VBR - video bitrate, data rate
VBR entry
It is the amount of data in a particular space of time (eg. a second) - it is a property for both digital video and audio. If a video is said to have a constant data rate or constant BITRate of 150 bytes per second, it means that in every second of video, 150 bytes is used to store the video. BITRate can be constant (CBR) or variable (VBR). CBR means that the stated BITRate will be constant throughout the video, while VBR will mean that the parts of the video that needs more BITRate will get it, while parts that don't need it will have a lower BITRate.
Standard MP3 bitrates are 64 Kbps (kilobits per second), 96 Kbps, 128 Kbps, and 160 Kbps. Different bitrates yield MP3s of varying sound quality. The higher the bitrate, the more times per second the original sound is sampled, thus yielding a more faithful reproduction and better sound. When choosing an MP3, weigh the advantage of a higher bitrate against the size of the file. Generally speaking, a bitrate of 128 kbps or higher will yield satisfactory sound quality.
160 Kbps
MP3s encoded at 160 Kbps have a 9:1 compression ratio. One minute of music will equal approximately 1.5MB of disk space. For this setting, expect CD-quality files.
128 Kbps
MP3s encoded at 128 Kbps have an 11:1 compression ratio. One minute of music will equal approximately 1MB of disk space. For this setting, expect CD-quality files.
96 Kbps
MP3s encoded at 96 Kbps have a 15:1 compression ratio. One minute of music will equal approximately 700KB of disk space. For this setting, expect near CD-quality files.
64 Kbps
MP3s encoded at 64 Kbps have a 15:1 compression ratio. One minute of music will equal approximately 400KB of disk space. For this setting, expect FM radio-quality files.
VBR and CBR in details
Variable Bit Rate (VBR) is an MP3 encoding method that's used when file size is not an issue. Use VBR encoding when you want the highest audio quality.
Constant Bit Rate (CBR) encoding maintains the same bitrate throughout an encoded file. Use this method when file size is critical and audio quality is of little importance. |
