avformat/iamf_writer: constify some function parameters

Signed-off-by: James Almer <jamrial@gmail.com>

libavformat/iamf_writer.c

@@ -979,7 +979,7 @@ static int write_parameter_block(const IAMFContext *iamf, AVIOContext *pb,
 }
 
 int ff_iamf_write_parameter_blocks(const IAMFContext *iamf, AVIOContext *pb,
-                                   AVPacket *pkt, void *log_ctx)
+                                   const AVPacket *pkt, void *log_ctx)
 {
     AVIAMFParamDefinition *mix =
         (AVIAMFParamDefinition *)av_packet_get_side_data(pkt,
@@ -1014,7 +1014,7 @@ int ff_iamf_write_parameter_blocks(const IAMFContext *iamf, AVIOContext *pb,
 }
 
 int ff_iamf_write_audio_frame(const IAMFContext *iamf, AVIOContext *pb,
-                              unsigned audio_substream_id, AVPacket *pkt)
+                              unsigned audio_substream_id, const AVPacket *pkt)
 {
     uint8_t header[MAX_IAMF_OBU_HEADER_SIZE];
     PutBitContext pbc;

libavformat/iamf_writer.h

@@ -35,8 +35,8 @@ int ff_iamf_add_mix_presentation(IAMFContext *iamf, const AVStreamGroup *stg, vo
 int ff_iamf_write_descriptors(const IAMFContext *iamf, AVIOContext *pb, void *log_ctx);
 
 int ff_iamf_write_parameter_blocks(const IAMFContext *iamf, AVIOContext *pb,
-                                   AVPacket *pkt, void *log_ctx);
+                                   const AVPacket *pkt, void *log_ctx);
 int ff_iamf_write_audio_frame(const IAMFContext *iamf, AVIOContext *pb,
-                              unsigned audio_substream_id, AVPacket *pkt);
+                              unsigned audio_substream_id, const AVPacket *pkt);
 
 #endif /* AVFORMAT_IAMF_WRITER_H */