Video and Audio Properties
Frame rate is the number of images that are displayed per second. In video streams, the playback rate of the video is described as the frame rate. The higher the frame rate, the smoother is the motion in the video. Generally, you should reduce the Frame Rate, if you have chosen a very low Bitrate.
Bitrate is the amount of information processed per second. Lowering the bitrate reduces the quality of the recorded audio and creates smaller files. If you set a bitrate to 2000 Kbps, a 10 second video file will contain 20, 000 kilo bits of information in the video (including the audio information). The higher the bitrate, the higher the quality of the video and the larger the file size. Generally, smaller dimensions allows you to use a lower bitrate and still have a good quality picture.
The width and the height of a video are together termed as dimension of a video. For instance, if a video is 320 pixels wide and 240 pixels in height, it is said to have a dimension of 320 x 240 pixels. The videos that are to be played on the Internet have low dimensions. For desktop videos, the dimensions are set to a higher values. Note that choosing Custom dimensions other than the ones in the drop-down list may produce a file which the device may not be able to play. Reducing the dimensions and lowering the Bitrate can produce smaller file sizes at the expense of low quality.
The Aspect Ratio of a video image is the relationship between the width and the height. Standard TV has an aspect ratio of 4:3. Movies and HD TV have wider pictures with a different aspect ratio. Before converting a widescreen movie, make sure that the dimensions you select are in the correct ratio.
Audio Frequency is the number of times the audio signal can be adjusted per second. Higher frequency values give better sound quality but also increase the size of the audio. Generally, use higher frequency for music and lower frequency for speech. Lowering the frequency reduces the audio fidelity.
Select Mono to include only one sound channel with your output file, and Stereo to include channels for both left and right speakers. Using Stereo produces slightly larger files.