# Proper AAC profile bit settings in ADTS headers **URL:** \ **Category:** Wowza Streaming Engine\ **Created:** [April 19, 2010, 9:54am UTC](https://community.wowza.com/t/proper-aac-profile-bit-settings-in-adts-headers/34345 "2010-04-19T09:54:29Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![Brett\_Mitchell](https://avatars.discourse-cdn.com/v4/letter/b/858c86/32.png) [@Brett\_Mitchell](https://community.wowza.com/u/Brett_Mitchell)\ **Post date:** [April 19, 2010, 9:54am UTC](https://community.wowza.com/t/proper-aac-profile-bit-settings-in-adts-headers/34345/1 "2010-04-19T09:54:29Z")
Charlie- Posting here to document the ADTS header issue we talked about at NAB. Scenario - Inbound stream: RTMP h.264 baseline video / AAC-LC audio Outbound stream: HTTP Live Streaming Digging into the ADTS headers in the outbound TS files, the AAC profile bits are being set to ‘00’ which is AAC/Main. You indicated that this was most likely due to the RTMP feed having no meta data about the AAC payload, and your re-encap taking blind interpretation in the face of no data. Would love to see: A) a way to find some hinting (if it exists in the RTMP stream anywhere) and appropriately set the bits – and/or – B) have a setting similar to “forceH264BaselineProfile” that was added on the video front, where one could set a specific value if explicitly know. As I mentioned previously, this doesn’t seem to affect apple implementations of HLS, as the support both AAC-Main and AAC-LC, with the AAC-LC making it through (even if erroneously). The ‘less forgiving’ hardware that we are working with has no support for Main and kicks out the audio stream before even passing it to the ACC-LC codec. Thanks for taking a look. regards Brett Mitchell CTO Mediafly, Inc. p.s. Glad to meet you in person at NAB. ---
**Author:** ![Brett\_Mitchell](https://avatars.discourse-cdn.com/v4/letter/b/858c86/32.png) [@Brett\_Mitchell](https://community.wowza.com/u/Brett_Mitchell)\ **Post date:** [May 4, 2010, 9:53am UTC](https://community.wowza.com/t/proper-aac-profile-bit-settings-in-adts-headers/34345/2 "2010-05-04T09:53:55Z")
Charlie- Just checking in to see if this has been looked at. thx Brett ---
**Author:** ![Charlie\_Good](https://sea2.discourse-cdn.com/flex002/user_avatar/community.wowza.com/charlie_good/32/383_2.png) [@Charlie\_Good](https://community.wowza.com/u/Charlie_Good)\ **Post date:** [May 4, 2010, 2:06pm UTC](https://community.wowza.com/t/proper-aac-profile-bit-settings-in-adts-headers/34345/3 "2010-05-04T14:06:25Z")
I will email you directly. Charlie ---
**Author:** ![Tim\_Dougherty](https://sea2.discourse-cdn.com/flex002/user_avatar/community.wowza.com/tim_dougherty/32/596_2.png) [@Tim\_Dougherty](https://community.wowza.com/u/Tim_Dougherty)\ **Post date:** [January 27, 2014, 2:16pm UTC](https://community.wowza.com/t/proper-aac-profile-bit-settings-in-adts-headers/34345/4 "2014-01-27T14:16:29Z")
Hello Carlos Peña, This is a duplicate question. Please do not post the same question in multiple locations. This can create confusion and delay in response time. We will respond [in this post](https://www.wowza.com/forums/showthread.php?5636-Wowza-and-AAC-LC&p=132337#post132337). Thank you, -Tim ---
**Author:** ![Carlos\_Pena](https://avatars.discourse-cdn.com/v4/letter/c/a4c791/32.png) [@Carlos\_Pena](https://community.wowza.com/u/Carlos_Pena)\ **Post date:** [January 27, 2014, 5:20pm UTC](https://community.wowza.com/t/proper-aac-profile-bit-settings-in-adts-headers/34345/5 "2014-01-27T17:20:54Z")
Hello I have configured my LC AAC encoder and I can not have audio, I can do to fix it