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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.
38 * Audio sample formats
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.
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.
47 * - The data layout as used in av_samples_fill_arrays() and elsewhere in FFmpeg
48 * (such as AVFrame in libavcodec) is as follows:
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.
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
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
72 AV_SAMPLE_FMT_NB ///< Number of sample formats. DO NOT USE if linking dynamically
76 * Return the name of sample_fmt, or NULL if sample_fmt is not
79 const char *av_get_sample_fmt_name(enum AVSampleFormat sample_fmt);
82 * Return a sample format corresponding to name, or AV_SAMPLE_FMT_NONE
85 enum AVSampleFormat av_get_sample_fmt(const char *name);
88 * Return the planar<->packed alternative form of the given sample format, or
89 * AV_SAMPLE_FMT_NONE on error. If the passed sample_fmt is already in the
90 * requested planar/packed format, the format returned is the same as the
93 enum AVSampleFormat av_get_alt_sample_fmt(enum AVSampleFormat sample_fmt, int planar);
96 * Get the packed alternative form of the given sample format.
98 * If the passed sample_fmt is already in packed format, the format returned is
99 * the same as the input.
101 * @return the packed alternative form of the given sample format or
102 AV_SAMPLE_FMT_NONE on error.
104 enum AVSampleFormat av_get_packed_sample_fmt(enum AVSampleFormat sample_fmt);
107 * Get the planar alternative form of the given sample format.
109 * If the passed sample_fmt is already in planar format, the format returned is
110 * the same as the input.
112 * @return the planar alternative form of the given sample format or
113 AV_SAMPLE_FMT_NONE on error.
115 enum AVSampleFormat av_get_planar_sample_fmt(enum AVSampleFormat sample_fmt);
118 * Generate a string corresponding to the sample format with
119 * sample_fmt, or a header if sample_fmt is negative.
121 * @param buf the buffer where to write the string
122 * @param buf_size the size of buf
123 * @param sample_fmt the number of the sample format to print the
124 * corresponding info string, or a negative value to print the
125 * corresponding header.
126 * @return the pointer to the filled buffer or NULL if sample_fmt is
127 * unknown or in case of other errors
129 char *av_get_sample_fmt_string(char *buf, int buf_size, enum AVSampleFormat sample_fmt);
132 * Return number of bytes per sample.
134 * @param sample_fmt the sample format
135 * @return number of bytes per sample or zero if unknown for the given
138 int av_get_bytes_per_sample(enum AVSampleFormat sample_fmt);
141 * Check if the sample format is planar.
143 * @param sample_fmt the sample format to inspect
144 * @return 1 if the sample format is planar, 0 if it is interleaved
146 int av_sample_fmt_is_planar(enum AVSampleFormat sample_fmt);
149 * Get the required buffer size for the given audio parameters.
151 * @param[out] linesize calculated linesize, may be NULL
152 * @param nb_channels the number of channels
153 * @param nb_samples the number of samples in a single channel
154 * @param sample_fmt the sample format
155 * @param align buffer size alignment (0 = default, 1 = no alignment)
156 * @return required buffer size, or negative error code on failure
158 int av_samples_get_buffer_size(int *linesize, int nb_channels, int nb_samples,
159 enum AVSampleFormat sample_fmt, int align);
164 * @defgroup lavu_sampmanip Samples manipulation
166 * Functions that manipulate audio samples
171 * Fill plane data pointers and linesize for samples with sample
174 * The audio_data array is filled with the pointers to the samples data planes:
175 * for planar, set the start point of each channel's data within the buffer,
176 * for packed, set the start point of the entire buffer only.
178 * The value pointed to by linesize is set to the aligned size of each
179 * channel's data buffer for planar layout, or to the aligned size of the
180 * buffer for all channels for packed layout.
182 * The buffer in buf must be big enough to contain all the samples
183 * (use av_samples_get_buffer_size() to compute its minimum size),
184 * otherwise the audio_data pointers will point to invalid data.
186 * @see enum AVSampleFormat
187 * The documentation for AVSampleFormat describes the data layout.
189 * @param[out] audio_data array to be filled with the pointer for each channel
190 * @param[out] linesize calculated linesize, may be NULL
191 * @param buf the pointer to a buffer containing the samples
192 * @param nb_channels the number of channels
193 * @param nb_samples the number of samples in a single channel
194 * @param sample_fmt the sample format
195 * @param align buffer size alignment (0 = default, 1 = no alignment)
196 * @return >=0 on success or a negative error code on failure
197 * @todo return minimum size in bytes required for the buffer in case
198 * of success at the next bump
200 int av_samples_fill_arrays(uint8_t **audio_data, int *linesize,
202 int nb_channels, int nb_samples,
203 enum AVSampleFormat sample_fmt, int align);
206 * Allocate a samples buffer for nb_samples samples, and fill data pointers and
207 * linesize accordingly.
208 * The allocated samples buffer can be freed by using av_freep(&audio_data[0])
209 * Allocated data will be initialized to silence.
211 * @see enum AVSampleFormat
212 * The documentation for AVSampleFormat describes the data layout.
214 * @param[out] audio_data array to be filled with the pointer for each channel
215 * @param[out] linesize aligned size for audio buffer(s), may be NULL
216 * @param nb_channels number of audio channels
217 * @param nb_samples number of samples per channel
218 * @param align buffer size alignment (0 = default, 1 = no alignment)
219 * @return >=0 on success or a negative error code on failure
220 * @todo return the size of the allocated buffer in case of success at the next bump
221 * @see av_samples_fill_arrays()
222 * @see av_samples_alloc_array_and_samples()
224 int av_samples_alloc(uint8_t **audio_data, int *linesize, int nb_channels,
225 int nb_samples, enum AVSampleFormat sample_fmt, int align);
228 * Allocate a data pointers array, samples buffer for nb_samples
229 * samples, and fill data pointers and linesize accordingly.
231 * This is the same as av_samples_alloc(), but also allocates the data
234 * @see av_samples_alloc()
236 int av_samples_alloc_array_and_samples(uint8_t ***audio_data, int *linesize, int nb_channels,
237 int nb_samples, enum AVSampleFormat sample_fmt, int align);
240 * Copy samples from src to dst.
242 * @param dst destination array of pointers to data planes
243 * @param src source array of pointers to data planes
244 * @param dst_offset offset in samples at which the data will be written to dst
245 * @param src_offset offset in samples at which the data will be read from src
246 * @param nb_samples number of samples to be copied
247 * @param nb_channels number of audio channels
248 * @param sample_fmt audio sample format
250 int av_samples_copy(uint8_t **dst, uint8_t * const *src, int dst_offset,
251 int src_offset, int nb_samples, int nb_channels,
252 enum AVSampleFormat sample_fmt);
255 * Fill an audio buffer with silence.
257 * @param audio_data array of pointers to data planes
258 * @param offset offset in samples at which to start filling
259 * @param nb_samples number of samples to fill
260 * @param nb_channels number of audio channels
261 * @param sample_fmt audio sample format
263 int av_samples_set_silence(uint8_t **audio_data, int offset, int nb_samples,
264 int nb_channels, enum AVSampleFormat sample_fmt);
270 #endif /* AVUTIL_SAMPLEFMT_H */