diff options
Diffstat (limited to 'libs/gst/dataprotocol/dataprotocol.c')
| -rw-r--r-- | libs/gst/dataprotocol/dataprotocol.c | 768 |
1 files changed, 0 insertions, 768 deletions
diff --git a/libs/gst/dataprotocol/dataprotocol.c b/libs/gst/dataprotocol/dataprotocol.c deleted file mode 100644 index 3b2e18220..000000000 --- a/libs/gst/dataprotocol/dataprotocol.c +++ /dev/null @@ -1,768 +0,0 @@ -/* GStreamer - * Copyright (C) <1999> Erik Walthinsen <omega@cse.ogi.edu> - * Copyright (C) 2004,2006 Thomas Vander Stichele <thomas at apestaart dot org> - * - * dataprotocol.c: Functions implementing the GStreamer Data Protocol - * - * This library is free software; you can redistribute it and/or - * modify it under the terms of the GNU Library General Public - * License as published by the Free Software Foundation; either - * version 2 of the License, or (at your option) any later version. - * - * This library is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - * Library General Public License for more details. - * - * You should have received a copy of the GNU Library General Public - * License along with this library; if not, write to the - * Free Software Foundation, Inc., 59 Temple Place - Suite 330, - * Boston, MA 02111-1307, USA. - */ - -/** - * SECTION:gstdataprotocol - * @short_description: Serialization of caps, buffers and events. - * @see_also: #GstCaps, #GstEvent, #GstBuffer - * - * This helper library provides serialization of GstBuffer, GstCaps and - * GstEvent structures. - * - * This serialization is useful when GStreamer needs to interface with - * the outside world to transport data between distinct GStreamer pipelines. - * The connections with the outside world generally don't have mechanisms - * to transport properties of these structures. - * - * For example, transporting buffers across named pipes or network connections - * doesn't maintain the buffer size and separation. - * - * This data protocol assumes a reliable connection-oriented transport, such as - * TCP, a pipe, or a file. The protocol does not serialize the caps for - * each buffer; instead, it transport the caps only when they change in the - * stream. This implies that there will always be a caps packet before any - * buffer packets. - * - * The versioning of the protocol is independent of GStreamer's version. - * The major number gets incremented, and the minor reset, for incompatible - * changes. The minor number gets incremented for compatible changes that - * allow clients who do not completely understand the newer protocol version - * to still decode what they do understand. - * - * Version 0.2 serializes only a small subset of all events, with a custom - * payload for each type. Also, all GDP streams start with the initial caps - * packet. - * - * Version 1.0 serializes all events by taking the string representation of - * the event as the payload. In addition, GDP streams can now start with - * events as well, as required by the new data stream model in GStreamer 0.10. - * - * Converting buffers, caps and events to GDP buffers is done using a - * #GstDPPacketizer object and invoking its packetizer functions. - * For backwards-compatibility reasons, the old 0.2 methods are still - * available but deprecated. - * - * For reference, this image shows the byte layout of the GDP header: - * - * <inlinegraphic format="PNG" fileref="gdp-header.png"></inlinegraphic> - */ - -#ifdef HAVE_CONFIG_H -#include "config.h" -#endif - -#include <gst/gst.h> -#include <gst/dataprotocol/dataprotocol.h> -#include <glib/gprintf.h> /* g_sprintf */ -#include <string.h> /* strlen */ -#include "dp-private.h" - -/* debug category */ -GST_DEBUG_CATEGORY_STATIC (data_protocol_debug); -#define GST_CAT_DEFAULT data_protocol_debug - -/* helper macros */ - -/* write first 6 bytes of header */ -#define GST_DP_INIT_HEADER(h, version, flags, type) \ -G_STMT_START { \ - gint maj = 0, min = 0; \ - switch (version) { \ - case GST_DP_VERSION_0_2: maj = 0; min = 2; break; \ - case GST_DP_VERSION_1_0: maj = 1; min = 0; break; \ - } \ - h[0] = (guint8) maj; \ - h[1] = (guint8) min; \ - h[2] = (guint8) flags; \ - h[3] = 0; /* padding byte */ \ - GST_WRITE_UINT16_BE (h + 4, type); \ -} 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 */ -/* - * this code snippet is adapted from a web page I found - * it is identical except for cleanups, and a final XOR with 0xffff - * as outlined in the uecp spec - * - * XMODEM x^16 + x^12 + x^5 + 1 - */ - -#define POLY 0x1021 -#define CRC_INIT 0xFFFF - -/*** HELPER FUNCTIONS ***/ - -static gboolean -gst_dp_header_from_buffer_any (const GstBuffer * buffer, GstDPHeaderFlag flags, - guint * length, guint8 ** header, GstDPVersion version) -{ - guint8 *h; - guint16 flags_mask; - guint8 *data; - gsize size; - - g_return_val_if_fail (GST_IS_BUFFER (buffer), FALSE); - g_return_val_if_fail (length, FALSE); - g_return_val_if_fail (header, FALSE); - - *length = GST_DP_HEADER_LENGTH; - h = g_malloc0 (GST_DP_HEADER_LENGTH); - - /* version, flags, type */ - GST_DP_INIT_HEADER (h, version, flags, GST_DP_PAYLOAD_BUFFER); - - data = gst_buffer_map ((GstBuffer *) buffer, &size, NULL, GST_MAP_READ); - - /* buffer properties */ - GST_WRITE_UINT32_BE (h + 6, size); - GST_WRITE_UINT64_BE (h + 10, GST_BUFFER_TIMESTAMP (buffer)); - GST_WRITE_UINT64_BE (h + 18, GST_BUFFER_DURATION (buffer)); - GST_WRITE_UINT64_BE (h + 26, GST_BUFFER_OFFSET (buffer)); - GST_WRITE_UINT64_BE (h + 34, GST_BUFFER_OFFSET_END (buffer)); - - /* data flags; eats two bytes from the ABI area */ - /* we copy everything but the read-only flags */ - flags_mask = GST_BUFFER_FLAG_LIVE | GST_BUFFER_FLAG_DISCONT | - GST_BUFFER_FLAG_IN_CAPS | GST_BUFFER_FLAG_GAP | - GST_BUFFER_FLAG_DELTA_UNIT; - - GST_WRITE_UINT16_BE (h + 42, GST_BUFFER_FLAGS (buffer) & flags_mask); - - GST_DP_SET_CRC (h, flags, data, size); - - gst_buffer_unmap ((GstBuffer *) buffer, data, size); - - GST_LOG ("created header from buffer:"); - gst_dp_dump_byte_array (h, GST_DP_HEADER_LENGTH); - *header = h; - return TRUE; -} - -static gboolean -gst_dp_packet_from_caps_any (const GstCaps * caps, GstDPHeaderFlag flags, - guint * length, guint8 ** header, guint8 ** payload, GstDPVersion version) -{ - guint8 *h; - guchar *string; - guint payload_length; - - g_return_val_if_fail (GST_IS_CAPS (caps), FALSE); - g_return_val_if_fail (length, FALSE); - g_return_val_if_fail (header, FALSE); - g_return_val_if_fail (payload, FALSE); - - *length = GST_DP_HEADER_LENGTH; - h = g_malloc0 (GST_DP_HEADER_LENGTH); - - string = (guchar *) gst_caps_to_string (caps); - payload_length = strlen ((gchar *) string) + 1; /* include trailing 0 */ - - /* version, flags, type */ - GST_DP_INIT_HEADER (h, version, flags, GST_DP_PAYLOAD_CAPS); - - /* buffer properties */ - GST_WRITE_UINT32_BE (h + 6, payload_length); - GST_WRITE_UINT64_BE (h + 10, (guint64) 0); - GST_WRITE_UINT64_BE (h + 18, (guint64) 0); - GST_WRITE_UINT64_BE (h + 26, (guint64) 0); - GST_WRITE_UINT64_BE (h + 34, (guint64) 0); - - GST_DP_SET_CRC (h, flags, string, payload_length); - - GST_LOG ("created header from caps:"); - gst_dp_dump_byte_array (h, GST_DP_HEADER_LENGTH); - *header = h; - *payload = string; - return TRUE; -} - - -/*** PUBLIC FUNCTIONS ***/ - -static const guint16 gst_dp_crc_table[256] = { - 0x0000, 0x1021, 0x2042, 0x3063, 0x4084, 0x50a5, 0x60c6, 0x70e7, - 0x8108, 0x9129, 0xa14a, 0xb16b, 0xc18c, 0xd1ad, 0xe1ce, 0xf1ef, - 0x1231, 0x0210, 0x3273, 0x2252, 0x52b5, 0x4294, 0x72f7, 0x62d6, - 0x9339, 0x8318, 0xb37b, 0xa35a, 0xd3bd, 0xc39c, 0xf3ff, 0xe3de, - 0x2462, 0x3443, 0x0420, 0x1401, 0x64e6, 0x74c7, 0x44a4, 0x5485, - 0xa56a, 0xb54b, 0x8528, 0x9509, 0xe5ee, 0xf5cf, 0xc5ac, 0xd58d, - 0x3653, 0x2672, 0x1611, 0x0630, 0x76d7, 0x66f6, 0x5695, 0x46b4, - 0xb75b, 0xa77a, 0x9719, 0x8738, 0xf7df, 0xe7fe, 0xd79d, 0xc7bc, - 0x48c4, 0x58e5, 0x6886, 0x78a7, 0x0840, 0x1861, 0x2802, 0x3823, - 0xc9cc, 0xd9ed, 0xe98e, 0xf9af, 0x8948, 0x9969, 0xa90a, 0xb92b, - 0x5af5, 0x4ad4, 0x7ab7, 0x6a96, 0x1a71, 0x0a50, 0x3a33, 0x2a12, - 0xdbfd, 0xcbdc, 0xfbbf, 0xeb9e, 0x9b79, 0x8b58, 0xbb3b, 0xab1a, - 0x6ca6, 0x7c87, 0x4ce4, 0x5cc5, 0x2c22, 0x3c03, 0x0c60, 0x1c41, - 0xedae, 0xfd8f, 0xcdec, 0xddcd, 0xad2a, 0xbd0b, 0x8d68, 0x9d49, - 0x7e97, 0x6eb6, 0x5ed5, 0x4ef4, 0x3e13, 0x2e32, 0x1e51, 0x0e70, - 0xff9f, 0xefbe, 0xdfdd, 0xcffc, 0xbf1b, 0xaf3a, 0x9f59, 0x8f78, - 0x9188, 0x81a9, 0xb1ca, 0xa1eb, 0xd10c, 0xc12d, 0xf14e, 0xe16f, - 0x1080, 0x00a1, 0x30c2, 0x20e3, 0x5004, 0x4025, 0x7046, 0x6067, - 0x83b9, 0x9398, 0xa3fb, 0xb3da, 0xc33d, 0xd31c, 0xe37f, 0xf35e, - 0x02b1, 0x1290, 0x22f3, 0x32d2, 0x4235, 0x5214, 0x6277, 0x7256, - 0xb5ea, 0xa5cb, 0x95a8, 0x8589, 0xf56e, 0xe54f, 0xd52c, 0xc50d, - 0x34e2, 0x24c3, 0x14a0, 0x0481, 0x7466, 0x6447, 0x5424, 0x4405, - 0xa7db, 0xb7fa, 0x8799, 0x97b8, 0xe75f, 0xf77e, 0xc71d, 0xd73c, - 0x26d3, 0x36f2, 0x0691, 0x16b0, 0x6657, 0x7676, 0x4615, 0x5634, - 0xd94c, 0xc96d, 0xf90e, 0xe92f, 0x99c8, 0x89e9, 0xb98a, 0xa9ab, - 0x5844, 0x4865, 0x7806, 0x6827, 0x18c0, 0x08e1, 0x3882, 0x28a3, - 0xcb7d, 0xdb5c, 0xeb3f, 0xfb1e, 0x8bf9, 0x9bd8, 0xabbb, 0xbb9a, - 0x4a75, 0x5a54, 0x6a37, 0x7a16, 0x0af1, 0x1ad0, 0x2ab3, 0x3a92, - 0xfd2e, 0xed0f, 0xdd6c, 0xcd4d, 0xbdaa, 0xad8b, 0x9de8, 0x8dc9, - 0x7c26, 0x6c07, 0x5c64, 0x4c45, 0x3ca2, 0x2c83, 0x1ce0, 0x0cc1, - 0xef1f, 0xff3e, 0xcf5d, 0xdf7c, 0xaf9b, 0xbfba, 0x8fd9, 0x9ff8, - 0x6e17, 0x7e36, 0x4e55, 0x5e74, 0x2e93, 0x3eb2, 0x0ed1, 0x1ef0 -}; - -/** - * gst_dp_crc: - * @buffer: array of bytes - * @length: the length of @buffer - * - * Calculate a CRC for the given buffer over the given number of bytes. - * This is only provided for verification purposes; typical GDP users - * will not need this function. - * - * Returns: a two-byte CRC checksum. - */ -guint16 -gst_dp_crc (const guint8 * buffer, guint length) -{ - guint16 crc_register = CRC_INIT; - - g_return_val_if_fail (buffer != NULL || length == 0, 0); - - /* calc CRC */ - for (; length--;) { - crc_register = (guint16) ((crc_register << 8) ^ - gst_dp_crc_table[((crc_register >> 8) & 0x00ff) ^ *buffer++]); - } - return (0xffff ^ crc_register); -} - -/* debugging function; dumps byte array values per 8 bytes */ -/* FIXME: would be nice to merge this with gst_util_dump_mem () */ -void -gst_dp_dump_byte_array (guint8 * array, guint length) -{ - int i; - int n = 8; /* number of bytes per line */ - gchar *line = g_malloc0 (3 * n + 1); - - GST_LOG ("dumping byte array of length %d", length); - for (i = 0; i < length; ++i) { - g_sprintf (line + 3 * (i % n), "%02x ", array[i]); - if (i % n == (n - 1)) { - GST_LOG ("%03d: %s", i - (n - 1), line); - } - } - if (i % n != 0) { - GST_LOG ("%03d: %s", (i / n) * n, line); - } - g_free (line); -} - -GType -gst_dp_version_get_type (void) -{ - static gsize gst_dp_version_type = 0; - static const GEnumValue gst_dp_version[] = { - {GST_DP_VERSION_0_2, "GST_DP_VERSION_0_2", "0.2"}, - {GST_DP_VERSION_1_0, "GST_DP_VERSION_1_0", "1.0"}, - {0, NULL, NULL}, - }; - - if (g_once_init_enter (&gst_dp_version_type)) { - GType tmp = g_enum_register_static ("GstDPVersion", gst_dp_version); - g_once_init_leave (&gst_dp_version_type, tmp); - } - - return (GType) gst_dp_version_type; -}; - -/** - * gst_dp_init: - * - * Initialize GStreamer Data Protocol library. - * - * Should be called before using these functions from source linking - * to this source file. - */ -void -gst_dp_init (void) -{ - static gboolean _gst_dp_initialized = FALSE; - - if (_gst_dp_initialized) - return; - - _gst_dp_initialized = TRUE; - - g_type_class_ref (gst_dp_version_get_type ()); - - GST_DEBUG_CATEGORY_INIT (data_protocol_debug, "gdp", 0, - "GStreamer Data Protocol"); -} - -/** - * gst_dp_header_payload_length: - * @header: the byte header of the packet array - * - * Get the length of the payload described by @header. - * - * Returns: the length of the payload this header describes. - */ -guint32 -gst_dp_header_payload_length (const guint8 * header) -{ - g_return_val_if_fail (header != NULL, 0); - - return GST_DP_HEADER_PAYLOAD_LENGTH (header); -} - -/** - * gst_dp_header_payload_type: - * @header: the byte header of the packet array - * - * Get the type of the payload described by @header. - * - * Returns: the #GstDPPayloadType the payload this header describes. - */ -GstDPPayloadType -gst_dp_header_payload_type (const guint8 * header) -{ - g_return_val_if_fail (header != NULL, GST_DP_PAYLOAD_NONE); - - return GST_DP_HEADER_PAYLOAD_TYPE (header); -} - -/*** PACKETIZER FUNCTIONS ***/ - -static gboolean -gst_dp_header_from_buffer_1_0 (const GstBuffer * buffer, GstDPHeaderFlag flags, - guint * length, guint8 ** header) -{ - return gst_dp_header_from_buffer_any (buffer, flags, length, header, - GST_DP_VERSION_1_0); -} - -static gboolean -gst_dp_packet_from_caps_1_0 (const GstCaps * caps, GstDPHeaderFlag flags, - guint * length, guint8 ** header, guint8 ** payload) -{ - return gst_dp_packet_from_caps_any (caps, flags, length, header, payload, - GST_DP_VERSION_1_0); -} - -static gboolean -gst_dp_packet_from_event_1_0 (const GstEvent * event, GstDPHeaderFlag flags, - guint * length, guint8 ** header, guint8 ** payload) -{ - guint8 *h; - guint32 pl_length; /* length of payload */ - guchar *string = NULL; - const GstStructure *structure; - - g_return_val_if_fail (GST_IS_EVENT (event), FALSE); - g_return_val_if_fail (length, FALSE); - g_return_val_if_fail (header, FALSE); - g_return_val_if_fail (payload, FALSE); - - *length = GST_DP_HEADER_LENGTH; - h = g_malloc0 (GST_DP_HEADER_LENGTH); - - structure = gst_event_get_structure ((GstEvent *) event); - if (structure) { - string = (guchar *) gst_structure_to_string (structure); - GST_LOG ("event %p has structure, string %s", event, string); - pl_length = strlen ((gchar *) string) + 1; /* include trailing 0 */ - } else { - GST_LOG ("event %p has no structure", event); - pl_length = 0; - } - - /* version, flags, type */ - GST_DP_INIT_HEADER (h, GST_DP_VERSION_1_0, flags, - GST_DP_PAYLOAD_EVENT_NONE + GST_EVENT_TYPE (event)); - - /* length */ - GST_WRITE_UINT32_BE (h + 6, pl_length); - /* timestamp */ - GST_WRITE_UINT64_BE (h + 10, GST_EVENT_TIMESTAMP (event)); - - GST_DP_SET_CRC (h, flags, string, pl_length); - - GST_LOG ("created header from event:"); - gst_dp_dump_byte_array (h, GST_DP_HEADER_LENGTH); - *header = h; - *payload = string; - return TRUE; -} - -/*** DEPACKETIZING FUNCTIONS ***/ - -/** - * gst_dp_buffer_from_header: - * @header_length: the length of the packet header - * @header: the byte array of the packet header - * - * Creates a newly allocated #GstBuffer from the given header. - * The buffer data needs to be copied into it before validating. - * - * Use this function if you want to pre-allocate a buffer based on the - * packet header to read the packet payload in to. - * - * This function does not check the header passed to it, use - * gst_dp_validate_header() first if the header data is unchecked. - * - * Returns: A #GstBuffer if the buffer was successfully created, or NULL. - */ -GstBuffer * -gst_dp_buffer_from_header (guint header_length, const guint8 * header) -{ - GstBuffer *buffer; - - g_return_val_if_fail (header != NULL, NULL); - g_return_val_if_fail (header_length >= GST_DP_HEADER_LENGTH, NULL); - g_return_val_if_fail (GST_DP_HEADER_PAYLOAD_TYPE (header) == - GST_DP_PAYLOAD_BUFFER, NULL); - - buffer = - gst_buffer_new_allocate (NULL, - (guint) GST_DP_HEADER_PAYLOAD_LENGTH (header), 0); - - GST_BUFFER_TIMESTAMP (buffer) = GST_DP_HEADER_TIMESTAMP (header); - GST_BUFFER_DURATION (buffer) = GST_DP_HEADER_DURATION (header); - GST_BUFFER_OFFSET (buffer) = GST_DP_HEADER_OFFSET (header); - GST_BUFFER_OFFSET_END (buffer) = GST_DP_HEADER_OFFSET_END (header); - GST_BUFFER_FLAGS (buffer) = GST_DP_HEADER_BUFFER_FLAGS (header); - - return buffer; -} - -/** - * gst_dp_caps_from_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 - * - * Creates a newly allocated #GstCaps from the given packet. - * - * This function does not check the arguments passed to it, use - * gst_dp_validate_packet() first if the header and payload data are - * unchecked. - * - * Returns: A #GstCaps containing the caps represented in the packet, - * or NULL if the packet could not be converted. - */ -GstCaps * -gst_dp_caps_from_packet (guint header_length, const guint8 * header, - const guint8 * payload) -{ - GstCaps *caps; - gchar *string; - - g_return_val_if_fail (header, NULL); - g_return_val_if_fail (header_length >= GST_DP_HEADER_LENGTH, NULL); - g_return_val_if_fail (GST_DP_HEADER_PAYLOAD_TYPE (header) == - GST_DP_PAYLOAD_CAPS, NULL); - g_return_val_if_fail (payload, NULL); - - /* 0 sized payload length will work create NULL string */ - string = g_strndup ((gchar *) payload, GST_DP_HEADER_PAYLOAD_LENGTH (header)); - caps = gst_caps_from_string (string); - g_free (string); - - return caps; -} - -static GstEvent * -gst_dp_event_from_packet_0_2 (guint header_length, const guint8 * header, - const guint8 * payload) -{ - GstEvent *event = NULL; - GstEventType type; - - type = GST_DP_HEADER_PAYLOAD_TYPE (header) - GST_DP_PAYLOAD_EVENT_NONE; - switch (type) { - case GST_EVENT_UNKNOWN: - GST_WARNING ("Unknown event, ignoring"); - return NULL; - case GST_EVENT_EOS: - case GST_EVENT_FLUSH_START: - case GST_EVENT_FLUSH_STOP: - case GST_EVENT_SEGMENT: - event = gst_event_new_custom (type, NULL); - GST_EVENT_TIMESTAMP (event) = GST_DP_HEADER_TIMESTAMP (header); - break; - case GST_EVENT_SEEK: - { - gdouble rate; - GstFormat format; - GstSeekFlags flags; - GstSeekType cur_type, stop_type; - gint64 cur, stop; - - g_return_val_if_fail (payload != NULL, NULL); - - /* FIXME, read rate */ - rate = 1.0; - format = (GstFormat) GST_READ_UINT32_BE (payload); - flags = (GstSeekFlags) GST_READ_UINT32_BE (payload + 4); - cur_type = (GstSeekType) GST_READ_UINT32_BE (payload + 8); - cur = (gint64) GST_READ_UINT64_BE (payload + 12); - stop_type = (GstSeekType) GST_READ_UINT32_BE (payload + 20); - stop = (gint64) GST_READ_UINT64_BE (payload + 24); - - event = gst_event_new_seek (rate, format, flags, cur_type, cur, - stop_type, stop); - GST_EVENT_TIMESTAMP (event) = GST_DP_HEADER_TIMESTAMP (header); - break; - } - case GST_EVENT_QOS: - case GST_EVENT_NAVIGATION: - case GST_EVENT_TAG: - GST_WARNING ("Unhandled event type %d, ignoring", type); - return NULL; - default: - GST_WARNING ("Unknown event type %d, ignoring", type); - return NULL; - } - - return event; -} - -static GstEvent * -gst_dp_event_from_packet_1_0 (guint header_length, const guint8 * header, - const guint8 * payload) -{ - GstEvent *event = NULL; - GstEventType type; - gchar *string = NULL; - GstStructure *s = NULL; - - type = GST_DP_HEADER_PAYLOAD_TYPE (header) - GST_DP_PAYLOAD_EVENT_NONE; - if (payload) { - string = - g_strndup ((gchar *) payload, GST_DP_HEADER_PAYLOAD_LENGTH (header)); - s = gst_structure_from_string (string, NULL); - g_free (string); - } - event = gst_event_new_custom (type, s); - return event; -} - - -/** - * gst_dp_event_from_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 - * - * Creates a newly allocated #GstEvent from the given packet. - * - * This function does not check the arguments passed to it, use - * gst_dp_validate_packet() first if the header and payload data are - * unchecked. - * - * Returns: A #GstEvent if the event was successfully created, - * or NULL if an event could not be read from the payload. - */ -GstEvent * -gst_dp_event_from_packet (guint header_length, const guint8 * header, - const guint8 * payload) -{ - guint8 major, minor; - - g_return_val_if_fail (header, NULL); - g_return_val_if_fail (header_length >= GST_DP_HEADER_LENGTH, NULL); - - major = GST_DP_HEADER_MAJOR_VERSION (header); - minor = GST_DP_HEADER_MINOR_VERSION (header); - - if (major == 0 && minor == 2) - return gst_dp_event_from_packet_0_2 (header_length, header, payload); - else if (major == 1 && minor == 0) - return gst_dp_event_from_packet_1_0 (header_length, header, payload); - else { - GST_ERROR ("Unknown GDP version %d.%d", major, minor); - return NULL; - } -} - -/** - * 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; - - g_return_val_if_fail (header != NULL, FALSE); - g_return_val_if_fail (header_length >= GST_DP_HEADER_LENGTH, FALSE); - - if (!(GST_DP_HEADER_FLAGS (header) & GST_DP_HEADER_FLAG_CRC_HEADER)) - return TRUE; - - crc_read = GST_DP_HEADER_CRC_HEADER (header); - - /* don't include the last two crc fields for the crc check */ - crc_calculated = gst_dp_crc (header, header_length - 4); - if (crc_read != crc_calculated) - goto crc_error; - - GST_LOG ("header crc validation: %02x", crc_read); - return TRUE; - - /* ERRORS */ -crc_error: - { - GST_WARNING ("header crc mismatch: read %02x, calculated %02x", crc_read, - crc_calculated); - return FALSE; - } -} - -/** - * 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; - - g_return_val_if_fail (header != NULL, FALSE); - g_return_val_if_fail (header_length >= GST_DP_HEADER_LENGTH, FALSE); - - 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) - goto crc_error; - - GST_LOG ("payload crc validation: %02x", crc_read); - return TRUE; - - /* ERRORS */ -crc_error: - { - GST_WARNING ("payload crc mismatch: read %02x, calculated %02x", crc_read, - crc_calculated); - return FALSE; - } -} - -/** - * 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; -} - -/** - * gst_dp_packetizer_new: - * @version: the #GstDPVersion of the protocol to packetize for. - * - * Creates a new packetizer. - * - * Returns: a newly allocated #GstDPPacketizer - */ -GstDPPacketizer * -gst_dp_packetizer_new (GstDPVersion version) -{ - GstDPPacketizer *ret; - - ret = g_malloc0 (sizeof (GstDPPacketizer)); - ret->version = version; - - switch (version) { - case GST_DP_VERSION_1_0: - ret->header_from_buffer = gst_dp_header_from_buffer_1_0; - ret->packet_from_caps = gst_dp_packet_from_caps_1_0; - ret->packet_from_event = gst_dp_packet_from_event_1_0; - break; - default: - g_free (ret); - ret = NULL; - break; - } - - return ret; -} - -/** - * gst_dp_packetizer_free: - * @packetizer: the #GstDPPacketizer to free. - * - * Free the given packetizer. - */ -void -gst_dp_packetizer_free (GstDPPacketizer * packetizer) -{ - g_free (packetizer); -} |