Nvidia Shadowplay

Nvidia ShadowPlay is a hardware accelerated screen recording utility for Windows PCs using GeForce GPUs, made by Nvidia Corp as part of its Geforce Experience software. It is similar to programs like FRAPS but uses new dedicated frame capture API which eliminates the traditional 50+% FPS loss from framebuffer capturing. It also utilizes dedicated H.264 video encoding hardware found in 600 and 700 series graphics cards to allow the captured content to be compressed in real time to further improve performance.^[1] ShadowPlay can be configured to record continuously with a rolling buffer of customizable length, allowing the user to save the video retrospectively if something interesting has happened in their game, without having to remember to start recording beforehand.^[2] ShadowPlay currently only supports games that use DirectX 9 or higher.^[3]

Under traditional methods of video capture, the act of capturing a frame prevents it from being sent to the monitor and forces a refresh, this halves the framerate before any additional overhead (which reduces performance even further). The captured frame then has to be encoded in some manner, typically a lightly compressed or uncompressed format to minimize further loss of performance. Then the resulting video is saved to a hard drive. With ShadowPlay's first release nvidia announced two new frame capturing methods, Frame Buffer Capture (NVFBC) and Inband Frame Readback (NVIFR). Both of which are integrated into the driver to allow frames to be captured with very low overhead (under 5%). NVFBC provides the best performance, but can only be used in full screen mode, it is the API used by ShadowPlay. NVIFR can be used in either fullscreen or window mode, but has somewhat higher performance impact (although still much lower than traditional methods), it is likely to be the capture method of choice for 3rd party utilities (unless they choose to implement both). Once ShadowPlay captures a frame, it encodes it using the dedicated hardware encoding embedded in the Nvidia GPU. This leaves the general hardware of the CPU and GPU available for other tasks and ensures the performance impact is almost nonexistent. As an additional benefit, the hardware encoding uses h264 which greatly reduces the size of the resulting video, this serves to both reduce the impact on the HDD speed as well as making ram buffering practical.^[4]

ShadowPlay is free for all owners of GTX 650 and higher series desktop graphics cards. It was supposed to be released alongside Nvidia Shield in late June 2013, but was delayed. It was also later planned for release by the end of summer 2013, but the release was silently postponed. On the 20th of September, an Nvidia forum representative posted a thread to the GeForce forums, citing that the delay was due to problems they had with video formats, and stated that they planned to start "sharing this new feature with you soon." It was released in a public beta on October 28, 2013 in the 331.65 driver,^[5] available to all graphic cards higher than the desktop 650 series.^[6][7]

With GeForce Experience 1.8, two of the most common requests were addressed with ShadowPlay: ability to include microphone voice in the recording via the settings menu, as well as allowing Windows 7 users to have an indefinite amount of manual recording (where it was previously capped to 4 GB per recording) and 20 minutes of "shadow time" which were previously only possible on Windows 8 and Windows 8.1.^[8]

References

External links

• http://www.geforce.co.uk/whats-new/articles/geforce-experience-official-release