[RFC PATCH v2 13/13] apps: cam: Write raw file if PPM cannot be written

[Milan Zamazal]

`cam' application can be requested to write its output as a PPM file.
However, this is supported only for certain formats (only BGR888
currently).  If the output format cannot be written, `cam' reports an
error and doesn't write anything.

This is all right with a single stream input but impractical with
multiple streams of different output formats (e.g. a processed stream +
a raw stream) where some of them can be written in the supported format
while the other not.  In such a case, it's better to write the supported
formats as PPM files and the unsupported formats as raw files, with the
corresponding warning on stderr.  `.raw' extension is added to the file
name in such a case to make clear it's not a PPM file.

This is a sort of hack but serves the purpose for the moment.

Signed-off-by: Milan Zamazal <mzamazal at redhat.com>
---
 src/apps/cam/file_sink.cpp | 16 +++++++++++-----
 1 file changed, 11 insertions(+), 5 deletions(-)

diff --git a/src/apps/cam/file_sink.cpp b/src/apps/cam/file_sink.cpp
index 76e21db9..1a866137 100644
--- a/src/apps/cam/file_sink.cpp
+++ b/src/apps/cam/file_sink.cpp
@@ -7,6 +7,7 @@
 
 #include <array>
 #include <assert.h>
+#include <errno.h>
 #include <fcntl.h>
 #include <iomanip>
 #include <iostream>
@@ -133,11 +134,16 @@ void FileSink::writeBuffer(const Stream *stream, FrameBuffer *buffer,
 	if (fileType_ == FileType::Ppm) {
 		ret = PPMWriter::write(filename.c_str(), stream->configuration(),
 				       image->data(0));
-		if (ret < 0)
-			std::cerr << "failed to write PPM file `" << filename
-				  << "'" << std::endl;
-
-		return;
+		if (ret == -EINVAL) {
+			filename += ".raw";
+			std::cerr << "cannot write file in PPM format, writing `"
+				  << filename << "' instead" << std::endl;
+		} else {
+			if (ret < 0)
+				std::cerr << "failed to write PPM file `" << filename
+					  << "'" << std::endl;
+			return;
+		}
 	}
 
 	fd = open(filename.c_str(), O_CREAT | O_WRONLY |
-- 
2.48.1