You can configure all video capture settings right in a game by pressing hotkeys to open Playclaw. Main parameters can be set directly in the main window. Note that the current version of Playclaw can differ slightly from the one described here, but the main information is true for all versions.
You can set two combinations of hotkeys to record video: “Start/Stop Shortcut” and “Stop and Delete Shortcut”. By pressing the first combination once, you can start recording video. Pressing that combination again stops recording. The second combination of hotkeys stops video recording and deletes a file. It may be necessary if you are not satisfied with the record and do not want to produce too many useless files.
The “Resize Frame to” option allows you to resize an output frame in real time before its compression. In most cases, it is used to reduce the workload on the codec. For example, 1920×1080 frame can be resized to 1280х720 and the workload on the codec can decrease by 1.5-2 times. Resizing takes much less time than compression.
The current version of Playclaw offers two encoding modes: uncompressed and MJPEG codec. The first option lets you retain original quality of a picture, without any considerable impact on the processor. However, the amount of data written to the hard drive is simply enormous. For example, if you have 1920х1080 frame size and FPS=30, the size of recorded data will be equal to 178 megabytes per second. As you can guess, the overwhelming majority of modern hard drives cannot provide this recording speed (you’ll have to use RAID array or SSD). And one minute of recording will take about 10 gigabytes of disk space, which is incredibly too much!
MJPEG codec allows you to configure compression quality (the higher, the closer to the original). Also you can configure RGB to YUV compression. Although compression may have a slight effect on image quality, it considerably reduces the size of compressed data (almost by two times), which is good for performance.
The “Video File FPS” option lets you select the desired recoding speed. Playclaw does not bind game FPS to FPS of video capture, trying to provide maximum performance in a game, without frame loss. If you do not need 60 frames per second in video, you won’t have to set 60 FPS to keep it high in a game (as some competing applications require you to do). Just select standard 30 FPS for video and play a game with 60-90-120 FPS.
From the first version, Playclaw has been developed as a program that takes advantage of multi-core processors. You can select the number of threads (processor cores) that will be used for video compression. In theory, if you increase the number of threads by two times, it’ll boost the performance of a codec by two times as well. In practice, this correlation is not quite linear, and everything depends on hardware configuration, games and other things. For most games, it’ll be enough to set the number of threads to be half of the number of physical cores of the processor. For example, you need to select two threads for quad processors. Bear in mind that processors with HyperThreading have twice as many logical cores than physical ones. “Extra” cores for video compression give almost no effect.
The “Capture Cursor” option speaks for itself. It allows you to capture the cursor, which may help people to understand the actions of the player in some games.
The “Smooth Frame Rate” option forces Playclaw to average time for one frame when recording video, while slightly increasing the load on the graphic card driver. This means that under standard conditions, when game FPS is much higher than FPS of recoding, Playclaw spends 1,5-2 times more time on a frame than for an intermediate frame when the program does not require new data for a codec. This effect looks like “jerking” when scenes in a frame change quickly. So, Playclaw tries to smooth all frames, which leads to a small loss of FPS in a game and automatically reduces the load on the graphic card and delivers smoother game play.