# Constant Audio Delay With HTTP HLS Streaming

**URL:** <https://community.wowza.com/t/constant-audio-delay-with-http-hls-streaming/47028>\
**Category:** Wowza Streaming Engine\
**Created:** [May 11, 2016, 8:39am UTC](https://community.wowza.com/t/constant-audio-delay-with-http-hls-streaming/47028 "2016-05-11T08:39:23Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![Colin\_Rosenthal](https://avatars.discourse-cdn.com/v4/letter/c/5f8ce5/32.png) [@Colin\_Rosenthal](https://community.wowza.com/u/Colin_Rosenthal)\
**Post date:** [May 11, 2016, 8:39am UTC](https://community.wowza.com/t/constant-audio-delay-with-http-hls-streaming/47028/1 "2016-05-11T08:39:23Z")

</div>

Hi,

(tl;dr We have a problem with certain mp4 files which always stream with a 0.5 second audio delay from beginning to end.)

We have a substantial archive (about 1.2 million files) of video files consisting of h.264 video + mp3 audio in a .flv

container. We currently stream these on-demand using rtmp. We would like to remux these files to mp4 for streaming via http (cupertino).

We have carried out a number of tests using

- various demuxers/remuxers (ffmpeg and MP4Box), and various muxing parameters

- various input samples

- the mp4 file plays fine on a local vlc

- when streamed via wowza (v4.0.3) the sound is delayed by 0.5 seconds. The delay appears to be very close to exactly 0.5 seconds, for all files tested, and throughout the whole file (which may be more than an hour long). _There is no drifting **[NOTE: now upgraded to 4.4.1 with the same results.]**_.

- If we download one of the chunk .ts-files and play that locally then the audio is _already delayed by 0.5 seconds in the chunk_.

---

<div class="post-metadata">

**Author:** ![Colin\_Rosenthal](https://avatars.discourse-cdn.com/v4/letter/c/5f8ce5/32.png) [@Colin\_Rosenthal](https://community.wowza.com/u/Colin_Rosenthal)\
**Post date:** [May 17, 2016, 7:48am UTC](https://community.wowza.com/t/constant-audio-delay-with-http-hls-streaming/47028/2 "2016-05-17T07:48:16Z")

</div>

For anyone else interested:

Wowza Support have responded to this issue by pointing me to [https://www.wowza.com/docs/how-to-use-ffmpeg-with-wowza-media-server-mpeg-ts](https://www.wowza.com/docs/how-to-use-ffmpeg-with-wowza-media-server-mpeg-ts) which correctly describes the problem and provides a usable solution/workaround.

Colin Rosenthal

State And University Library

Aarhus, Denmark

---

<div class="post-metadata">

**Author:** ![Jason\_Hilton](https://sea2.discourse-cdn.com/flex002/user_avatar/community.wowza.com/jason_hilton/32/437_2.png) [@Jason\_Hilton](https://community.wowza.com/u/Jason_Hilton)\
**Post date:** [May 17, 2016, 9:43am UTC](https://community.wowza.com/t/constant-audio-delay-with-http-hls-streaming/47028/3 "2016-05-17T09:43:07Z")

</div>

Hi Colin,

I’m glad you found the information you needed and the issue is now resolved.

Thanks for sharing this in the update for others to benefit from.

Regards,

Jason