swresample/swresample: Constify swr_convert()

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:
 
+2024-02-28 - xxxxxxxxxx - swr   4.14.100 - swresample.h
+  swr_convert() now accepts arrays of const pointers (to input and output).
+
 2024-02-28 - xxxxxxxxxx - lavu 58.40.100 - timestamp.h
   av_ts_make_time_string() now accepts a pointer to const AVRational.
 

libswresample/swresample.c

@@ -563,7 +563,8 @@ static void copy(AudioData *out, AudioData *in,
         memcpy(out->ch[0], in->ch[0], count*out->ch_count*out->bps);
 }
 
-static void fill_audiodata(AudioData *out, uint8_t *in_arg [SWR_CH_MAX]){
+static void fill_audiodata(AudioData *out, uint8_t *const in_arg [SWR_CH_MAX])
+{
     int i;
     if(!in_arg){
         memset(out->ch, 0, sizeof(out->ch));
@@ -835,8 +836,8 @@ int swr_is_initialized(struct SwrContext *s) {
 }
 
 int attribute_align_arg swr_convert(struct SwrContext *s,
-                                          uint8_t **out_arg, int out_count,
-                                    const uint8_t **in_arg,  int in_count)
+                                          uint8_t * const *out_arg, int out_count,
+                                    const uint8_t * const *in_arg,  int in_count)
 {
     AudioData * in= &s->in;
     AudioData *out= &s->out;

libswresample/swresample.h

@@ -340,8 +340,8 @@ void swr_close(struct SwrContext *s);
  *
  * @return number of samples output per channel, negative value on error
  */
-int swr_convert(struct SwrContext *s, uint8_t **out, int out_count,
-                                const uint8_t **in , int in_count);
+int swr_convert(struct SwrContext *s, uint8_t * const *out, int out_count,
+                                const uint8_t * const *in , int in_count);
 
 /**
  * Convert the next timestamp from input to output

libswresample/version.h

@@ -30,7 +30,7 @@
 
 #include "version_major.h"
 
-#define LIBSWRESAMPLE_VERSION_MINOR  13
+#define LIBSWRESAMPLE_VERSION_MINOR  14
 #define LIBSWRESAMPLE_VERSION_MICRO 100
 
 #define LIBSWRESAMPLE_VERSION_INT  AV_VERSION_INT(LIBSWRESAMPLE_VERSION_MAJOR, \