dvb/si: Add support for descriptor 0x4c (Time shifted service descriptor).

README

@@ -109,6 +109,7 @@ Supported DVB descriptors
  * Descriptor 0x49: Country availability descriptor
  * Descriptor 0x4a: Linkage descriptor (partially implemented)
  * Descriptor 0x4b: NVOD reference descriptor
+ * Descriptor 0x4c: Time shifted service descriptor
  * Descriptor 0x4d: Short event descriptor
  * Descriptor 0x4e: Extended event descriptor
  * Descriptor 0x52: Stream identifier descriptor

TODO

@@ -14,7 +14,6 @@ so if you like something just do it and send a patch.
   - Descriptor 0x6a: AC-3 descriptor
 
 - Add support (parser, generator, example) for these DVB descriptors:
-  - Descriptor 0x4c: time_shifted_service_descriptor
   - Descriptor 0x4f: time_shifted_event_descriptor
   - Descriptor 0x50: component_descriptor
   - Descriptor 0x51: mosaic_descriptor

dvb/si/desc_4c.h

+/*****************************************************************************
+ * desc_4c.h: ETSI EN 300 468 Descriptor 0x4c: (Time shifted service descriptor)
+ *****************************************************************************
+ * Copyright (C) 2011 Unix Solutions Ltd.
+ *
+ * Authors: Georgi Chorbadzhiyski <georgi@unixsol.org>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject
+ * to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ *****************************************************************************/
+
+/*
+ * Normative references:
+ *  - ETSI EN 300 468 V1.11.1 (2010-04) (SI in DVB systems)
+ */
+
+#ifndef __BITSTREAM_MPEG_DESC_4C_H__
+#define __BITSTREAM_MPEG_DESC_4C_H__
+
+#include <bitstream/common.h>
+#include <bitstream/mpeg/psi/descriptors.h>
+
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+
+/*****************************************************************************
+ * Descriptor 0x4c: Time shifted service descriptor
+ *****************************************************************************/
+#define DESC4C_HEADER_SIZE      (DESC_HEADER_SIZE + 2)
+
+static inline void desc4c_init(uint8_t *p_desc)
+{
+    desc_set_tag(p_desc, 0x4c);
+    desc_set_length(p_desc, DESC4C_HEADER_SIZE - DESC_HEADER_SIZE);
+}
+
+static inline uint16_t desc4c_get_reference_sid(const uint8_t *p_desc)
+{
+    return (p_desc[2] << 8) | p_desc[3];
+}
+
+static inline void desc4c_set_reference_sid(uint8_t *p_desc, uint16_t i_reference_sid)
+{
+    p_desc[2] = (i_reference_sid >> 8) & 0xff;
+    p_desc[3] =  i_reference_sid       & 0xff;
+}
+
+static inline bool desc4c_validate(const uint8_t *p_desc)
+{
+    return desc_get_length(p_desc) >= DESC4C_HEADER_SIZE - DESC_HEADER_SIZE;
+}
+
+static inline void desc4c_print(const uint8_t *p_desc, f_print pf_print,
+                                void *opaque, print_type_t i_print_type)
+{
+    switch (i_print_type) {
+    case PRINT_XML:
+        pf_print(opaque, "<TIME_SHIFTED_SERVICE_DESC reference_sid=\"%u\"/>",
+                 desc4c_get_reference_sid(p_desc));
+        break;
+    default:
+        pf_print(opaque, "    - desc 4c time_shifted_service reference_sid=%u",
+                 desc4c_get_reference_sid(p_desc));
+    }
+}
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif

dvb/si/descs_list.h

@@ -46,6 +46,7 @@
 #include <bitstream/dvb/si/desc_49.h>
 #include <bitstream/dvb/si/desc_4a.h>
 #include <bitstream/dvb/si/desc_4b.h>
+#include <bitstream/dvb/si/desc_4c.h>
 #include <bitstream/dvb/si/desc_4d.h>
 #include <bitstream/dvb/si/desc_4e.h>
 #include <bitstream/dvb/si/desc_52.h>

examples/dvb_gen_si.c

@@ -564,7 +564,12 @@ static void build_desc4b(uint8_t *desc, bool b_available) {
     desc_set_length(desc, ref_n - desc - DESC_HEADER_SIZE);
 }
 
-/* ---  Descriptor 0x4c: time_shifted_service_descriptor */
+/* DVB  Descriptor 0x4c: time_shifted_service_descriptor */
+static void build_desc4c(uint8_t *desc) {
+    desc4c_init(desc);
+    desc4c_set_reference_sid(desc, sid + 1000);
+}
+
 /* DVB  Descriptor 0x4d: Short event descriptor */
 static void build_desc4d(uint8_t *desc) {
     char *event_name = "Major TV event";
@@ -1332,6 +1337,9 @@ static void generate_sdt(void) {
             desc = descs_get_desc(desc_loop, desc_counter++);
             build_desc48(desc);
 
+            desc = descs_get_desc(desc_loop, desc_counter++);
+            build_desc4c(desc);
+
             desc = descs_get_desc(desc_loop, desc_counter++);
             build_desc5f(desc);
 

mpeg/psi/descs_print.h

@@ -141,6 +141,7 @@ static inline void descl_print(uint8_t *p_descl, uint16_t i_length,
         CASE_DESC(49)
         CASE_DESC(4a)
         CASE_DESC(4b)
+        CASE_DESC(4c)
         CASE_DESC_ICONV(4d)
         CASE_DESC_ICONV(4e)
         CASE_DESC(52)