avutil/samplefmt: Constify some pointees

This is the samplefmt analog of the imgutils changes
from the preceding commit.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>

doc/APIchanges

@@ -2,6 +2,9 @@ The last version increases of all libraries were on 2023-02-09
 
 API changes, most recent first:
 
+2023-09-07 - xxxxxxxxxx - lavu 58.21.100 - samplefmt.h
+  Constify some pointees in av_samples_copy() and av_samples_set_silence().
+
 2023-09-07 - xxxxxxxxxx - lavu 58.20.100 - imgutils.h
   Constify some pointees in av_image_copy(), av_image_copy_uc_from() and
   av_image_fill_black().

libavutil/samplefmt.c

@@ -219,7 +219,7 @@ int av_samples_alloc_array_and_samples(uint8_t ***audio_data, int *linesize, int
     return ret;
 }
 
-int av_samples_copy(uint8_t **dst, uint8_t * const *src, int dst_offset,
+int av_samples_copy(uint8_t * const *dst, uint8_t * const *src, int dst_offset,
                     int src_offset, int nb_samples, int nb_channels,
                     enum AVSampleFormat sample_fmt)
 {
@@ -243,7 +243,7 @@ int av_samples_copy(uint8_t **dst, uint8_t * const *src, int dst_offset,
     return 0;
 }
 
-int av_samples_set_silence(uint8_t **audio_data, int offset, int nb_samples,
+int av_samples_set_silence(uint8_t * const *audio_data, int offset, int nb_samples,
                            int nb_channels, enum AVSampleFormat sample_fmt)
 {
     int planar      = av_sample_fmt_is_planar(sample_fmt);

libavutil/samplefmt.h

@@ -246,7 +246,7 @@ int av_samples_alloc_array_and_samples(uint8_t ***audio_data, int *linesize, int
  * @param nb_channels number of audio channels
  * @param sample_fmt audio sample format
  */
-int av_samples_copy(uint8_t **dst, uint8_t * const *src, int dst_offset,
+int av_samples_copy(uint8_t * const *dst, uint8_t * const *src, int dst_offset,
                     int src_offset, int nb_samples, int nb_channels,
                     enum AVSampleFormat sample_fmt);
 
@@ -259,7 +259,7 @@ int av_samples_copy(uint8_t **dst, uint8_t * const *src, int dst_offset,
  * @param nb_channels number of audio channels
  * @param sample_fmt  audio sample format
  */
-int av_samples_set_silence(uint8_t **audio_data, int offset, int nb_samples,
+int av_samples_set_silence(uint8_t * const *audio_data, int offset, int nb_samples,
                            int nb_channels, enum AVSampleFormat sample_fmt);
 
 /**

libavutil/version.h

@@ -79,7 +79,7 @@
  */
 
 #define LIBAVUTIL_VERSION_MAJOR  58
-#define LIBAVUTIL_VERSION_MINOR  20
+#define LIBAVUTIL_VERSION_MINOR  21
 #define LIBAVUTIL_VERSION_MICRO 100
 
 #define LIBAVUTIL_VERSION_INT   AV_VERSION_INT(LIBAVUTIL_VERSION_MAJOR, \