isodump - format of IEEE 1394 isochronous packets dump file
The isodump format stores a series of IEEE 1394 isochronous stream
packets (possibly from multiple channels), including their headers.
Its main use is as the output format of dumpiso(1) and the input format
The 32 byte header starts at offset 0 with the string "1394 isodump v1"
followed by a zero byte. The next 8 bytes form a 64 bit big endian
integer, which represents a bit mask of the channels that were dumped.
A set bit at position (1 << x) signifies that channel x was being
listened on. The following 8 bytes are set to zero.
The iso packets follow the header and are appended to the data stream
in the order they were received. The packets consist of the header
quadlet as originally received and the data quadlets following
directly. The CRC quadlets after header and data do not appear and
everything is in big endian, as seen on the bus.
There is no further framing of the packets in the format, packet
boundaries can be found by looking at the data size field in the header
quadlet of each packet. The data size field appears in the most
significant 16 bits of the header quadlet, contain the size in bytes
(the actual packet is padded to a multiple of four bytes) and do not
include the header packet.
This format was introduced with the iso send and dump tools distributed
with libraw1394. No one else uses it so far.
Andreas Bombe <email@example.com>