avformat/hlsplaylist: Audio rendition's name and defaultness made configurable

Reviewed-by: Steven Liu <lq@chinaffmpeg.org>

libavformat/hlsenc.c

@@ -1169,7 +1169,7 @@ static int create_master_playlist(AVFormatContext *s,
             goto fail;
         }
 
-        ff_hls_write_audio_rendition(hls->m3u8_out, vs->agroup, m3u8_rel_name);
+        ff_hls_write_audio_rendition(hls->m3u8_out, vs->agroup, m3u8_rel_name, 0, 1);
 
         av_freep(&m3u8_rel_name);
     }

libavformat/hlsplaylist.c

@@ -36,12 +36,13 @@ void ff_hls_write_playlist_version(AVIOContext *out, int version) {
 }
 
 void ff_hls_write_audio_rendition(AVIOContext *out, char *agroup,
-                                  char *filename) {
+                                  char *filename, int name_id, int is_default) {
     if (!out || !agroup || !filename)
         return;
 
     avio_printf(out, "#EXT-X-MEDIA:TYPE=AUDIO,GROUP-ID=\"group_%s\"", agroup);
-    avio_printf(out, ",NAME=\"audio_0\",DEFAULT=YES,URI=\"%s\"\n", filename);
+    avio_printf(out, ",NAME=\"audio_%d\",DEFAULT=%s,URI=\"%s\"\n", name_id,
+                     is_default ? "YES" : "NO", filename);
 }
 
 void ff_hls_write_stream_info(AVStream *st, AVIOContext *out,

libavformat/hlsplaylist.h

@@ -37,7 +37,8 @@ typedef enum {
 } PlaylistType;
 
 void ff_hls_write_playlist_version(AVIOContext *out, int version);
-void ff_hls_write_audio_rendition(AVIOContext *out, char *agroup, char *filename);
+void ff_hls_write_audio_rendition(AVIOContext *out, char *agroup,
+                                  char *filename, int name_id, int is_default);
 void ff_hls_write_stream_info(AVStream *st, AVIOContext *out,
                               int bandwidth, char *filename, char *agroup);
 void ff_hls_write_playlist_header(AVIOContext *out, int version, int allowcache,