title: Transcoding, Formats & Codecs
---
-<h2>Video Formats and Codecs</h2>
<p>
-A short primer on video-files, formats and codecs – because it is often cause for confusion:
+ This chapter provides a short primer on video files, formats and
+ codecs – because it is often cause for confusion:
</p>
<p>
-A video file is a <em>container</em>. It usually contains one video-track and one or more audio-tracks.
+ A video file is a <dfn>container</dfn>. It usually contains one
+ <dfn>video track</dfn> and one or more <dfn>audio tracks</dfn>.
+ How these tracks are stored in the file is defined by the
+ <dfn>file format</dfn>. Common formats are
+ avi, mov, ogg, mkv, mpeg, mpeg-ts, mp4, flv, or vob.
</p>
-
<p>
-How these tracks are stored in the file is defined by the <em>file-format</em>. Common formats are avi, mov, ogg, mkv, mpeg, mpeg-ts, mp4, flv, vob
+ Each of the tracks by itself is encoded using a <abbr
+ title="Coder-Decoder"><dfn>Codec</dfn></abbr>. Common video codecs
+ are h264, mpeg2, mpeg4, theora, mjpeg, wmv3. Common audio codecs are
+ mp2, mp3, dts, aac, wav/pcm.
</p>
-
-<p>
-Each of the tracks by itself in <em>encoded</em> - using a <abbr title="Coder-Decoder">Codec</abbr>. Common Video-Codecs are h264, mpeg2, mpeg4, theora, mjpeg, wmv3. Audio-Codecs: mp2, mp3, dts, aac, wav/pcm.
-</p>
-
<p>
-Not all codecs can be packed into a given format. For example the 'mpeg' format is limited to mpeg2, mpeg4 and mp3 codecs (not entirely true). DVDs do have stringent limitations as well. The opposite would be .avi; pretty much every audio/video codec combination can be contained in an avi file-format.
+ Not all codecs can be packed into a given format. For example the
+ mpeg format is limited to mpeg2, mpeg4 and mp3 codecs (not entirely true).
+ DVDs do have stringent limitations as well. The opposite would be .avi;
+ pretty much every audio/video codec combination can be contained in an avi
+ file-format.
</p>
-
<p>
-To make things worse, naming conventions for video codecs and formats are often identical (esp mpeg ones) which leads to confusion.
-All in all it is a very wide and deep field. Suffice there are different uses for different codecs and formats.
+ To make things worse, naming conventions for video codecs and formats are
+ often identical (especially MPEG ones) which leads to confusion.
+ All in all it is a very wide and deep field. Suffice there are different
+ uses for different codecs and formats.
</p>
-<h2>Ardour specific</h2>
-
+<h2>Ardour specific issues</h2>
<p>
-Ardour supports a wide variety of video file-formats and video-codecs. More specifically, Ardour itself actually does not support any video at all but delegates handling of video files to <a href="http://ffmpeg.org">ffmpeg</a> which supports over 350 different video-codecs and more than 250 file-formats.
+ Ardour supports a wide variety of video file formats codecs. More
+ specifically, Ardour itself actually does not support any video at all
+ but delegates handling of video files to <a
+ href="http://ffmpeg.org">ffmpeg</a>, which supports over 350 different
+ video codecs and more than 250 file formats.
</p>
-
<p>
-When importing a video into Ardour, it will be <em>transcoded</em> (transcoding: change from one format and codec to another) to avi/mjpeg for internal use (this allows reliable seeking to frames at low CPU cost - the file-size will increase, but hard-disks are large and fast).
+ When importing a video into Ardour, it will be <dfn>transcoded</dfn>
+ (changed from one format and codec to another) to avi/mjpeg for internal
+ use (this allows reliable seeking to frames at low CPU cost — the
+ file size will increase, but hard disks are large and fast).
</p>
-
<p>
-The export dialog includes presets for common format & codec combinations (such as DVD, web-video,..). If in doubt use one of the presets.
+ The export dialog includes presets for common format and codec
+ combinations (such as DVD, web-video,..). If in doubt use one of the
+ presets.
</p>
-
<p>
-As last note: Every time a video is transcoded the quality can only get worse. Hence for the final mastering/<abbr title="Multiplexing Audio and Video">muxing</abbr> process, one should always to back and use the original source of the video.
+ As last note: every time a video is transcoded, the quality can only get
+ worse. Hence for the final mastering/<abbr
+ title="Multiplexing Audio and Video">muxing</abbr> process, one should
+ always to back and use the original source of the video.
</p>
projects / ardour-manual / blobdiff