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samplefmt.h
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1 /*
2  * This file is part of FFmpeg.
3  *
4  * FFmpeg is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU Lesser General Public
6  * License as published by the Free Software Foundation; either
7  * version 2.1 of the License, or (at your option) any later version.
8  *
9  * FFmpeg is distributed in the hope that it will be useful,
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11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12  * Lesser General Public License for more details.
13  *
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15  * License along with FFmpeg; if not, write to the Free Software
16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17  */
18 
19 #ifndef AVUTIL_SAMPLEFMT_H
20 #define AVUTIL_SAMPLEFMT_H
21 
22 #include <stdint.h>
23 
24 #include "avutil.h"
25 #include "attributes.h"
26 
27 /**
28  * @addtogroup lavu_audio
29  * @{
30  *
31  * @defgroup lavu_sampfmts Audio sample formats
32  *
33  * Audio sample format enumeration and related convenience functions.
34  * @{
35  *
36  */
37 
38 /**
39  * Audio sample formats
40  *
41  * - The data described by the sample format is always in native-endian order.
42  * Sample values can be expressed by native C types, hence the lack of a signed
43  * 24-bit sample format even though it is a common raw audio data format.
44  *
45  * - The floating-point formats are based on full volume being in the range
46  * [-1.0, 1.0]. Any values outside this range are beyond full volume level.
47  *
48  * - The data layout as used in av_samples_fill_arrays() and elsewhere in FFmpeg
49  * (such as AVFrame in libavcodec) is as follows:
50  *
51  * @par
52  * For planar sample formats, each audio channel is in a separate data plane,
53  * and linesize is the buffer size, in bytes, for a single plane. All data
54  * planes must be the same size. For packed sample formats, only the first data
55  * plane is used, and samples for each channel are interleaved. In this case,
56  * linesize is the buffer size, in bytes, for the 1 plane.
57  *
58  */
61  AV_SAMPLE_FMT_U8, ///< unsigned 8 bits
62  AV_SAMPLE_FMT_S16, ///< signed 16 bits
63  AV_SAMPLE_FMT_S32, ///< signed 32 bits
64  AV_SAMPLE_FMT_FLT, ///< float
65  AV_SAMPLE_FMT_DBL, ///< double
66 
67  AV_SAMPLE_FMT_U8P, ///< unsigned 8 bits, planar
68  AV_SAMPLE_FMT_S16P, ///< signed 16 bits, planar
69  AV_SAMPLE_FMT_S32P, ///< signed 32 bits, planar
70  AV_SAMPLE_FMT_FLTP, ///< float, planar
71  AV_SAMPLE_FMT_DBLP, ///< double, planar
72 
73  AV_SAMPLE_FMT_NB ///< Number of sample formats. DO NOT USE if linking dynamically
74 };
75 
76 /**
77  * Return the name of sample_fmt, or NULL if sample_fmt is not
78  * recognized.
79  */
80 const char *av_get_sample_fmt_name(enum AVSampleFormat sample_fmt);
81 
82 /**
83  * Return a sample format corresponding to name, or AV_SAMPLE_FMT_NONE
84  * on error.
85  */
86 enum AVSampleFormat av_get_sample_fmt(const char *name);
87 
88 /**
89  * Return the planar<->packed alternative form of the given sample format, or
90  * AV_SAMPLE_FMT_NONE on error. If the passed sample_fmt is already in the
91  * requested planar/packed format, the format returned is the same as the
92  * input.
93  */
94 enum AVSampleFormat av_get_alt_sample_fmt(enum AVSampleFormat sample_fmt, int planar);
95 
96 /**
97  * Get the packed alternative form of the given sample format.
98  *
99  * If the passed sample_fmt is already in packed format, the format returned is
100  * the same as the input.
101  *
102  * @return the packed alternative form of the given sample format or
103  AV_SAMPLE_FMT_NONE on error.
104  */
106 
107 /**
108  * Get the planar alternative form of the given sample format.
109  *
110  * If the passed sample_fmt is already in planar format, the format returned is
111  * the same as the input.
112  *
113  * @return the planar alternative form of the given sample format or
114  AV_SAMPLE_FMT_NONE on error.
115  */
117 
118 /**
119  * Generate a string corresponding to the sample format with
120  * sample_fmt, or a header if sample_fmt is negative.
121  *
122  * @param buf the buffer where to write the string
123  * @param buf_size the size of buf
124  * @param sample_fmt the number of the sample format to print the
125  * corresponding info string, or a negative value to print the
126  * corresponding header.
127  * @return the pointer to the filled buffer or NULL if sample_fmt is
128  * unknown or in case of other errors
129  */
130 char *av_get_sample_fmt_string(char *buf, int buf_size, enum AVSampleFormat sample_fmt);
131 
132 /**
133  * Return number of bytes per sample.
134  *
135  * @param sample_fmt the sample format
136  * @return number of bytes per sample or zero if unknown for the given
137  * sample format
138  */
139 int av_get_bytes_per_sample(enum AVSampleFormat sample_fmt);
140 
141 /**
142  * Check if the sample format is planar.
143  *
144  * @param sample_fmt the sample format to inspect
145  * @return 1 if the sample format is planar, 0 if it is interleaved
146  */
147 int av_sample_fmt_is_planar(enum AVSampleFormat sample_fmt);
148 
149 /**
150  * Get the required buffer size for the given audio parameters.
151  *
152  * @param[out] linesize calculated linesize, may be NULL
153  * @param nb_channels the number of channels
154  * @param nb_samples the number of samples in a single channel
155  * @param sample_fmt the sample format
156  * @param align buffer size alignment (0 = default, 1 = no alignment)
157  * @return required buffer size, or negative error code on failure
158  */
159 int av_samples_get_buffer_size(int *linesize, int nb_channels, int nb_samples,
160  enum AVSampleFormat sample_fmt, int align);
161 
162 /**
163  * @}
164  *
165  * @defgroup lavu_sampmanip Samples manipulation
166  *
167  * Functions that manipulate audio samples
168  * @{
169  */
170 
171 /**
172  * Fill plane data pointers and linesize for samples with sample
173  * format sample_fmt.
174  *
175  * The audio_data array is filled with the pointers to the samples data planes:
176  * for planar, set the start point of each channel's data within the buffer,
177  * for packed, set the start point of the entire buffer only.
178  *
179  * The value pointed to by linesize is set to the aligned size of each
180  * channel's data buffer for planar layout, or to the aligned size of the
181  * buffer for all channels for packed layout.
182  *
183  * The buffer in buf must be big enough to contain all the samples
184  * (use av_samples_get_buffer_size() to compute its minimum size),
185  * otherwise the audio_data pointers will point to invalid data.
186  *
187  * @see enum AVSampleFormat
188  * The documentation for AVSampleFormat describes the data layout.
189  *
190  * @param[out] audio_data array to be filled with the pointer for each channel
191  * @param[out] linesize calculated linesize, may be NULL
192  * @param buf the pointer to a buffer containing the samples
193  * @param nb_channels the number of channels
194  * @param nb_samples the number of samples in a single channel
195  * @param sample_fmt the sample format
196  * @param align buffer size alignment (0 = default, 1 = no alignment)
197  * @return >=0 on success or a negative error code on failure
198  * @todo return minimum size in bytes required for the buffer in case
199  * of success at the next bump
200  */
201 int av_samples_fill_arrays(uint8_t **audio_data, int *linesize,
202  const uint8_t *buf,
203  int nb_channels, int nb_samples,
204  enum AVSampleFormat sample_fmt, int align);
205 
206 /**
207  * Allocate a samples buffer for nb_samples samples, and fill data pointers and
208  * linesize accordingly.
209  * The allocated samples buffer can be freed by using av_freep(&audio_data[0])
210  * Allocated data will be initialized to silence.
211  *
212  * @see enum AVSampleFormat
213  * The documentation for AVSampleFormat describes the data layout.
214  *
215  * @param[out] audio_data array to be filled with the pointer for each channel
216  * @param[out] linesize aligned size for audio buffer(s), may be NULL
217  * @param nb_channels number of audio channels
218  * @param nb_samples number of samples per channel
219  * @param align buffer size alignment (0 = default, 1 = no alignment)
220  * @return >=0 on success or a negative error code on failure
221  * @todo return the size of the allocated buffer in case of success at the next bump
222  * @see av_samples_fill_arrays()
223  * @see av_samples_alloc_array_and_samples()
224  */
225 int av_samples_alloc(uint8_t **audio_data, int *linesize, int nb_channels,
226  int nb_samples, enum AVSampleFormat sample_fmt, int align);
227 
228 /**
229  * Allocate a data pointers array, samples buffer for nb_samples
230  * samples, and fill data pointers and linesize accordingly.
231  *
232  * This is the same as av_samples_alloc(), but also allocates the data
233  * pointers array.
234  *
235  * @see av_samples_alloc()
236  */
237 int av_samples_alloc_array_and_samples(uint8_t ***audio_data, int *linesize, int nb_channels,
238  int nb_samples, enum AVSampleFormat sample_fmt, int align);
239 
240 /**
241  * Copy samples from src to dst.
242  *
243  * @param dst destination array of pointers to data planes
244  * @param src source array of pointers to data planes
245  * @param dst_offset offset in samples at which the data will be written to dst
246  * @param src_offset offset in samples at which the data will be read from src
247  * @param nb_samples number of samples to be copied
248  * @param nb_channels number of audio channels
249  * @param sample_fmt audio sample format
250  */
251 int av_samples_copy(uint8_t **dst, uint8_t * const *src, int dst_offset,
252  int src_offset, int nb_samples, int nb_channels,
253  enum AVSampleFormat sample_fmt);
254 
255 /**
256  * Fill an audio buffer with silence.
257  *
258  * @param audio_data array of pointers to data planes
259  * @param offset offset in samples at which to start filling
260  * @param nb_samples number of samples to fill
261  * @param nb_channels number of audio channels
262  * @param sample_fmt audio sample format
263  */
264 int av_samples_set_silence(uint8_t **audio_data, int offset, int nb_samples,
265  int nb_channels, enum AVSampleFormat sample_fmt);
266 
267 /**
268  * @}
269  * @}
270  */
271 #endif /* AVUTIL_SAMPLEFMT_H */