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Original commit message from CVS: * libs/gst/dataprotocol/dataprotocol.c: (gst_dp_crc): Fix threadsafety of the crc checking function.
638 lines
19 KiB
C
638 lines
19 KiB
C
/* GStreamer
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* Copyright (C) <1999> Erik Walthinsen <omega@cse.ogi.edu>
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* Copyright (C) <2004> Thomas Vander Stichele <thomas at apestaart dot org>
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*
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* dataprotocol.c: Functions implementing the GStreamer Data Protocol
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Library General Public
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* License as published by the Free Software Foundation; either
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* version 2 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Library General Public License for more details.
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*
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* You should have received a copy of the GNU Library General Public
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* License along with this library; if not, write to the
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* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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* Boston, MA 02111-1307, USA.
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*/
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#ifdef HAVE_CONFIG_H
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#include "config.h"
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#endif
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#include <gst/gst.h>
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#include <gst/dataprotocol/dataprotocol.h>
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#include <glib/gprintf.h> /* g_sprintf */
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#include <string.h> /* strlen */
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#include "dp-private.h"
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/* debug category */
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GST_DEBUG_CATEGORY (data_protocol_debug);
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#define GST_CAT_DEFAULT data_protocol_debug
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/* calculate a CCITT 16 bit CRC check value for a given byte array */
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/*
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* this code snippet is adapted from a web page I found
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* it is identical except for cleanups, and a final XOR with 0xffff
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* as outlined in the uecp spec
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*
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* XMODEM x^16 + x^12 + x^5 + 1
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*/
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#define POLY 0x1021
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#define CRC_INIT 0xFFFF
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static guint16
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gst_dp_crc (const guint8 * buffer, register guint length)
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{
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static gboolean initialized = FALSE;
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static guint16 crc_table[256];
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guint16 crc_register;
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unsigned long i, j, k;
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if (!initialized) {
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for (i = 0; i < 256; i++) {
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j = i << 8;
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for (k = 8; k--;) {
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j = j & 0x8000 ? (j << 1) ^ POLY : j << 1;
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}
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crc_table[i] = (guint16) j;
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}
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initialized = TRUE;
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}
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crc_register = CRC_INIT; /* always init register */
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/* calc CRC */
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for (; length--;) {
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crc_register = (guint16) ((crc_register << 8) ^
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crc_table[((crc_register >> 8) & 0x00ff) ^ *buffer++]);
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}
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return (0xffff ^ crc_register);
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}
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/* debugging function; dumps byte array values per 8 bytes */
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/* FIXME: would be nice to merge this with gst_util_dump_mem () */
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void
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gst_dp_dump_byte_array (guint8 * array, guint length)
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{
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int i;
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int n = 8; /* number of bytes per line */
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gchar *line = g_malloc (3 * n);
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GST_LOG ("dumping byte array of length %d", length);
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for (i = 0; i < length; ++i) {
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g_sprintf (line + 3 * (i % n), "%02x ", array[i]);
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if (i % n == (n - 1)) {
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GST_LOG ("%03d: %s", i - (n - 1), line);
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}
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}
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if (i % n != 0) {
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GST_LOG ("%03d: %s", (i / n) * n, line);
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}
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g_free (line);
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}
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/**
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* gst_dp_init:
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*
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* Initialize GStreamer Data Protocol library.
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*
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* Should be called before using these functions; either from source linking
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* to this source file or from plugin_init.
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*/
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void
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gst_dp_init (void)
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{
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static gboolean _gst_dp_initialized = FALSE;
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if (_gst_dp_initialized)
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return;
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_gst_dp_initialized = TRUE;
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GST_DEBUG_CATEGORY_INIT (data_protocol_debug, "gdp", 0,
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"GStreamer Data Protocol");
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}
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/*** PUBLIC FUNCTIONS ***/
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/**
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* gst_dp_header_payload_length:
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* @header: the byte header of the packet array
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*
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* Returns: the length of the payload this header describes.
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*/
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guint32
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gst_dp_header_payload_length (const guint8 * header)
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{
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return GST_DP_HEADER_PAYLOAD_LENGTH (header);
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}
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/**
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* gst_dp_header_payload_type:
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* @header: the byte header of the packet array
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*
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* Returns: the #GstDPPayloadType the payload this header describes.
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*/
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GstDPPayloadType
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gst_dp_header_payload_type (const guint8 * header)
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{
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return GST_DP_HEADER_PAYLOAD_TYPE (header);
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}
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/**
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* gst_dp_header_from_buffer:
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* @buffer: a #GstBuffer to create a header for
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* @flags: the #GDPHeaderFlags to create the header with
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* @length: a guint pointer to store the header length in
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* @header: a guint8 * pointer to store a newly allocated header byte array in
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*
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* Creates a GDP header from the given buffer.
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*
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* Returns: %TRUE if the header was successfully created.
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*/
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gboolean
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gst_dp_header_from_buffer (const GstBuffer * buffer, GstDPHeaderFlag flags,
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guint * length, guint8 ** header)
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{
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guint8 *h;
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guint16 crc;
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guint16 flags_mask;
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g_return_val_if_fail (GST_IS_BUFFER (buffer), FALSE);
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g_return_val_if_fail (GST_BUFFER_REFCOUNT_VALUE (buffer) > 0, FALSE);
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g_return_val_if_fail (header, FALSE);
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*length = GST_DP_HEADER_LENGTH;
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h = g_malloc (GST_DP_HEADER_LENGTH);
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/* version, flags, type */
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h[0] = (guint8) GST_DP_VERSION_MAJOR;
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h[1] = (guint8) GST_DP_VERSION_MINOR;
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h[2] = (guint8) flags;
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h[3] = GST_DP_PAYLOAD_BUFFER;
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/* buffer properties */
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GST_WRITE_UINT32_BE (h + 4, GST_BUFFER_SIZE (buffer));
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GST_WRITE_UINT64_BE (h + 8, GST_BUFFER_TIMESTAMP (buffer));
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GST_WRITE_UINT64_BE (h + 16, GST_BUFFER_DURATION (buffer));
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GST_WRITE_UINT64_BE (h + 24, GST_BUFFER_OFFSET (buffer));
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GST_WRITE_UINT64_BE (h + 32, GST_BUFFER_OFFSET_END (buffer));
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/* data flags */
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/* we only copy KEY_UNIT,DELTA_UNIT and IN_CAPS flags */
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flags_mask = GST_DATA_FLAG_SHIFT (GST_BUFFER_KEY_UNIT) |
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GST_DATA_FLAG_SHIFT (GST_BUFFER_IN_CAPS) |
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GST_DATA_FLAG_SHIFT (GST_BUFFER_DELTA_UNIT);
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GST_WRITE_UINT16_BE (h + 40, GST_BUFFER_FLAGS (buffer) & flags_mask);
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/* ABI padding */
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GST_WRITE_UINT16_BE (h + 42, (guint64) 0);
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GST_WRITE_UINT32_BE (h + 44, (guint64) 0);
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GST_WRITE_UINT64_BE (h + 48, (guint64) 0);
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/* CRC */
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crc = 0;
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if (flags & GST_DP_HEADER_FLAG_CRC_HEADER) {
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/* we don't crc the last four bytes of the header since they are crc's */
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crc = gst_dp_crc (h, 56);
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}
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GST_WRITE_UINT16_BE (h + 56, crc);
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crc = 0;
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if (flags & GST_DP_HEADER_FLAG_CRC_PAYLOAD) {
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crc = gst_dp_crc (GST_BUFFER_DATA (buffer), GST_BUFFER_SIZE (buffer));
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}
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GST_WRITE_UINT16_BE (h + 58, crc);
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GST_LOG ("created header from buffer:");
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gst_dp_dump_byte_array (h, GST_DP_HEADER_LENGTH);
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*header = h;
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return TRUE;
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}
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/**
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* gst_dp_packet_from_caps:
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* @caps: a #GstCaps to create a packet for
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* @flags: the #GDPHeaderFlags to create the header with
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* @length: a guint pointer to store the header length in
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* @header: a guint8 pointer to store a newly allocated header byte array in
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* @payload: a guint8 pointer to store a newly allocated payload byte array in
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*
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* Creates a GDP packet from the given caps.
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*
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* Returns: %TRUE if the packet was successfully created.
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*/
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gboolean
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gst_dp_packet_from_caps (const GstCaps * caps, GstDPHeaderFlag flags,
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guint * length, guint8 ** header, guint8 ** payload)
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{
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guint8 *h;
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guint16 crc;
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gchar *string;
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/* FIXME: GST_IS_CAPS doesn't work
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g_return_val_if_fail (GST_IS_CAPS (caps), FALSE); */
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g_return_val_if_fail (caps, FALSE);
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g_return_val_if_fail (header, FALSE);
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g_return_val_if_fail (payload, FALSE);
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*length = GST_DP_HEADER_LENGTH;
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h = g_malloc (GST_DP_HEADER_LENGTH);
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string = gst_caps_to_string (caps);
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/* version, flags, type */
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h[0] = (guint8) GST_DP_VERSION_MAJOR;
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h[1] = (guint8) GST_DP_VERSION_MINOR;
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h[2] = (guint8) flags;
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h[3] = GST_DP_PAYLOAD_CAPS;
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/* buffer properties */
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GST_WRITE_UINT32_BE (h + 4, strlen (string) + 1); /* include trailing 0 */
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GST_WRITE_UINT64_BE (h + 8, (guint64) 0);
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GST_WRITE_UINT64_BE (h + 16, (guint64) 0);
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GST_WRITE_UINT64_BE (h + 24, (guint64) 0);
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GST_WRITE_UINT64_BE (h + 32, (guint64) 0);
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/* ABI padding */
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GST_WRITE_UINT64_BE (h + 40, (guint64) 0);
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GST_WRITE_UINT64_BE (h + 48, (guint64) 0);
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/* CRC */
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crc = 0;
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if (flags & GST_DP_HEADER_FLAG_CRC_HEADER) {
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crc = gst_dp_crc (h, 56);
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}
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GST_WRITE_UINT16_BE (h + 56, crc);
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crc = 0;
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if (flags & GST_DP_HEADER_FLAG_CRC_PAYLOAD) {
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crc = gst_dp_crc (string, strlen (string) + 1);
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}
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GST_WRITE_UINT16_BE (h + 58, crc);
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GST_LOG ("created header from caps:");
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gst_dp_dump_byte_array (h, GST_DP_HEADER_LENGTH);
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*header = h;
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*payload = string;
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return TRUE;
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}
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/**
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* gst_dp_packet_from_event:
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* @event: a #GstEvent to create a packet for
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* @flags: the #GDPHeaderFlags to create the header with
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* @length: a guint pointer to store the header length in
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* @header: a guint8 pointer to store a newly allocated header byte array in
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* @payload: a guint8 pointer to store a newly allocated payload byte array in
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*
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* Creates a GDP packet from the given event.
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*
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* Returns: %TRUE if the packet was successfully created.
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*/
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gboolean
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gst_dp_packet_from_event (const GstEvent * event, GstDPHeaderFlag flags,
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guint * length, guint8 ** header, guint8 ** payload)
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{
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guint8 *h;
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guint16 crc;
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guint pl_length; /* length of payload */
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g_return_val_if_fail (event, FALSE);
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g_return_val_if_fail (GST_IS_EVENT (event), FALSE);
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g_return_val_if_fail (header, FALSE);
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g_return_val_if_fail (payload, FALSE);
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*length = GST_DP_HEADER_LENGTH;
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h = g_malloc0 (GST_DP_HEADER_LENGTH);
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/* first construct payload, since we need the length */
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switch (GST_EVENT_TYPE (event)) {
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case GST_EVENT_UNKNOWN:
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g_warning ("Unknown event, ignoring");
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*length = 0;
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g_free (h);
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return FALSE;
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case GST_EVENT_EOS:
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case GST_EVENT_FLUSH:
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case GST_EVENT_EMPTY:
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case GST_EVENT_DISCONTINUOUS:
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GST_WRITE_UINT64_BE (h + 8, GST_EVENT_TIMESTAMP (event));
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pl_length = 0;
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*payload = NULL;
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break;
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case GST_EVENT_SEEK:
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pl_length = 4 + 8 + 4;
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*payload = g_malloc0 (pl_length);
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GST_WRITE_UINT32_BE (*payload, (guint32) GST_EVENT_SEEK_TYPE (event));
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GST_WRITE_UINT64_BE (*payload + 4,
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(guint64) GST_EVENT_SEEK_OFFSET (event));
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GST_WRITE_UINT32_BE (*payload + 12,
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(guint32) GST_EVENT_SEEK_ACCURACY (event));
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break;
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case GST_EVENT_SEEK_SEGMENT:
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pl_length = 4 + 8 + 8 + 4;
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*payload = g_malloc0 (pl_length);
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GST_WRITE_UINT32_BE (*payload, (guint32) GST_EVENT_SEEK_TYPE (event));
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GST_WRITE_UINT64_BE (*payload + 4,
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(guint64) GST_EVENT_SEEK_OFFSET (event));
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GST_WRITE_UINT64_BE (*payload + 12,
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(guint64) GST_EVENT_SEEK_ENDOFFSET (event));
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GST_WRITE_UINT32_BE (*payload + 20,
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(guint32) GST_EVENT_SEEK_ACCURACY (event));
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break;
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case GST_EVENT_QOS:
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case GST_EVENT_SEGMENT_DONE:
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case GST_EVENT_SIZE:
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case GST_EVENT_RATE:
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case GST_EVENT_FILLER:
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case GST_EVENT_TS_OFFSET:
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case GST_EVENT_INTERRUPT:
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case GST_EVENT_NAVIGATION:
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case GST_EVENT_TAG:
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g_warning ("Unhandled event type %d, ignoring", GST_EVENT_TYPE (event));
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return FALSE;
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default:
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g_warning ("Unknown event type %d, ignoring", GST_EVENT_TYPE (event));
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*length = 0;
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g_free (h);
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return FALSE;
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}
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/* version, flags, type */
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h[0] = (guint8) GST_DP_VERSION_MAJOR;
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h[1] = (guint8) GST_DP_VERSION_MINOR;
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h[2] = (guint8) flags;
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h[3] = GST_DP_PAYLOAD_EVENT_NONE + GST_EVENT_TYPE (event);
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/* length */
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GST_WRITE_UINT32_BE (h + 4, (guint32) pl_length);
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/* timestamp */
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GST_WRITE_UINT64_BE (h + 8, GST_EVENT_TIMESTAMP (event));
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/* ABI padding */
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GST_WRITE_UINT64_BE (h + 40, (guint64) 0);
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GST_WRITE_UINT64_BE (h + 48, (guint64) 0);
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/* CRC */
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crc = 0;
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if (flags & GST_DP_HEADER_FLAG_CRC_HEADER) {
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crc = gst_dp_crc (h, 56);
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}
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GST_WRITE_UINT16_BE (h + 56, crc);
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crc = 0;
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/* events can have a NULL payload */
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if (*payload && flags & GST_DP_HEADER_FLAG_CRC_PAYLOAD) {
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crc = gst_dp_crc (*payload, strlen (*payload) + 1);
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}
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GST_WRITE_UINT16_BE (h + 58, crc);
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GST_LOG ("created header from event:");
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gst_dp_dump_byte_array (h, GST_DP_HEADER_LENGTH);
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*header = h;
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return TRUE;
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}
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/**
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* gst_dp_buffer_from_header:
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* @header_length: the length of the packet header
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* @header: the byte array of the packet header
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*
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* Creates a newly allocated #GstBuffer from the given header.
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* The buffer data needs to be copied into it before validating.
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*
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* Use this function if you want to pre-allocate a buffer based on the
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* packet header to read the packet payload in to.
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*
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* Returns: %TRUE if the buffer was successfully created.
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*/
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GstBuffer *
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gst_dp_buffer_from_header (guint header_length, const guint8 * header)
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{
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GstBuffer *buffer;
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g_return_val_if_fail (GST_DP_HEADER_PAYLOAD_TYPE (header) ==
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GST_DP_PAYLOAD_BUFFER, FALSE);
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buffer =
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gst_buffer_new_and_alloc ((guint) GST_DP_HEADER_PAYLOAD_LENGTH (header));
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GST_BUFFER_TIMESTAMP (buffer) = GST_DP_HEADER_TIMESTAMP (header);
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GST_BUFFER_DURATION (buffer) = GST_DP_HEADER_DURATION (header);
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GST_BUFFER_OFFSET (buffer) = GST_DP_HEADER_OFFSET (header);
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GST_BUFFER_OFFSET_END (buffer) = GST_DP_HEADER_OFFSET_END (header);
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GST_BUFFER_FLAGS (buffer) = GST_DP_HEADER_BUFFER_FLAGS (header);
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return buffer;
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}
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/**
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* gst_dp_caps_from_packet:
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* @header_length: the length of the packet header
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* @header: the byte array of the packet header
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* @payload: the byte array of the packet payload
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*
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* Creates a newly allocated #GstCaps from the given packet.
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*
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* Returns: %TRUE if the caps was successfully created.
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*/
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GstCaps *
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gst_dp_caps_from_packet (guint header_length, const guint8 * header,
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const guint8 * payload)
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{
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GstCaps *caps;
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const gchar *string;
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g_return_val_if_fail (header, FALSE);
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g_return_val_if_fail (payload, FALSE);
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g_return_val_if_fail (GST_DP_HEADER_PAYLOAD_TYPE (header) ==
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GST_DP_PAYLOAD_CAPS, FALSE);
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string = payload;
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caps = gst_caps_from_string (string);
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return caps;
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}
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/**
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* gst_dp_event_from_packet:
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* @header_length: the length of the packet header
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* @header: the byte array of the packet header
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* @payload: the byte array of the packet payload
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*
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* Creates a newly allocated #GstEvent from the given packet.
|
|
*
|
|
* Returns: %TRUE if the event was successfully created.
|
|
*/
|
|
GstEvent *
|
|
gst_dp_event_from_packet (guint header_length, const guint8 * header,
|
|
const guint8 * payload)
|
|
{
|
|
GstEvent *event = NULL;
|
|
GstEventType type;
|
|
|
|
g_return_val_if_fail (header, FALSE);
|
|
/* payload can be NULL, e.g. for an EOS event */
|
|
|
|
type = GST_DP_HEADER_PAYLOAD_TYPE (header) - GST_DP_PAYLOAD_EVENT_NONE;
|
|
switch (type) {
|
|
case GST_EVENT_UNKNOWN:
|
|
g_warning ("Unknown event, ignoring");
|
|
return FALSE;
|
|
case GST_EVENT_EOS:
|
|
case GST_EVENT_FLUSH:
|
|
case GST_EVENT_EMPTY:
|
|
case GST_EVENT_DISCONTINUOUS:
|
|
event = gst_event_new (type);
|
|
GST_EVENT_TIMESTAMP (event) = GST_DP_HEADER_TIMESTAMP (header);
|
|
break;
|
|
case GST_EVENT_SEEK:
|
|
{
|
|
GstSeekType type;
|
|
gint64 offset;
|
|
GstSeekAccuracy accuracy;
|
|
|
|
type = (GstSeekType) GST_READ_UINT32_BE (payload);
|
|
offset = (gint64) GST_READ_UINT64_BE (payload + 4);
|
|
accuracy = (GstSeekAccuracy) GST_READ_UINT32_BE (payload + 12);
|
|
event = gst_event_new_seek (type, offset);
|
|
GST_EVENT_TIMESTAMP (event) = GST_DP_HEADER_TIMESTAMP (header);
|
|
GST_EVENT_SEEK_ACCURACY (event) = accuracy;
|
|
break;
|
|
}
|
|
case GST_EVENT_SEEK_SEGMENT:
|
|
{
|
|
GstSeekType type;
|
|
gint64 offset, endoffset;
|
|
GstSeekAccuracy accuracy;
|
|
|
|
type = (GstSeekType) GST_READ_UINT32_BE (payload);
|
|
offset = (gint64) GST_READ_UINT64_BE (payload + 4);
|
|
endoffset = (gint64) GST_READ_UINT64_BE (payload + 12);
|
|
accuracy = (GstSeekAccuracy) GST_READ_UINT32_BE (payload + 20);
|
|
event = gst_event_new_segment_seek (type, offset, endoffset);
|
|
GST_EVENT_TIMESTAMP (event) = GST_DP_HEADER_TIMESTAMP (header);
|
|
GST_EVENT_SEEK_ACCURACY (event) = accuracy;
|
|
break;
|
|
}
|
|
case GST_EVENT_QOS:
|
|
case GST_EVENT_SEGMENT_DONE:
|
|
case GST_EVENT_SIZE:
|
|
case GST_EVENT_RATE:
|
|
case GST_EVENT_FILLER:
|
|
case GST_EVENT_TS_OFFSET:
|
|
case GST_EVENT_INTERRUPT:
|
|
case GST_EVENT_NAVIGATION:
|
|
case GST_EVENT_TAG:
|
|
g_warning ("Unhandled event type %d, ignoring", GST_EVENT_TYPE (event));
|
|
return FALSE;
|
|
default:
|
|
g_warning ("Unknown event type %d, ignoring", GST_EVENT_TYPE (event));
|
|
return FALSE;
|
|
}
|
|
|
|
return event;
|
|
}
|
|
|
|
/**
|
|
* gst_dp_validate_header:
|
|
* @header_length: the length of the packet header
|
|
* @header: the byte array of the packet header
|
|
*
|
|
* Validates the given packet header by checking the CRC checksum.
|
|
*
|
|
* Returns: %TRUE if the CRC matches, or no CRC checksum is present.
|
|
*/
|
|
gboolean
|
|
gst_dp_validate_header (guint header_length, const guint8 * header)
|
|
{
|
|
guint16 crc_read, crc_calculated;
|
|
|
|
if (!(GST_DP_HEADER_FLAGS (header) & GST_DP_HEADER_FLAG_CRC_HEADER))
|
|
return TRUE;
|
|
crc_read = GST_DP_HEADER_CRC_HEADER (header);
|
|
/* don't included the last two crc fields for the crc check */
|
|
crc_calculated = gst_dp_crc (header, header_length - 4);
|
|
if (crc_read != crc_calculated) {
|
|
GST_WARNING ("header crc mismatch: read %02x, calculated %02x", crc_read,
|
|
crc_calculated);
|
|
return FALSE;
|
|
}
|
|
GST_LOG ("header crc validation: %02x", crc_read);
|
|
return TRUE;
|
|
}
|
|
|
|
/**
|
|
* gst_dp_validate_payload:
|
|
* @header_length: the length of the packet header
|
|
* @header: the byte array of the packet header
|
|
* @payload: the byte array of the packet payload
|
|
*
|
|
* Validates the given packet payload using the given packet header
|
|
* by checking the CRC checksum.
|
|
*
|
|
* Returns: %TRUE if the CRC matches, or no CRC checksum is present.
|
|
*/
|
|
gboolean
|
|
gst_dp_validate_payload (guint header_length, const guint8 * header,
|
|
const guint8 * payload)
|
|
{
|
|
guint16 crc_read, crc_calculated;
|
|
|
|
if (!(GST_DP_HEADER_FLAGS (header) & GST_DP_HEADER_FLAG_CRC_PAYLOAD))
|
|
return TRUE;
|
|
crc_read = GST_DP_HEADER_CRC_PAYLOAD (header);
|
|
crc_calculated = gst_dp_crc (payload, GST_DP_HEADER_PAYLOAD_LENGTH (header));
|
|
if (crc_read != crc_calculated) {
|
|
GST_WARNING ("payload crc mismatch: read %02x, calculated %02x", crc_read,
|
|
crc_calculated);
|
|
return FALSE;
|
|
}
|
|
GST_LOG ("payload crc validation: %02x", crc_read);
|
|
return TRUE;
|
|
}
|
|
|
|
/**
|
|
* gst_dp_validate_packet:
|
|
* @header_length: the length of the packet header
|
|
* @header: the byte array of the packet header
|
|
* @payload: the byte array of the packet payload
|
|
*
|
|
* Validates the given packet by checking version information and checksums.
|
|
*
|
|
* Returns: %TRUE if the packet validates.
|
|
*/
|
|
gboolean
|
|
gst_dp_validate_packet (guint header_length, const guint8 * header,
|
|
const guint8 * payload)
|
|
{
|
|
if (!gst_dp_validate_header (header_length, header))
|
|
return FALSE;
|
|
if (!gst_dp_validate_payload (header_length, header, payload))
|
|
return FALSE;
|
|
|
|
return TRUE;
|
|
}
|
|
|
|
/*** PLUGIN STUFF ***/
|
|
static gboolean
|
|
plugin_init (GstPlugin * plugin)
|
|
{
|
|
gst_dp_init ();
|
|
|
|
return TRUE;
|
|
}
|
|
|
|
GST_PLUGIN_DEFINE (GST_VERSION_MAJOR,
|
|
GST_VERSION_MINOR,
|
|
"gstdataprotocol",
|
|
"a data protocol to serialize buffers, caps and events",
|
|
plugin_init, VERSION, GST_LICENSE, GST_PACKAGE, GST_ORIGIN)
|