Keep the retransmission sources of the participants out of the public API

8.15.2 added them to AbstractGroupCallParticipant (a public, persisted event object) only because the controller
builds the sources it passes to GroupConnection from those objects: nobody receiving a participant needs them, and a
readonly property added to a persisted class needed a ?? [] for the participants saved before. GroupCallController
keeps them in a private map instead, from the same source groups (and a min update keeps them for the streams it
doesn't carry). Participants saved by 8.15.2 just carry the dropped property until they're next updated.

Claude-Session: https://claude.ai/code/session_01EWcRgSSwNQ2fE6pPhgTfXw

Author: danog

src/API.php

@@ -54,7 +54,7 @@ final class API extends AbstractAPI
      *
      * @var string
      */
-    public const RELEASE = '8.15.2';
+    public const RELEASE = '8.15.3';
     /**
      * We're not logged in.
      *

src/EventHandler/Calls/AbstractGroupCallParticipant.php

@@ -71,13 +71,6 @@ public function __construct(
         public readonly ?int $raiseHandRating,
         /** Whether the participant's volume was set by an admin. */
         public readonly bool $volumeByAdmin,
-        /**
-         * The retransmission (RTX) SSRC of each of the {@see self::$videoSources} and {@see self::$presentationSources} that
-         * has one (the second source of its FID group), signed, by SSRC: the SFU resends the lost packets of the stream on it.
-         *
-         * @var array<int, int>
-         */
-        public readonly array $retransmissionSources = [],
     ) {
         parent::__construct($peerId);
     }
@@ -103,20 +96,14 @@ final protected static function commonArgs(array $participant, int $peerId, ?sel
         $presentation = self::videoSources($participant['presentation'] ?? null);
         $videoEndpoint = self::endpoint($participant['video'] ?? null);
         $presentationEndpoint = self::endpoint($participant['presentation'] ?? null);
-        $videoRtx = self::retransmissionSources($participant['video'] ?? null);
-        $presentationRtx = self::retransmissionSources($participant['presentation'] ?? null);
         if ($min && $cached !== null) {
-            // Participants saved by versions that didn't keep the retransmission sources have none.
-            $cachedRtx = $cached->retransmissionSources ?? [];
             if (!\is_array($participant['video'] ?? null)) {
                 $video = $cached->videoSources;
                 $videoEndpoint = $cached->videoEndpoint;
-                $videoRtx = array_intersect_key($cachedRtx, array_flip($video));
             }
             if (!\is_array($participant['presentation'] ?? null)) {
                 $presentation = $cached->presentationSources;
                 $presentationEndpoint = $cached->presentationEndpoint;
-                $presentationRtx = array_intersect_key($cachedRtx, array_flip($presentation));
             }
         }
         return [
@@ -138,15 +125,14 @@ final protected static function commonArgs(array $participant, int $peerId, ?sel
             'about' => $participant['about'] ?? null,
             'raiseHandRating' => $participant['raise_hand_rating'] ?? null,
             'volumeByAdmin' => $participant['volume_by_admin'],
-            'retransmissionSources' => $videoRtx + $presentationRtx,
         ];
     }
 
     /**
      * Flatten the source SSRCs of a
      * [groupCallParticipantVideo](https://core.telegram.org/constructor/groupCallParticipantVideo),
      * taking each source group's primary (first) source and every simulcast layer, deduplicated.
-     * Retransmission (FID) pairs contribute only their main source: the other is in {@see self::retransmissionSources()}.
+     * Retransmission (FID) pairs contribute only their main source (GroupCallController keeps the other).
      *
      * @param mixed $video The `video` or `presentation` field of a groupCallParticipant, if present.
      *
@@ -171,30 +157,6 @@ private static function videoSources(mixed $video): array
         return array_values(array_keys($sources));
     }
 
-    /**
-     * The retransmission SSRC of each SSRC of a groupCallParticipantVideo that has one: the second source of its FID
-     * group (tgcalls declares one per simulcast layer).
-     *
-     * @param mixed $video The `video` or `presentation` field of a groupCallParticipant, if present.
-     *
-     * @return array<int, int> Signed SSRCs, by signed SSRC.
-     *
-     * @psalm-pure
-     */
-    private static function retransmissionSources(mixed $video): array
-    {
-        if (!\is_array($video) || ($video['paused'] ?? false)) {
-            return [];
-        }
-        $sources = [];
-        foreach ($video['source_groups'] ?? [] as $group) {
-            if (($group['semantics'] ?? '') === 'FID' && isset($group['sources'][0], $group['sources'][1])) {
-                $sources[$group['sources'][0]] = $group['sources'][1];
-            }
-        }
-        return $sources;
-    }
-
     /**
      * The `endpoint` of a groupCallParticipantVideo, the key used to subscribe to that stream over
      * the colibri data channel.

src/EventHandler/Calls/LiveStoryParticipant.php

@@ -28,7 +28,6 @@ final class LiveStoryParticipant extends AbstractGroupCallParticipant
      *
      * @param list<int> $videoSources
      * @param list<int> $presentationSources
-     * @param array<int, int> $retransmissionSources
      * @param int<1, 20000> $volume Playback volume, from 1 to 20000 where 10000 is 100%.
      *
      * @psalm-mutation-free
@@ -54,7 +53,6 @@ public function __construct(
         bool $volumeByAdmin,
         /** Total Telegram Stars donated by this participant, if any. */
         public readonly ?int $paidStarsTotal,
-        array $retransmissionSources = [],
     ) {
         parent::__construct(
             $peerId,
@@ -75,7 +73,6 @@ public function __construct(
             $about,
             $raiseHandRating,
             $volumeByAdmin,
-            $retransmissionSources,
         );
     }
 

src/GroupCall/GroupCallController.php

@@ -97,6 +97,12 @@ final class GroupCallController implements CallControllerInterface, GroupConnect
     private array $participants = [];
     /** @var array<int, int> Signed source ID => bot API peer ID. */
     private array $sourceToPeer = [];
+    /**
+     * @var array<int, array<int, int>> The retransmission (RTX) SSRC of each video and screen-share SSRC of each
+     *                                  participant that has one (the second source of its FID group), signed, by SSRC,
+     *                                  by bot API peer ID: the SFU resends the lost packets of the stream on it.
+     */
+    private array $retransmission = [];
 
     /** Our own audio source ID, in the signed form used by the API. */
     private int $source = 0;
@@ -526,6 +532,7 @@ public function applyGroupCall(array $result): void
         }
         $this->participants = [];
         $this->sourceToPeer = [];
+        $this->retransmission = [];
         foreach ($result['participants'] as $participant) {
             $this->applyParticipant($participant);
         }
@@ -604,6 +611,35 @@ public function onParticipantsUpdate(array $participants, int $version): void
         $this->syncSources();
     }
 
+    /**
+     * The retransmission SSRC of each video and screen-share SSRC of a participant that has one: from the source
+     * groups of the update, or kept from the previous one for a stream a min update doesn't carry.
+     *
+     * @param array<int, int> $previous
+     *
+     * @return array<int, int> Signed SSRCs, by signed SSRC.
+     *
+     * @psalm-pure
+     */
+    private static function retransmissionSources(array $participant, AbstractGroupCallParticipant $parsed, array $previous): array
+    {
+        $sources = [];
+        foreach (['video', 'presentation'] as $key) {
+            $video = $participant[$key] ?? null;
+            if (!\is_array($video)) {
+                continue;
+            }
+            foreach ($video['source_groups'] ?? [] as $group) {
+                if (($group['semantics'] ?? '') === 'FID' && isset($group['sources'][0], $group['sources'][1])) {
+                    $sources[$group['sources'][0]] = $group['sources'][1];
+                }
+            }
+        }
+        // Only the streams the participant sends (not a paused one, say).
+        $current = array_flip([...$parsed->videoSources, ...$parsed->presentationSources]);
+        return array_intersect_key($sources + $previous, $current);
+    }
+
     private function applyParticipant(array $participant): void
     {
         $peerId = $this->API->getIdInternal($participant['peer']);
@@ -615,6 +651,7 @@ private function applyParticipant(array $participant): void
             if ($old !== null) {
                 unset($this->sourceToPeer[$old->source], $this->participants[$peerId]);
             }
+            unset($this->retransmission[$peerId]);
             if (($participant['self'] ?? false)
                 && $this->callState === GroupCallState::JOINED
                 && (int) ($participant['source'] ?? 0) === $this->source
@@ -630,6 +667,7 @@ private function applyParticipant(array $participant): void
             ? LiveStoryParticipant::fromRaw($participant, $peerId, $this->participants[$peerId] ?? null)
             : GroupCallParticipant::fromRaw($participant, $peerId, $this->participants[$peerId] ?? null);
         $this->participants[$peerId] = $parsed;
+        $this->retransmission[$peerId] = self::retransmissionSources($participant, $parsed, $this->retransmission[$peerId] ?? []);
         if ($parsed->source !== 0) {
             $this->sourceToPeer[$parsed->source] = $peerId;
             $this->sourcePeers[$parsed->source] = $peerId;
@@ -650,7 +688,7 @@ private function syncSources(): void
             return;
         }
         $sources = [];
-        foreach ($this->participants as $participant) {
+        foreach ($this->participants as $peerId => $participant) {
             if ($participant->source !== 0 && $participant->source !== $this->source) {
                 $sources[] = [
                     'audio' => $participant->source,
@@ -659,8 +697,7 @@ private function syncSources(): void
                     'presentation' => $participant->presentationSources,
                     'videoEndpoint' => $participant->videoEndpoint,
                     'presentationEndpoint' => $participant->presentationEndpoint,
-                    // Participants saved by versions that didn't keep the retransmission sources have none.
-                    'rtx' => $participant->retransmissionSources ?? [],
+                    'rtx' => $this->retransmission[$peerId] ?? [],
                 ];
             }
         }

…delineProto/GroupCallParticipantTest.php …o/GroupCallRetransmissionSourcesTest.phptests/danog/MadelineProto/GroupCallParticipantTest.php renamed to tests/danog/MadelineProto/GroupCallRetransmissionSourcesTest.php tests/danog/MadelineProto/GroupCallParticipantTest.php renamed to tests/danog/MadelineProto/GroupCallRetransmissionSourcesTest.php

@@ -17,12 +17,15 @@
 namespace danog\MadelineProto\Test;
 
 use danog\MadelineProto\EventHandler\Calls\GroupCallParticipant;
+use danog\MadelineProto\GroupCall\GroupCallController;
 use PHPUnit\Framework\TestCase;
+use ReflectionMethod;
 
 /**
- * The video sources of a participant, from the source groups of its groupCallParticipantVideo.
+ * The retransmission (RTX) SSRCs of a participant's videos, kept by the controller (not by the participant objects
+ * the event handlers get) from the FID groups of its groupCallParticipantVideo.
  */
-final class GroupCallParticipantTest extends TestCase
+final class GroupCallRetransmissionSourcesTest extends TestCase
 {
     private static function raw(bool $min, ?array $video): array
     {
@@ -40,27 +43,40 @@ private static function raw(bool $min, ?array $video): array
         ] + ($video === null ? [] : ['video' => $video]);
     }
 
+    /**
+     * @param array<int, int> $previous
+     * @return array<int, int>
+     */
+    private static function sources(array $raw, GroupCallParticipant $parsed, array $previous = []): array
+    {
+        return (new ReflectionMethod(GroupCallController::class, 'retransmissionSources'))->invoke(null, $raw, $parsed, $previous);
+    }
+
     public function testTheRetransmissionSourceOfEachVideoSourceIsKept(): void
     {
-        $participant = GroupCallParticipant::fromRaw(self::raw(false, [
+        $raw = self::raw(false, [
             'endpoint' => 'e',
             'source_groups' => [
                 ['semantics' => 'SIM', 'sources' => [10, 20]],
                 ['semantics' => 'FID', 'sources' => [10, 11]],
                 ['semantics' => 'FID', 'sources' => [20, -21]],
             ],
-        ]), 1);
+        ]);
+        $participant = GroupCallParticipant::fromRaw($raw, 1);
         $this->assertSame([10, 20], $participant->videoSources);
-        $this->assertSame([10 => 11, 20 => -21], $participant->retransmissionSources);
+        $rtx = self::sources($raw, $participant);
+        $this->assertSame([10 => 11, 20 => -21], $rtx);
 
         // A min update without the video keeps the known one, with its retransmission sources.
-        $min = GroupCallParticipant::fromRaw(self::raw(true, null), 1, $participant);
+        $raw = self::raw(true, null);
+        $min = GroupCallParticipant::fromRaw($raw, 1, $participant);
         $this->assertSame([10, 20], $min->videoSources);
-        $this->assertSame([10 => 11, 20 => -21], $min->retransmissionSources);
+        $this->assertSame([10 => 11, 20 => -21], self::sources($raw, $min, $rtx));
 
-        // The video stopping takes them away.
-        $stopped = GroupCallParticipant::fromRaw(self::raw(false, ['endpoint' => 'e', 'paused' => true, 'source_groups' => [['semantics' => 'FID', 'sources' => [10, 11]]]]), 1, $participant);
+        // The video pausing takes them away.
+        $raw = self::raw(false, ['endpoint' => 'e', 'paused' => true, 'source_groups' => [['semantics' => 'FID', 'sources' => [10, 11]]]]);
+        $stopped = GroupCallParticipant::fromRaw($raw, 1, $participant);
         $this->assertSame([], $stopped->videoSources);
-        $this->assertSame([], $stopped->retransmissionSources);
+        $this->assertSame([], self::sources($raw, $stopped, $rtx));
     }
 }