Writing.md

@@ -0,0 +1,36 @@
+Writing in the context of libburnia means the transfer of a byte stream
+onto optical media or into disk filesystem objects which are handled
+much like optical media.
+
+The various types of optical media show quite different capabilities
+and behavior. CD media can carry raw audio streams as well as data 
+blocks which are protected by checksums and error correction. DVD
+and BD media can only carry data blocks. Eventual audio or video
+information is encoded in these blocks and not in raw streams.
+
+There is the class of multi-session media:
+CD-R, CD-RW, DVD-R, DVD-RW, DVD+R, BD-R, which have a table of
+content describing their session history. They may only be written
+sequentially and in large sessions.
+
+The other class is the one of overwriteable media:
+formatted DVD-RW, DVD+RW, DVD-RAM, BD-RE, which
+offers no session history but can perform random access
+writing with a certain granularity. 
+
+libburnia performs its writing via [libburn](Libburn) which
+demands a certain respect towards the peculiarities of the media
+type. Under the special assumption that only ISO 9660 filesystems
+with Rock Ridge extensions get written, [libisoburn](Libisoburn)
+offers writing capabilities which are nearly independent of the media
+type.
+
+libburnia has two programs which perform writing under command
+line control: cdrecord-emulator [cdrskin](Cdrskin), and
+ISO 9660 multi-session tool [xorriso](Xorriso).
+
+Formatted CD-RW are not yet supported by libburn.
+
+Regular disk files and block devices may be used like overwriteable
+media. Other disk filesystem objects may be used as empty
+multi-session media.