NVidia GPU-accelerated H264-encoder plugin, ready for public testing

Hi all,

I have written a 'proof-of-concept' GPU-accelerated H264-encoder for Adobe Media Encoder (CS6).  It requires an NVidia 6xx/7xx series "Kepler" GPU (CUDA capability 3.0), and uses the dedicated GPU's builtin hardware-encoder (NVENC) to offload the H264-encoding process from the host-CPU.  This software is "proof-of-concept", so it's missing some critical features (no interlaced-video support, no AAC-audio or Dolby AC-3 audio), and of course, it could be buggy!  But it's free.

!!!! Disclaimer: NVENC-export is third-party software that is not supported by either Adobe or NVidia.  It comes with no warranty -- use at your own risk.

Software/hardware Requirements:

(1)Adobe Premiere Pro CS6 or Media Encoder CS6 (Windows version)

Sorry, MacOSX is not supported. (NVidia NVENC SDK doesn't support MacOSX.)

(1)NVidia Kepler GPU <GKxxx> with 1GB VRAM or more  (GTX650 or above, GT650M or above)

(Sorry, NVidia Fermi <GFxxx> is NOT supported, it doesn't have the NVENC hardware feature)

Note,if you have MPE-acceleration enabled, keep in mind the NVENC-plugin consumes some additional VRAM because it uses your GPU to perform H264-encoding.

Strongly recommend a 2GB card

(2) Microsoft Visual C++ 2010 SP1 x64 redistributables

          (download this from Microsoft's website)

Installation instructions:

     In Adobe Premiere Pro CS6:

     (1)      On your system, locate the installation-directory for Premiere Pro CS6.

               Usually, this is C:/Program Files/Adobe/Adobe Premiere Pro CS6

    (2)     Copy the included file Plug-ins/Common/nvenc_export.prm

               to <installation dir>/Plug-ins/Common/

     -> To choose the NVENC-plugin in Premiere Pro,

          In the format-menu, select <NVENC_export>

     In Adobe Media Encoder CS6:

     (1)    On your system, locate the installation-directory for Media Encoder CS6.

          Usually, this is C:/Program Files/Adobe/Adobe Media Encoder CS6

     (2)     Copy the included file Plug-ins/Common/nvenc_export.prm

          to <installation dir>/Plug-ins/Common/

     -> To choose the NVENC-plugin in Media Encoder,

          in the format-menu, select <NVENC_export>

Performance & quality notes:

(1) How much faster is NVENC-export than Adobe's built-in Mainconcept H264 encoder?

Depends on your PC system.  On my test-system, which is ordinary desktop PC with Intel i5-3570K (4-core 3.4GHz), NVENC-plugin is roughly 4x faster than Mainconcept. On a dual-socket Xeon Ivy Bridge-E system, NVENC would probably only be 2x faster (in Media Encoder.)

(2)How does the video-quality compare?

Comparing similar settings/video-bitrate, Mainconcept performs better at lower-bitrates(less artifacts).  At medium-high bitrates, NVENC is comparable to Mainconcept.

(3) How does NVENC-export encode the video?

The plugin fetches videoFrames from the Adobe application, then converts the frames from YUV420 to NV12 surface-format (using host-CPU.)  Then it passes the converted frames to the NVENC front-end.  From here, NVENC hardware takes over, and handles all aspects of the video compression. When NVENC hardware is done, it calls the plugin to output write the elementary bitstream (to the selected filepath.) NVENC-hardware does NOT encode audio, nor does not multiplex the A/Vbitstreams -- this is still done in software (on the host-CPU)

The NVENC hardware block has very little CPU-overhead.  But since video-encoding is just 1 step in the entire Adobe rendering path, CPU-usage will likely still be quite high when using NVENC-plugin.

(4) What's the maximum-size video NVENC-export can handle?

H264 High-profile @ Level 5.1, which works out to roughly 3840x2160 @ 30fps. (Note the actual encoding-speed will probably be less than 30fps.)

(5) How fast is the NVENC-export hardware in Kepler GPU?

Assuming the Adobe application host is infinitely fast (i.e. can send video to plugin in zero-time), NVENC-hardware will encode High-profile (CABAC, 2 refframes, 1-bframe) 1920x1080p video @ ~100fps. At 3840x2160p (4k video), the hardware encode-speed drops to roughly 20-25fps.  That is still faster than a desktop PC.

NVENC-speed is generally same across the Kepler family - the high-end Geforce GTX Titan (or GTX780) is no faster than the entry-level Geforce GTX650, because all Kepler models share the same NVENC hardware-block, which is totally separate and independent of the GPU's 3D-graphics engine.

In premiere Pro 6, MPE acceleration will greatly affect how quickly Adobe can render video to the exporter.  So a more powerful Kepler GPU will probalby complete projects faster than a less powerful one (up to NVENC's performance ceiling.)  For more info, please refer to NVidia's NVENC whitepaper at their developer website (public)

(6) I have a multi-GPU setup, can I encode with multiple GPUs?

No, NVENC targets and uses only a single physical GPU.  (You can choose which one.)

Known limitations and problems:

NVENC-plugin is a 'proof-of-concept' program -- it is not a finished product.  So it's missing some features, and other things are known to be broken:

• Interlaced video encdoing does not work at all (not supported in current consumer Geforce drivers)

• Audio support is very limited: uncompressed PCM)

no AAC or Dolby-Digital

• Multiplexer support is very limited: MPEG-2 TS only, using an included third-party tool TSMuxer.EXE

no MPEG-4 muxing (*.MP4)

• When the muxed MPEG-2 TS file in Windows Media Player (WMP), there is no sound.  This is because WMP doesn't recognize PCM-audio in mpeg-2 ts files.  You have 2 choices; you can use a third-party media-player such as MPC-HC or VLC.  Or you can postprocess the audio-WAV file into a compatible format (Dolby Digital/AC-3)

• in the pop-up plugin User-interface, the <multiplexer> tab is missing or not shown properly.

(To fix: Select a different codec, then re-select NVENC_export.)

• Doesn't support older NVidia GPUs (GTX5xx and older, GT630 and lower)

Sorry, NVENC hardware was introduced with NVidia's Kepler family (2012)  Anything older than that will NOT work with the plugin.