@@ -827,6 +827,18 @@ be a video only stream with video bitrate 1000k, the second variant stream will
be an audio only stream with bitrate 64k and the third variant stream will be a
video only stream with bitrate 256k. Here, three media playlist with file names
out_1.m3u8, out_2.m3u8 and out_3.m3u8 will be created.
+@example
+ffmpeg -re -i in.ts -b:a:0 32k -b:a:1 64k -b:v:0 1000k -b:v:1 3000k \
+ -map 0:a -map 0:a -map 0:v -map 0:v -f hls \
+ -var_stream_map "a:0,agroup:aud_low a:1,agroup:aud_high v:0,agroup:aud_low v:1,agroup:aud_high" \
+ -master_pl_name master.m3u8 \
+ http://example.com/live/out.m3u8
+@end example
+This example creates two audio only and two video only variant streams. In
+addition to the #EXT-X-STREAM-INF tag for each variant stream in the master
+playlist, #EXT-X-MEDIA tag is also added for the two audio only variant streams
+and they are mapped to the two video only variant streams with audio group names
+'aud_low' and 'aud_high'.
By default, a single hls variant containing all the encoded streams is created.
@@ -146,6 +146,7 @@ typedef struct VariantStream {
AVStream **streams;
unsigned int nb_streams;
int m3u8_created; /* status of media play-list creation */
+ char *agroup; /* audio group name */
char *baseurl;
} VariantStream;
@@ -1068,7 +1069,7 @@ static int create_master_playlist(AVFormatContext *s,
VariantStream * const input_vs)
{
HLSContext *hls = s->priv_data;
- VariantStream *vs;
+ VariantStream *vs, *temp_vs;
AVStream *vid_st, *aud_st;
AVIOContext *master_pb = 0;
AVDictionary *options = NULL;
@@ -1104,6 +1105,34 @@ static int create_master_playlist(AVFormatContext *s,
avio_printf(master_pb, "#EXTM3U\n");
avio_printf(master_pb, "#EXT-X-VERSION:%d\n", hls->version);
+ /* 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]);
+
+ if (vs->has_video || vs->has_subtitle || !vs->agroup)
+ continue;
+
+ m3u8_name_size = strlen(vs->m3u8_name) + 1;
+ m3U8_rel_name = av_malloc(m3u8_name_size);
+ if (!m3U8_rel_name) {
+ ret = AVERROR(ENOMEM);
+ goto fail;
+ }
+ av_strlcpy(m3U8_rel_name, vs->m3u8_name, m3u8_name_size);
+ ret = get_relative_url(hls->master_m3u8_url, vs->m3u8_name,
+ m3U8_rel_name, m3u8_name_size);
+ if (ret < 0) {
+ av_log(NULL, AV_LOG_ERROR, "Unable to find relative URL\n");
+ goto fail;
+ }
+
+ avio_printf(master_pb, "#EXT-X-MEDIA:TYPE=AUDIO,GROUP-ID=\"group_%s\"",
+ vs->agroup);
+ avio_printf(master_pb, ",NAME=\"audio_0\",DEFAULT=YES,URI=\"%s\"\n",
+ m3U8_rel_name);
+ av_freep(&m3U8_rel_name);
+ }
+
/* For variant streams with video add #EXT-X-STREAM-INF tag with attributes*/
for (i = 0; i < hls->nb_varstreams; i++) {
vs = &(hls->var_streams[i]);
@@ -1136,6 +1165,25 @@ static int create_master_playlist(AVFormatContext *s,
continue;
}
+ /**
+ * Traverse through the list of audio only rendition streams and find
+ * the rendition which has highest bitrate in the same audio group
+ */
+ if (vs->agroup) {
+ for (j = 0; j < hls->nb_varstreams; j++) {
+ temp_vs = &(hls->var_streams[j]);
+ if (!temp_vs->has_video && !temp_vs->has_subtitle &&
+ temp_vs->agroup &&
+ !strcmp(temp_vs->agroup, vs->agroup)) {
+ if (!aud_st)
+ aud_st = temp_vs->streams[0];
+ if (temp_vs->streams[0]->codecpar->bit_rate >
+ aud_st->codecpar->bit_rate)
+ aud_st = temp_vs->streams[0];
+ }
+ }
+ }
+
bandwidth = 0;
if (vid_st)
bandwidth += vid_st->codecpar->bit_rate;
@@ -1154,6 +1202,10 @@ static int create_master_playlist(AVFormatContext *s,
if (vid_st && vid_st->codecpar->width > 0 && vid_st->codecpar->height > 0)
avio_printf(master_pb, ",RESOLUTION=%dx%d", vid_st->codecpar->width,
vid_st->codecpar->height);
+
+ if (vs->agroup && aud_st)
+ avio_printf(master_pb, ",AUDIO=\"group_%s\"", vs->agroup);
+
avio_printf(master_pb, "\n%s\n\n", m3U8_rel_name);
av_freep(&m3U8_rel_name);
@@ -1539,6 +1591,7 @@ static int parse_variant_stream_mapstring(AVFormatContext *s)
/**
* Expected format for var_stream_map string is as below:
* "a:0,v:0 a:1,v:1"
+ * "a:0,agroup:a0 a:1,agroup:a1 v:0,agroup:a0 v:1,agroup:a1"
* This string specifies how to group the audio, video and subtitle streams
* into different variant streams. The variant stream groups are separated
* by space.
@@ -1547,6 +1600,7 @@ static int parse_variant_stream_mapstring(AVFormatContext *s)
* respectively. Allowed values are 0 to 9 digits (limited just based on
* practical usage)
*
+ * agroup: is key to specify audio group. A string can be given as value.
*/
p = av_strdup(hls->var_stream_map);
q = p;
@@ -1585,7 +1639,10 @@ static int parse_variant_stream_mapstring(AVFormatContext *s)
while (keyval = av_strtok(varstr, ",", &saveptr2)) {
varstr = NULL;
- if (av_strstart(keyval, "v:", &val)) {
+ if (av_strstart(keyval, "agroup:", &val)) {
+ vs->agroup = av_strdup(val);
+ continue;
+ } else if (av_strstart(keyval, "v:", &val)) {
codec_type = AVMEDIA_TYPE_VIDEO;
} else if (av_strstart(keyval, "a:", &val)) {
codec_type = AVMEDIA_TYPE_AUDIO;
@@ -2035,6 +2092,7 @@ fail:
av_freep(&vs->m3u8_name);
av_freep(&vs->vtt_m3u8_name);
av_freep(&vs->streams);
+ av_freep(&vs->agroup);
av_freep(&vs->baseurl);
if (vs->avf)
avformat_free_context(vs->avf);
@@ -2274,6 +2332,7 @@ static int hls_write_trailer(struct AVFormatContext *s)
av_free(old_filename);
av_freep(&vs->m3u8_name);
av_freep(&vs->streams);
+ av_freep(&vs->agroup);
av_freep(&vs->baseurl);
}