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19 #ifndef AVUTIL_SAMPLEFMT_H
20 #define AVUTIL_SAMPLEFMT_H
25 #include "attributes.h"
28 * @addtogroup lavu_audio
31 * @defgroup lavu_sampfmts Audio sample formats
33 * Audio sample format enumeration and related convenience functions.
39 * Audio sample formats
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.
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.
48 * - The data layout as used in av_samples_fill_arrays() and elsewhere in FFmpeg
49 * (such as AVFrame in libavcodec) is as follows:
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.
60 AV_SAMPLE_FMT_NONE = -1,
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
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
73 AV_SAMPLE_FMT_NB ///< Number of sample formats. DO NOT USE if linking dynamically
77 * Return the name of sample_fmt, or NULL if sample_fmt is not
80 const char *av_get_sample_fmt_name(enum AVSampleFormat sample_fmt);
83 * Return a sample format corresponding to name, or AV_SAMPLE_FMT_NONE
86 enum AVSampleFormat av_get_sample_fmt(const char *name);
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
94 enum AVSampleFormat av_get_alt_sample_fmt(enum AVSampleFormat sample_fmt, int planar);
97 * Get the packed alternative form of the given sample format.
99 * If the passed sample_fmt is already in packed format, the format returned is
100 * the same as the input.
102 * @return the packed alternative form of the given sample format or
103 AV_SAMPLE_FMT_NONE on error.
105 enum AVSampleFormat av_get_packed_sample_fmt(enum AVSampleFormat sample_fmt);
108 * Get the planar alternative form of the given sample format.
110 * If the passed sample_fmt is already in planar format, the format returned is
111 * the same as the input.
113 * @return the planar alternative form of the given sample format or
114 AV_SAMPLE_FMT_NONE on error.
116 enum AVSampleFormat av_get_planar_sample_fmt(enum AVSampleFormat sample_fmt);
119 * Generate a string corresponding to the sample format with
120 * sample_fmt, or a header if sample_fmt is negative.
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
130 char *av_get_sample_fmt_string(char *buf, int buf_size, enum AVSampleFormat sample_fmt);
133 * Return number of bytes per sample.
135 * @param sample_fmt the sample format
136 * @return number of bytes per sample or zero if unknown for the given
139 int av_get_bytes_per_sample(enum AVSampleFormat sample_fmt);
142 * Check if the sample format is planar.
144 * @param sample_fmt the sample format to inspect
145 * @return 1 if the sample format is planar, 0 if it is interleaved
147 int av_sample_fmt_is_planar(enum AVSampleFormat sample_fmt);
150 * Get the required buffer size for the given audio parameters.
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
159 int av_samples_get_buffer_size(int *linesize, int nb_channels, int nb_samples,
160 enum AVSampleFormat sample_fmt, int align);
165 * @defgroup lavu_sampmanip Samples manipulation
167 * Functions that manipulate audio samples
172 * Fill plane data pointers and linesize for samples with sample
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.
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.
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.
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 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
201 int av_samples_fill_arrays(uint8_t **audio_data, int *linesize,
203 int nb_channels, int nb_samples,
204 enum AVSampleFormat sample_fmt, int align);
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.
212 * @see enum AVSampleFormat
213 * The documentation for AVSampleFormat describes the data layout.
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()
225 int av_samples_alloc(uint8_t **audio_data, int *linesize, int nb_channels,
226 int nb_samples, enum AVSampleFormat sample_fmt, int align);
229 * Allocate a data pointers array, samples buffer for nb_samples
230 * samples, and fill data pointers and linesize accordingly.
232 * This is the same as av_samples_alloc(), but also allocates the data
235 * @see av_samples_alloc()
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);
241 * Copy samples from src to dst.
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
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);
256 * Fill an audio buffer with silence.
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
264 int av_samples_set_silence(uint8_t **audio_data, int offset, int nb_samples,
265 int nb_channels, enum AVSampleFormat sample_fmt);
271 #endif /* AVUTIL_SAMPLEFMT_H */