Differences

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

--- timecode [2016/06/21 00:18]
slackermedia
+++ timecode [2021/06/03 19:48] (current)
@@ Line 1: / Line 1: @@
 ====== SMPTE Timecode ======
-Different film gauges and standards involve different numbers of frames in each second, and audio has no frames at all. Without a standardised reference point, there would be no clear or efficient way to communicate to start playback, for instance, at a certain point in two separate media; you would have to say things like "start the film at 250 frames in, if 35mm stock in the UK, 240 frames if in the USA, or 180 frames in, if super-8 stock, and play the audio at 10 seconds from the start of the tape, allowing for 3 seconds (or so) of pre-roll." It can work, but it's verbose and not very precise.
+Different film gauges and standards involve different numbers of frames in each second, and audio has no frames at all. Without a standardised reference point, there would be no clear or efficient way to communicate when to start playback, for instance, at a certain point in two separate media. At best, communication of such a simple concept would become over-verbose, and at worst there would be several different ways of expressing it across the industry.
 The Society of Motion Picture and Television Engineers (SMPTE) developed a standard called **Timecode** or **SMPTE Timecode**, which assigns timestamps to media. For strict and accurate timecode, the media must be digital; analogue media cannot truly retain timecode, although it can have timecode "burned" into it, or it can be controlled by a digital player which may be able to assign timecode from known positions (but you lose accuracy, which is the point of timecode).
@@ Line 19: / Line 19: @@
 And so on.
-It is also, //time// being what it is, possibly to specify units less than a whole frame. The timecode ''00:00:12:12.5'' indicates 12 seconds, 12 frames, and a half of a frame. If you know how many frames are in one second, you can convert that value to milliseconds. For instance, if there are 24 frames per second, then 12.5 frames is ''.5208'' second or ''520.8'' milliseconds (because 12.5 divided by 24 frames is 0.5208, with 24 frames being a value equal to 1 second).
+It is also (//time// being what it is) possible to specify units less than a whole frame. The timecode ''00:00:14:12.5'' indicates 14 seconds, 12 frames, and a half of a frame. If you know how many frames are in one second, you can convert that value to milliseconds. For instance, if there are 24 frames per second, then 12.5 frames is ''.5208'' second or ''520.8'' milliseconds (because 12.5 divided by 24 frames is 0.5208, with 24 frames being a value equal to 1 second).
 ==== Time Base ====
@@ Line 39: / Line 39: @@
 Timecode is available across both video and audio. Strictly speaking, you don't need to use SMPTE timecode if you are not working to video, but pragmatically it is probably available to you if you find it useful. Many DAWs display timecode just as happily as they display traditional hour-and-minutes counters or measures-and-beats.
+You can manually burn in timecode to video files using [[https://opensource.com/life/15/12/10-kdenlive-tools|Kdenlive]], or even [[ffmpeg]] (thanks to Github user [[https://gist.githubusercontent.com/reidransom/2630650/raw/63e4748b3cd903b916291658c14f97f81c6ae3e4/gistfile1.sh|reidransom]]):
+<code>
+$ ffmpeg -i video.mp4 -vcodec copy -acodec copy \
+-vf "drawtext=fontfile=DroidSansMono.ttf: timecode='01\:00\:00\:00': r=24: \
+x=(w-tw)/2: y=h-(2*lh): fontcolor=white: box=1: boxcolor=0x00000099" \
+-threads 6 -y output.mp4
+</code>
+Or you can use a video player that dynamically displays timecode, like [[xjadeo]]
 <WRAP centeralign>