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19 #ifndef AVUTIL_SAMPLEFMT_H
20 #define AVUTIL_SAMPLEFMT_H
25 * Audio Sample Formats
28 * The data described by the sample format is always in native-endian order.
29 * Sample values can be expressed by native C types, hence the lack of a signed
30 * 24-bit sample format even though it is a common raw audio data format.
33 * The floating-point formats are based on full volume being in the range
34 * [-1.0, 1.0]. Any values outside this range are beyond full volume level.
37 * The data layout as used in av_samples_fill_arrays() and elsewhere in Libav
38 * (such as AVFrame in libavcodec) is as follows:
40 * For planar sample formats, each audio channel is in a separate data plane,
41 * and linesize is the buffer size, in bytes, for a single plane. All data
42 * planes must be the same size. For packed sample formats, only the first data
43 * plane is used, and samples for each channel are interleaved. In this case,
44 * linesize is the buffer size, in bytes, for the 1 plane.
47 AV_SAMPLE_FMT_NONE = -1,
48 AV_SAMPLE_FMT_U8, ///< unsigned 8 bits
49 AV_SAMPLE_FMT_S16, ///< signed 16 bits
50 AV_SAMPLE_FMT_S32, ///< signed 32 bits
51 AV_SAMPLE_FMT_FLT, ///< float
52 AV_SAMPLE_FMT_DBL, ///< double
54 AV_SAMPLE_FMT_U8P, ///< unsigned 8 bits, planar
55 AV_SAMPLE_FMT_S16P, ///< signed 16 bits, planar
56 AV_SAMPLE_FMT_S32P, ///< signed 32 bits, planar
57 AV_SAMPLE_FMT_FLTP, ///< float, planar
58 AV_SAMPLE_FMT_DBLP, ///< double, planar
60 AV_SAMPLE_FMT_NB ///< Number of sample formats. DO NOT USE if linking dynamically
64 * Return the name of sample_fmt, or NULL if sample_fmt is not
67 const char *av_get_sample_fmt_name(enum AVSampleFormat sample_fmt);
70 * Return a sample format corresponding to name, or AV_SAMPLE_FMT_NONE
73 enum AVSampleFormat av_get_sample_fmt(const char *name);
76 * Return the planar<->packed alternative form of the given sample format, or
77 * AV_SAMPLE_FMT_NONE on error. If the passed sample_fmt is already in the
78 * requested planar/packed format, the format returned is the same as the
81 enum AVSampleFormat av_get_alt_sample_fmt(enum AVSampleFormat sample_fmt, int planar);
84 * Get the packed alternative form of the given sample format.
86 * If the passed sample_fmt is already in packed format, the format returned is
87 * the same as the input.
89 * @return the packed alternative form of the given sample format or
90 AV_SAMPLE_FMT_NONE on error.
92 enum AVSampleFormat av_get_packed_sample_fmt(enum AVSampleFormat sample_fmt);
95 * Get the planar alternative form of the given sample format.
97 * If the passed sample_fmt is already in planar format, the format returned is
98 * the same as the input.
100 * @return the planar alternative form of the given sample format or
101 AV_SAMPLE_FMT_NONE on error.
103 enum AVSampleFormat av_get_planar_sample_fmt(enum AVSampleFormat sample_fmt);
106 * Generate a string corresponding to the sample format with
107 * sample_fmt, or a header if sample_fmt is negative.
109 * @param buf the buffer where to write the string
110 * @param buf_size the size of buf
111 * @param sample_fmt the number of the sample format to print the
112 * corresponding info string, or a negative value to print the
113 * corresponding header.
114 * @return the pointer to the filled buffer or NULL if sample_fmt is
115 * unknown or in case of other errors
117 char *av_get_sample_fmt_string(char *buf, int buf_size, enum AVSampleFormat sample_fmt);
119 #if FF_API_GET_BITS_PER_SAMPLE_FMT
121 * @deprecated Use av_get_bytes_per_sample() instead.
124 int av_get_bits_per_sample_fmt(enum AVSampleFormat sample_fmt);
128 * Return number of bytes per sample.
130 * @param sample_fmt the sample format
131 * @return number of bytes per sample or zero if unknown for the given
134 int av_get_bytes_per_sample(enum AVSampleFormat sample_fmt);
137 * Check if the sample format is planar.
139 * @param sample_fmt the sample format to inspect
140 * @return 1 if the sample format is planar, 0 if it is interleaved
142 int av_sample_fmt_is_planar(enum AVSampleFormat sample_fmt);
145 * Get the required buffer size for the given audio parameters.
147 * @param[out] linesize calculated linesize, may be NULL
148 * @param nb_channels the number of channels
149 * @param nb_samples the number of samples in a single channel
150 * @param sample_fmt the sample format
151 * @param align buffer size alignment (0 = default, 1 = no alignment)
152 * @return required buffer size, or negative error code on failure
154 int av_samples_get_buffer_size(int *linesize, int nb_channels, int nb_samples,
155 enum AVSampleFormat sample_fmt, int align);
158 * Fill channel data pointers and linesize for samples with sample
161 * The pointers array is filled with the pointers to the samples data:
162 * for planar, set the start point of each channel's data within the buffer,
163 * for packed, set the start point of the entire buffer only.
165 * The linesize array is filled with the aligned size of each channel's data
166 * buffer for planar layout, or the aligned size of the buffer for all channels
169 * @see enum AVSampleFormat
170 * The documentation for AVSampleFormat describes the data layout.
172 * @param[out] audio_data array to be filled with the pointer for each channel
173 * @param[out] linesize calculated linesize, may be NULL
174 * @param buf the pointer to a buffer containing the samples
175 * @param nb_channels the number of channels
176 * @param nb_samples the number of samples in a single channel
177 * @param sample_fmt the sample format
178 * @param align buffer size alignment (0 = default, 1 = no alignment)
179 * @return 0 on success or a negative error code on failure
181 int av_samples_fill_arrays(uint8_t **audio_data, int *linesize,
183 int nb_channels, int nb_samples,
184 enum AVSampleFormat sample_fmt, int align);
187 * Allocate a samples buffer for nb_samples samples, and fill data pointers and
188 * linesize accordingly.
189 * The allocated samples buffer can be freed by using av_freep(&audio_data[0])
191 * @see enum AVSampleFormat
192 * The documentation for AVSampleFormat describes the data layout.
194 * @param[out] audio_data array to be filled with the pointer for each channel
195 * @param[out] linesize aligned size for audio buffer(s), may be NULL
196 * @param nb_channels number of audio channels
197 * @param nb_samples number of samples per channel
198 * @param align buffer size alignment (0 = default, 1 = no alignment)
199 * @return 0 on success or a negative error code on failure
200 * @see av_samples_fill_arrays()
202 int av_samples_alloc(uint8_t **audio_data, int *linesize, int nb_channels,
203 int nb_samples, enum AVSampleFormat sample_fmt, int align);
206 * Copy samples from src to dst.
208 * @param dst destination array of pointers to data planes
209 * @param src source array of pointers to data planes
210 * @param dst_offset offset in samples at which the data will be written to dst
211 * @param src_offset offset in samples at which the data will be read from src
212 * @param nb_samples number of samples to be copied
213 * @param nb_channels number of audio channels
214 * @param sample_fmt audio sample format
216 int av_samples_copy(uint8_t **dst, uint8_t * const *src, int dst_offset,
217 int src_offset, int nb_samples, int nb_channels,
218 enum AVSampleFormat sample_fmt);
221 * Fill an audio buffer with silence.
223 * @param audio_data array of pointers to data planes
224 * @param offset offset in samples at which to start filling
225 * @param nb_samples number of samples to fill
226 * @param nb_channels number of audio channels
227 * @param sample_fmt audio sample format
229 int av_samples_set_silence(uint8_t **audio_data, int offset, int nb_samples,
230 int nb_channels, enum AVSampleFormat sample_fmt);
232 #endif /* AVUTIL_SAMPLEFMT_H */