I think you want to stream h264 video from hardware encoder. This feature is already implemented in WebRTC for Android.
At present it doesn't support all the SOC. ( I think most of the latest Qualcomm processors are supported )
So if you use WebRTC for Android and supported SOC you can stream directly from hardware encoder.
If you want to use it on non supported platform, you can not do it just pushing encoded raw data from the encoder. As WebRTC needs to change frame rate, bit rate and others
encoder is closely integrated with it.
If your hardware encoder supports OpenMAX, you can change some code to support it.
Thanks,
Shakeeb