How to Reduce the Size of Recorded Video Files When Recording Games (NVIDIA Codec)
If you are using the NVIDIA NVENC H.264 codec by default, the recorded file size may be very large.
Click the Codec menu in oCam to check whether you are using the NVENC H.264 codec, as shown below.
In the oCam Codec menu, click Hardware Encoder Settings.
The Hardware Encoder Settings window will appear as shown below. You can reduce the size of the recorded video file by changing the options highlighted in the yellow box.
First, let's look at how to reduce the size of the recorded file using variable bitrate.
( Rate Control must be set to 1-PASS VBR. )
The Quantizer value can be set from 1 to 51.
The lower the Quantizer value, the better the video quality, and the higher the Quantizer value, the lower the video quality.
In other words, the recording quality is defined by the range from the minimum Quantizer value to the maximum Quantizer value.
For example,
If the minimum Quantizer value is 1 and the maximum Quantizer value is 13, the recording quality range is 1 to 13.
If the minimum Quantizer value is 1 and the maximum Quantizer value is 51, the recording quality range is 1 to 51.
If the minimum Quantizer value is 13 and the maximum Quantizer value is 51, the recording quality range is 13 to 51.
In conclusion, to reduce the size of a recorded video file, increasing the minimum and maximum Quantizer values will lower the recording quality and reduce the file size.
You can adjust the Quantizer values depending on your needs, as follows.
If you want to maintain the highest recording quality while lowering the quality at certain points to reduce the size of the recorded video, set the minimum Quantizer value to 1 and set the maximum Quantizer value to a higher number depending on how much you want to reduce the quality.
( Example: Minimum Quantizer: 1, Maximum Quantizer: 30 )
If you want to maintain medium quality while lowering the quality as much as possible at certain points to reduce the size of the recorded video, set the minimum Quantizer to 26 and the maximum Quantizer value to 51.
For reference, the minimum Quantizer value cannot be greater than the maximum Quantizer value.
That is, the minimum Quantizer value <= the maximum Quantizer value.
Caution: If you set both the minimum Quantizer value and the maximum Quantizer value to 1, the recorded video file size will become extremely large, so do not use this setting.
The default values in oCam are a minimum Quantizer value of 1 and a maximum Quantizer value of 13, and we recommend setting them within the following range.
Minimum Quantizer >= 1 and Maximum Quantizer value >= 13
Next is how to reduce the size of the recorded video file using constant bitrate.
Change Rate Control to 1-PASS CBR and then set the average bitrate.
The higher the average bitrate, the better the video quality. The lower the bitrate, the lower the video quality and the smaller the recorded file size.
Finally, there is a method that uses a fixed Quantizer parameter.
Set Rate Control to 1-PASS Fixed Quantizer Parameter.
Unlike VBR, there is no concept of minimum and maximum Quantizer values, and the quality is set using a fixed Quantizer value.
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How to Record Losslessly Using x264vfw
Before getting started, you must install the x264 codec in advance. If you do not know how to install it, please refer to the Help section.
Click the Codec menu in oCam, then click the External Codec menu item.
Select Use External Codec, choose the x264vfw codec, and then click the Settings button.
Using the default x264vfw settings as a base, change the parts highlighted in the yellow box in the image below as shown.
The following settings need to be changed.
Preset - Ultrafast ( Set this to improve encoding speed. The file size may become larger, but if you choose other options, significant lag may occur. )
Profile - High 4:4:4 ( The default profile may cause quality loss, so change it to High 4:4:4 for lossless encoding. )
Keep input colorspace - Keeps the color space of the internally received input buffer. ( If you use other options, encoding may fail. )
Rate control - Single pass - lossless - Change this for lossless encoding.
Click the OK button to apply the settings.
When recording 64-bit games, the settings are applied to x264vfw64 for 64-bit, so run x264vfw - Configure x264vfw64 from the Start menu and configure it in the same way as shown above.
If you record with the above settings, the video will be recorded losslessly. One important point is that if you want to play back the lossless video without quality loss, you must change the settings in your video player.
Below is how to check a lossless video using PotPlayer.
Run PotPlayer, then click Preferences ( F5 ).
In the Preferences window,
click Video - Color Space/Attributes on the left, then in the Color Space group box on the right, select Convert manually if possible - Default output color space. ( If you do not configure this, even if the recording is lossless, the screen colors may still be altered during playback. )
Click OK, then play the video recorded losslessly.
At this point, press Ctrl + F1 in PotPlayer. As shown below, the output format of the video codec must be displayed as RGB(32 Bits).
Also, in the playback information under the File Information tab, the following properties must match as shown below.
Format profile : High 4:4:4 Predictive@L3
Color space : RGB
Color range : Full
Matrix coefficients : RGB
Please note that Windows Media Player does not play this properly, and preview thumbnails will not be displayed in Windows Explorer.