diff --git a/ngx_rtmp_flv_module.c b/ngx_rtmp_flv_module.c
index cea72ec..148bac8 100644
--- a/ngx_rtmp_flv_module.c
+++ b/ngx_rtmp_flv_module.c
@@ -44,6 +44,7 @@ typedef struct {
 
 #define NGX_RTMP_FLV_BUFFER             (1024*1024)
 #define NGX_RTMP_FLV_DEFAULT_BUFLEN     1000
+#define NGX_RTMP_FLV_BUFLEN_ADDON       1000
 #define NGX_RTMP_FLV_TAG_HEADER         11
 #define NGX_RTMP_FLV_DATA_OFFSET        13
 
@@ -526,7 +527,8 @@ next:
         return NGX_OK;
     }
 
-    buflen = (s->buflen ? s->buflen : NGX_RTMP_FLV_DEFAULT_BUFLEN);
+    buflen = (s->buflen ? s->buflen + NGX_RTMP_FLV_BUFLEN_ADDON:
+                                      NGX_RTMP_FLV_DEFAULT_BUFLEN);
     end_timestamp = (ngx_current_msec - ctx->epoch) +
                      ctx->start_timestamp + buflen;
 
@@ -604,6 +606,7 @@ ngx_rtmp_flv_seek(ngx_rtmp_session_t *s, ngx_file_t *f, ngx_uint_t timestamp)
                   "flv: seek timestamp=%ui", timestamp);
 
     ctx->start_timestamp = timestamp;
+    ctx->epoch = ngx_current_msec;
     ctx->offset = -1;
     ctx->msg_mask = 0;
 
diff --git a/ngx_rtmp_mp4_module.c b/ngx_rtmp_mp4_module.c
index 0c95849..cd466b0 100644
--- a/ngx_rtmp_mp4_module.c
+++ b/ngx_rtmp_mp4_module.c
@@ -196,6 +196,7 @@ ngx_rtmp_mp4_from_rtmp_timestamp(ngx_rtmp_mp4_track_t *t, uint32_t ts)
 
 
 #define NGX_RTMP_MP4_DEFAULT_BUFLEN     1000
+#define NGX_RTMP_MP4_BUFLEN_ADDON       1000
 
 
 static u_char                           ngx_rtmp_mp4_buffer[1024*1024];
@@ -1959,7 +1960,8 @@ ngx_rtmp_mp4_send(ngx_rtmp_session_t *s, ngx_file_t *f, ngx_uint_t *ts)
         return rc;
     }
 
-    buflen = (s->buflen ? s->buflen : NGX_RTMP_MP4_DEFAULT_BUFLEN);
+    buflen = (s->buflen ? s->buflen + NGX_RTMP_MP4_BUFLEN_ADDON:
+                                      NGX_RTMP_MP4_DEFAULT_BUFLEN);
 
     t = ctx->tracks;
 
@@ -2263,6 +2265,7 @@ ngx_rtmp_mp4_seek(ngx_rtmp_session_t *s, ngx_file_t *f, ngx_uint_t timestamp)
     }
 
     ctx->start_timestamp = timestamp;
+    ctx->epoch = ngx_current_msec;
 
     return ngx_rtmp_mp4_reset(s);
 }