[FFmpeg-devel] [PATCH v1 3/4] avformat: add subtitle support in master playlist m3u8
lance.lmwang at gmail.com
lance.lmwang at gmail.com
Thu Mar 26 15:56:59 EET 2020
From: Limin Wang <lance.lmwang at gmail.com>
Test with the following command for the webvtt subtitle:
$ ./ffmpeg -y -i input_with_subtitle.mkv \
-b:v:0 5250k -c:v h264 -pix_fmt yuv420p -profile:v main -level 4.1 \
-b:a:0 256k \
-c:s webvtt -c:a mp2 -ar 48000 -ac 2 -map 0:v -map 0:a:0 -map 0:s:0 \
-f hls -var_stream_map "v:0,a:0,s:0,sgroup:subtitle" \
-master_pl_name master.m3u8 -t 300 -hls_time 10 -hls_init_time 4 -hls_list_size \
10 -master_pl_publish_rate 10 -hls_flags \
delete_segments+discont_start+split_by_time ./tmp/video.m3u8
Check the master m3u8:
$ cat tmp/master.m3u8
#EXTM3U
#EXT-X-VERSION:3
#EXT-X-MEDIA:TYPE=SUBTITLES,GROUP-ID="subtitle",NAME="subtitle_0",DEFAULT=YES,URI="video_vtt.m3u8"
#EXT-X-STREAM-INF:BANDWIDTH=6056600,RESOLUTION=1280x720,CODECS="avc1.4d4829,mp4a.40.33",SUBTITLES="subtitle"
video.m3u8
Check the result by convert to mkv:
$ ./ffmpeg -strict experimental -i ./tmp/master.m3u8 -c:v copy -c:a mp2 -c:s srt ./test.mkv
Signed-off-by: Limin Wang <lance.lmwang at gmail.com>
---
libavformat/dashenc.c | 2 +-
libavformat/hlsenc.c | 26 ++++++++++++++++++++++++--
libavformat/hlsplaylist.c | 17 ++++++++++++++++-
libavformat/hlsplaylist.h | 4 +++-
4 files changed, 44 insertions(+), 5 deletions(-)
diff --git a/libavformat/dashenc.c b/libavformat/dashenc.c
index 94d463972a..d1fe90b00c 100644
--- a/libavformat/dashenc.c
+++ b/libavformat/dashenc.c
@@ -1311,7 +1311,7 @@ static int write_manifest(AVFormatContext *s, int final)
get_hls_playlist_name(playlist_file, sizeof(playlist_file), NULL, i);
ff_hls_write_stream_info(st, c->m3u8_out, stream_bitrate,
playlist_file, agroup,
- codec_str_ptr, NULL);
+ codec_str_ptr, NULL, NULL);
}
dashenc_io_close(s, &c->m3u8_out, temp_filename);
if (use_rename)
diff --git a/libavformat/hlsenc.c b/libavformat/hlsenc.c
index a0a3a4647b..d7b9c0e20a 100644
--- a/libavformat/hlsenc.c
+++ b/libavformat/hlsenc.c
@@ -164,6 +164,7 @@ typedef struct VariantStream {
int is_default; /* default status of audio group */
char *language; /* audio lauguage name */
char *agroup; /* audio group name */
+ char *sgroup; /* subtitle group name */
char *ccgroup; /* closed caption group name */
char *baseurl;
char *varname; // variant name
@@ -1289,7 +1290,9 @@ static int create_master_playlist(AVFormatContext *s,
unsigned int i, j;
int ret, bandwidth;
const char *m3u8_rel_name = NULL;
+ const char *vtt_m3u8_rel_name = NULL;
char *ccgroup;
+ char *sgroup = NULL;
ClosedCaptionsStream *ccs;
const char *proto = avio_find_protocol_name(hls->master_m3u8_url);
int is_file_proto = proto && !strcmp(proto, "file");
@@ -1412,13 +1415,24 @@ static int create_master_playlist(AVFormatContext *s,
vs->ccgroup);
}
+ if (vid_st && vs->sgroup) {
+ sgroup = vs->sgroup;
+ vtt_m3u8_rel_name = get_relative_url(hls->master_m3u8_url, vs->vtt_m3u8_name);
+ if (!vtt_m3u8_rel_name) {
+ av_log(s, AV_LOG_WARNING, "Unable to find relative subtitle URL\n");
+ break;
+ }
+
+ ff_hls_write_subtitle_rendition(hls->m3u8_out, sgroup, vtt_m3u8_rel_name, vs->language, i, hls->has_default_key ? vs->is_default : 1);
+ }
+
if (!hls->has_default_key || !hls->has_video_m3u8) {
ff_hls_write_stream_info(vid_st, hls->m3u8_out, bandwidth, m3u8_rel_name,
- aud_st ? vs->agroup : NULL, vs->codec_attr, ccgroup);
+ aud_st ? vs->agroup : NULL, vs->codec_attr, ccgroup, sgroup);
} else {
if (vid_st) {
ff_hls_write_stream_info(vid_st, hls->m3u8_out, bandwidth, m3u8_rel_name,
- aud_st ? vs->agroup : NULL, vs->codec_attr, ccgroup);
+ aud_st ? vs->agroup : NULL, vs->codec_attr, ccgroup, sgroup);
}
}
}
@@ -1893,6 +1907,7 @@ static int parse_variant_stream_mapstring(AVFormatContext *s)
* practical usage)
*
* agroup: is key to specify audio group. A string can be given as value.
+ * sgroup: is key to specify subtitle group. A string can be given as value.
*/
p = av_strdup(hls->var_stream_map);
if (!p)
@@ -1960,6 +1975,12 @@ static int parse_variant_stream_mapstring(AVFormatContext *s)
if (!vs->agroup)
return AVERROR(ENOMEM);
continue;
+ } else if (av_strstart(keyval, "sgroup:", &val)) {
+ av_free(vs->sgroup);
+ vs->sgroup = av_strdup(val);
+ if (!vs->sgroup)
+ return AVERROR(ENOMEM);
+ continue;
} else if (av_strstart(keyval, "ccgroup:", &val)) {
av_free(vs->ccgroup);
vs->ccgroup = av_strdup(val);
@@ -2516,6 +2537,7 @@ static void hls_free_variant_streams(struct HLSContext *hls)
av_freep(&vs->m3u8_name);
av_freep(&vs->streams);
av_freep(&vs->agroup);
+ av_freep(&vs->sgroup);
av_freep(&vs->language);
av_freep(&vs->ccgroup);
av_freep(&vs->baseurl);
diff --git a/libavformat/hlsplaylist.c b/libavformat/hlsplaylist.c
index 56244496c0..43f9d281ba 100644
--- a/libavformat/hlsplaylist.c
+++ b/libavformat/hlsplaylist.c
@@ -48,9 +48,22 @@ void ff_hls_write_audio_rendition(AVIOContext *out, char *agroup,
avio_printf(out, "URI=\"%s\"\n", filename);
}
+void ff_hls_write_subtitle_rendition(AVIOContext *out, char *sgroup,
+ const char *filename, char *language, int name_id, int is_default) {
+ if (!out || !filename)
+ return;
+
+ avio_printf(out, "#EXT-X-MEDIA:TYPE=SUBTITLES,GROUP-ID=\"%s\"", sgroup);
+ avio_printf(out, ",NAME=\"subtitle_%d\",DEFAULT=%s,", name_id, is_default ? "YES" : "NO");
+ if (language) {
+ avio_printf(out, "LANGUAGE=\"%s\",", language);
+ }
+ avio_printf(out, "URI=\"%s\"\n", filename);
+}
+
void ff_hls_write_stream_info(AVStream *st, AVIOContext *out,
int bandwidth, const char *filename, char *agroup,
- char *codecs, char *ccgroup) {
+ char *codecs, char *ccgroup, char *sgroup) {
if (!out || !filename)
return;
@@ -71,6 +84,8 @@ void ff_hls_write_stream_info(AVStream *st, AVIOContext *out,
avio_printf(out, ",AUDIO=\"group_%s\"", agroup);
if (ccgroup && ccgroup[0])
avio_printf(out, ",CLOSED-CAPTIONS=\"%s\"", ccgroup);
+ if (sgroup && sgroup[0])
+ avio_printf(out, ",SUBTITLES=\"%s\"", sgroup);
avio_printf(out, "\n%s\n\n", filename);
}
diff --git a/libavformat/hlsplaylist.h b/libavformat/hlsplaylist.h
index a8d29d62d3..a124bdcffb 100644
--- a/libavformat/hlsplaylist.h
+++ b/libavformat/hlsplaylist.h
@@ -39,9 +39,11 @@ typedef enum {
void ff_hls_write_playlist_version(AVIOContext *out, int version);
void ff_hls_write_audio_rendition(AVIOContext *out, char *agroup,
const char *filename, char *language, int name_id, int is_default);
+void ff_hls_write_subtitle_rendition(AVIOContext *out, char *sgroup,
+ const char *filename, char *language, int name_id, int is_default);
void ff_hls_write_stream_info(AVStream *st, AVIOContext *out,
int bandwidth, const char *filename, char *agroup,
- char *codecs, char *ccgroup);
+ char *codecs, char *ccgroup, char *sgroup);
void ff_hls_write_playlist_header(AVIOContext *out, int version, int allowcache,
int target_duration, int64_t sequence,
uint32_t playlist_type, int iframe_mode);
--
2.21.0
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