Various encoders use different compression schemes to compress the information. When exporting a movie file for playback on a specific type of device at a certain bandwidth, you must first choose an encoder ( codec). Compression is essential for reducing the size of movies so that they can be stored, transmitted, and played back effectively. Most formats use compression to reduce file size and bitrate by selectively reducing quality. When ready press the OK button to accept the changes you have made.Recording video and audio to a digital format involves balancing quality with file size and bitrate. If you are not sure which settings to use you can press the Restore Defaults button to discard the changes and restore default settings. This setting indicates how motion vectors for B-frames are derived: Spatial uses neighboring blocks in the same frame, which may result in a higher PSNR (it can be used for animated content as it better handles inconsistent motion jumps), whereas Temporal makes use of neighboring frames - which many people perceive as higher quality (better used for real-life content with fluid motion). It results in more accurate and efficient B-frames, therefore increasing quality.ĭirect B-frame mode allows B-frames to use predicted motion vectors instead of coding the actual motion, thus saving space and increasing compression efficiency. Weighted bipredictional setting allows B-frames to be predicted more heavily from one P frame or another. This increases quality of the output video. The default value is 0.īidirectional ME parameter allows the codec to predict some B-frames using motion before and after them. The possible values vary from -100 to 100. For most videos, the optimal number of B-frames will be chosen at Bias value of 0. Setting this to -100 will mean that almost no B-frames are used. Setting this parameter to 100, for instance, will force the codec to use the maximum number of B-frames specified in the Max consecutive box - it will be the same as uncheck Adaptive check-box. The higher this number, the more frequently B-frames will be dropped in. Without this feature, the codec will always put as many B-frames in a row as set in the Max consecutive field.īias lets the codec increase or decrease the probability that B-frames are being used. The default value is 0.Īdaptive activates adaptive use of B-frames. You can use up to 5 consecutive B-frames, but using 2-3 is the most sensible choice. Max consecutive indicates how many B-frames will be used consecutively. This setting should be activated when using more than 2 consecutive B-frames (See the Max consecutive setting below). Checking this setting might increase quality slightly because these B-frames can be predicted from one another instead of being limited to the P-frames around them for prediction and at the same time the time of the conversion will also increase. Use as reference allows a B-frame to reference another B-frame. The B-Frames section comprises the following codec parameters: Thus you should make sure your device supports High profile AVC, otherwise you might not be able to playback the resulting output video file.Īll the Partitions settings can be either checked or unchecked. Both of these options increase quality to a significant degree, but the usage of the the 8x8 Transform would make your video High Profile AVC compatible and would break the encoded video's compatibility with Main Profile AVC. The 8x8 Transform feature is a very powerful compression technique which acts upon larger blocks of visual information and enables the usage of other high-quality partition options such as the 8x8 Intra search which would otherwise be unusable without the 8x8 Transform. Disabling any partition search and decision options will speed up the encoding process at the expense of the quality. As a general rule, the more searches types of searches the codec performs on the visual information, the more accurately and efficiently it can predict and encode them. The partition search and decisions increase the accuracy and thus the quality and compression efficiency of the codec, enabling higher quality output. The Partitions section comprises the following codec parameters:
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