[FFmpeg-devel,HLS] Add LANGUAGE attribute to #EXT-X-MEDIA tag for audio-only variant streams.

Submitted by Steven Liu on Nov. 13, 2018, 2:29 a.m.

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Message ID 1560DEDB-A8E6-45F9-82FE-5AEE9E56B8E1@chinaffmpeg.org
State New
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Commit Message

Steven Liu Nov. 13, 2018, 2:29 a.m.
> 在 2018年11月13日,上午6:36,Philippe Symons <philippe.symons@gmail.com> 写道:
> 
> Hello everyone,
> 
> This is my first patch to FFMpeg or any open-source project for that
> matter. In this patch, I've added the LANGUAGE attribute to the
> #EXT-X-MEDIA tag for for audio only variant streams for HLS streams.
> 
> This attribute will be added to the output in
> avformats' ff_hls_write_audio_rendition() function, if the language code
> can be found in the metadata of the variant stream.
> 
> The reason why I implemented this, was because I was working with a player
> which needs this attribute to determine the language of the audio stream.
> After asking the question on StackOverflow (
> https://stackoverflow.com/questions/53205283/ffmpeg-hls-multiple-audio-languages-with-var-stream-map-ext-x-mediatype-doesn/53206492#53206492),
> I noticed that it wasn't implemented.
> 
> I've tested these changes with the following command:
> 
> ffmpeg -re -i /home/philippe/Videos/example.ts -map 0:v -c:v copy -map 0:a
> -c:a copy -f hls -hls_time 6 -hls_list_size 10 -hls_flags
> delete_segments+program_date_time -hls_segment_filename
> "/var/www/html/live/stream_%v_%d.ts" -var_stream_map "v:0,agroup:lang
> a:0,agroup:lang a:1,agroup:lang a:2,agroup:lang a:
> 3,agroup:lang" -master_pl_name master.m3u8 /var/www/html/live/stream-%v.m3u8
> 
> Looking forward to your feedback. I hope it's okay.
> 

Signed-off-by: Philippe Symons <philippe.symons@gmail.com>
---
 libavformat/dashenc.c     |  2 +-
 libavformat/hlsenc.c      | 24 ++++++++++++++++++++++--
 libavformat/hlsplaylist.c |  6 +++++-
 libavformat/hlsplaylist.h |  2 +-
 4 files changed, 29 insertions(+), 5 deletions(-)

Patch hide | download patch | download mbox

diff --git a/libavformat/dashenc.c b/libavformat/dashenc.c
index f8b3d106d5..ca5ef01e3f 100644
--- a/libavformat/dashenc.c
+++ b/libavformat/dashenc.c
@@ -897,7 +897,7 @@  static int write_manifest(AVFormatContext *s, int final)
             if (st->codecpar->codec_type != AVMEDIA_TYPE_AUDIO)
                 continue;
             get_hls_playlist_name(playlist_file, sizeof(playlist_file), NULL, i);
-            ff_hls_write_audio_rendition(c->m3u8_out, (char *)audio_group,
+            ff_hls_write_audio_rendition(c->m3u8_out, (char *)audio_group, NULL, 
                                          playlist_file, i, is_default);
             max_audio_bitrate = FFMAX(st->codecpar->bit_rate +
                                       os->muxer_overhead, max_audio_bitrate);
diff --git a/libavformat/hlsenc.c b/libavformat/hlsenc.c
index e0048aa9d8..b31daa108e 100644
--- a/libavformat/hlsenc.c
+++ b/libavformat/hlsenc.c
@@ -1205,7 +1205,6 @@  static int create_master_playlist(AVFormatContext *s,
     }
 
     set_http_options(s, &options, hls);
-
     ret = hlsenc_io_open(s, &hls->m3u8_out, hls->master_m3u8_url, &options);
     av_dict_free(&options);
     if (ret < 0) {
@@ -1228,12 +1227,33 @@  static int create_master_playlist(AVFormatContext *s,
 
     /* For audio only variant streams add #EXT-X-MEDIA tag with attributes*/
     for (i = 0; i < hls->nb_varstreams; i++) {
+        AVFormatContext* var_context;
+        char* language = NULL;
+
         vs = &(hls->var_streams[i]);
+        var_context = vs->avf;
 
         if (vs->has_video || vs->has_subtitle || !vs->agroup)
             continue;
 
         m3u8_name_size = strlen(vs->m3u8_name) + 1;
+        
+        /*
+         * Try to obtain the language code of the audio stream.
+         * -if available- it will be used to write the LANGUAGE
+         * attribute in the #EXT-X-MEDIA tag
+         */
+        if(var_context && var_context->nb_streams > 0)
+        {
if (var_context && var_context->nb_streams > 0) {
+            AVDictionary* meta_dict = vs->streams[0]->metadata;
+            AVDictionaryEntry *langEntry = av_dict_get(meta_dict, "language", NULL, 0);
+            if(langEntry)
+            {
 if (langEntry) {
+                language = langEntry->value;
+            }
+        }
+
+

two empty line?
         m3u8_rel_name = av_malloc(m3u8_name_size);
         if (!m3u8_rel_name) {
             ret = AVERROR(ENOMEM);
@@ -1247,7 +1267,7 @@  static int create_master_playlist(AVFormatContext *s,
             goto fail;
         }
 
-        ff_hls_write_audio_rendition(hls->m3u8_out, vs->agroup, m3u8_rel_name, 0, 1);
+        ff_hls_write_audio_rendition(hls->m3u8_out, vs->agroup, language, m3u8_rel_name, 0, 1);
 
         av_freep(&m3u8_rel_name);
     }
diff --git a/libavformat/hlsplaylist.c b/libavformat/hlsplaylist.c
index efcbff0009..42c7cf5727 100644
--- a/libavformat/hlsplaylist.c
+++ b/libavformat/hlsplaylist.c
@@ -35,12 +35,16 @@  void ff_hls_write_playlist_version(AVIOContext *out, int version) {
     avio_printf(out, "#EXT-X-VERSION:%d\n", version);
 }
 
-void ff_hls_write_audio_rendition(AVIOContext *out, char *agroup,
+void ff_hls_write_audio_rendition(AVIOContext *out, char *agroup, char* language, 
                                   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);
+
+    if(language)
+        avio_printf(out, ",LANGUAGE=\"%s\"", language);
+
     avio_printf(out, ",NAME=\"audio_%d\",DEFAULT=%s,URI=\"%s\"\n", name_id,
                      is_default ? "YES" : "NO", filename);
 }
diff --git a/libavformat/hlsplaylist.h b/libavformat/hlsplaylist.h
index 5054b01c8f..faf1ccdd02 100644
--- a/libavformat/hlsplaylist.h
+++ b/libavformat/hlsplaylist.h
@@ -37,7 +37,7 @@  typedef enum {
 } PlaylistType;
 
 void ff_hls_write_playlist_version(AVIOContext *out, int version);
-void ff_hls_write_audio_rendition(AVIOContext *out, char *agroup,
+void ff_hls_write_audio_rendition(AVIOContext *out, char *agroup, char* language, 
                                   char *filename, int name_id, int is_default);
 void ff_hls_write_stream_info(AVStream *st, AVIOContext *out,
                               int bandwidth, char *filename, char *agroup,