avformat/hlsenc: Add CHANNELS to EXT-X-MEDIA for Audio

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

libavformat/dashenc.c

@@ -1284,7 +1284,8 @@ static int write_manifest(AVFormatContext *s, int final)
                     continue;
                 get_hls_playlist_name(playlist_file, sizeof(playlist_file), NULL, i);
                 ff_hls_write_audio_rendition(c->m3u8_out, audio_group,
-                                             playlist_file, NULL, i, is_default);
+                                             playlist_file, NULL, i, is_default,
+                                             s->streams[i]->codecpar->ch_layout.nb_channels);
                 max_audio_bitrate = FFMAX(st->codecpar->bit_rate +
                                           os->muxer_overhead, max_audio_bitrate);
                 if (!av_strnstr(audio_codec_str, os->codec_str, sizeof(audio_codec_str))) {

libavformat/hlsenc.c

@@ -1386,6 +1386,7 @@ static int create_master_playlist(AVFormatContext *s,
     int is_file_proto = proto && !strcmp(proto, "file");
     int use_temp_file = is_file_proto && ((hls->flags & HLS_TEMP_FILE) || hls->master_publish_rate);
     char temp_filename[MAX_URL_SIZE];
+    int nb_channels;
 
     input_vs->m3u8_created = 1;
     if (!hls->master_m3u8_created) {
@@ -1434,8 +1435,13 @@ static int create_master_playlist(AVFormatContext *s,
             av_log(s, AV_LOG_ERROR, "Unable to find relative URL\n");
             goto fail;
         }
+        nb_channels = 0;
+        for (j = 0; j < vs->nb_streams; j++)
+            if (vs->streams[j]->codecpar->codec_type == AVMEDIA_TYPE_AUDIO)
+                if (vs->streams[j]->codecpar->ch_layout.nb_channels > nb_channels)
+                    nb_channels = vs->streams[j]->codecpar->ch_layout.nb_channels;
 
-        ff_hls_write_audio_rendition(hls->m3u8_out, vs->agroup, m3u8_rel_name, vs->language, i, hls->has_default_key ? vs->is_default : 1);
+        ff_hls_write_audio_rendition(hls->m3u8_out, vs->agroup, m3u8_rel_name, vs->language, i, hls->has_default_key ? vs->is_default : 1, nb_channels);
     }
 
     /* For variant streams with video add #EXT-X-STREAM-INF tag with attributes*/

libavformat/hlsplaylist.c

@@ -39,7 +39,7 @@ void ff_hls_write_playlist_version(AVIOContext *out, int version)
 
 void ff_hls_write_audio_rendition(AVIOContext *out, const char *agroup,
                                   const char *filename, const char *language,
-                                  int name_id, int is_default)
+                                  int name_id, int is_default, int nb_channels)
 {
     if (!out || !agroup || !filename)
         return;
@@ -49,6 +49,9 @@ void ff_hls_write_audio_rendition(AVIOContext *out, const char *agroup,
     if (language) {
         avio_printf(out, "LANGUAGE=\"%s\",", language);
     }
+    if (nb_channels) {
+        avio_printf(out, "CHANNELS=\"%d\",", nb_channels);
+    }
     avio_printf(out, "URI=\"%s\"\n", filename);
 }
 

libavformat/hlsplaylist.h

@@ -38,7 +38,7 @@ typedef enum {
 void ff_hls_write_playlist_version(AVIOContext *out, int version);
 void ff_hls_write_audio_rendition(AVIOContext *out, const char *agroup,
                                   const char *filename, const char *language,
-                                  int name_id, int is_default);
+                                  int name_id, int is_default, int nb_channels);
 void ff_hls_write_subtitle_rendition(AVIOContext *out, const char *sgroup,
                                      const char *filename, const char *language,
                                      int name_id, int is_default);