gdp: factor out CRC code

Original commit message from CVS:
* libs/gst/dataprotocol/dataprotocol.c:
(gst_dp_header_from_buffer), (gst_dp_packet_from_caps),
(gst_dp_packet_from_event):
factor out CRC code
This commit is contained in:
Thomas Vander Stichele 2006-06-02 16:46:19 +00:00 committed by Tim-Philipp Müller
parent 10d21bc171
commit 19ea4af5b3

View file

@ -39,7 +39,6 @@ GST_DEBUG_CATEGORY (data_protocol_debug);
/* write first 6 bytes of header, as well as ABI padding */
#define GST_DP_INIT_HEADER(h, maj, min, flags, type) \
G_STMT_START { \
\
h[0] = (guint8) maj; \
h[1] = (guint8) min; \
h[2] = (guint8) flags; \
@ -50,6 +49,19 @@ G_STMT_START { \
GST_WRITE_UINT64_BE (h + 50, (guint64) 0); /* ABI padding */ \
} G_STMT_END
#define GST_DP_SET_CRC(h, flags, payload, length); \
G_STMT_START { \
guint16 crc = 0; \
if (flags & GST_DP_HEADER_FLAG_CRC_HEADER) \
/* we don't crc the last four bytes since they are crc's */ \
crc = gst_dp_crc (h, 58); \
GST_WRITE_UINT16_BE (h + 58, crc); \
\
crc = 0; \
if (length && (flags & GST_DP_HEADER_FLAG_CRC_PAYLOAD)) \
crc = gst_dp_crc (payload, length); \
GST_WRITE_UINT16_BE (h + 60, crc); \
} G_STMT_END
/* calculate a CCITT 16 bit CRC check value for a given byte array */
/*
@ -191,7 +203,6 @@ gst_dp_header_from_buffer (const GstBuffer * buffer, GstDPHeaderFlag flags,
guint * length, guint8 ** header)
{
guint8 *h;
guint16 crc;
guint16 flags_mask;
g_return_val_if_fail (GST_IS_BUFFER (buffer), FALSE);
@ -218,19 +229,7 @@ gst_dp_header_from_buffer (const GstBuffer * buffer, GstDPHeaderFlag flags,
GST_WRITE_UINT16_BE (h + 42, GST_BUFFER_FLAGS (buffer) & flags_mask);
/* CRC */
crc = 0;
if (flags & GST_DP_HEADER_FLAG_CRC_HEADER) {
/* we don't crc the last four bytes of the header since they are crc's */
crc = gst_dp_crc (h, 58);
}
GST_WRITE_UINT16_BE (h + 58, crc);
crc = 0;
if (flags & GST_DP_HEADER_FLAG_CRC_PAYLOAD) {
crc = gst_dp_crc (GST_BUFFER_DATA (buffer), GST_BUFFER_SIZE (buffer));
}
GST_WRITE_UINT16_BE (h + 60, crc);
GST_DP_SET_CRC (h, flags, GST_BUFFER_DATA (buffer), GST_BUFFER_SIZE (buffer));
GST_LOG ("created header from buffer:");
gst_dp_dump_byte_array (h, GST_DP_HEADER_LENGTH);
@ -255,7 +254,6 @@ gst_dp_packet_from_caps (const GstCaps * caps, GstDPHeaderFlag flags,
guint * length, guint8 ** header, guint8 ** payload)
{
guint8 *h;
guint16 crc;
guchar *string;
/* FIXME: GST_IS_CAPS doesn't work
@ -280,18 +278,7 @@ gst_dp_packet_from_caps (const GstCaps * caps, GstDPHeaderFlag flags,
GST_WRITE_UINT64_BE (h + 26, (guint64) 0);
GST_WRITE_UINT64_BE (h + 34, (guint64) 0);
/* CRC */
crc = 0;
if (flags & GST_DP_HEADER_FLAG_CRC_HEADER) {
crc = gst_dp_crc (h, 58);
}
GST_WRITE_UINT16_BE (h + 58, crc);
crc = 0;
if (flags & GST_DP_HEADER_FLAG_CRC_PAYLOAD) {
crc = gst_dp_crc (string, strlen ((gchar *) string) + 1);
}
GST_WRITE_UINT16_BE (h + 60, crc);
GST_DP_SET_CRC (h, flags, string, strlen ((gchar *) string) + 1);
GST_LOG ("created header from caps:");
gst_dp_dump_byte_array (h, GST_DP_HEADER_LENGTH);
@ -317,7 +304,6 @@ gst_dp_packet_from_event (const GstEvent * event, GstDPHeaderFlag flags,
guint * length, guint8 ** header, guint8 ** payload)
{
guint8 *h;
guint16 crc;
guint pl_length; /* length of payload */
g_return_val_if_fail (event, FALSE);
@ -387,19 +373,7 @@ gst_dp_packet_from_event (const GstEvent * event, GstDPHeaderFlag flags,
/* timestamp */
GST_WRITE_UINT64_BE (h + 10, GST_EVENT_TIMESTAMP (event));
/* CRC */
crc = 0;
if (flags & GST_DP_HEADER_FLAG_CRC_HEADER) {
crc = gst_dp_crc (h, 58);
}
GST_WRITE_UINT16_BE (h + 58, crc);
crc = 0;
/* events can have a NULL payload */
if (*payload && flags & GST_DP_HEADER_FLAG_CRC_PAYLOAD) {
crc = gst_dp_crc (*payload, strlen ((gchar *) * payload) + 1);
}
GST_WRITE_UINT16_BE (h + 60, crc);
GST_DP_SET_CRC (h, flags, *payload, pl_length);
GST_LOG ("created header from event:");
gst_dp_dump_byte_array (h, GST_DP_HEADER_LENGTH);