avcodec: Mark argument in av_{parser|hwaccel|bitstream_filter}_next as const

libavcodec/avcodec.h

@@ -3800,7 +3800,7 @@ typedef struct AVCodecParser {
     struct AVCodecParser *next;
 } AVCodecParser;
 
-AVCodecParser *av_parser_next(AVCodecParser *c);
+AVCodecParser *av_parser_next(const AVCodecParser *c);
 
 void av_register_codec_parser(AVCodecParser *parser);
 AVCodecParserContext *av_parser_init(int codec_id);
@@ -4281,7 +4281,7 @@ int av_bitstream_filter_filter(AVBitStreamFilterContext *bsfc,
                                const uint8_t *buf, int buf_size, int keyframe);
 void av_bitstream_filter_close(AVBitStreamFilterContext *bsf);
 
-AVBitStreamFilter *av_bitstream_filter_next(AVBitStreamFilter *f);
+AVBitStreamFilter *av_bitstream_filter_next(const AVBitStreamFilter *f);
 
 /* memory */
 
@@ -4343,7 +4343,7 @@ void av_register_hwaccel(AVHWAccel *hwaccel);
  * if hwaccel is non-NULL, returns the next registered hardware accelerator
  * after hwaccel, or NULL if hwaccel is the last one.
  */
-AVHWAccel *av_hwaccel_next(AVHWAccel *hwaccel);
+AVHWAccel *av_hwaccel_next(const AVHWAccel *hwaccel);
 
 
 /**

libavcodec/bitstream_filter.c

@@ -25,7 +25,7 @@
 
 static AVBitStreamFilter *first_bitstream_filter = NULL;
 
-AVBitStreamFilter *av_bitstream_filter_next(AVBitStreamFilter *f)
+AVBitStreamFilter *av_bitstream_filter_next(const AVBitStreamFilter *f)
 {
     if (f)
         return f->next;

libavcodec/parser.c

@@ -29,7 +29,7 @@
 
 static AVCodecParser *av_first_parser = NULL;
 
-AVCodecParser *av_parser_next(AVCodecParser *p)
+AVCodecParser *av_parser_next(const AVCodecParser *p)
 {
     if (p)
         return p->next;

libavcodec/utils.c

@@ -2279,7 +2279,7 @@ void av_register_hwaccel(AVHWAccel *hwaccel)
     hwaccel->next = NULL;
 }
 
-AVHWAccel *av_hwaccel_next(AVHWAccel *hwaccel)
+AVHWAccel *av_hwaccel_next(const AVHWAccel *hwaccel)
 {
     return hwaccel ? hwaccel->next : first_hwaccel;
 }