samplefmt.h (8652B)
1 /* 2 * This file is part of Libav. 3 * 4 * Libav 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 * Libav 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 Libav; 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 * Audio Sample Formats 29 * 30 * @par 31 * The data described by the sample format is always in native-endian order. 32 * Sample values can be expressed by native C types, hence the lack of a signed 33 * 24-bit sample format even though it is a common raw audio data format. 34 * 35 * @par 36 * The floating-point formats are based on full volume being in the range 37 * [-1.0, 1.0]. Any values outside this range are beyond full volume level. 38 * 39 * @par 40 * The data layout as used in av_samples_fill_arrays() and elsewhere in Libav 41 * (such as AVFrame in libavcodec) is as follows: 42 * 43 * For planar sample formats, each audio channel is in a separate data plane, 44 * and linesize is the buffer size, in bytes, for a single plane. All data 45 * planes must be the same size. For packed sample formats, only the first data 46 * plane is used, and samples for each channel are interleaved. In this case, 47 * linesize is the buffer size, in bytes, for the 1 plane. 48 */ 49 enum AVSampleFormat { 50 AV_SAMPLE_FMT_NONE = -1, 51 AV_SAMPLE_FMT_U8, ///< unsigned 8 bits 52 AV_SAMPLE_FMT_S16, ///< signed 16 bits 53 AV_SAMPLE_FMT_S32, ///< signed 32 bits 54 AV_SAMPLE_FMT_FLT, ///< float 55 AV_SAMPLE_FMT_DBL, ///< double 56 57 AV_SAMPLE_FMT_U8P, ///< unsigned 8 bits, planar 58 AV_SAMPLE_FMT_S16P, ///< signed 16 bits, planar 59 AV_SAMPLE_FMT_S32P, ///< signed 32 bits, planar 60 AV_SAMPLE_FMT_FLTP, ///< float, planar 61 AV_SAMPLE_FMT_DBLP, ///< double, planar 62 63 AV_SAMPLE_FMT_NB ///< Number of sample formats. DO NOT USE if linking dynamically 64 }; 65 66 /** 67 * Return the name of sample_fmt, or NULL if sample_fmt is not 68 * recognized. 69 */ 70 const char *av_get_sample_fmt_name(enum AVSampleFormat sample_fmt); 71 72 /** 73 * Return a sample format corresponding to name, or AV_SAMPLE_FMT_NONE 74 * on error. 75 */ 76 enum AVSampleFormat av_get_sample_fmt(const char *name); 77 78 /** 79 * Get the packed alternative form of the given sample format. 80 * 81 * If the passed sample_fmt is already in packed format, the format returned is 82 * the same as the input. 83 * 84 * @return the packed alternative form of the given sample format or 85 AV_SAMPLE_FMT_NONE on error. 86 */ 87 enum AVSampleFormat av_get_packed_sample_fmt(enum AVSampleFormat sample_fmt); 88 89 /** 90 * Get the planar alternative form of the given sample format. 91 * 92 * If the passed sample_fmt is already in planar format, the format returned is 93 * the same as the input. 94 * 95 * @return the planar alternative form of the given sample format or 96 AV_SAMPLE_FMT_NONE on error. 97 */ 98 enum AVSampleFormat av_get_planar_sample_fmt(enum AVSampleFormat sample_fmt); 99 100 /** 101 * Generate a string corresponding to the sample format with 102 * sample_fmt, or a header if sample_fmt is negative. 103 * 104 * @param buf the buffer where to write the string 105 * @param buf_size the size of buf 106 * @param sample_fmt the number of the sample format to print the 107 * corresponding info string, or a negative value to print the 108 * corresponding header. 109 * @return the pointer to the filled buffer or NULL if sample_fmt is 110 * unknown or in case of other errors 111 */ 112 char *av_get_sample_fmt_string(char *buf, int buf_size, enum AVSampleFormat sample_fmt); 113 114 /** 115 * Return number of bytes per sample. 116 * 117 * @param sample_fmt the sample format 118 * @return number of bytes per sample or zero if unknown for the given 119 * sample format 120 */ 121 int av_get_bytes_per_sample(enum AVSampleFormat sample_fmt); 122 123 /** 124 * Check if the sample format is planar. 125 * 126 * @param sample_fmt the sample format to inspect 127 * @return 1 if the sample format is planar, 0 if it is interleaved 128 */ 129 int av_sample_fmt_is_planar(enum AVSampleFormat sample_fmt); 130 131 /** 132 * Get the required buffer size for the given audio parameters. 133 * 134 * @param[out] linesize calculated linesize, may be NULL 135 * @param nb_channels the number of channels 136 * @param nb_samples the number of samples in a single channel 137 * @param sample_fmt the sample format 138 * @param align buffer size alignment (0 = default, 1 = no alignment) 139 * @return required buffer size, or negative error code on failure 140 */ 141 int av_samples_get_buffer_size(int *linesize, int nb_channels, int nb_samples, 142 enum AVSampleFormat sample_fmt, int align); 143 144 /** 145 * Fill channel data pointers and linesize for samples with sample 146 * format sample_fmt. 147 * 148 * The pointers array is filled with the pointers to the samples data: 149 * for planar, set the start point of each channel's data within the buffer, 150 * for packed, set the start point of the entire buffer only. 151 * 152 * The linesize array is filled with the aligned size of each channel's data 153 * buffer for planar layout, or the aligned size of the buffer for all channels 154 * for packed layout. 155 * 156 * @see enum AVSampleFormat 157 * The documentation for AVSampleFormat describes the data layout. 158 * 159 * @param[out] audio_data array to be filled with the pointer for each channel 160 * @param[out] linesize calculated linesize, may be NULL 161 * @param buf the pointer to a buffer containing the samples 162 * @param nb_channels the number of channels 163 * @param nb_samples the number of samples in a single channel 164 * @param sample_fmt the sample format 165 * @param align buffer size alignment (0 = default, 1 = no alignment) 166 * @return 0 on success or a negative error code on failure 167 */ 168 int av_samples_fill_arrays(uint8_t **audio_data, int *linesize, 169 const uint8_t *buf, 170 int nb_channels, int nb_samples, 171 enum AVSampleFormat sample_fmt, int align); 172 173 /** 174 * Allocate a samples buffer for nb_samples samples, and fill data pointers and 175 * linesize accordingly. 176 * The allocated samples buffer can be freed by using av_freep(&audio_data[0]) 177 * Allocated data will be initialized to silence. 178 * 179 * @see enum AVSampleFormat 180 * The documentation for AVSampleFormat describes the data layout. 181 * 182 * @param[out] audio_data array to be filled with the pointer for each channel 183 * @param[out] linesize aligned size for audio buffer(s), may be NULL 184 * @param nb_channels number of audio channels 185 * @param nb_samples number of samples per channel 186 * @param align buffer size alignment (0 = default, 1 = no alignment) 187 * @return 0 on success or a negative error code on failure 188 * @see av_samples_fill_arrays() 189 */ 190 int av_samples_alloc(uint8_t **audio_data, int *linesize, int nb_channels, 191 int nb_samples, enum AVSampleFormat sample_fmt, int align); 192 193 /** 194 * Copy samples from src to dst. 195 * 196 * @param dst destination array of pointers to data planes 197 * @param src source array of pointers to data planes 198 * @param dst_offset offset in samples at which the data will be written to dst 199 * @param src_offset offset in samples at which the data will be read from src 200 * @param nb_samples number of samples to be copied 201 * @param nb_channels number of audio channels 202 * @param sample_fmt audio sample format 203 */ 204 int av_samples_copy(uint8_t **dst, uint8_t * const *src, int dst_offset, 205 int src_offset, int nb_samples, int nb_channels, 206 enum AVSampleFormat sample_fmt); 207 208 /** 209 * Fill an audio buffer with silence. 210 * 211 * @param audio_data array of pointers to data planes 212 * @param offset offset in samples at which to start filling 213 * @param nb_samples number of samples to fill 214 * @param nb_channels number of audio channels 215 * @param sample_fmt audio sample format 216 */ 217 int av_samples_set_silence(uint8_t **audio_data, int offset, int nb_samples, 218 int nb_channels, enum AVSampleFormat sample_fmt); 219 220 #endif /* AVUTIL_SAMPLEFMT_H */