libavutil/samplefmt.h

   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 */