nutenc: add namespace to the api facing functions

Rename write_{header,packet,trailer} to nut_write_{header,packet,trailer}
in order to make easier debugging them.

libavformat/nutenc.c

@@ -578,7 +578,7 @@ static int write_headers(AVFormatContext *avctx, AVIOContext *bc){
     return 0;
 }
 
-static int write_header(AVFormatContext *s){
+static int nut_write_header(AVFormatContext *s){
     NUTContext *nut = s->priv_data;
     AVIOContext *bc = s->pb;
     int i, j, ret;
@@ -691,7 +691,7 @@ static int find_best_header_idx(NUTContext *nut, AVPacket *pkt){
     return best_i;
 }
 
-static int write_packet(AVFormatContext *s, AVPacket *pkt){
+static int nut_write_packet(AVFormatContext *s, AVPacket *pkt){
     NUTContext *nut = s->priv_data;
     StreamContext *nus= &nut->stream[pkt->stream_index];
     AVIOContext *bc = s->pb, *dyn_bc;
@@ -845,7 +845,7 @@ static int write_packet(AVFormatContext *s, AVPacket *pkt){
     return 0;
 }
 
-static int write_trailer(AVFormatContext *s){
+static int nut_write_trailer(AVFormatContext *s){
     NUTContext *nut= s->priv_data;
     AVIOContext *bc= s->pb;
 
@@ -874,9 +874,9 @@ AVOutputFormat ff_nut_muxer = {
     .audio_codec    = CODEC_ID_MP2,
 #endif
     .video_codec    = CODEC_ID_MPEG4,
-    .write_header   = write_header,
-    .write_packet   = write_packet,
-    .write_trailer  = write_trailer,
+    .write_header   = nut_write_header,
+    .write_packet   = nut_write_packet,
+    .write_trailer  = nut_write_trailer,
     .flags = AVFMT_GLOBALHEADER | AVFMT_VARIABLE_FPS,
     .codec_tag = (const AVCodecTag * const []){ ff_codec_bmp_tags, ff_nut_video_tags, ff_codec_wav_tags, ff_nut_subtitle_tags, 0 },
 };