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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 * Get the packed alternative form of the given sample format.
78 * If the passed sample_fmt is already in packed format, the format returned is
79 * the same as the input.
81 * @return the packed alternative form of the given sample format or
82 AV_SAMPLE_FMT_NONE on error.
84 enum AVSampleFormat av_get_packed_sample_fmt(enum AVSampleFormat sample_fmt);
87 * Get the planar alternative form of the given sample format.
89 * If the passed sample_fmt is already in planar format, the format returned is
90 * the same as the input.
92 * @return the planar alternative form of the given sample format or
93 AV_SAMPLE_FMT_NONE on error.
95 enum AVSampleFormat av_get_planar_sample_fmt(enum AVSampleFormat sample_fmt);
98 * Generate a string corresponding to the sample format with
99 * sample_fmt, or a header if sample_fmt is negative.
101 * @param buf the buffer where to write the string
102 * @param buf_size the size of buf
103 * @param sample_fmt the number of the sample format to print the
104 * corresponding info string, or a negative value to print the
105 * corresponding header.
106 * @return the pointer to the filled buffer or NULL if sample_fmt is
107 * unknown or in case of other errors
109 char *av_get_sample_fmt_string(char *buf, int buf_size, enum AVSampleFormat sample_fmt);
111 #if FF_API_GET_BITS_PER_SAMPLE_FMT
113 * @deprecated Use av_get_bytes_per_sample() instead.
116 int av_get_bits_per_sample_fmt(enum AVSampleFormat sample_fmt);
120 * Return number of bytes per sample.
122 * @param sample_fmt the sample format
123 * @return number of bytes per sample or zero if unknown for the given
126 int av_get_bytes_per_sample(enum AVSampleFormat sample_fmt);
129 * Check if the sample format is planar.
131 * @param sample_fmt the sample format to inspect
132 * @return 1 if the sample format is planar, 0 if it is interleaved
134 int av_sample_fmt_is_planar(enum AVSampleFormat sample_fmt);
137 * Get the required buffer size for the given audio parameters.
139 * @param[out] linesize calculated linesize, may be NULL
140 * @param nb_channels the number of channels
141 * @param nb_samples the number of samples in a single channel
142 * @param sample_fmt the sample format
143 * @param align buffer size alignment (0 = default, 1 = no alignment)
144 * @return required buffer size, or negative error code on failure
146 int av_samples_get_buffer_size(int *linesize, int nb_channels, int nb_samples,
147 enum AVSampleFormat sample_fmt, int align);
150 * Fill channel data pointers and linesize for samples with sample
153 * The pointers array is filled with the pointers to the samples data:
154 * for planar, set the start point of each channel's data within the buffer,
155 * for packed, set the start point of the entire buffer only.
157 * The linesize array is filled with the aligned size of each channel's data
158 * buffer for planar layout, or the aligned size of the buffer for all channels
161 * @see enum AVSampleFormat
162 * The documentation for AVSampleFormat describes the data layout.
164 * @param[out] audio_data array to be filled with the pointer for each channel
165 * @param[out] linesize calculated linesize, may be NULL
166 * @param buf the pointer to a buffer containing the samples
167 * @param nb_channels the number of channels
168 * @param nb_samples the number of samples in a single channel
169 * @param sample_fmt the sample format
170 * @param align buffer size alignment (0 = default, 1 = no alignment)
171 * @return 0 on success or a negative error code on failure
173 int av_samples_fill_arrays(uint8_t **audio_data, int *linesize,
175 int nb_channels, int nb_samples,
176 enum AVSampleFormat sample_fmt, int align);
179 * Allocate a samples buffer for nb_samples samples, and fill data pointers and
180 * linesize accordingly.
181 * The allocated samples buffer can be freed by using av_freep(&audio_data[0])
183 * @see enum AVSampleFormat
184 * The documentation for AVSampleFormat describes the data layout.
186 * @param[out] audio_data array to be filled with the pointer for each channel
187 * @param[out] linesize aligned size for audio buffer(s), may be NULL
188 * @param nb_channels number of audio channels
189 * @param nb_samples number of samples per channel
190 * @param align buffer size alignment (0 = default, 1 = no alignment)
191 * @return 0 on success or a negative error code on failure
192 * @see av_samples_fill_arrays()
194 int av_samples_alloc(uint8_t **audio_data, int *linesize, int nb_channels,
195 int nb_samples, enum AVSampleFormat sample_fmt, int align);
197 #endif /* AVUTIL_SAMPLEFMT_H */