/* GStreamer * Copyright (C) <1999> Erik Walthinsen * Copyright (C) 2004,2006 Thomas Vander Stichele * * 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., 51 Franklin St, Fifth Floor, * Boston, MA 02110-1301, 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: * * */ #ifdef HAVE_CONFIG_H #include "config.h" #endif #include #include "dataprotocol.h" #include /* g_sprintf */ #include /* strlen */ #include "dp-private.h" /* debug category */ GST_DEBUG_CATEGORY_STATIC (data_protocol_debug); #ifndef GST_CAT_DEFAULT #define GST_CAT_DEFAULT data_protocol_debug #endif /* 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; GstMapInfo map; 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); gst_buffer_map ((GstBuffer *) buffer, &map, GST_MAP_READ); /* buffer properties */ GST_WRITE_UINT32_BE (h + 6, map.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_HEADER | 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, map.data, map.size); gst_buffer_unmap ((GstBuffer *) buffer, &map); GST_MEMDUMP ("created header from buffer", 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_MEMDUMP ("created header from caps", 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); } 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_MEMDUMP ("created header from event", 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), NULL); 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 start_type, stop_type; gint64 start, 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); start_type = (GstSeekType) GST_READ_UINT32_BE (payload + 8); start = (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, start_type, start, 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); } GST_LOG ("Creating event of type 0x%x with structure '%" GST_PTR_FORMAT "'", type, s); 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); }