diff mbox

[FFmpeg-devel,v3,1/1] avformat/hlsenc: closed caption tags in the master playlist

Message ID 1516684880-26191-1-git-send-email-vdixit@akamai.com
State Accepted
Commit 1948b76a1beabbcf36480c4b2c2af891886ead88
Headers show

Commit Message

Dixit, Vishwanath Jan. 23, 2018, 5:21 a.m. UTC
From: Vishwanath Dixit <vdixit@akamai.com>

---
 doc/muxers.texi           |  37 +++++++++++
 libavformat/dashenc.c     |   2 +-
 libavformat/hlsenc.c      | 155 +++++++++++++++++++++++++++++++++++++++++++++-
 libavformat/hlsplaylist.c |   5 +-
 libavformat/hlsplaylist.h |   2 +-
 5 files changed, 196 insertions(+), 5 deletions(-)

Comments

Steven Liu Jan. 23, 2018, 5:28 a.m. UTC | #1
> 在 2018年1月23日,下午1:21,vdixit@akamai.com 写道:
> 
> From: Vishwanath Dixit <vdixit@akamai.com>
> 
> ---
> doc/muxers.texi           |  37 +++++++++++
> libavformat/dashenc.c     |   2 +-
> libavformat/hlsenc.c      | 155 +++++++++++++++++++++++++++++++++++++++++++++-
> libavformat/hlsplaylist.c |   5 +-
> libavformat/hlsplaylist.h |   2 +-
> 5 files changed, 196 insertions(+), 5 deletions(-)
> 
> diff --git a/doc/muxers.texi b/doc/muxers.texi
> index b060c4f..d9a5cc0 100644
> --- a/doc/muxers.texi
> +++ b/doc/muxers.texi
> @@ -901,6 +901,43 @@ and they are mapped to the two video only variant streams with audio group names
> 
> By default, a single hls variant containing all the encoded streams is created.
> 
> +@item cc_stream_map
> +Map string which specifies different closed captions groups and their
> +attributes. The closed captions stream groups are separated by space.
> +Expected string format is like this
> +"ccgroup:<group name>,instreamid:<INSTREAM-ID>,language:<language code> ....".
> +'ccgroup' and 'instreamid' are mandatory attributes. 'language' is an optional
> +attribute.
> +The closed captions groups configured using this option are mapped to different
> +variant streams by providing the same 'ccgroup' name in the
> +@code{var_stream_map} string. If @code{var_stream_map} is not set, then the
> +first available ccgroup in @code{cc_stream_map} is mapped to the output variant
> +stream. The examples for these two use cases are given below.
> +
> +@example
> +ffmpeg -re -i in.ts -b:v 1000k -b:a 64k -a53cc 1 -f hls \
> +  -cc_stream_map "ccgroup:cc,instreamid:CC1,language:en" \
> +  -master_pl_name master.m3u8 \
> +  http://example.com/live/out.m3u8
> +@end example
> +This example adds @code{#EXT-X-MEDIA} tag with @code{TYPE=CLOSED-CAPTIONS} in
> +the master playlist with group name 'cc', langauge 'en' (english) and
> +INSTREAM-ID 'CC1'. Also, it adds @code{CLOSED-CAPTIONS} attribute with group
> +name 'cc' for the output variant stream.
> +@example
> +ffmpeg -re -i in.ts -b:v:0 1000k -b:v:1 256k -b:a:0 64k -b:a:1 32k \
> +  -a53cc:0 1 -a53cc:1 1\
> +  -map 0:v -map 0:a -map 0:v -map 0:a -f hls \
> +  -cc_stream_map "ccgroup:cc,instreamid:CC1,language:en ccgroup:cc,instreamid:CC2,language:sp" \
> +  -var_stream_map "v:0,a:0,ccgroup:cc v:1,a:1,ccgroup:cc" \
> +  -master_pl_name master.m3u8 \
> +  http://example.com/live/out_%v.m3u8
> +@end example
> +This example adds two @code{#EXT-X-MEDIA} tags with @code{TYPE=CLOSED-CAPTIONS} in
> +the master playlist for the INSTREAM-IDs 'CC1' and 'CC2'. Also, it adds
> +@code{CLOSED-CAPTIONS} attribute with group name 'cc' for the two output variant
> +streams.
> +
> @item master_pl_name
> Create HLS master playlist with the given name.
> 
> diff --git a/libavformat/dashenc.c b/libavformat/dashenc.c
> index 39d0afe..5ece100 100644
> --- a/libavformat/dashenc.c
> +++ b/libavformat/dashenc.c
> @@ -820,7 +820,7 @@ static int write_manifest(AVFormatContext *s, int final)
>                 stream_bitrate += max_audio_bitrate;
>             }
>             get_hls_playlist_name(playlist_file, sizeof(playlist_file), NULL, i);
> -            ff_hls_write_stream_info(st, out, stream_bitrate, playlist_file, agroup, NULL);
> +            ff_hls_write_stream_info(st, out, stream_bitrate, playlist_file, agroup, NULL, NULL);
>         }
>         avio_close(out);
>         if (use_rename)
> diff --git a/libavformat/hlsenc.c b/libavformat/hlsenc.c
> index 42e437f..aab21f2 100644
> --- a/libavformat/hlsenc.c
> +++ b/libavformat/hlsenc.c
> @@ -152,9 +152,16 @@ typedef struct VariantStream {
>     unsigned int nb_streams;
>     int m3u8_created; /* status of media play-list creation */
>     char *agroup; /* audio group name */
> +    char *ccgroup; /* closed caption group name */
>     char *baseurl;
> } VariantStream;
> 
> +typedef struct ClosedCaptionsStream {
> +    char *ccgroup; /* closed caption group name */
> +    char *instreamid; /* closed captions INSTREAM-ID */
> +    char *language; /* closed captions langauge */
> +} ClosedCaptionsStream;
> +
> typedef struct HLSContext {
>     const AVClass *class;  // Class for private options.
>     int64_t start_sequence;
> @@ -203,11 +210,14 @@ typedef struct HLSContext {
> 
>     VariantStream *var_streams;
>     unsigned int nb_varstreams;
> +    ClosedCaptionsStream *cc_streams;
> +    unsigned int nb_ccstreams;
> 
>     int master_m3u8_created; /* status of master play-list creation */
>     char *master_m3u8_url; /* URL of the master m3u8 file */
>     int version; /* HLS version */
>     char *var_stream_map; /* user specified variant stream map string */
> +    char *cc_stream_map; /* user specified closed caption streams map string */
>     char *master_pl_name;
>     unsigned int master_publish_rate;
>     int http_persistent;
> @@ -1167,7 +1177,8 @@ static int create_master_playlist(AVFormatContext *s,
>     AVDictionary *options = NULL;
>     unsigned int i, j;
>     int m3u8_name_size, ret, bandwidth;
> -    char *m3u8_rel_name;
> +    char *m3u8_rel_name, *ccgroup;
> +    ClosedCaptionsStream *ccs;
> 
>     input_vs->m3u8_created = 1;
>     if (!hls->master_m3u8_created) {
> @@ -1194,6 +1205,16 @@ static int create_master_playlist(AVFormatContext *s,
> 
>     ff_hls_write_playlist_version(hls->m3u8_out, hls->version);
> 
> +    for (i = 0; i < hls->nb_ccstreams; i++) {
> +        ccs = &(hls->cc_streams[i]);
> +        avio_printf(hls->m3u8_out, "#EXT-X-MEDIA:TYPE=CLOSED-CAPTIONS");
> +        avio_printf(hls->m3u8_out, ",GROUP-ID=\"%s\"", ccs->ccgroup);
> +        avio_printf(hls->m3u8_out, ",NAME=\"%s\"", ccs->instreamid);
> +        if (ccs->language)
> +            avio_printf(hls->m3u8_out, ",LANGUAGE=\"%s\"", ccs->language);
> +        avio_printf(hls->m3u8_out, ",INSTREAM-ID=\"%s\"\n", ccs->instreamid);
> +    }
> +
>     /* For audio only variant streams add #EXT-X-MEDIA tag with attributes*/
>     for (i = 0; i < hls->nb_varstreams; i++) {
>         vs = &(hls->var_streams[i]);
> @@ -1278,8 +1299,23 @@ static int create_master_playlist(AVFormatContext *s,
>             bandwidth += aud_st->codecpar->bit_rate;
>         bandwidth += bandwidth / 10;
> 
> +        ccgroup = NULL;
> +        if (vid_st && vs->ccgroup) {
> +            /* check if this group name is available in the cc map string */
> +            for (j = 0; j < hls->nb_ccstreams; j++) {
> +                ccs = &(hls->cc_streams[j]);
> +                if (!av_strcasecmp(ccs->ccgroup, vs->ccgroup)) {
> +                    ccgroup = vs->ccgroup;
> +                    break;
> +                }
> +            }
> +            if (j == hls->nb_ccstreams)
> +                av_log(NULL, AV_LOG_WARNING, "mapping ccgroup %s not found\n",
> +                        vs->ccgroup);
> +        }
> +
>         ff_hls_write_stream_info(vid_st, hls->m3u8_out, bandwidth, m3u8_rel_name,
> -                aud_st ? vs->agroup : NULL, vs->codec_attr);
> +                aud_st ? vs->agroup : NULL, vs->codec_attr, ccgroup);
> 
>         av_freep(&m3u8_rel_name);
>     }
> @@ -1766,6 +1802,11 @@ static int parse_variant_stream_mapstring(AVFormatContext *s)
>                 if (!vs->agroup)
>                     return AVERROR(ENOMEM);
>                 continue;
> +            } else if (av_strstart(keyval, "ccgroup:", &val)) {
> +                vs->ccgroup = av_strdup(val);
> +                if (!vs->ccgroup)
> +                    return AVERROR(ENOMEM);
> +                continue;
>             } else if (av_strstart(keyval, "v:", &val)) {
>                 codec_type = AVMEDIA_TYPE_VIDEO;
>             } else if (av_strstart(keyval, "a:", &val)) {
> @@ -1796,9 +1837,94 @@ static int parse_variant_stream_mapstring(AVFormatContext *s)
>     return 0;
> }
> 
> +static int parse_cc_stream_mapstring(AVFormatContext *s)
> +{
> +    HLSContext *hls = s->priv_data;
> +    int nb_ccstreams;
> +    char *p, *q, *saveptr1, *saveptr2, *ccstr, *keyval;
> +    const char *val;
> +    ClosedCaptionsStream *ccs;
> +
> +    p = av_strdup(hls->cc_stream_map);
> +    q = p;
> +    while(av_strtok(q, " \t", &saveptr1)) {
> +        q = NULL;
> +        hls->nb_ccstreams++;
> +    }
> +    av_freep(&p);
> +
> +    hls->cc_streams = av_mallocz(sizeof(*hls->cc_streams) * hls->nb_ccstreams);
> +    if (!hls->cc_streams)
> +        return AVERROR(ENOMEM);
> +
> +    p = hls->cc_stream_map;
> +    nb_ccstreams = 0;
> +    while (ccstr = av_strtok(p, " \t", &saveptr1)) {
> +        p = NULL;
> +
> +        if (nb_ccstreams < hls->nb_ccstreams)
> +            ccs = &(hls->cc_streams[nb_ccstreams++]);
> +        else
> +            return AVERROR(EINVAL);
> +
> +        while (keyval = av_strtok(ccstr, ",", &saveptr2)) {
> +            ccstr = NULL;
> +
> +            if (av_strstart(keyval, "ccgroup:", &val)) {
> +                ccs->ccgroup = av_strdup(val);
> +                if (!ccs->ccgroup)
> +                    return AVERROR(ENOMEM);
> +            } else if (av_strstart(keyval, "instreamid:", &val)) {
> +                ccs->instreamid = av_strdup(val);
> +                if (!ccs->instreamid)
> +                    return AVERROR(ENOMEM);
> +            } else if (av_strstart(keyval, "language:", &val)) {
> +                ccs->language = av_strdup(val);
> +                if (!ccs->language)
> +                    return AVERROR(ENOMEM);
> +            } else {
> +                av_log(s, AV_LOG_ERROR, "Invalid keyval %s\n", keyval);
> +                return AVERROR(EINVAL);
> +            }
> +        }
> +
> +        if (!ccs->ccgroup || !ccs->instreamid) {
> +            av_log(s, AV_LOG_ERROR, "Insufficient parameters in cc stream map string\n");
> +            return AVERROR(EINVAL);
> +        }
> +
> +        if (av_strstart(ccs->instreamid, "CC", &val)) {
> +            if(atoi(val) < 1 || atoi(val) > 4) {
> +                av_log(s, AV_LOG_ERROR, "Invalid instream ID CC index %d in %s, range 1-4\n",
> +                       atoi(val), ccs->instreamid);
> +                return AVERROR(EINVAL);
> +            }
> +        } else if (av_strstart(ccs->instreamid, "SERVICE", &val)) {
> +            if(atoi(val) < 1 || atoi(val) > 63) {
> +                av_log(s, AV_LOG_ERROR, "Invalid instream ID SERVICE index %d in %s, range 1-63 \n",
> +                       atoi(val), ccs->instreamid);
> +                return AVERROR(EINVAL);
> +            }
> +        } else {
> +            av_log(s, AV_LOG_ERROR, "Invalid instream ID %s, supported are CCn or SERIVICEn\n",
> +                   ccs->instreamid);
> +            return AVERROR(EINVAL);
> +        }
> +    }
> +
> +    return 0;
> +}
> +
> static int update_variant_stream_info(AVFormatContext *s) {
>     HLSContext *hls = s->priv_data;
>     unsigned int i;
> +    int ret = 0;
> +
> +    if (hls->cc_stream_map) {
> +        ret = parse_cc_stream_mapstring(s);
> +        if (ret < 0)
> +            return ret;
> +    }
> 
>     if (hls->var_stream_map) {
>         return parse_variant_stream_mapstring(s);
> @@ -1816,6 +1942,13 @@ static int update_variant_stream_info(AVFormatContext *s) {
>         if (!hls->var_streams[0].streams)
>             return AVERROR(ENOMEM);
> 
> +        //by default, the first available ccgroup is mapped to the variant stream
> +        if (hls->nb_ccstreams) {
> +            hls->var_streams[0].ccgroup = av_strdup(hls->cc_streams[0].ccgroup);
> +            if (!hls->var_streams[0].ccgroup)
> +                return AVERROR(ENOMEM);
> +        }
> +
>         for (i = 0; i < s->nb_streams; i++)
>             hls->var_streams[0].streams[i] = s->streams[i];
>     }
> @@ -2192,13 +2325,22 @@ failed:
>     av_freep(&vs->m3u8_name);
>     av_freep(&vs->streams);
>     av_freep(&vs->agroup);
> +    av_freep(&vs->ccgroup);
>     av_freep(&vs->baseurl);
>     }
> 
> +    for (i = 0; i < hls->nb_ccstreams; i++) {
> +        ClosedCaptionsStream *ccs = &hls->cc_streams[i];
> +        av_freep(&ccs->ccgroup);
> +        av_freep(&ccs->instreamid);
> +        av_freep(&ccs->language);
> +    }
> +
>     ff_format_io_close(s, &hls->m3u8_out);
>     ff_format_io_close(s, &hls->sub_m3u8_out);
>     av_freep(&hls->key_basename);
>     av_freep(&hls->var_streams);
> +    av_freep(&hls->cc_streams);
>     av_freep(&hls->master_m3u8_url);
>     return 0;
> }
> @@ -2535,13 +2677,21 @@ fail:
>             av_freep(&vs->vtt_m3u8_name);
>             av_freep(&vs->streams);
>             av_freep(&vs->agroup);
> +            av_freep(&vs->ccgroup);
>             av_freep(&vs->baseurl);
>             if (vs->avf)
>                 avformat_free_context(vs->avf);
>             if (vs->vtt_avf)
>                 avformat_free_context(vs->vtt_avf);
>         }
> +        for (i = 0; i < hls->nb_ccstreams; i++) {
> +            ClosedCaptionsStream *ccs = &hls->cc_streams[i];
> +            av_freep(&ccs->ccgroup);
> +            av_freep(&ccs->instreamid);
> +            av_freep(&ccs->language);
> +        }
>         av_freep(&hls->var_streams);
> +        av_freep(&hls->cc_streams);
>         av_freep(&hls->master_m3u8_url);
>     }
> 
> @@ -2601,6 +2751,7 @@ static const AVOption options[] = {
>     {"datetime", "current datetime as YYYYMMDDhhmmss", 0, AV_OPT_TYPE_CONST, {.i64 = HLS_START_SEQUENCE_AS_FORMATTED_DATETIME }, INT_MIN, INT_MAX, E, "start_sequence_source_type" },
>     {"http_user_agent", "override User-Agent field in HTTP header", OFFSET(user_agent), AV_OPT_TYPE_STRING, {.str = NULL},  0, 0,    E},
>     {"var_stream_map", "Variant stream map string", OFFSET(var_stream_map), AV_OPT_TYPE_STRING, {.str = NULL},  0, 0,    E},
> +    {"cc_stream_map", "Closed captions stream map string", OFFSET(cc_stream_map), AV_OPT_TYPE_STRING, {.str = NULL},  0, 0,    E},
>     {"master_pl_name", "Create HLS master playlist with this name", OFFSET(master_pl_name), AV_OPT_TYPE_STRING, {.str = NULL},  0, 0,    E},
>     {"master_pl_publish_rate", "Publish master play list every after this many segment intervals", OFFSET(master_publish_rate), AV_OPT_TYPE_INT, {.i64 = 0}, 0, UINT_MAX, E},
>     {"http_persistent", "Use persistent HTTP connections", OFFSET(http_persistent), AV_OPT_TYPE_BOOL, {.i64 = 0 }, 0, 1, E },
> diff --git a/libavformat/hlsplaylist.c b/libavformat/hlsplaylist.c
> index b8a3a14..efcbff0 100644
> --- a/libavformat/hlsplaylist.c
> +++ b/libavformat/hlsplaylist.c
> @@ -47,7 +47,8 @@ void ff_hls_write_audio_rendition(AVIOContext *out, char *agroup,
> 
> void ff_hls_write_stream_info(AVStream *st, AVIOContext *out,
>                               int bandwidth, char *filename, char *agroup,
> -                              char *codecs) {
> +                              char *codecs, char *ccgroup) {
> +
>     if (!out || !filename)
>         return;
> 
> @@ -65,6 +66,8 @@ void ff_hls_write_stream_info(AVStream *st, AVIOContext *out,
>         avio_printf(out, ",CODECS=\"%s\"", codecs);
>     if (agroup && strlen(agroup) > 0)
>         avio_printf(out, ",AUDIO=\"group_%s\"", agroup);
> +    if (ccgroup && strlen(ccgroup) > 0)
> +        avio_printf(out, ",CLOSED-CAPTIONS=\"%s\"", ccgroup);
>     avio_printf(out, "\n%s\n\n", filename);
> }
> 
> diff --git a/libavformat/hlsplaylist.h b/libavformat/hlsplaylist.h
> index 7532e37..5054b01 100644
> --- a/libavformat/hlsplaylist.h
> +++ b/libavformat/hlsplaylist.h
> @@ -41,7 +41,7 @@ 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,
> -                              char *codecs);
> +                              char *codecs, char *ccgroup);
> void ff_hls_write_playlist_header(AVIOContext *out, int version, int allowcache,
>                                   int target_duration, int64_t sequence,
>                                   uint32_t playlist_type);
> -- 
> 1.9.1
> 
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel@ffmpeg.org
> http://ffmpeg.org/mailman/listinfo/ffmpeg-devel

will apply this patch if there have no objections.


Thanks
Steven
diff mbox

Patch

diff --git a/doc/muxers.texi b/doc/muxers.texi
index b060c4f..d9a5cc0 100644
--- a/doc/muxers.texi
+++ b/doc/muxers.texi
@@ -901,6 +901,43 @@  and they are mapped to the two video only variant streams with audio group names
 
 By default, a single hls variant containing all the encoded streams is created.
 
+@item cc_stream_map
+Map string which specifies different closed captions groups and their
+attributes. The closed captions stream groups are separated by space.
+Expected string format is like this
+"ccgroup:<group name>,instreamid:<INSTREAM-ID>,language:<language code> ....".
+'ccgroup' and 'instreamid' are mandatory attributes. 'language' is an optional
+attribute.
+The closed captions groups configured using this option are mapped to different
+variant streams by providing the same 'ccgroup' name in the
+@code{var_stream_map} string. If @code{var_stream_map} is not set, then the
+first available ccgroup in @code{cc_stream_map} is mapped to the output variant
+stream. The examples for these two use cases are given below.
+
+@example
+ffmpeg -re -i in.ts -b:v 1000k -b:a 64k -a53cc 1 -f hls \
+  -cc_stream_map "ccgroup:cc,instreamid:CC1,language:en" \
+  -master_pl_name master.m3u8 \
+  http://example.com/live/out.m3u8
+@end example
+This example adds @code{#EXT-X-MEDIA} tag with @code{TYPE=CLOSED-CAPTIONS} in
+the master playlist with group name 'cc', langauge 'en' (english) and
+INSTREAM-ID 'CC1'. Also, it adds @code{CLOSED-CAPTIONS} attribute with group
+name 'cc' for the output variant stream.
+@example
+ffmpeg -re -i in.ts -b:v:0 1000k -b:v:1 256k -b:a:0 64k -b:a:1 32k \
+  -a53cc:0 1 -a53cc:1 1\
+  -map 0:v -map 0:a -map 0:v -map 0:a -f hls \
+  -cc_stream_map "ccgroup:cc,instreamid:CC1,language:en ccgroup:cc,instreamid:CC2,language:sp" \
+  -var_stream_map "v:0,a:0,ccgroup:cc v:1,a:1,ccgroup:cc" \
+  -master_pl_name master.m3u8 \
+  http://example.com/live/out_%v.m3u8
+@end example
+This example adds two @code{#EXT-X-MEDIA} tags with @code{TYPE=CLOSED-CAPTIONS} in
+the master playlist for the INSTREAM-IDs 'CC1' and 'CC2'. Also, it adds
+@code{CLOSED-CAPTIONS} attribute with group name 'cc' for the two output variant
+streams.
+
 @item master_pl_name
 Create HLS master playlist with the given name.
 
diff --git a/libavformat/dashenc.c b/libavformat/dashenc.c
index 39d0afe..5ece100 100644
--- a/libavformat/dashenc.c
+++ b/libavformat/dashenc.c
@@ -820,7 +820,7 @@  static int write_manifest(AVFormatContext *s, int final)
                 stream_bitrate += max_audio_bitrate;
             }
             get_hls_playlist_name(playlist_file, sizeof(playlist_file), NULL, i);
-            ff_hls_write_stream_info(st, out, stream_bitrate, playlist_file, agroup, NULL);
+            ff_hls_write_stream_info(st, out, stream_bitrate, playlist_file, agroup, NULL, NULL);
         }
         avio_close(out);
         if (use_rename)
diff --git a/libavformat/hlsenc.c b/libavformat/hlsenc.c
index 42e437f..aab21f2 100644
--- a/libavformat/hlsenc.c
+++ b/libavformat/hlsenc.c
@@ -152,9 +152,16 @@  typedef struct VariantStream {
     unsigned int nb_streams;
     int m3u8_created; /* status of media play-list creation */
     char *agroup; /* audio group name */
+    char *ccgroup; /* closed caption group name */
     char *baseurl;
 } VariantStream;
 
+typedef struct ClosedCaptionsStream {
+    char *ccgroup; /* closed caption group name */
+    char *instreamid; /* closed captions INSTREAM-ID */
+    char *language; /* closed captions langauge */
+} ClosedCaptionsStream;
+
 typedef struct HLSContext {
     const AVClass *class;  // Class for private options.
     int64_t start_sequence;
@@ -203,11 +210,14 @@  typedef struct HLSContext {
 
     VariantStream *var_streams;
     unsigned int nb_varstreams;
+    ClosedCaptionsStream *cc_streams;
+    unsigned int nb_ccstreams;
 
     int master_m3u8_created; /* status of master play-list creation */
     char *master_m3u8_url; /* URL of the master m3u8 file */
     int version; /* HLS version */
     char *var_stream_map; /* user specified variant stream map string */
+    char *cc_stream_map; /* user specified closed caption streams map string */
     char *master_pl_name;
     unsigned int master_publish_rate;
     int http_persistent;
@@ -1167,7 +1177,8 @@  static int create_master_playlist(AVFormatContext *s,
     AVDictionary *options = NULL;
     unsigned int i, j;
     int m3u8_name_size, ret, bandwidth;
-    char *m3u8_rel_name;
+    char *m3u8_rel_name, *ccgroup;
+    ClosedCaptionsStream *ccs;
 
     input_vs->m3u8_created = 1;
     if (!hls->master_m3u8_created) {
@@ -1194,6 +1205,16 @@  static int create_master_playlist(AVFormatContext *s,
 
     ff_hls_write_playlist_version(hls->m3u8_out, hls->version);
 
+    for (i = 0; i < hls->nb_ccstreams; i++) {
+        ccs = &(hls->cc_streams[i]);
+        avio_printf(hls->m3u8_out, "#EXT-X-MEDIA:TYPE=CLOSED-CAPTIONS");
+        avio_printf(hls->m3u8_out, ",GROUP-ID=\"%s\"", ccs->ccgroup);
+        avio_printf(hls->m3u8_out, ",NAME=\"%s\"", ccs->instreamid);
+        if (ccs->language)
+            avio_printf(hls->m3u8_out, ",LANGUAGE=\"%s\"", ccs->language);
+        avio_printf(hls->m3u8_out, ",INSTREAM-ID=\"%s\"\n", ccs->instreamid);
+    }
+
     /* For audio only variant streams add #EXT-X-MEDIA tag with attributes*/
     for (i = 0; i < hls->nb_varstreams; i++) {
         vs = &(hls->var_streams[i]);
@@ -1278,8 +1299,23 @@  static int create_master_playlist(AVFormatContext *s,
             bandwidth += aud_st->codecpar->bit_rate;
         bandwidth += bandwidth / 10;
 
+        ccgroup = NULL;
+        if (vid_st && vs->ccgroup) {
+            /* check if this group name is available in the cc map string */
+            for (j = 0; j < hls->nb_ccstreams; j++) {
+                ccs = &(hls->cc_streams[j]);
+                if (!av_strcasecmp(ccs->ccgroup, vs->ccgroup)) {
+                    ccgroup = vs->ccgroup;
+                    break;
+                }
+            }
+            if (j == hls->nb_ccstreams)
+                av_log(NULL, AV_LOG_WARNING, "mapping ccgroup %s not found\n",
+                        vs->ccgroup);
+        }
+
         ff_hls_write_stream_info(vid_st, hls->m3u8_out, bandwidth, m3u8_rel_name,
-                aud_st ? vs->agroup : NULL, vs->codec_attr);
+                aud_st ? vs->agroup : NULL, vs->codec_attr, ccgroup);
 
         av_freep(&m3u8_rel_name);
     }
@@ -1766,6 +1802,11 @@  static int parse_variant_stream_mapstring(AVFormatContext *s)
                 if (!vs->agroup)
                     return AVERROR(ENOMEM);
                 continue;
+            } else if (av_strstart(keyval, "ccgroup:", &val)) {
+                vs->ccgroup = av_strdup(val);
+                if (!vs->ccgroup)
+                    return AVERROR(ENOMEM);
+                continue;
             } else if (av_strstart(keyval, "v:", &val)) {
                 codec_type = AVMEDIA_TYPE_VIDEO;
             } else if (av_strstart(keyval, "a:", &val)) {
@@ -1796,9 +1837,94 @@  static int parse_variant_stream_mapstring(AVFormatContext *s)
     return 0;
 }
 
+static int parse_cc_stream_mapstring(AVFormatContext *s)
+{
+    HLSContext *hls = s->priv_data;
+    int nb_ccstreams;
+    char *p, *q, *saveptr1, *saveptr2, *ccstr, *keyval;
+    const char *val;
+    ClosedCaptionsStream *ccs;
+
+    p = av_strdup(hls->cc_stream_map);
+    q = p;
+    while(av_strtok(q, " \t", &saveptr1)) {
+        q = NULL;
+        hls->nb_ccstreams++;
+    }
+    av_freep(&p);
+
+    hls->cc_streams = av_mallocz(sizeof(*hls->cc_streams) * hls->nb_ccstreams);
+    if (!hls->cc_streams)
+        return AVERROR(ENOMEM);
+
+    p = hls->cc_stream_map;
+    nb_ccstreams = 0;
+    while (ccstr = av_strtok(p, " \t", &saveptr1)) {
+        p = NULL;
+
+        if (nb_ccstreams < hls->nb_ccstreams)
+            ccs = &(hls->cc_streams[nb_ccstreams++]);
+        else
+            return AVERROR(EINVAL);
+
+        while (keyval = av_strtok(ccstr, ",", &saveptr2)) {
+            ccstr = NULL;
+
+            if (av_strstart(keyval, "ccgroup:", &val)) {
+                ccs->ccgroup = av_strdup(val);
+                if (!ccs->ccgroup)
+                    return AVERROR(ENOMEM);
+            } else if (av_strstart(keyval, "instreamid:", &val)) {
+                ccs->instreamid = av_strdup(val);
+                if (!ccs->instreamid)
+                    return AVERROR(ENOMEM);
+            } else if (av_strstart(keyval, "language:", &val)) {
+                ccs->language = av_strdup(val);
+                if (!ccs->language)
+                    return AVERROR(ENOMEM);
+            } else {
+                av_log(s, AV_LOG_ERROR, "Invalid keyval %s\n", keyval);
+                return AVERROR(EINVAL);
+            }
+        }
+
+        if (!ccs->ccgroup || !ccs->instreamid) {
+            av_log(s, AV_LOG_ERROR, "Insufficient parameters in cc stream map string\n");
+            return AVERROR(EINVAL);
+        }
+
+        if (av_strstart(ccs->instreamid, "CC", &val)) {
+            if(atoi(val) < 1 || atoi(val) > 4) {
+                av_log(s, AV_LOG_ERROR, "Invalid instream ID CC index %d in %s, range 1-4\n",
+                       atoi(val), ccs->instreamid);
+                return AVERROR(EINVAL);
+            }
+        } else if (av_strstart(ccs->instreamid, "SERVICE", &val)) {
+            if(atoi(val) < 1 || atoi(val) > 63) {
+                av_log(s, AV_LOG_ERROR, "Invalid instream ID SERVICE index %d in %s, range 1-63 \n",
+                       atoi(val), ccs->instreamid);
+                return AVERROR(EINVAL);
+            }
+        } else {
+            av_log(s, AV_LOG_ERROR, "Invalid instream ID %s, supported are CCn or SERIVICEn\n",
+                   ccs->instreamid);
+            return AVERROR(EINVAL);
+        }
+    }
+
+    return 0;
+}
+
 static int update_variant_stream_info(AVFormatContext *s) {
     HLSContext *hls = s->priv_data;
     unsigned int i;
+    int ret = 0;
+
+    if (hls->cc_stream_map) {
+        ret = parse_cc_stream_mapstring(s);
+        if (ret < 0)
+            return ret;
+    }
 
     if (hls->var_stream_map) {
         return parse_variant_stream_mapstring(s);
@@ -1816,6 +1942,13 @@  static int update_variant_stream_info(AVFormatContext *s) {
         if (!hls->var_streams[0].streams)
             return AVERROR(ENOMEM);
 
+        //by default, the first available ccgroup is mapped to the variant stream
+        if (hls->nb_ccstreams) {
+            hls->var_streams[0].ccgroup = av_strdup(hls->cc_streams[0].ccgroup);
+            if (!hls->var_streams[0].ccgroup)
+                return AVERROR(ENOMEM);
+        }
+
         for (i = 0; i < s->nb_streams; i++)
             hls->var_streams[0].streams[i] = s->streams[i];
     }
@@ -2192,13 +2325,22 @@  failed:
     av_freep(&vs->m3u8_name);
     av_freep(&vs->streams);
     av_freep(&vs->agroup);
+    av_freep(&vs->ccgroup);
     av_freep(&vs->baseurl);
     }
 
+    for (i = 0; i < hls->nb_ccstreams; i++) {
+        ClosedCaptionsStream *ccs = &hls->cc_streams[i];
+        av_freep(&ccs->ccgroup);
+        av_freep(&ccs->instreamid);
+        av_freep(&ccs->language);
+    }
+
     ff_format_io_close(s, &hls->m3u8_out);
     ff_format_io_close(s, &hls->sub_m3u8_out);
     av_freep(&hls->key_basename);
     av_freep(&hls->var_streams);
+    av_freep(&hls->cc_streams);
     av_freep(&hls->master_m3u8_url);
     return 0;
 }
@@ -2535,13 +2677,21 @@  fail:
             av_freep(&vs->vtt_m3u8_name);
             av_freep(&vs->streams);
             av_freep(&vs->agroup);
+            av_freep(&vs->ccgroup);
             av_freep(&vs->baseurl);
             if (vs->avf)
                 avformat_free_context(vs->avf);
             if (vs->vtt_avf)
                 avformat_free_context(vs->vtt_avf);
         }
+        for (i = 0; i < hls->nb_ccstreams; i++) {
+            ClosedCaptionsStream *ccs = &hls->cc_streams[i];
+            av_freep(&ccs->ccgroup);
+            av_freep(&ccs->instreamid);
+            av_freep(&ccs->language);
+        }
         av_freep(&hls->var_streams);
+        av_freep(&hls->cc_streams);
         av_freep(&hls->master_m3u8_url);
     }
 
@@ -2601,6 +2751,7 @@  static const AVOption options[] = {
     {"datetime", "current datetime as YYYYMMDDhhmmss", 0, AV_OPT_TYPE_CONST, {.i64 = HLS_START_SEQUENCE_AS_FORMATTED_DATETIME }, INT_MIN, INT_MAX, E, "start_sequence_source_type" },
     {"http_user_agent", "override User-Agent field in HTTP header", OFFSET(user_agent), AV_OPT_TYPE_STRING, {.str = NULL},  0, 0,    E},
     {"var_stream_map", "Variant stream map string", OFFSET(var_stream_map), AV_OPT_TYPE_STRING, {.str = NULL},  0, 0,    E},
+    {"cc_stream_map", "Closed captions stream map string", OFFSET(cc_stream_map), AV_OPT_TYPE_STRING, {.str = NULL},  0, 0,    E},
     {"master_pl_name", "Create HLS master playlist with this name", OFFSET(master_pl_name), AV_OPT_TYPE_STRING, {.str = NULL},  0, 0,    E},
     {"master_pl_publish_rate", "Publish master play list every after this many segment intervals", OFFSET(master_publish_rate), AV_OPT_TYPE_INT, {.i64 = 0}, 0, UINT_MAX, E},
     {"http_persistent", "Use persistent HTTP connections", OFFSET(http_persistent), AV_OPT_TYPE_BOOL, {.i64 = 0 }, 0, 1, E },
diff --git a/libavformat/hlsplaylist.c b/libavformat/hlsplaylist.c
index b8a3a14..efcbff0 100644
--- a/libavformat/hlsplaylist.c
+++ b/libavformat/hlsplaylist.c
@@ -47,7 +47,8 @@  void ff_hls_write_audio_rendition(AVIOContext *out, char *agroup,
 
 void ff_hls_write_stream_info(AVStream *st, AVIOContext *out,
                               int bandwidth, char *filename, char *agroup,
-                              char *codecs) {
+                              char *codecs, char *ccgroup) {
+
     if (!out || !filename)
         return;
 
@@ -65,6 +66,8 @@  void ff_hls_write_stream_info(AVStream *st, AVIOContext *out,
         avio_printf(out, ",CODECS=\"%s\"", codecs);
     if (agroup && strlen(agroup) > 0)
         avio_printf(out, ",AUDIO=\"group_%s\"", agroup);
+    if (ccgroup && strlen(ccgroup) > 0)
+        avio_printf(out, ",CLOSED-CAPTIONS=\"%s\"", ccgroup);
     avio_printf(out, "\n%s\n\n", filename);
 }
 
diff --git a/libavformat/hlsplaylist.h b/libavformat/hlsplaylist.h
index 7532e37..5054b01 100644
--- a/libavformat/hlsplaylist.h
+++ b/libavformat/hlsplaylist.h
@@ -41,7 +41,7 @@  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,
-                              char *codecs);
+                              char *codecs, char *ccgroup);
 void ff_hls_write_playlist_header(AVIOContext *out, int version, int allowcache,
                                   int target_duration, int64_t sequence,
                                   uint32_t playlist_type);