2 * This file is part of Libav.
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.
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.
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
19 #ifndef AVUTIL_SAMPLEFMT_H
20 #define AVUTIL_SAMPLEFMT_H
25 #include "attributes.h"
28 * Audio Sample Formats
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.
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.
40 * The data layout as used in av_samples_fill_arrays() and elsewhere in Libav
41 * (such as AVFrame in libavcodec) is as follows:
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.
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
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
63 AV_SAMPLE_FMT_NB ///< Number of sample formats. DO NOT USE if linking dynamically
67 * Return the name of sample_fmt, or NULL if sample_fmt is not
70 const char *av_get_sample_fmt_name(enum AVSampleFormat sample_fmt);
73 * Return a sample format corresponding to name, or AV_SAMPLE_FMT_NONE
76 enum AVSampleFormat av_get_sample_fmt(const char *name);
79 * Get the packed alternative form of the given sample format.
81 * If the passed sample_fmt is already in packed format, the format returned is
82 * the same as the input.
84 * @return the packed alternative form of the given sample format or
85 AV_SAMPLE_FMT_NONE on error.
87 enum AVSampleFormat av_get_packed_sample_fmt(enum AVSampleFormat sample_fmt);
90 * Get the planar alternative form of the given sample format.
92 * If the passed sample_fmt is already in planar format, the format returned is
93 * the same as the input.
95 * @return the planar alternative form of the given sample format or
96 AV_SAMPLE_FMT_NONE on error.
98 enum AVSampleFormat av_get_planar_sample_fmt(enum AVSampleFormat sample_fmt);
101 * Generate a string corresponding to the sample format with
102 * sample_fmt, or a header if sample_fmt is negative.
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
112 char *av_get_sample_fmt_string(char *buf, int buf_size, enum AVSampleFormat sample_fmt);
114 #if FF_API_GET_BITS_PER_SAMPLE_FMT
116 * @deprecated Use av_get_bytes_per_sample() instead.
119 int av_get_bits_per_sample_fmt(enum AVSampleFormat sample_fmt);
123 * Return number of bytes per sample.
125 * @param sample_fmt the sample format
126 * @return number of bytes per sample or zero if unknown for the given
129 int av_get_bytes_per_sample(enum AVSampleFormat sample_fmt);
132 * Check if the sample format is planar.
134 * @param sample_fmt the sample format to inspect
135 * @return 1 if the sample format is planar, 0 if it is interleaved
137 int av_sample_fmt_is_planar(enum AVSampleFormat sample_fmt);
140 * Get the required buffer size for the given audio parameters.
142 * @param[out] linesize calculated linesize, may be NULL
143 * @param nb_channels the number of channels
144 * @param nb_samples the number of samples in a single channel
145 * @param sample_fmt the sample format
146 * @param align buffer size alignment (0 = default, 1 = no alignment)
147 * @return required buffer size, or negative error code on failure
149 int av_samples_get_buffer_size(int *linesize, int nb_channels, int nb_samples,
150 enum AVSampleFormat sample_fmt, int align);
153 * Fill channel data pointers and linesize for samples with sample
156 * The pointers array is filled with the pointers to the samples data:
157 * for planar, set the start point of each channel's data within the buffer,
158 * for packed, set the start point of the entire buffer only.
160 * The linesize array is filled with the aligned size of each channel's data
161 * buffer for planar layout, or the aligned size of the buffer for all channels
164 * @see enum AVSampleFormat
165 * The documentation for AVSampleFormat describes the data layout.
167 * @param[out] audio_data array to be filled with the pointer for each channel
168 * @param[out] linesize calculated linesize, may be NULL
169 * @param buf the pointer to a buffer containing the samples
170 * @param nb_channels the number of channels
171 * @param nb_samples the number of samples in a single channel
172 * @param sample_fmt the sample format
173 * @param align buffer size alignment (0 = default, 1 = no alignment)
174 * @return 0 on success or a negative error code on failure
176 int av_samples_fill_arrays(uint8_t **audio_data, int *linesize,
178 int nb_channels, int nb_samples,
179 enum AVSampleFormat sample_fmt, int align);
182 * Allocate a samples buffer for nb_samples samples, and fill data pointers and
183 * linesize accordingly.
184 * The allocated samples buffer can be freed by using av_freep(&audio_data[0])
185 * Allocated data will be initialized to silence.
187 * @see enum AVSampleFormat
188 * The documentation for AVSampleFormat describes the data layout.
190 * @param[out] audio_data array to be filled with the pointer for each channel
191 * @param[out] linesize aligned size for audio buffer(s), may be NULL
192 * @param nb_channels number of audio channels
193 * @param nb_samples number of samples per channel
194 * @param align buffer size alignment (0 = default, 1 = no alignment)
195 * @return 0 on success or a negative error code on failure
196 * @see av_samples_fill_arrays()
198 int av_samples_alloc(uint8_t **audio_data, int *linesize, int nb_channels,
199 int nb_samples, enum AVSampleFormat sample_fmt, int align);
202 * Copy samples from src to dst.
204 * @param dst destination array of pointers to data planes
205 * @param src source array of pointers to data planes
206 * @param dst_offset offset in samples at which the data will be written to dst
207 * @param src_offset offset in samples at which the data will be read from src
208 * @param nb_samples number of samples to be copied
209 * @param nb_channels number of audio channels
210 * @param sample_fmt audio sample format
212 int av_samples_copy(uint8_t **dst, uint8_t * const *src, int dst_offset,
213 int src_offset, int nb_samples, int nb_channels,
214 enum AVSampleFormat sample_fmt);
217 * Fill an audio buffer with silence.
219 * @param audio_data array of pointers to data planes
220 * @param offset offset in samples at which to start filling
221 * @param nb_samples number of samples to fill
222 * @param nb_channels number of audio channels
223 * @param sample_fmt audio sample format
225 int av_samples_set_silence(uint8_t **audio_data, int offset, int nb_samples,
226 int nb_channels, enum AVSampleFormat sample_fmt);
228 #endif /* AVUTIL_SAMPLEFMT_H */