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1 /*
2  * This file is part of FFmpeg.
3  *
4  * FFmpeg 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.
8  *
9  * FFmpeg 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.
13  *
14  * You should have received a copy of the GNU Lesser General Public
15  * License along with FFmpeg; if not, write to the Free Software
16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17  */
18 
19 #ifndef AVUTIL_SAMPLEFMT_H
20 #define AVUTIL_SAMPLEFMT_H
21 
22 #include <stdint.h>
23 
24 /**
25  * @addtogroup lavu_audio
26  * @{
27  *
28  * @defgroup lavu_sampfmts Audio sample formats
29  *
30  * Audio sample format enumeration and related convenience functions.
31  * @{
32  */
33 
34 /**
35  * Audio sample formats
36  *
37  * - The data described by the sample format is always in native-endian order.
38  *   Sample values can be expressed by native C types, hence the lack of a signed
39  *   24-bit sample format even though it is a common raw audio data format.
40  *
41  * - The floating-point formats are based on full volume being in the range
42  *   [-1.0, 1.0]. Any values outside this range are beyond full volume level.
43  *
44  * - The data layout as used in av_samples_fill_arrays() and elsewhere in FFmpeg
45  *   (such as AVFrame in libavcodec) is as follows:
46  *
47  * @par
48  * For planar sample formats, each audio channel is in a separate data plane,
49  * and linesize is the buffer size, in bytes, for a single plane. All data
50  * planes must be the same size. For packed sample formats, only the first data
51  * plane is used, and samples for each channel are interleaved. In this case,
52  * linesize is the buffer size, in bytes, for the 1 plane.
53  *
54  */
55 enum AVSampleFormat {
56     AV_SAMPLE_FMT_NONE = -1,
57     AV_SAMPLE_FMT_U8,          ///< unsigned 8 bits
58     AV_SAMPLE_FMT_S16,         ///< signed 16 bits
59     AV_SAMPLE_FMT_S32,         ///< signed 32 bits
60     AV_SAMPLE_FMT_FLT,         ///< float
61     AV_SAMPLE_FMT_DBL,         ///< double
62 
63     AV_SAMPLE_FMT_U8P,         ///< unsigned 8 bits, planar
64     AV_SAMPLE_FMT_S16P,        ///< signed 16 bits, planar
65     AV_SAMPLE_FMT_S32P,        ///< signed 32 bits, planar
66     AV_SAMPLE_FMT_FLTP,        ///< float, planar
67     AV_SAMPLE_FMT_DBLP,        ///< double, planar
68     AV_SAMPLE_FMT_S64,         ///< signed 64 bits
69     AV_SAMPLE_FMT_S64P,        ///< signed 64 bits, planar
70 
71     AV_SAMPLE_FMT_NB           ///< Number of sample formats. DO NOT USE if linking dynamically
72 };
73 
74 /**
75  * Return the name of sample_fmt, or NULL if sample_fmt is not
76  * recognized.
77  */
78 const char *av_get_sample_fmt_name(enum AVSampleFormat sample_fmt);
79 
80 /**
81  * Return a sample format corresponding to name, or AV_SAMPLE_FMT_NONE
82  * on error.
83  */
84 enum AVSampleFormat av_get_sample_fmt(const char *name);
85 
86 /**
87  * Return the planar<->packed alternative form of the given sample format, or
88  * AV_SAMPLE_FMT_NONE on error. If the passed sample_fmt is already in the
89  * requested planar/packed format, the format returned is the same as the
90  * input.
91  */
92 enum AVSampleFormat av_get_alt_sample_fmt(enum AVSampleFormat sample_fmt, int planar);
93 
94 /**
95  * Get the packed alternative form of the given sample format.
96  *
97  * If the passed sample_fmt is already in packed format, the format returned is
98  * the same as the input.
99  *
100  * @return  the packed alternative form of the given sample format or
101             AV_SAMPLE_FMT_NONE on error.
102  */
103 enum AVSampleFormat av_get_packed_sample_fmt(enum AVSampleFormat sample_fmt);
104 
105 /**
106  * Get the planar alternative form of the given sample format.
107  *
108  * If the passed sample_fmt is already in planar format, the format returned is
109  * the same as the input.
110  *
111  * @return  the planar alternative form of the given sample format or
112             AV_SAMPLE_FMT_NONE on error.
113  */
114 enum AVSampleFormat av_get_planar_sample_fmt(enum AVSampleFormat sample_fmt);
115 
116 /**
117  * Generate a string corresponding to the sample format with
118  * sample_fmt, or a header if sample_fmt is negative.
119  *
120  * @param buf the buffer where to write the string
121  * @param buf_size the size of buf
122  * @param sample_fmt the number of the sample format to print the
123  * corresponding info string, or a negative value to print the
124  * corresponding header.
125  * @return the pointer to the filled buffer or NULL if sample_fmt is
126  * unknown or in case of other errors
127  */
128 char *av_get_sample_fmt_string(char *buf, int buf_size, enum AVSampleFormat sample_fmt);
129 
130 /**
131  * Return number of bytes per sample.
132  *
133  * @param sample_fmt the sample format
134  * @return number of bytes per sample or zero if unknown for the given
135  * sample format
136  */
137 int av_get_bytes_per_sample(enum AVSampleFormat sample_fmt);
138 
139 /**
140  * Check if the sample format is planar.
141  *
142  * @param sample_fmt the sample format to inspect
143  * @return 1 if the sample format is planar, 0 if it is interleaved
144  */
145 int av_sample_fmt_is_planar(enum AVSampleFormat sample_fmt);
146 
147 /**
148  * Get the required buffer size for the given audio parameters.
149  *
150  * @param[out] linesize calculated linesize, may be NULL
151  * @param nb_channels   the number of channels
152  * @param nb_samples    the number of samples in a single channel
153  * @param sample_fmt    the sample format
154  * @param align         buffer size alignment (0 = default, 1 = no alignment)
155  * @return              required buffer size, or negative error code on failure
156  */
157 int av_samples_get_buffer_size(int *linesize, int nb_channels, int nb_samples,
158                                enum AVSampleFormat sample_fmt, int align);
159 
160 /**
161  * @}
162  *
163  * @defgroup lavu_sampmanip Samples manipulation
164  *
165  * Functions that manipulate audio samples
166  * @{
167  */
168 
169 /**
170  * Fill plane data pointers and linesize for samples with sample
171  * format sample_fmt.
172  *
173  * The audio_data array is filled with the pointers to the samples data planes:
174  * for planar, set the start point of each channel's data within the buffer,
175  * for packed, set the start point of the entire buffer only.
176  *
177  * The value pointed to by linesize is set to the aligned size of each
178  * channel's data buffer for planar layout, or to the aligned size of the
179  * buffer for all channels for packed layout.
180  *
181  * The buffer in buf must be big enough to contain all the samples
182  * (use av_samples_get_buffer_size() to compute its minimum size),
183  * otherwise the audio_data pointers will point to invalid data.
184  *
185  * @see enum AVSampleFormat
186  * The documentation for AVSampleFormat describes the data layout.
187  *
188  * @param[out] audio_data  array to be filled with the pointer for each channel
189  * @param[out] linesize    calculated linesize, may be NULL
190  * @param buf              the pointer to a buffer containing the samples
191  * @param nb_channels      the number of channels
192  * @param nb_samples       the number of samples in a single channel
193  * @param sample_fmt       the sample format
194  * @param align            buffer size alignment (0 = default, 1 = no alignment)
195  * @return                 minimum size in bytes required for the buffer on success,
196  *                         or a negative error code on failure
197  */
198 int av_samples_fill_arrays(uint8_t **audio_data, int *linesize,
199                            const uint8_t *buf,
200                            int nb_channels, int nb_samples,
201                            enum AVSampleFormat sample_fmt, int align);
202 
203 /**
204  * Allocate a samples buffer for nb_samples samples, and fill data pointers and
205  * linesize accordingly.
206  * The allocated samples buffer can be freed by using av_freep(&audio_data[0])
207  * Allocated data will be initialized to silence.
208  *
209  * @see enum AVSampleFormat
210  * The documentation for AVSampleFormat describes the data layout.
211  *
212  * @param[out] audio_data  array to be filled with the pointer for each channel
213  * @param[out] linesize    aligned size for audio buffer(s), may be NULL
214  * @param nb_channels      number of audio channels
215  * @param nb_samples       number of samples per channel
216  * @param align            buffer size alignment (0 = default, 1 = no alignment)
217  * @return                 >=0 on success or a negative error code on failure
218  * @todo return the size of the allocated buffer in case of success at the next bump
219  * @see av_samples_fill_arrays()
220  * @see av_samples_alloc_array_and_samples()
221  */
222 int av_samples_alloc(uint8_t **audio_data, int *linesize, int nb_channels,
223                      int nb_samples, enum AVSampleFormat sample_fmt, int align);
224 
225 /**
226  * Allocate a data pointers array, samples buffer for nb_samples
227  * samples, and fill data pointers and linesize accordingly.
228  *
229  * This is the same as av_samples_alloc(), but also allocates the data
230  * pointers array.
231  *
232  * @see av_samples_alloc()
233  */
234 int av_samples_alloc_array_and_samples(uint8_t ***audio_data, int *linesize, int nb_channels,
235                                        int nb_samples, enum AVSampleFormat sample_fmt, int align);
236 
237 /**
238  * Copy samples from src to dst.
239  *
240  * @param dst destination array of pointers to data planes
241  * @param src source array of pointers to data planes
242  * @param dst_offset offset in samples at which the data will be written to dst
243  * @param src_offset offset in samples at which the data will be read from src
244  * @param nb_samples number of samples to be copied
245  * @param nb_channels number of audio channels
246  * @param sample_fmt audio sample format
247  */
248 int av_samples_copy(uint8_t **dst, uint8_t * const *src, int dst_offset,
249                     int src_offset, int nb_samples, int nb_channels,
250                     enum AVSampleFormat sample_fmt);
251 
252 /**
253  * Fill an audio buffer with silence.
254  *
255  * @param audio_data  array of pointers to data planes
256  * @param offset      offset in samples at which to start filling
257  * @param nb_samples  number of samples to fill
258  * @param nb_channels number of audio channels
259  * @param sample_fmt  audio sample format
260  */
261 int av_samples_set_silence(uint8_t **audio_data, int offset, int nb_samples,
262                            int nb_channels, enum AVSampleFormat sample_fmt);
263 
264 /**
265  * @}
266  * @}
267  */
268 #endif /* AVUTIL_SAMPLEFMT_H */
269