diff --git a/hls/ngx_rtmp_hls_module.c b/hls/ngx_rtmp_hls_module.c
index 5d7b6fb..8d46af6 100644
--- a/hls/ngx_rtmp_hls_module.c
+++ b/hls/ngx_rtmp_hls_module.c
@@ -58,6 +58,7 @@ typedef struct {
     unsigned                            opened:1;
     unsigned                            audio:1;
     unsigned                            video:1;
+    unsigned                            header_sent:1;
 
     ngx_str_t                           playlist;
     ngx_str_t                           playlist_bak;
@@ -78,6 +79,7 @@ typedef struct {
 typedef struct {
     ngx_flag_t                          hls;
     ngx_msec_t                          fraglen;
+    ngx_msec_t                          muxdelay;
     ngx_msec_t                          playlen;
     size_t                              nfrags;
     ngx_rtmp_hls_ctx_t                **ctx;
@@ -116,6 +118,14 @@ static ngx_command_t ngx_rtmp_hls_commands[] = {
       offsetof(ngx_rtmp_hls_app_conf_t, playlen),
       NULL },
 
+    { ngx_string("hls_muxdelay"),
+      NGX_RTMP_MAIN_CONF|NGX_RTMP_SRV_CONF|NGX_RTMP_APP_CONF|NGX_CONF_TAKE1,
+      ngx_conf_set_msec_slot,
+      NGX_RTMP_APP_CONF_OFFSET,
+      offsetof(ngx_rtmp_hls_app_conf_t, muxdelay),
+      NULL },
+
+
     ngx_null_command
 };
 
@@ -262,7 +272,7 @@ ngx_rtmp_hls_init_video(ngx_rtmp_session_t *s)
     stream->codec->codec_id = CODEC_ID_H264;
     stream->codec->codec_type = AVMEDIA_TYPE_VIDEO;
     stream->codec->pix_fmt = PIX_FMT_YUV420P;
-    stream->codec->time_base.den = 1;
+    stream->codec->time_base.den = 25;
     stream->codec->time_base.num = 1;
     stream->codec->width  = 100;
     stream->codec->height = 100;
@@ -316,7 +326,7 @@ ngx_rtmp_hls_init_audio(ngx_rtmp_session_t *s)
     stream->codec->sample_fmt = (codec_ctx->sample_size == 1 ?
             AV_SAMPLE_FMT_U8 : AV_SAMPLE_FMT_S16);
     stream->codec->sample_rate = 48000;/*codec_ctx->sample_rate;*/
-    stream->codec->bit_rate = 128000;
+    stream->codec->bit_rate = 2000000;
     stream->codec->channels = codec_ctx->audio_channels;
 
     ctx->out_astream = stream->index;
@@ -406,8 +416,10 @@ static ngx_int_t
 ngx_rtmp_hls_initialize(ngx_rtmp_session_t *s)
 {
     ngx_rtmp_hls_ctx_t             *ctx;
+    ngx_rtmp_hls_app_conf_t        *hacf;
     AVOutputFormat                 *format;
 
+    hacf = ngx_rtmp_get_module_app_conf(s, ngx_rtmp_hls_module);
     ctx = ngx_rtmp_get_module_ctx(s, ngx_rtmp_hls_module);
     if (ctx == NULL || ctx->out_format || ctx->publishing == 0) {
         return NGX_OK;
@@ -430,6 +442,7 @@ ngx_rtmp_hls_initialize(ngx_rtmp_session_t *s)
         return NGX_ERROR;
     }
     ctx->out_format->oformat = format;
+    ctx->out_format->max_delay = (int64_t)hacf->muxdelay * AV_TIME_BASE / 1000;
 
     return NGX_ERROR;
 }
@@ -449,6 +462,10 @@ ngx_rtmp_hls_open_file(ngx_rtmp_session_t *s, u_char *fpath)
         return NGX_OK;
     }
 
+    if (!ctx->video || !ctx->audio) {
+        return NGX_OK;
+    }
+
     ngx_log_debug1(NGX_LOG_DEBUG_RTMP, s->connection->log, 0,
             "hls: open stream file '%s'", fpath);
 
@@ -475,11 +492,14 @@ ngx_rtmp_hls_open_file(ngx_rtmp_session_t *s, u_char *fpath)
     }
 
     /* write header */
-    if (avformat_write_header(ctx->out_format, NULL) < 0) {
+    if (!ctx->header_sent &&
+        avformat_write_header(ctx->out_format, NULL) < 0) 
+    {
         ngx_log_error(NGX_LOG_ERR, s->connection->log, 0,
                 "hls: avformat_write_header failed");
         return NGX_ERROR;
     }
+    ctx->header_sent = 1;
 
     if (astream) {
         astream->codec->extradata = NULL;
@@ -651,10 +671,11 @@ ngx_rtmp_hls_close_file(ngx_rtmp_session_t *s)
 
     ctx = ngx_rtmp_get_module_ctx(s, ngx_rtmp_hls_module);
 
+    /*
     if (av_write_trailer(ctx->out_format) < 0) {
         ngx_log_error(NGX_LOG_ERR, s->connection->log, 0,
                 "hls: av_write_trailer failed");
-    }
+    }*/
 
     avio_flush(ctx->out_format->pb);
 
@@ -1028,10 +1049,11 @@ ngx_rtmp_hls_video(ngx_rtmp_session_t *s, ngx_rtmp_header_t *h,
     packet.dts = h->timestamp * 90L;
     packet.pts = packet.dts + cts * 90;
     packet.stream_index = ctx->out_vstream;
-    /*
+
     if (ftype == 1) {
         packet.flags |= AV_PKT_FLAG_KEY;
-    }*/
+    }
+
     packet.data = buffer;
     packet.size = out.pos - buffer;
 
@@ -1056,6 +1078,7 @@ ngx_rtmp_hls_create_app_conf(ngx_conf_t *cf)
 
     conf->hls = NGX_CONF_UNSET;
     conf->fraglen = NGX_CONF_UNSET;
+    conf->muxdelay = NGX_CONF_UNSET;
     conf->playlen = NGX_CONF_UNSET;
     conf->nbuckets = 1024;
 
@@ -1071,6 +1094,7 @@ ngx_rtmp_hls_merge_app_conf(ngx_conf_t *cf, void *parent, void *child)
 
     ngx_conf_merge_value(conf->hls, prev->hls, 0);
     ngx_conf_merge_msec_value(conf->fraglen, prev->fraglen, 5000);
+    ngx_conf_merge_msec_value(conf->muxdelay, prev->muxdelay, 700);
     ngx_conf_merge_msec_value(conf->playlen, prev->playlen, 30000);
     ngx_conf_merge_str_value(conf->path, prev->path, "");
     conf->ctx = ngx_pcalloc(cf->pool,