Skip to content

cvd: Support media devices in multi-instance fleets #3136

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
changyeon-jo wants to merge 1 commit into
base: main
Choose a base branch
from
Open

cvd: Support media devices in multi-instance fleets #3136

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
9 changes: 8 additions & 1 deletion base/cvd/cuttlefish/host/commands/assemble_cvd/flags.cc
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1380,7 +1380,14 @@ Result<CuttlefishConfig> InitializeCuttlefishConfiguration(
CF_EXPECT_EQ(media_configs_bindings.size(), 1,
"Expected a single binding?");
auto media_configs = media_configs_bindings[0]->GetConfigs();
instance.set_media_configs(media_configs);
std::vector<CuttlefishConfig::MediaConfig> instance_media_configs;
for (const auto& config : media_configs) {
if (!config.instance_index.has_value() ||
config.instance_index.value() == instance_index) {
instance_media_configs.push_back(config);
}
}
instance.set_media_configs(instance_media_configs);

instance_index++;
} // end of num_instances loop
Expand Down
7 changes: 7 additions & 0 deletions base/cvd/cuttlefish/host/commands/assemble_cvd/media.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -118,6 +118,9 @@ class MediaConfigsFragmentImpl : public MediaConfigsFragment {
Json::Value json(Json::objectValue);
json[kType] = static_cast<int>(config.type);
json[kLensFacing] = config.lens_facing;
if (config.instance_index.has_value()) {
json[kInstanceIndex] = *config.instance_index;
}
configs_json.append(json);
}
return configs_json;
Expand All @@ -139,6 +142,9 @@ class MediaConfigsFragmentImpl : public MediaConfigsFragment {
if (json.isMember(kLensFacing)) {
config.lens_facing = json[kLensFacing].asString();
}
if (json.isMember(kInstanceIndex)) {
config.instance_index = json[kInstanceIndex].asInt();
}
configs.emplace_back(config);
}

Expand All @@ -150,6 +156,7 @@ class MediaConfigsFragmentImpl : public MediaConfigsFragment {
static constexpr char kMediaConfigs[] = "media_configs";
static constexpr char kType[] = "type";
static constexpr char kLensFacing[] = "lens_facing";
static constexpr char kInstanceIndex[] = "instance_index";
MediaConfigs& configs_;
};

Expand Down
116 changes: 116 additions & 0 deletions base/cvd/cuttlefish/host/commands/cvd/cli/parser/flags_parser_test.cc
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -479,6 +479,122 @@ TEST(FlagsParserTest, ParseMediaV4l2Proxy) {
<< "media flag is missing or wrongly formatted";
}

TEST(FlagsParserTest, ParseMediaMultiInstanceSingleMedia) {
const char* test_string = R""""(
{
"instances" :
[
{},
{
"media": {
"devices": [
{
"v4l2_stream_proxy": {
"input_path": "/tmp/v4l2_fifo",
"input_width": 320,
"input_height": 240,
"input_fps": "10"
}
}
]
}
}
]
}
)"""";

Json::Value json_configs;
std::string json_text(test_string);
EXPECT_TRUE(ParseJsonString(json_text, json_configs))
<< "Invalid Json string";

auto serialized_data = LaunchCvdParserTester(json_configs);

ASSERT_THAT(serialized_data, IsOk());
EXPECT_TRUE(FindConfig(
*serialized_data,
"--media=v4l2_stream_proxy:input_path=/tmp/v4l2_fifo:input_width=320:input_height=240:input_fps=10:instance=1"))
<< "media flag is missing or wrongly formatted";
}

TEST(FlagsParserTest, ParseMediaMultiInstanceFirstInstanceMedia) {
const char* test_string = R""""(
{
"instances" :
[
{
"media": {
"devices": [
{
"v4l2_stream_proxy": {
"input_path": "/tmp/v4l2_fifo",
"input_width": 320,
"input_height": 240,
"input_fps": "10"
}
}
]
}
},
{}
]
}
)"""";

Json::Value json_configs;
std::string json_text(test_string);
EXPECT_TRUE(ParseJsonString(json_text, json_configs))
<< "Invalid Json string";

auto serialized_data = LaunchCvdParserTester(json_configs);

ASSERT_THAT(serialized_data, IsOk());
EXPECT_TRUE(FindConfig(
*serialized_data,
"--media=v4l2_stream_proxy:input_path=/tmp/v4l2_fifo:input_width=320:input_height=240:input_fps=10:instance=0"))
<< "media flag is missing or wrongly formatted";
}

TEST(FlagsParserTest, ParseMediaMultiInstanceMultipleMediaFails) {
const char* test_string = R""""(
{
"instances" :
[
{
"media": {
"devices": [
{
"v4l2_stream_proxy": {
"input_path": "/tmp/v4l2_fifo_1"
}
}
]
}
},
{
"media": {
"devices": [
{
"v4l2_stream_proxy": {
"input_path": "/tmp/v4l2_fifo_2"
}
}
]
}
}
]
}
)"""";

Json::Value json_configs;
std::string json_text(test_string);
EXPECT_TRUE(ParseJsonString(json_text, json_configs))
<< "Invalid Json string";

auto serialized_data = LaunchCvdParserTester(json_configs);
EXPECT_FALSE(serialized_data.has_value());
}

TEST(ConnectivityFlagsParserTest, ParseModemSimulatorSimTypeValidInt) {
const char* test_string = R""""(
{
Expand Down
8 changes: 6 additions & 2 deletions base/cvd/cuttlefish/host/commands/cvd/cli/parser/instance/cf_media_configs.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -34,10 +34,11 @@ Result<std::vector<std::string>> GenerateMediaFlags(
int has_media_count =
std::count_if(cfg.instances().rbegin(), cfg.instances().rend(),
[](const auto& v) { return v.has_media(); });
CF_EXPECT(has_media_count == 0 || cfg.instances().size() == 1,
CF_EXPECT(has_media_count <= 1,
"TODO(b/520098369): support media devices for multiple instances");
std::vector<std::string> flags;
for (const auto& instance : cfg.instances()) {
for (size_t i = 0; i < cfg.instances().size(); ++i) {
const auto& instance = cfg.instances(i);
if (instance.has_media()) {
for (const auto& device : instance.media().devices()) {
std::string flag = "--media=";
Expand All @@ -63,6 +64,9 @@ Result<std::vector<std::string>> GenerateMediaFlags(
if (device.has_lens_facing()) {
flag += ":lens_facing=" + device.lens_facing();
}
if (cfg.instances().size() > 1) {
flag += ":instance=" + std::to_string(i);

@bridadan bridadan Sep 9, 2026

Copy link
Copy Markdown
Collaborator

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

For existing devices or configuration options, is this how they handle addressing which instance the value applies to when specified using CLI flags? Is there a precedent for this? @ser-io

@changyeon-jo changyeon-jo Sep 26, 2026

Copy link
Copy Markdown
Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Good question. I didn't find any precedent for addressing individual instances inside a repeatable flag. I'd like to move this PR to the pattern displays already use:

  • Add an InstancesMedia proto to launch_cvd.proto (per-instance lists of the same MediaDevice shape as load_config.proto), with --media_binproto/--media_textproto flags, the same way --displays_binproto/--displays_textproto work.
  • The JSON parser emits --media_binproto, which lifts the single-instance restriction. The JSON schema doesn't change.
  • Plain --media returns an error when num_instances > 1. Today it copies the same devices to every instance, so two instances read from one FIFO or share one /dev/videoN. It's also an error to combine it with --media_*proto.
  • :instance=<i> goes away.

One open question for @ser-io @bridadan: do you know of any users or CI that launch multi-instance fleets with --media today? The new error would break them. If there are some, the fallback is to keep duplicating emulated cameras and only reject FIFO- and device-backed types.

}
flags.push_back(flag);
}
}
Expand Down
1 change: 1 addition & 0 deletions base/cvd/cuttlefish/host/libs/config/cuttlefish_config.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -124,6 +124,7 @@ class CuttlefishConfig {
struct MediaConfig {
MediaType type;
std::string lens_facing;
std::optional<int> instance_index;

struct V4l2StreamProxyConfig {
std::string input_path;
Expand Down
7 changes: 7 additions & 0 deletions base/cvd/cuttlefish/host/libs/config/cuttlefish_config_instance.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -2054,6 +2054,7 @@ static constexpr char kMediaInputPath[] = "input_path";
static constexpr char kMediaInputWidth[] = "input_width";
static constexpr char kMediaInputHeight[] = "input_height";
static constexpr char kMediaInputFps[] = "input_fps";
static constexpr char kMediaInstanceIndex[] = "instance_index";

std::vector<CuttlefishConfig::MediaConfig>
CuttlefishConfig::InstanceSpecific::media_configs() const {
Expand All @@ -2065,6 +2066,9 @@ CuttlefishConfig::InstanceSpecific::media_configs() const {
if (json.isMember(kMediaLensFacing)) {
config.lens_facing = json[kMediaLensFacing].asString();
}
if (json.isMember(kMediaInstanceIndex)) {
config.instance_index = json[kMediaInstanceIndex].asInt();
}
if (config.type == CuttlefishConfig::MediaType::kV4l2StreamProxy) {
CuttlefishConfig::MediaConfig::V4l2StreamProxyConfig stream_config = {};
if (json.isMember(kMediaInputPath)) {
Expand Down Expand Up @@ -2094,6 +2098,9 @@ void CuttlefishConfig::MutableInstanceSpecific::set_media_configs(
Json::Value json(Json::objectValue);
json[kMediaType] = static_cast<int>(config.type);
json[kMediaLensFacing] = config.lens_facing;
if (config.instance_index.has_value()) {
json[kMediaInstanceIndex] = *config.instance_index;
}
if (config.type == CuttlefishConfig::MediaType::kV4l2StreamProxy &&
config.v4l2_stream_proxy.has_value()) {
json[kMediaInputPath] = config.v4l2_stream_proxy->input_path;
Expand Down
15 changes: 15 additions & 0 deletions base/cvd/cuttlefish/host/libs/config/media.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -79,6 +79,16 @@ Result<std::optional<CuttlefishConfig::MediaConfig>> ParseMediaConfig(
"Invalid lens_facing value: " << lens_facing);
}

std::optional<int> instance_index;
auto instance_it = props.find("instance");
if (instance_it != props.end()) {
int idx = 0;
CF_EXPECT(android::base::ParseInt(instance_it->second, &idx),
"Failed to parse instance index: " << instance_it->second);
CF_EXPECT(idx >= 0, "instance index must be non-negative: " << idx);
instance_index = idx;
}

std::optional<CuttlefishConfig::MediaConfig::V4l2StreamProxyConfig>
v4l2_stream_proxy;
if (type == CuttlefishConfig::MediaType::kV4l2StreamProxy) {
Expand All @@ -87,6 +97,8 @@ Result<std::optional<CuttlefishConfig::MediaConfig>> ParseMediaConfig(
auto source_it = props.find("input_path");
CF_EXPECT(source_it != props.end(),
"Missing 'input_path' for v4l2_stream_proxy");
CF_EXPECT(!source_it->second.empty(),
"'input_path' must not be empty for v4l2_stream_proxy");
stream_config.input_path = source_it->second;

auto width_it = props.find("input_width");
Expand All @@ -110,6 +122,8 @@ Result<std::optional<CuttlefishConfig::MediaConfig>> ParseMediaConfig(
auto fps_it = props.find("input_fps");
CF_EXPECT(fps_it != props.end(),
"Missing 'input_fps' for v4l2_stream_proxy");
CF_EXPECT(!fps_it->second.empty(),
"'input_fps' must not be empty for v4l2_stream_proxy");
stream_config.input_fps = fps_it->second;

v4l2_stream_proxy = stream_config;
Expand All @@ -118,6 +132,7 @@ Result<std::optional<CuttlefishConfig::MediaConfig>> ParseMediaConfig(
return CuttlefishConfig::MediaConfig{
.type = type,
.lens_facing = lens_facing,
.instance_index = instance_index,
.v4l2_stream_proxy = v4l2_stream_proxy,
};
}
Expand Down
3 changes: 2 additions & 1 deletion base/cvd/cuttlefish/host/libs/config/media.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -41,7 +41,8 @@ constexpr const char kMediaHelp[] =
" 'input_fps': frames per second (e.g., 30 or 30000/1001)\n\n"
"Supported keys:\n"
" 'lens_facing': optional, supported values: 'FRONT', 'BACK', "
"'EXTERNAL'\n\n"
"'EXTERNAL'\n"
" 'instance': optional, zero-based instance index to attach device to\n\n"
"Example usage:\n"
" --media=v4l2_emulated_camera_mplane:lens_facing=BACK\n"
" --media=v4l2_stream_proxy:input_path=/tmp/fifo:"
Expand Down
Loading