media: Add URL-player renderer client and GetMediaUrl by abhijeetk · Pull Request #10998 · youtube/cobalt

abhijeetk · 2026-06-20T23:52:57Z

Implement UrlPlayerRendererClient for the renderer-process side of
URL-based playback on tvOS. The client extends MojoRendererWrapper,
invokes InitializeWithUrl() on the Mojo renderer pipe, and implements
StarboardRendererClientExtension callbacks for video-hole painting,
rendering mode updates, and SbWindow handle delivery.

Add MediaResource::GetMediaUrl() behind USE_STARBOARD_URL_PLAYER so
URL-based MediaResource implementations can provide the source URL.
The default returns an empty GURL; UrlPlayerDemuxer overrides it in
a later CL.

Build: ninja -C out/tvos-arm64-simulator_qa cobalt nplb media_unittests

Bug: 512045535

github-actions · 2026-06-20T23:53:28Z

🤖 Gemini Suggested Commit Message

media: Add URL-player renderer and GetMediaUrl

Implement UrlPlayerRendererClient to support URL-based playback on
tvOS. This client facilitates playback over Mojo by invoking
InitializeWithUrl on the renderer pipe, specifically for scenarios
where the platform handles media processing (e.g., HLS via AVPlayer).

Add MediaResource::GetMediaUrl() behind the STARBOARD_URL_PLAYER
build flag to allow the renderer to fetch the necessary URL from
the demuxer. This change includes the Mojo plumbing and wrapper
classes required to bridge the renderer and GPU processes.

Bug: 512045535

💡 Pro Tips for a Better Commit Message:

Influence the Result: Want to change the output? You can write custom prompts or instructions directly in the Pull Request description. The model uses that text to generate the message.
Re-run the Generator: Post a comment with: /generate-commit-message

Add use_starboard_url_player GN capability flag, derived from use_starboard_media and tvOS platform detection. Expose it as BUILDFLAG(USE_STARBOARD_URL_PLAYER) through build_config.h and register matching Mojo enabled_features entry. Add RendererType::kUrlPlayer = 13 to the C++ enum, Mojom enum, traits mapping, and histogram. The new enum is gated behind USE_STARBOARD_URL_PLAYER so non-tvOS builds are unaffected. This establishes the capability boundary for all subsequent URL-player CLs. Bug: 512045535

Introduce InitializeWithUrl(client, source_url) on the Mojo renderer pipe to carry the media URL from the renderer process to the GPU process, keeping URL delivery and initialization ordered on the same pipe. On the GPU side, add UrlPlayerRenderer for tvOS URL-based playback via SbPlayerBridge in punch-out mode, and UrlPlayerRendererWrapper as the Mojo service bridge. The wrapper sets the URL on the renderer then calls Initialize(). On the renderer-process side, MojoRenderer and MojoRendererWrapper forward InitializeWithUrl over the Mojo pipe. MojoRendererService validates the renderer type and URL before forwarding, with runtime guards for unexpected state and invalid URLs. Bug: 512045535

Implement UrlPlayerRendererClient for the renderer-process side of URL-based playback on tvOS. The client extends MojoRendererWrapper, invokes InitializeWithUrl() on the Mojo renderer pipe, and implements StarboardRendererClientExtension callbacks for video-hole painting, rendering mode updates, and SbWindow handle delivery. Add MediaResource::GetMediaUrl() behind USE_STARBOARD_URL_PLAYER so URL-based MediaResource implementations can provide the source URL. The default returns an empty GURL; UrlPlayerDemuxer overrides it in a later CL. Build: ninja -C out/tvos-arm64-simulator_qa cobalt nplb media_unittests Bug: 512045535

abhijeetk · 2026-06-26T16:34:59Z

cc : @rakuco @jkim-julie @Gyuyoung

gemini-code-assist

Code Review

This pull request introduces a new URL-based player renderer (UrlPlayerRenderer) and its associated Mojo wrapper and client components to support platform-mediated playback (such as HLS via AVPlayer on tvOS) using punch-out mode. The review feedback highlights several opportunities to improve robustness and error handling. Key recommendations include adding null checks for client_ and cdm_context to prevent potential null pointer dereferences, gracefully handling a null video_geometry_setter_service_ during initialization, notifying the client of errors when encountering unsupported rendering modes post-initialization, adding a default case for unknown player errors, and correctly handling counter resets for decoded or dropped frames to ensure accurate statistics reporting.

gemini-code-assist · 2026-06-26T16:36:20Z

+  if (!init_cb_.is_null()) {
+    std::move(init_cb_).Run(PIPELINE_ERROR_DISCONNECTED);
+    return;
+  }
+  client_->OnError(PIPELINE_ERROR_DISCONNECTED);


If a connection error occurs after initialization has failed or completed, client_ might be null or the object might be in a state where client_ is not set. Adding a null check for client_ prevents potential null pointer dereference crashes.

if (!init_cb_.is_null()) { std::move(init_cb_).Run(PIPELINE_ERROR_DISCONNECTED); return; } if (client_) { client_->OnError(PIPELINE_ERROR_DISCONNECTED); }

gemini-code-assist · 2026-06-26T16:36:21Z

+      if (!init_cb_.is_null()) {
+        std::move(init_cb_).Run(pipeline_status());
+      }
+      return;
+    case StarboardRenderingMode::kInvalid:
+      LOG(ERROR) << "Invalid rendering mode.";
+      SetMojoRendererInitialized(
+          PipelineStatus(PIPELINE_ERROR_INITIALIZATION_FAILED,
+                         "Invalid rendering mode for URL player"));
+      if (!init_cb_.is_null()) {
+        std::move(init_cb_).Run(pipeline_status());
+      }


If the rendering mode changes to an unsupported mode (like kDecodeToTexture or kInvalid) after initialization has already completed (meaning init_cb_ is null), the client should be notified of the error via client_->OnError(...) rather than silently returning.

if (!init_cb_.is_null()) { std::move(init_cb_).Run(pipeline_status()); } else if (client_) { client_->OnError(pipeline_status()); } return; case StarboardRenderingMode::kInvalid: LOG(ERROR) << "Invalid rendering mode."; SetMojoRendererInitialized( PipelineStatus(PIPELINE_ERROR_INITIALIZATION_FAILED, "Invalid rendering mode for URL player")); if (!init_cb_.is_null()) { std::move(init_cb_).Run(pipeline_status()); } else if (client_) { client_->OnError(pipeline_status()); }

gemini-code-assist · 2026-06-26T16:36:21Z

+  // Subscribe to video geometry changes.
+  DCHECK(video_geometry_setter_service_);
+  video_geometry_setter_service_->GetVideoGeometryChangeSubscriber(


video_geometry_setter_service_ is a raw pointer and could potentially be null. Checking it and failing initialization gracefully with an error callback is safer than relying solely on DCHECK which is disabled in debug builds.

Suggested change

// Subscribe to video geometry changes.

DCHECK(video_geometry_setter_service_);

video_geometry_setter_service_->GetVideoGeometryChangeSubscriber(

if (!video_geometry_setter_service_) {

std::move(init_cb).Run(PIPELINE_ERROR_INITIALIZATION_FAILED);

return;

}

// Subscribe to video geometry changes.

video_geometry_setter_service_->GetVideoGeometryChangeSubscriber(

gemini-code-assist · 2026-06-26T16:36:21Z

+  DCHECK(task_runner_->RunsTasksInCurrentSequence());
+  DCHECK(cdm_context);
+
+  if (cdm_context_ || SbDrmSystemIsValid(drm_system_)) {


In release builds, cdm_context could potentially be null. Adding a null check prevents a null pointer dereference when calling cdm_context->GetSbDrmSystem().

DCHECK(task_runner_->RunsTasksInCurrentSequence()); if (!cdm_context) { std::move(cdm_attached_cb).Run(false); return; } if (cdm_context_ || SbDrmSystemIsValid(drm_system_)) {

gemini-code-assist · 2026-06-26T16:36:21Z

+    case kSbPlayerErrorMax:
+      NOTREACHED();
+      break;
+  }


If a new error is added to SbPlayerError in the future, the switch statement will not handle it, causing the player to transition to STATE_ERROR without notifying the pipeline. Adding a default case ensures that any unknown errors are handled and reported gracefully.

case kSbPlayerErrorMax: NOTREACHED(); break; default: MEDIA_LOG(ERROR, media_log_) << "Unknown player error: " << error << " message: " << message; NotifyError(PIPELINE_ERROR_DECODE); break; }

gemini-code-assist · 2026-06-26T16:36:21Z

+void UrlPlayerRenderer::NotifyError(PipelineStatus status) {
+  if (init_cb_) {
+    std::move(init_cb_).Run(status);
+  } else {
+    client_->OnError(status);
+  }


All other methods in this class check if client_ is null before invoking callbacks on it. NotifyError should also check if client_ is null to prevent potential null pointer dereference crashes.

Suggested change

void UrlPlayerRenderer::NotifyError(PipelineStatus status) {

if (init_cb_) {

std::move(init_cb_).Run(status);

} else {

client_->OnError(status);

}

void UrlPlayerRenderer::NotifyError(PipelineStatus status) {

if (init_cb_) {

std::move(init_cb_).Run(status);

} else if (client_) {

client_->OnError(status);

}

gemini-code-assist · 2026-06-26T16:36:21Z

+  if (video_frames_decoded > last_video_frames_decoded_) {
+    statistics.video_frames_decoded =
+        video_frames_decoded - last_video_frames_decoded_;
+    last_video_frames_decoded_ = video_frames_decoded;
+  }
+
+  if (video_frames_dropped > last_video_frames_dropped_) {
+    statistics.video_frames_dropped =
+        video_frames_dropped - last_video_frames_dropped_;
+    last_video_frames_dropped_ = video_frames_dropped;
+  }


If the underlying player is recreated or reset (e.g., after a seek or loop), the decoded/dropped frame counters can reset to 0. If video_frames_decoded becomes less than last_video_frames_decoded_, the statistics will not be updated correctly until the new count exceeds the old high value. Handling counter resets ensures accurate statistics reporting.

if (video_frames_decoded >= last_video_frames_decoded_) { statistics.video_frames_decoded = video_frames_decoded - last_video_frames_decoded_; } else { statistics.video_frames_decoded = video_frames_decoded; } last_video_frames_decoded_ = video_frames_decoded; if (video_frames_dropped >= last_video_frames_dropped_) { statistics.video_frames_dropped = video_frames_dropped - last_video_frames_dropped_; } else { statistics.video_frames_dropped = video_frames_dropped; } last_video_frames_dropped_ = video_frames_dropped;

borongc · 2026-06-26T17:00:50Z

 #define BUILDFLAG_INTERNAL_USE_STARBOARD_MEDIA() (0)
 #endif

+#if defined(ENABLE_BUILDFLAG_USE_STARBOARD_URL_PLAYER)


Same as #10979 (comment), I think introducing one more flag for a single Starboard platform is not ideal.

abhijeetk · 2026-07-23T08:02:51Z

Thanks for all review comments. We are moving ahead with approach in PR #10698 (UrlPlayer using StarboardRenderer).
Closing this PR.

abhijeetk force-pushed the url-player-2 branch from 0532b90 to 495d84a Compare June 24, 2026 19:19

abhijeetk mentioned this pull request Jun 25, 2026

tvos: Implement UrlPlayer for native HLS playback #10698

Open

rakuco reviewed Jun 26, 2026

View reviewed changes

Comment thread media/base/media_resource.h Outdated

Comment thread media/base/media_resource.h Outdated

Comment thread media/base/media_resource.cc Outdated

abhijeetk added 2 commits June 26, 2026 17:12

abhijeetk force-pushed the url-player-2 branch from 495d84a to caa75df Compare June 26, 2026 14:52

abhijeetk self-assigned this Jun 26, 2026

abhijeetk force-pushed the url-player-2 branch from caa75df to 3be6081 Compare June 26, 2026 16:32

abhijeetk marked this pull request as ready for review June 26, 2026 16:33

abhijeetk requested review from a team as code owners June 26, 2026 16:33

abhijeetk requested review from fayev-g, jasonzhangxx and y4vor June 26, 2026 16:33

gemini-code-assist Bot reviewed Jun 26, 2026

View reviewed changes

borongc reviewed Jun 26, 2026

View reviewed changes

abhijeetk closed this Jul 23, 2026

Uh oh!

Conversation

abhijeetk commented Jun 20, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

github-actions Bot commented Jun 20, 2026

🤖 Gemini Suggested Commit Message

Uh oh!

Uh oh!

Uh oh!

Uh oh!

abhijeetk commented Jun 26, 2026

Uh oh!

gemini-code-assist Bot left a comment

Choose a reason for hiding this comment

Code Review

Uh oh!

gemini-code-assist Bot Jun 26, 2026

Choose a reason for hiding this comment

Uh oh!

gemini-code-assist Bot Jun 26, 2026

Choose a reason for hiding this comment

Uh oh!

gemini-code-assist Bot Jun 26, 2026

Choose a reason for hiding this comment

Uh oh!

gemini-code-assist Bot Jun 26, 2026

Choose a reason for hiding this comment

Uh oh!

gemini-code-assist Bot Jun 26, 2026

Choose a reason for hiding this comment

Uh oh!

gemini-code-assist Bot Jun 26, 2026

Choose a reason for hiding this comment

Uh oh!

gemini-code-assist Bot Jun 26, 2026

Choose a reason for hiding this comment

Uh oh!

borongc Jun 26, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

abhijeetk commented Jul 23, 2026

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

3 participants

abhijeetk commented Jun 20, 2026 •

edited

Loading

borongc Jun 26, 2026 •

edited

Loading