• INTRODUCTION
• INTRODUCTION
• ABOUT THIS MANUAL
• WHAT IS?
• STREAMING?
• OGG THEORA?
• GETTING READY
• PREPRODUCTION
• THE CREW
• FOOD & COFFEE
• THE WEB PAGE
• SERVER DETAILS
• MODERATION
• HARDWARE
• HARDWARE
• CAMERA TECHNIQUE
• AUDIO TECHNIQUE
• SOFTWARE ENCODERS
• SETTINGS
• TSS
• INSTALLING TSS
• USING TSS
• TITLES AND STYLE
• OPENOFFICE.ORG
• EMBEDDING
• TESTING
• Testing
• REMOTE CONTRIBUTIONS
• MODERATION
• PLAYERS
• ARCHIVES
• EDITORS
• FFMPEG
• Pitivi
• KDENLIVE
• TRANSCODING
• TIPS N TRICKS
• Troubleshooting
• APPENDICES
• CREDITS
• Archives
• Equipment
• TheSchedule

Cutting and converting ogg files in ffmpeg

This requires the Linux software package ffmpeg, which is an audio and video encoder. It is a quick command-line based tool for cutting segments out of a larger ogg file.

You need to record certain time-based information during the stream for this to work. Specifically you need the time in the video from which you want the segment to start and the duration of the segment you wish to cut. The easiest way to do this is to dedicate a person to recording appropriate start and stop cut points while the event is happening. Alternatively you can do this after the event by watching through the video, but this is much more time consuming.

Cutting segment out of a big ogg file

Firstly, navigate to the folder with the files in them in the terminal (e.g. if they are in a folder 'event' on the Desktop)

$ cd (-> now you are in your home directory)
$ cd Desktop/event (-> now you are in the 'event' folder on the Desktop)
$ ls (-> display all the files and folders in the current folder)
$ pwd (-> show the path of where you are)

Then, to use ffmpeg: open Terminal window and copy and paste the following command.

$ ffmpeg -i conference_opening.ogg -s 394x288 -r 12 -ss 00:04:50 -t 00:01:00 -pass 1 -ab 40kb temp.ogg

Then adjust it, inserting in the correct data (file names, start point, duration):

-i conference_opening.ogg    This is the original large ogg file that needs to be cut.
-s 394x288    This allows you to resize the frame...
-r 12     ...but keep the framerate.
-ss 00:04:50     This is the timecode for the  starting point of the segment in hh:mm:ss (hours, minutes, seconds).
-t 00:01:00     The duration (not the end) of the segment.
-pass 1     Don't worry about this, just leave it!
-ab 40kb     This alters the bitrate of the audio.
temp.ogg    This is the name of the edited file you will create.

If you are unsure of the values, enter in the original filename, start point, duration and new filename and leave everything else as it is. The new file will be created in the folder you navigated the terminal to.