* - i_flags may not always be set (ie could be 0, even for a key frame
* it depends where you receive the buffer (before/after a packetizer
* and the demux/packetizer implementations.
- * - i_dts/i_pts could be 0, it means no pts
+ * - i_dts/i_pts could be VLC_TS_INVALID, it means no pts/dts
* - i_length: length in microseond of the packet, can be null except in the
* sout where it is mandatory.
* - i_rate 0 or a valid input rate, look at vlc_input.h