is vpx (vp8/vp9) using ivf format as default for storing video segment ?

[Swaminaathan Iyer]

is vpx (vp8/vp9) using *.ivf (http://wiki.multimedia.cx/index.php?title=IVF) format as default for storing video segment ?

if not then what is the format for vpx format , or

what is the vp9 format after demuxing webm file  ?  

[James Zern]

The vp9 bitstream can be stored in any frame-based container format.
If available at compilation, vpxenc will produce webm by default and
has the option to produce ivf. Some of the other examples for
simplicity may produce ivf output.