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,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Lesser General Public License for more details.
13 *
14 * You should have received a copy of the GNU Lesser General Public
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 * Audio sample formats
39 *
40 * - The data described by the sample format is always in native-endian order.
41 * Sample values can be expressed by native C types, hence the lack of a signed
42 * 24-bit sample format even though it is a common raw audio data format.
43 *
44 * - The floating-point formats are based on full volume being in the range
45 * [-1.0, 1.0]. Any values outside this range are beyond full volume level.
46 *
47 * - The data layout as used in av_samples_fill_arrays() and elsewhere in FFmpeg
48 * (such as AVFrame in libavcodec) is as follows:
49 *
50 * @par
51 * For planar sample formats, each audio channel is in a separate data plane,
52 * and linesize is the buffer size, in bytes, for a single plane. All data
53 * planes must be the same size. For packed sample formats, only the first data
54 * plane is used, and samples for each channel are interleaved. In this case,
55 * linesize is the buffer size, in bytes, for the 1 plane.
56 *
57 */
58enum AVSampleFormat {
59 AV_SAMPLE_FMT_NONE = -1,
60 AV_SAMPLE_FMT_U8, ///< unsigned 8 bits
61 AV_SAMPLE_FMT_S16, ///< signed 16 bits
62 AV_SAMPLE_FMT_S32, ///< signed 32 bits
63 AV_SAMPLE_FMT_FLT, ///< float
64 AV_SAMPLE_FMT_DBL, ///< double
65
66 AV_SAMPLE_FMT_U8P, ///< unsigned 8 bits, planar
67 AV_SAMPLE_FMT_S16P, ///< signed 16 bits, planar
68 AV_SAMPLE_FMT_S32P, ///< signed 32 bits, planar
69 AV_SAMPLE_FMT_FLTP, ///< float, planar
70 AV_SAMPLE_FMT_DBLP, ///< double, planar
71 AV_SAMPLE_FMT_S64, ///< signed 64 bits
72 AV_SAMPLE_FMT_S64P, ///< signed 64 bits, planar
73
74 AV_SAMPLE_FMT_NB ///< Number of sample formats. DO NOT USE if linking dynamically
75};
76
77/**
78 * Return the name of sample_fmt, or NULL if sample_fmt is not
79 * recognized.
80 */
81const char *av_get_sample_fmt_name(enum AVSampleFormat sample_fmt);
82
83/**
84 * Return a sample format corresponding to name, or AV_SAMPLE_FMT_NONE
85 * on error.
86 */
87enum AVSampleFormat av_get_sample_fmt(const char *name);
88
89/**
90 * Return the planar<->packed alternative form of the given sample format, or
91 * AV_SAMPLE_FMT_NONE on error. If the passed sample_fmt is already in the
92 * requested planar/packed format, the format returned is the same as the
93 * input.
94 */
95enum AVSampleFormat av_get_alt_sample_fmt(enum AVSampleFormat sample_fmt, int planar);
96
97/**
98 * Get the packed alternative form of the given sample format.
99 *
100 * If the passed sample_fmt is already in packed format, the format returned is
101 * the same as the input.
102 *
103 * @return the packed alternative form of the given sample format or
104 AV_SAMPLE_FMT_NONE on error.
105 */
106enum AVSampleFormat av_get_packed_sample_fmt(enum AVSampleFormat sample_fmt);
107
108/**
109 * Get the planar alternative form of the given sample format.
110 *
111 * If the passed sample_fmt is already in planar format, the format returned is
112 * the same as the input.
113 *
114 * @return the planar alternative form of the given sample format or
115 AV_SAMPLE_FMT_NONE on error.
116 */
117enum AVSampleFormat av_get_planar_sample_fmt(enum AVSampleFormat sample_fmt);
118
119/**
120 * Generate a string corresponding to the sample format with
121 * sample_fmt, or a header if sample_fmt is negative.
122 *
123 * @param buf the buffer where to write the string
124 * @param buf_size the size of buf
125 * @param sample_fmt the number of the sample format to print the
126 * corresponding info string, or a negative value to print the
127 * corresponding header.
128 * @return the pointer to the filled buffer or NULL if sample_fmt is
129 * unknown or in case of other errors
130 */
131char *av_get_sample_fmt_string(char *buf, int buf_size, enum AVSampleFormat sample_fmt);
132
133/**
134 * Return number of bytes per sample.
135 *
136 * @param sample_fmt the sample format
137 * @return number of bytes per sample or zero if unknown for the given
138 * sample format
139 */
140int av_get_bytes_per_sample(enum AVSampleFormat sample_fmt);
141
142/**
143 * Check if the sample format is planar.
144 *
145 * @param sample_fmt the sample format to inspect
146 * @return 1 if the sample format is planar, 0 if it is interleaved
147 */
148int av_sample_fmt_is_planar(enum AVSampleFormat sample_fmt);
149
150/**
151 * Get the required buffer size for the given audio parameters.
152 *
153 * @param[out] linesize calculated linesize, may be NULL
154 * @param nb_channels the number of channels
155 * @param nb_samples the number of samples in a single channel
156 * @param sample_fmt the sample format
157 * @param align buffer size alignment (0 = default, 1 = no alignment)
158 * @return required buffer size, or negative error code on failure
159 */
160int av_samples_get_buffer_size(int *linesize, int nb_channels, int nb_samples,
161 enum AVSampleFormat sample_fmt, int align);
162
163/**
164 * @}
165 *
166 * @defgroup lavu_sampmanip Samples manipulation
167 *
168 * Functions that manipulate audio samples
169 * @{
170 */
171
172/**
173 * Fill plane data pointers and linesize for samples with sample
174 * format sample_fmt.
175 *
176 * The audio_data array is filled with the pointers to the samples data planes:
177 * for planar, set the start point of each channel's data within the buffer,
178 * for packed, set the start point of the entire buffer only.
179 *
180 * The value pointed to by linesize is set to the aligned size of each
181 * channel's data buffer for planar layout, or to the aligned size of the
182 * buffer for all channels for packed layout.
183 *
184 * The buffer in buf must be big enough to contain all the samples
185 * (use av_samples_get_buffer_size() to compute its minimum size),
186 * otherwise the audio_data pointers will point to invalid data.
187 *
188 * @see enum AVSampleFormat
189 * The documentation for AVSampleFormat describes the data layout.
190 *
191 * @param[out] audio_data array to be filled with the pointer for each channel
192 * @param[out] linesize calculated linesize, may be NULL
193 * @param buf the pointer to a buffer containing the samples
194 * @param nb_channels the number of channels
195 * @param nb_samples the number of samples in a single channel
196 * @param sample_fmt the sample format
197 * @param align buffer size alignment (0 = default, 1 = no alignment)
198 * @return >=0 on success or a negative error code on failure
199 * @todo return minimum size in bytes required for the buffer in case
200 * of success at the next bump
201 */
202int av_samples_fill_arrays(uint8_t **audio_data, int *linesize,
203 const uint8_t *buf,
204 int nb_channels, int nb_samples,
205 enum AVSampleFormat sample_fmt, int align);
206
207/**
208 * Allocate a samples buffer for nb_samples samples, and fill data pointers and
209 * linesize accordingly.
210 * The allocated samples buffer can be freed by using av_freep(&audio_data[0])
211 * Allocated data will be initialized to silence.
212 *
213 * @see enum AVSampleFormat
214 * The documentation for AVSampleFormat describes the data layout.
215 *
216 * @param[out] audio_data array to be filled with the pointer for each channel
217 * @param[out] linesize aligned size for audio buffer(s), may be NULL
218 * @param nb_channels number of audio channels
219 * @param nb_samples number of samples per channel
220 * @param align buffer size alignment (0 = default, 1 = no alignment)
221 * @return >=0 on success or a negative error code on failure
222 * @todo return the size of the allocated buffer in case of success at the next bump
223 * @see av_samples_fill_arrays()
224 * @see av_samples_alloc_array_and_samples()
225 */
226int av_samples_alloc(uint8_t **audio_data, int *linesize, int nb_channels,
227 int nb_samples, enum AVSampleFormat sample_fmt, int align);
228
229/**
230 * Allocate a data pointers array, samples buffer for nb_samples
231 * samples, and fill data pointers and linesize accordingly.
232 *
233 * This is the same as av_samples_alloc(), but also allocates the data
234 * pointers array.
235 *
236 * @see av_samples_alloc()
237 */
238int av_samples_alloc_array_and_samples(uint8_t ***audio_data, int *linesize, int nb_channels,
239 int nb_samples, enum AVSampleFormat sample_fmt, int align);
240
241/**
242 * Copy samples from src to dst.
243 *
244 * @param dst destination array of pointers to data planes
245 * @param src source array of pointers to data planes
246 * @param dst_offset offset in samples at which the data will be written to dst
247 * @param src_offset offset in samples at which the data will be read from src
248 * @param nb_samples number of samples to be copied
249 * @param nb_channels number of audio channels
250 * @param sample_fmt audio sample format
251 */
252int av_samples_copy(uint8_t **dst, uint8_t * const *src, int dst_offset,
253 int src_offset, int nb_samples, int nb_channels,
254 enum AVSampleFormat sample_fmt);
255
256/**
257 * Fill an audio buffer with silence.
258 *
259 * @param audio_data array of pointers to data planes
260 * @param offset offset in samples at which to start filling
261 * @param nb_samples number of samples to fill
262 * @param nb_channels number of audio channels
263 * @param sample_fmt audio sample format
264 */
265int av_samples_set_silence(uint8_t **audio_data, int offset, int nb_samples,
266 int nb_channels, enum AVSampleFormat sample_fmt);
267
268/**
269 * @}
270 * @}
271 */
272#endif /* AVUTIL_SAMPLEFMT_H */
273

source code of include/x86_64-linux-gnu/libavutil/samplefmt.h