-A short primer on video-files, formats and codecs â because it is often cause for confusion: + This chapter provides a short primer on video files, formats and + codecs â because it is often cause for confusion:
-A video file is a container. It usually contains one video-track and one or more audio-tracks. + A video file is a container. It usually contains one + video track and one or more audio tracks. + How these tracks are stored in the file is defined by the + file format. Common formats are + avi, mov, ogg, mkv, mpeg, mpeg-ts, mp4, flv, or vob.
--How these tracks are stored in the file is defined by the file-format. Common formats are avi, mov, ogg, mkv, mpeg, mpeg-ts, mp4, flv, vob + Each of the tracks by itself is encoded using a Codec. Common video codecs + are h264, mpeg2, mpeg4, theora, mjpeg, wmv3. Common audio codecs are + mp2, mp3, dts, aac, wav/pcm.
- --Each of the tracks by itself in encoded - using a Codec. Common Video-Codecs are h264, mpeg2, mpeg4, theora, mjpeg, wmv3. Audio-Codecs: mp2, mp3, dts, aac, wav/pcm. -
--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.
--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.
--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 ffmpeg 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 ffmpeg, which supports over 350 different + video codecs and more than 250 file formats.
--When importing a video into Ardour, it will be transcoded (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 transcoded + (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).
--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.
--As last note: Every time a video is transcoded the quality can only get worse. Hence for the final mastering/muxing 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/muxing process, one should + always to back and use the original source of the video.