VSS H.264 Encoder

Profile support

• Baseline
• Main
• High-100
• Up to level 4.2

Input format

• Progressive, Interlace
• Pre Processing Library supports deinterlace and frame resize
• Square or specified pixel shape
• Color Space definition YUV 4:2:0
• Colorspace conversion library supports YUV 4:2:0, YUV 4:2:2, RGB formats
• Max picture size is 4096x2048
• Resize to any 2x2 (2x4 for interlace) multiple

Slicing

• Multiple slices per frame
• Slice groups in FMO
• Slicing by size or by number of macroblocks

Motion estimation

• Patented High Performance search algorithms
• 1, 1/2, 1/4 pel accuracy
• All macroblock subdivisions
• Motion Vectors over picture boundary
• Search Range up to 128 full Pel

Frames

• I, P
• B frames ( Main and High profiles) – spatial and temporal direct modes
• Bidirectional P frames in Baseline profile
• Multiple reference frames (up to 7 frames for progressive, up to 15 fields for interlace)

Coding tools

• Inloop deblocking filter
• Adjustable GOP size
• Intra prediction: all subdivisions and intra-prediction modes
• Field or Frame Coding
• MBAFF (adaptive frame/field coding on macroblock level)
• Adjustable complexity-based per-macroblock QP modulation
• FMO in Baseline
• 8x8 Transform in High Profile

Entropy coding

• CAVLC
• CABAC ( Main and High profiles)

Rate control

• From 4Kbps to 120Mbps
• Fixed QP, CBR and VBR
• Change bitrate settings on the fly

Output

• Annex B NAL units with optional start codes
• RTP for H.264 payload stream format
• RFC 3984 (Single NAL Unit and non-interleaved mode; interleaved mode)

Output delay

• Baseline Compression delay = 1 Frame
• Main/High Profile (depends on GOP) delay = 1 Frame + No of B Frames
• Mux/Demux delay – depends on elastic buffer – Est at 2-3 Frames
• Multi Threaded Encoding delay = 2-3 Frames

DirectShow encoder filter

• Automatic colorspace conversion on input pin
• Advanced encoding settings via GUI or via API
• Stable 24x7 live encoding
• Optional RTP payload output

Advanced tools

• B-frames emulation in Baseline profile provides 5-10% compression gain and more efficient multithreading
• Complexity Analysis
• Programmable Scene Change detection
• Flexible Rate control (CBR & VBR)
• QP Modulation (different quantization parameter per macroblock)
• Programmable Noise reduction
• Rate-distortion optimization (RD Opt)
• Multithreading support
• Error resilience
• Custom quant matrices (High profile only)

Real-time performance on PC (standard and hi- definition)

• high quality real-time SD encoding (with RDopt) on Intel Core2Duo
• high quality real-time 1080i encoding on Intel Dual QuadCore