Move _started from PictureAssetWriter into AssetWriter

and don't start the SoundAssetWriter until the first
thing is written to it.

5 files changed, 14 insertions, 10 deletions

diff --git a/src/asset_writer.cc b/src/asset_writer.cc
index 4611b38a..db2d4c53 100644
--- a/src/asset_writer.cc
+++ b/src/asset_writer.cc
@@ -38,6 +38,7 @@ AssetWriter::AssetWriter (MXF* mxf, boost::filesystem::path file)
 	, _file (file)
 	, _frames_written (0)
 	, _finalized (false)
+	, _started (false)
 	, _encryption_context (0)
 {
 	if (mxf->key ()) {
diff --git a/src/asset_writer.h b/src/asset_writer.h
index 31d2f7ae..66d7396f 100644
--- a/src/asset_writer.h
+++ b/src/asset_writer.h
@@ -59,6 +59,8 @@ protected:
 	int64_t _frames_written;
 	/** true if finalize() has been called on this object */
 	bool _finalized;
+	/** true if something has been written to this asset */
+	bool _started;
 	ASDCP::AESEncContext* _encryption_context;
 };
 
diff --git a/src/picture_asset_writer.cc b/src/picture_asset_writer.cc
index b47aaabd..3bb6a597 100644
--- a/src/picture_asset_writer.cc
+++ b/src/picture_asset_writer.cc
@@ -34,7 +34,6 @@ using namespace dcp;
 PictureAssetWriter::PictureAssetWriter (PictureAsset* asset, boost::filesystem::path file, Standard standard, bool overwrite)
 	: AssetWriter (asset, file)
 	, _picture_asset (asset)
-	, _started (false)
 	, _standard (standard)
 	, _overwrite (overwrite)
 {
diff --git a/src/picture_asset_writer.h b/src/picture_asset_writer.h
index e263d479..a815fbcd 100644
--- a/src/picture_asset_writer.h
+++ b/src/picture_asset_writer.h
@@ -74,7 +74,6 @@ protected:
 	PictureAssetWriter (PictureAsset *, boost::filesystem::path, Standard standard, bool);
 
 	PictureAsset* _picture_asset;
-	bool _started;
 	Standard _standard;
 	bool _overwrite;
 };
diff --git a/src/sound_asset_writer.cc b/src/sound_asset_writer.cc
index 4a27639e..f24605bb 100644
--- a/src/sound_asset_writer.cc
+++ b/src/sound_asset_writer.cc
@@ -56,13 +56,6 @@ SoundAssetWriter::SoundAssetWriter (SoundAsset* asset, boost::filesystem::path f
 	memset (_state->frame_buffer.Data(), 0, _state->frame_buffer.Capacity());
 
 	_sound_asset->fill_writer_info (&_state->writer_info, _sound_asset->id(), standard);
-
-	Kumu::Result_t r = _state->mxf_writer.OpenWrite (file.string().c_str(), _state->writer_info, _state->audio_desc);
-	if (ASDCP_FAILURE (r)) {
-		boost::throw_exception (FileError ("could not open audio MXF for writing", file.string(), r));
-	}
-
-	_sound_asset->set_file (file);
 }
 
 void
@@ -70,6 +63,16 @@ SoundAssetWriter::write (float const * const * data, int frames)
 {
 	DCP_ASSERT (!_finalized);
 
+	if (!_started) {
+		Kumu::Result_t r = _state->mxf_writer.OpenWrite (_file.string().c_str(), _state->writer_info, _state->audio_desc);
+		if (ASDCP_FAILURE (r)) {
+			boost::throw_exception (FileError ("could not open audio MXF for writing", _file.string(), r));
+		}
+
+		_sound_asset->set_file (_file);
+		_started = true;
+	}
+
 	for (int i = 0; i < frames; ++i) {
 
 		byte_t* out = _state->frame_buffer.Data() + _frame_buffer_offset;
@@ -112,7 +115,7 @@ SoundAssetWriter::finalize ()
 		write_current_frame ();
 	}
 
-	if (ASDCP_FAILURE (_state->mxf_writer.Finalize())) {
+	if (_started && ASDCP_FAILURE (_state->mxf_writer.Finalize())) {
 		boost::throw_exception (MiscError ("could not finalise audio MXF"));
 	}