I have the same problem, and here is my log
[10:19:56: No Intel graphics adapter visible in QSVHelper.exe, Optimus problem?
10:19:56: CUDA loaded successfully
10:19:56: 1 CUDA capable devices found
10:19:56: [ GPU #0 - < GeForce GT 720 > has Compute SM 3.5, NVENC Available ]
10:21:29: Open Broadcaster Software v0.651b - 32bit (´・ω・`)
10:21:29: -------------------------------
10:21:29: CPU Name: AMD FX(tm)-4300 Quad-Core Processor
10:21:29: CPU Speed: 3800MHz
10:21:29: Physical Memory: 4095MB Total, 4095MB Free
10:21:29: stepping id: 0, model 2, family 21, type 0, extmodel 0, extfamily 3, HTT 1, logical cores 4, total cores 2
10:21:29: monitor 1: pos={0, 0}, size={1920, 1080}
10:21:29: Windows Version: 6.2 Build 9200
10:21:29: Aero is Enabled
10:21:29: -------------------------------
10:21:29: OBS Modules:
10:21:29: Base Address Module
10:21:29: 00DC0000 OBS.exe
10:21:29: 6B820000 OBSApi.dll
10:21:29: 6BEE0000 DShowPlugin.dll
10:21:29: 6BEB0000 GraphicsCapture.dll
10:21:29: 6BE80000 NoiseGate.dll
10:21:29: 6BE60000 PSVPlugin.dll
10:21:29: 6BE40000 scenesw.dll
10:21:29: ------------------------------------------
10:21:29: Adapter 1
10:21:29: Video Adapter: NVIDIA GeForce GT 720
10:21:29: Video Adapter Dedicated Video Memory: 993718272
10:21:29: Video Adapter Shared System Memory: 3221549056
10:21:29: Video Adapter Output 1: pos={0, 0}, size={1920, 1080}, attached=true
10:21:29: =====Stream Start: 2015-06-02, 10:21:29===============================================
10:21:29: Multithreaded optimizations: On
10:21:29: Base resolution: 1920x1080
10:21:29: Output resolution: 1920x1080
10:21:29: ------------------------------------------
10:21:29: Loading up D3D10 on NVIDIA GeForce GT 720 (Adapter 1)...
10:21:29: ------------------------------------------
10:21:29: Audio Format: 48000 Hz
10:21:29: ------------------------------------------
10:21:29: Audio Channels: 2 Ch
10:21:29: Playback device Default
10:21:29: ------------------------------------------
10:21:29: Using desktop audio input: Speakers (Realtek High Definition Audio)
10:21:29: Global Audio time adjust: 0
10:21:29: ------------------------------------------
10:21:29: Audio Encoding: AAC
10:21:29: bitrate: 96
10:21:29: Using graphics capture
10:21:29: Trying to hook process: javaw.exe
10:21:29: Scene buffering time set to 700
10:21:29: NVENC internal init finished successfully
10:21:29: NVENC supports 8 h264 presets
10:21:29: ------------------------------------------
10:21:29: Video Encoding: NVENC
10:21:29: fps: 30
10:21:29: width: 1920, height: 1080
10:21:29: preset: llhq
10:21:29: profile: high
10:21:29: level: autoselect
10:21:29: keyint: -1
10:21:29: CBR: yes
10:21:29: CFR: yes
10:21:29: max bitrate: 1000
10:21:29: avg bitrate: 1000
10:21:29: buffer size: 1000
10:21:29: ------------------------------------------]