[libcamera-devel] [PATCH v2 3/4] cam: Extend request completion handler to deal with multiple streams

[Niklas Söderlund]

The completion handler needs to handle all buffers in the request. Solve
this by iterating over all buffers in the completed request and assign
each stream a name as we encounter them. The buffer writer needs to be
extended to learn about stream names so it can prefix the files it
writes with it.

Signed-off-by: Niklas Söderlund <niklas.soderlund at ragnatech.se>
---
 src/cam/buffer_writer.cpp |  5 +++--
 src/cam/buffer_writer.h   |  2 +-
 src/cam/main.cpp          | 42 ++++++++++++++++++++++++++++-----------
 3 files changed, 34 insertions(+), 15 deletions(-)

diff --git a/src/cam/buffer_writer.cpp b/src/cam/buffer_writer.cpp
index 2d2258b4cd1cbbc2..b82ffaded688226a 100644
--- a/src/cam/buffer_writer.cpp
+++ b/src/cam/buffer_writer.cpp
@@ -19,13 +19,14 @@ BufferWriter::BufferWriter(const std::string &pattern)
 {
 }
 
-int BufferWriter::write(libcamera::Buffer *buffer)
+int BufferWriter::write(libcamera::Buffer *buffer,
+			const std::string &streamName)
 {
 	std::string filename;
 	size_t pos;
 	int fd, ret = 0;
 
-	filename = pattern_;
+	filename = streamName + "-" + pattern_;
 	pos = filename.find_first_of('#');
 	if (pos != std::string::npos) {
 		std::stringstream ss;
diff --git a/src/cam/buffer_writer.h b/src/cam/buffer_writer.h
index 9705773e0e397d45..7bf785d1e83235ff 100644
--- a/src/cam/buffer_writer.h
+++ b/src/cam/buffer_writer.h
@@ -16,7 +16,7 @@ class BufferWriter
 public:
 	BufferWriter(const std::string &pattern = "frame-#.bin");
 
-	int write(libcamera::Buffer *buffer);
+	int write(libcamera::Buffer *buffer, const std::string &streamName);
 
 private:
 	std::string pattern_;
diff --git a/src/cam/main.cpp b/src/cam/main.cpp
index b47bda21cbb7f220..9af7907a3d937c28 100644
--- a/src/cam/main.cpp
+++ b/src/cam/main.cpp
@@ -145,28 +145,46 @@ static int prepareCameraConfig(std::map<Stream *, StreamConfiguration> *config)
 	return 0;
 }
 
+static std::string streamToName(const Stream *stream)
+{
+	static std::map<const Stream *, std::string> names;
+
+	if (names.find(stream) == names.end())
+		names[stream] = std::string("stream") + std::to_string(names.size());
+
+	return names[stream];
+}
+
 static void requestComplete(Request *request, const std::map<Stream *, Buffer *> &buffers)
 {
 	static uint64_t last = 0;
+	double fps = 0.0;
 
 	if (request->status() == Request::RequestCancelled)
 		return;
 
-	Buffer *buffer = buffers.begin()->second;
+	for (auto it = buffers.begin(); it != buffers.end(); ++it) {
+		Stream *stream = it->first;
+		Buffer *buffer = it->second;
+		std::string name = streamToName(stream);
 
-	double fps = buffer->timestamp() - last;
-	fps = last && fps ? 1000000000.0 / fps : 0.0;
-	last = buffer->timestamp();
+		if (it == buffers.begin()) {
+			fps = buffer->timestamp() - last;
+			fps = last && fps ? 1000000000.0 / fps : 0.0;
+			last = buffer->timestamp();
+		}
 
-	std::cout << "seq: " << std::setw(6) << std::setfill('0') << buffer->sequence()
-		  << " buf: " << buffer->index()
-		  << " bytesused: " << buffer->bytesused()
-		  << " timestamp: " << buffer->timestamp()
-		  << " fps: " << std::fixed << std::setprecision(2) << fps
-		  << std::endl;
+		std::cout << name << " seq: " << std::setw(6)
+			  << std::setfill('0') << buffer->sequence()
+			  << " buf: " << buffer->index()
+			  << " bytesused: " << buffer->bytesused()
+			  << " timestamp: " << buffer->timestamp()
+			  << " fps: " << std::fixed << std::setprecision(2) << fps
+			  << std::endl;
 
-	if (writer)
-		writer->write(buffer);
+		if (writer)
+			writer->write(buffer, name);
+	}
 
 	request = camera->createRequest();
 	if (!request) {
-- 
2.21.0