_DECLS
202 
203 #endif /* __GST_AUDIO_META_H__ */
204