Add logical channel numbering support

Author: phpbg

src/Descriptors/PrivateDescriptors/EACEM/LogicalChannel.php

@@ -0,0 +1,71 @@
+<?php
+
+/**
+ * MIT License
+ *
+ * Copyright (c) 2018 Samuel CHEMLA
+ *
+ * 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.
+ */
+
+namespace PhpBg\DvbPsi\Descriptors\PrivateDescriptors\EACEM;
+
+/**
+ * Class LogicalChannel
+ * @see EACEM IEC/CENELEC 62 216: « Baseline Digital Terrestrial TV Receiver Specification »
+ */
+class LogicalChannel
+{
+    /**
+     * Array of <service id> => <logical channel number>
+     * @var array
+     */
+    public $services = [];
+
+    /**
+     * NetworkName constructor.
+     * @param $data
+     * @throws \PhpBg\DvbPsi\Exception
+     */
+    public function __construct($data)
+    {
+        $len = strlen($data);
+        $currentPointer = 0;
+        while ($currentPointer < $len) {
+            $serviceId = unpack('n', substr($data, $currentPointer, 2))[1];
+            $currentPointer += 2;
+
+            $tmp = unpack('n', substr($data, $currentPointer, 2))[1];
+            $currentPointer += 2;
+            $lcn = $tmp & 0b1111111111;
+
+            $this->services[$serviceId] = $lcn;
+        }
+    }
+
+    public function __toString()
+    {
+        $msg = "Logical channels numbers:\n";
+        $msg .= "\tService ID > channel number\n";
+        foreach ($this->services as $serviceId => $lcn) {
+            $msg .= sprintf("\t%d (0x%x) > %d\n", $serviceId, $serviceId, $lcn);
+        }
+        return $msg;
+    }
+}

src/Descriptors/PrivateDescriptors/EACEM/readme.md

@@ -0,0 +1,5 @@
+# EACEM private descriptors
+
+All descriptors here belong to private_data_specifier `0x00000028`
+
+See `PhpBg\DvbPsi\Descriptors\PrivateDataSpecifier`

src/TableParsers/TableParserAbstract.php

@@ -33,6 +33,7 @@
 use PhpBg\DvbPsi\Descriptors\NetworkName;
 use PhpBg\DvbPsi\Descriptors\ParentalRating;
 use PhpBg\DvbPsi\Descriptors\PrivateDataSpecifier;
+use PhpBg\DvbPsi\Descriptors\PrivateDescriptors\EACEM\LogicalChannel;
 use PhpBg\DvbPsi\Descriptors\ServiceList;
 use PhpBg\DvbPsi\Descriptors\ShortEvent;
 use PhpBg\DvbPsi\Descriptors\TerrestrialDeliverySystem;
@@ -41,6 +42,12 @@
 abstract class TableParserAbstract implements TableParserInterface
 {
 
+    /**
+     * Private data specifier, used to select private descriptors parsers
+     * @var int | null
+     */
+    protected $privateDataSpecifier;
+
     /**
      * Parse a descriptor loop
      * @param string $data
@@ -61,6 +68,8 @@ protected function parseDescriptorsLoop(string $data, int $currentPointer, int $
         if ($descriptorsEnd > $dataLen) {
             throw new Exception("Descriptors loop parse overflow (data length exceeded)");
         }
+        // Reset private data specifier
+        $this->privateDataSpecifier = null;
         while ($currentPointer < $descriptorsEnd) {
             // Safeguard, again
             if ($currentPointer >= $dataLen) {
@@ -104,15 +113,16 @@ protected function parseDescriptor(int $descriptorId, string $data, int $current
         $descriptorData = substr($data, $currentPointer, $descriptorLength);
 
         switch ($descriptorId) {
-            //TODO handle private descriptor tag : 0x83 in case data specifier is 0x00000028 EACEM. In that case it provides logical channel numbering
             case Identifier::TERRESTRIAL_DELIVERY_SYSTEM_DESCRIPTOR:
                 return new TerrestrialDeliverySystem($descriptorData);
 
             case Identifier::NETWORK_NAME_DESCRIPTOR:
                 return new NetworkName($descriptorData);
 
             case Identifier::PRIVATE_DATA_SPECIFIER_DESCRIPTOR:
-                return new PrivateDataSpecifier($descriptorData);
+                $pds = new PrivateDataSpecifier($descriptorData);
+                $this->privateDataSpecifier = $pds->private_data_specifier;
+                return $pds;
 
             case Identifier::SERVICE_LIST_DESCRIPTOR:
                 return new ServiceList($descriptorData);
@@ -132,6 +142,14 @@ protected function parseDescriptor(int $descriptorId, string $data, int $current
             case Identifier::CONTENT_DESCRIPTOR:
                 return new Content($descriptorData);
 
+
+            // Private descriptors
+            case 0x83:
+                if (empty($this->privateDataSpecifier) || $this->privateDataSpecifier !== 0x28) {
+                    throw new Exception(sprintf("Unhandled descriptor tag : 0x%x", $descriptorId));
+                }
+                return new LogicalChannel($descriptorData);
+
             default:
                 throw new Exception(sprintf("Unhandled descriptor tag : 0x%x", $descriptorId));
         }

tests/ParserTest.php

@@ -27,6 +27,7 @@
 namespace PhpBg\DvbPsi\Tests;
 
 use PhpBg\DvbPsi\Descriptors\NetworkName;
+use PhpBg\DvbPsi\Descriptors\PrivateDescriptors\EACEM\LogicalChannel;
 use PhpBg\DvbPsi\Descriptors\TerrestrialDeliverySystem;
 use PhpBg\DvbPsi\Parser;
 use PhpBg\DvbPsi\ParserFactory;
@@ -271,19 +272,25 @@ public function testParseNit()
         $this->assertInstanceOf(NitTs::class, $stream004);
         $this->assertSame(0x20fa, $stream004->networkId);
 
-        // There are 4 descriptors, but the 0x83 one is not yet supported
-        $this->assertSame(3, count($stream004->descriptors));
+        $this->assertSame(4, count($stream004->descriptors));
 
         $tds = null;
+        $lcn = null;
         foreach ($stream004->descriptors as $descriptor) {
             if ($descriptor instanceof TerrestrialDeliverySystem) {
                 $tds = $descriptor;
             }
+            if ($descriptor instanceof LogicalChannel) {
+                $lcn = $descriptor;
+            }
         }
         $this->assertInstanceOf(TerrestrialDeliverySystem::class, $tds);
         $this->assertSame(42949672950, $tds->centreFrequency);
         $this->assertSame(8000000, $tds->bandwidth);
         $this->assertSame('64-QAM', TerrestrialDeliverySystem::CONSTELLATION_MAPPING[$tds->constellation]);
         $this->assertSame('1/8', TerrestrialDeliverySystem::GUARD_INTERVAL_MAPPING[$tds->guardInterval]);
+
+        $this->assertInstanceOf(LogicalChannel::class, $lcn);
+        $this->assertSame(5, count($lcn->services));
     }
 }