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Mike Fleming3933d922018-04-02 10:53:08 -07001/*
2 * This file is part of Libav.
3 *
4 * Libav 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 * Libav 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 Libav; 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 * Audio Sample Formats
29 *
30 * @par
31 * The data described by the sample format is always in native-endian order.
32 * Sample values can be expressed by native C types, hence the lack of a signed
33 * 24-bit sample format even though it is a common raw audio data format.
34 *
35 * @par
36 * The floating-point formats are based on full volume being in the range
37 * [-1.0, 1.0]. Any values outside this range are beyond full volume level.
38 *
39 * @par
40 * The data layout as used in av_samples_fill_arrays() and elsewhere in Libav
41 * (such as AVFrame in libavcodec) is as follows:
42 *
43 * For planar sample formats, each audio channel is in a separate data plane,
44 * and linesize is the buffer size, in bytes, for a single plane. All data
45 * planes must be the same size. For packed sample formats, only the first data
46 * plane is used, and samples for each channel are interleaved. In this case,
47 * linesize is the buffer size, in bytes, for the 1 plane.
48 */
49enum AVSampleFormat {
50 AV_SAMPLE_FMT_NONE = -1,
51 AV_SAMPLE_FMT_U8, ///< unsigned 8 bits
52 AV_SAMPLE_FMT_S16, ///< signed 16 bits
53 AV_SAMPLE_FMT_S32, ///< signed 32 bits
54 AV_SAMPLE_FMT_FLT, ///< float
55 AV_SAMPLE_FMT_DBL, ///< double
56
57 AV_SAMPLE_FMT_U8P, ///< unsigned 8 bits, planar
58 AV_SAMPLE_FMT_S16P, ///< signed 16 bits, planar
59 AV_SAMPLE_FMT_S32P, ///< signed 32 bits, planar
60 AV_SAMPLE_FMT_FLTP, ///< float, planar
61 AV_SAMPLE_FMT_DBLP, ///< double, planar
62
63 AV_SAMPLE_FMT_NB ///< Number of sample formats. DO NOT USE if linking dynamically
64};
65
66/**
67 * Return the name of sample_fmt, or NULL if sample_fmt is not
68 * recognized.
69 */
70const char *av_get_sample_fmt_name(enum AVSampleFormat sample_fmt);
71
72/**
73 * Return a sample format corresponding to name, or AV_SAMPLE_FMT_NONE
74 * on error.
75 */
76enum AVSampleFormat av_get_sample_fmt(const char *name);
77
78/**
79 * Get the packed alternative form of the given sample format.
80 *
81 * If the passed sample_fmt is already in packed format, the format returned is
82 * the same as the input.
83 *
84 * @return the packed alternative form of the given sample format or
85 AV_SAMPLE_FMT_NONE on error.
86 */
87enum AVSampleFormat av_get_packed_sample_fmt(enum AVSampleFormat sample_fmt);
88
89/**
90 * Get the planar alternative form of the given sample format.
91 *
92 * If the passed sample_fmt is already in planar format, the format returned is
93 * the same as the input.
94 *
95 * @return the planar alternative form of the given sample format or
96 AV_SAMPLE_FMT_NONE on error.
97 */
98enum AVSampleFormat av_get_planar_sample_fmt(enum AVSampleFormat sample_fmt);
99
100/**
101 * Generate a string corresponding to the sample format with
102 * sample_fmt, or a header if sample_fmt is negative.
103 *
104 * @param buf the buffer where to write the string
105 * @param buf_size the size of buf
106 * @param sample_fmt the number of the sample format to print the
107 * corresponding info string, or a negative value to print the
108 * corresponding header.
109 * @return the pointer to the filled buffer or NULL if sample_fmt is
110 * unknown or in case of other errors
111 */
112char *av_get_sample_fmt_string(char *buf, int buf_size, enum AVSampleFormat sample_fmt);
113
114/**
115 * Return number of bytes per sample.
116 *
117 * @param sample_fmt the sample format
118 * @return number of bytes per sample or zero if unknown for the given
119 * sample format
120 */
121int av_get_bytes_per_sample(enum AVSampleFormat sample_fmt);
122
123/**
124 * Check if the sample format is planar.
125 *
126 * @param sample_fmt the sample format to inspect
127 * @return 1 if the sample format is planar, 0 if it is interleaved
128 */
129int av_sample_fmt_is_planar(enum AVSampleFormat sample_fmt);
130
131/**
132 * Get the required buffer size for the given audio parameters.
133 *
134 * @param[out] linesize calculated linesize, may be NULL
135 * @param nb_channels the number of channels
136 * @param nb_samples the number of samples in a single channel
137 * @param sample_fmt the sample format
138 * @param align buffer size alignment (0 = default, 1 = no alignment)
139 * @return required buffer size, or negative error code on failure
140 */
141int av_samples_get_buffer_size(int *linesize, int nb_channels, int nb_samples,
142 enum AVSampleFormat sample_fmt, int align);
143
144/**
145 * Fill channel data pointers and linesize for samples with sample
146 * format sample_fmt.
147 *
148 * The pointers array is filled with the pointers to the samples data:
149 * for planar, set the start point of each channel's data within the buffer,
150 * for packed, set the start point of the entire buffer only.
151 *
152 * The linesize array is filled with the aligned size of each channel's data
153 * buffer for planar layout, or the aligned size of the buffer for all channels
154 * for packed layout.
155 *
156 * @see enum AVSampleFormat
157 * The documentation for AVSampleFormat describes the data layout.
158 *
159 * @param[out] audio_data array to be filled with the pointer for each channel
160 * @param[out] linesize calculated linesize, may be NULL
161 * @param buf the pointer to a buffer containing the samples
162 * @param nb_channels the number of channels
163 * @param nb_samples the number of samples in a single channel
164 * @param sample_fmt the sample format
165 * @param align buffer size alignment (0 = default, 1 = no alignment)
166 * @return 0 on success or a negative error code on failure
167 */
168int av_samples_fill_arrays(uint8_t **audio_data, int *linesize,
169 const uint8_t *buf,
170 int nb_channels, int nb_samples,
171 enum AVSampleFormat sample_fmt, int align);
172
173/**
174 * Allocate a samples buffer for nb_samples samples, and fill data pointers and
175 * linesize accordingly.
176 * The allocated samples buffer can be freed by using av_freep(&audio_data[0])
177 * Allocated data will be initialized to silence.
178 *
179 * @see enum AVSampleFormat
180 * The documentation for AVSampleFormat describes the data layout.
181 *
182 * @param[out] audio_data array to be filled with the pointer for each channel
183 * @param[out] linesize aligned size for audio buffer(s), may be NULL
184 * @param nb_channels number of audio channels
185 * @param nb_samples number of samples per channel
186 * @param align buffer size alignment (0 = default, 1 = no alignment)
187 * @return 0 on success or a negative error code on failure
188 * @see av_samples_fill_arrays()
189 */
190int av_samples_alloc(uint8_t **audio_data, int *linesize, int nb_channels,
191 int nb_samples, enum AVSampleFormat sample_fmt, int align);
192
193/**
194 * Copy samples from src to dst.
195 *
196 * @param dst destination array of pointers to data planes
197 * @param src source array of pointers to data planes
198 * @param dst_offset offset in samples at which the data will be written to dst
199 * @param src_offset offset in samples at which the data will be read from src
200 * @param nb_samples number of samples to be copied
201 * @param nb_channels number of audio channels
202 * @param sample_fmt audio sample format
203 */
204int av_samples_copy(uint8_t **dst, uint8_t * const *src, int dst_offset,
205 int src_offset, int nb_samples, int nb_channels,
206 enum AVSampleFormat sample_fmt);
207
208/**
209 * Fill an audio buffer with silence.
210 *
211 * @param audio_data array of pointers to data planes
212 * @param offset offset in samples at which to start filling
213 * @param nb_samples number of samples to fill
214 * @param nb_channels number of audio channels
215 * @param sample_fmt audio sample format
216 */
217int av_samples_set_silence(uint8_t **audio_data, int offset, int nb_samples,
218 int nb_channels, enum AVSampleFormat sample_fmt);
219
220#endif /* AVUTIL_SAMPLEFMT_H */