Differences

This shows you the differences between two versions of the page.

--- video_files:formulas [2025/05/16 22:56] – peter
+++ video_files:formulas [2025/05/17 07:24] (current) – peter
@@ Line 1: / Line 1: @@
 ====== Video Files - Formulas ======
+===== General =====
 <code>
@@ Line 69: / Line 71: @@
 ----
+===== Bitrate =====
+<code>
+Bitrate = file size / (number of minutes * .0075)
+Bitrate = (file size * 8) / (duration in seconds)
+Video Bitrate = Total Bitrate - Audio Bitrate
+</code>
+----
+===== Duration =====
+<code>
+Number of minutes = file size / (bitrate * .0075).
+</code>
+----
+===== Filesize =====
+<code>
+file size = bitrate * number of minutes * .0075
+file size = duration × frame rate × frame size
+  frame size = H × V × color depth
+  color depth = 8bitxRGB = 8*3 = 24
+Picture File Size = colour depth x width in pixels x height in pixels
+  colour depth = RGB=3 bytes; RGBA=4 bytes
+file size = bitrate * time
+file size = duration × file size per sec / 8
+  file size per second = fps × frame size
+Video File Size = (Bitrate / 8) × Duration
+File Size (in Bytes)=(Video Bitrate × Duration)+Audio Bitrate
+File Size (in Bytes)=(Video Bitrate × Duration)+((Audio Bitrate x Audio Size)/Audio Channels*6)
+Compressed Video File Size (GB) = (Bitrate (Mbps) * Total Time (seconds)) / (8 * 1024)
+</code>
+----
+===== Sound Bitdepth =====
+See **bits per raw sample** field.
+An approximation of the sound bitdepth can be calculated by using variables: audio sample rate, audio channels and audio bitrate.
+<code>
+audio bitdepth = audio bitrate / audio_channels / audio sample rate
+</code>
+<WRAP info>
+**NOTE:**  The audio bitrate may need to be multiplied by 1,000 to be in bits.
+  * This formula should produce a value such as 1, 2, 3 or 4; which is the number of bytes.
+    * When these bytes are multiplied by 8 to convert them to bits, this will result in 8, 16, 24, or 32 bits.
+</WRAP>
+----
+===== Sound Bitrate =====
+<code>
+bit rate = audio sample rate * audio channels * audio bit depth
+</code>
+----
+===== Sound File Size =====
+<code>
+Sound File Size = sample rate x duration x bit depth x number of channels
+</code>