samplefmt.h (10211B)
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 #include "avutil.h" 25 #include "attributes.h" 26 27 /** 28 * @addtogroup lavu_audio 29 * @{ 30 * 31 * @defgroup lavu_sampfmts Audio sample formats 32 * 33 * Audio sample format enumeration and related convenience functions. 34 * @{ 35 * 36 */ 37 38 /** 39 * Audio sample formats 40 * 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. 44 * 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. 47 * 48 * - The data layout as used in av_samples_fill_arrays() and elsewhere in FFmpeg 49 * (such as AVFrame in libavcodec) is as follows: 50 * 51 * @par 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. 57 * 58 */ 59 enum AVSampleFormat { 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 66 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 72 73 AV_SAMPLE_FMT_NB ///< Number of sample formats. DO NOT USE if linking dynamically 74 }; 75 76 /** 77 * Return the name of sample_fmt, or NULL if sample_fmt is not 78 * recognized. 79 */ 80 const char *av_get_sample_fmt_name(enum AVSampleFormat sample_fmt); 81 82 /** 83 * Return a sample format corresponding to name, or AV_SAMPLE_FMT_NONE 84 * on error. 85 */ 86 enum AVSampleFormat av_get_sample_fmt(const char *name); 87 88 /** 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 92 * input. 93 */ 94 enum AVSampleFormat av_get_alt_sample_fmt(enum AVSampleFormat sample_fmt, int planar); 95 96 /** 97 * Get the packed alternative form of the given sample format. 98 * 99 * If the passed sample_fmt is already in packed format, the format returned is 100 * the same as the input. 101 * 102 * @return the packed alternative form of the given sample format or 103 AV_SAMPLE_FMT_NONE on error. 104 */ 105 enum AVSampleFormat av_get_packed_sample_fmt(enum AVSampleFormat sample_fmt); 106 107 /** 108 * Get the planar alternative form of the given sample format. 109 * 110 * If the passed sample_fmt is already in planar format, the format returned is 111 * the same as the input. 112 * 113 * @return the planar alternative form of the given sample format or 114 AV_SAMPLE_FMT_NONE on error. 115 */ 116 enum AVSampleFormat av_get_planar_sample_fmt(enum AVSampleFormat sample_fmt); 117 118 /** 119 * Generate a string corresponding to the sample format with 120 * sample_fmt, or a header if sample_fmt is negative. 121 * 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 129 */ 130 char *av_get_sample_fmt_string(char *buf, int buf_size, enum AVSampleFormat sample_fmt); 131 132 /** 133 * Return number of bytes per sample. 134 * 135 * @param sample_fmt the sample format 136 * @return number of bytes per sample or zero if unknown for the given 137 * sample format 138 */ 139 int av_get_bytes_per_sample(enum AVSampleFormat sample_fmt); 140 141 /** 142 * Check if the sample format is planar. 143 * 144 * @param sample_fmt the sample format to inspect 145 * @return 1 if the sample format is planar, 0 if it is interleaved 146 */ 147 int av_sample_fmt_is_planar(enum AVSampleFormat sample_fmt); 148 149 /** 150 * Get the required buffer size for the given audio parameters. 151 * 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 158 */ 159 int av_samples_get_buffer_size(int *linesize, int nb_channels, int nb_samples, 160 enum AVSampleFormat sample_fmt, int align); 161 162 /** 163 * @} 164 * 165 * @defgroup lavu_sampmanip Samples manipulation 166 * 167 * Functions that manipulate audio samples 168 * @{ 169 */ 170 171 /** 172 * Fill plane data pointers and linesize for samples with sample 173 * format sample_fmt. 174 * 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. 178 * 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. 182 * 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. 186 * 187 * @see enum AVSampleFormat 188 * The documentation for AVSampleFormat describes the data layout. 189 * 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 200 */ 201 int av_samples_fill_arrays(uint8_t **audio_data, int *linesize, 202 const uint8_t *buf, 203 int nb_channels, int nb_samples, 204 enum AVSampleFormat sample_fmt, int align); 205 206 /** 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. 211 * 212 * @see enum AVSampleFormat 213 * The documentation for AVSampleFormat describes the data layout. 214 * 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() 224 */ 225 int av_samples_alloc(uint8_t **audio_data, int *linesize, int nb_channels, 226 int nb_samples, enum AVSampleFormat sample_fmt, int align); 227 228 /** 229 * Allocate a data pointers array, samples buffer for nb_samples 230 * samples, and fill data pointers and linesize accordingly. 231 * 232 * This is the same as av_samples_alloc(), but also allocates the data 233 * pointers array. 234 * 235 * @see av_samples_alloc() 236 */ 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); 239 240 /** 241 * Copy samples from src to dst. 242 * 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 250 */ 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); 254 255 /** 256 * Fill an audio buffer with silence. 257 * 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 263 */ 264 int av_samples_set_silence(uint8_t **audio_data, int offset, int nb_samples, 265 int nb_channels, enum AVSampleFormat sample_fmt); 266 267 /** 268 * @} 269 * @} 270 */ 271 #endif /* AVUTIL_SAMPLEFMT_H */