Add simple support for generating audio MXFs from part of a WAV file (for multi-reel...

[libdcp.git] / src / sound_asset.cc

diff --git a/src/sound_asset.cc b/src/sound_asset.cc
index e987239a498eef3686a8cd80d00f249f4e07e831..98266b2805d486164f75545b6b5dd67b98ce2e8d 100644 (file)
--- a/src/sound_asset.cc
+++ b/src/sound_asset.cc
@@ -42,12 +42,15 @@ using boost::lexical_cast;
 using namespace libdcp;
 
 SoundAsset::SoundAsset (
-       vector<string> const & files, string directory, string mxf_name, boost::signals2::signal<void (float)>* progress, int fps, int length
+       vector<string> const & files, string directory, string mxf_name, boost::signals2::signal<void (float)>* progress, int fps, int length, int start_frame
        )
        : MXFAsset (directory, mxf_name, progress, fps, 0, length)
        , _channels (files.size ())
        , _sampling_rate (0)
+       , _start_frame (start_frame)
 {
+       assert (_channels);
+       
        construct (boost::bind (&SoundAsset::path_from_channel, this, _1, files));
 }
 
@@ -56,18 +59,22 @@ SoundAsset::SoundAsset (
        string directory,
        string mxf_name,
        boost::signals2::signal<void (float)>* progress,
-       int fps, int length, int channels
+       int fps, int length, int start_frame, int channels
        )
        : MXFAsset (directory, mxf_name, progress, fps, 0, length)
        , _channels (channels)
        , _sampling_rate (0)
+       , _start_frame (start_frame)
 {
+       assert (_channels);
+       
        construct (get_path);
 }
 
 SoundAsset::SoundAsset (string directory, string mxf_name, int fps, int entry_point, int length)
        : MXFAsset (directory, mxf_name, 0, fps, entry_point, length)
        , _channels (0)
+       , _start_frame (0)
 {
        ASDCP::PCM::MXFReader reader;
        if (ASDCP_FAILURE (reader.OpenRead (path().string().c_str()))) {
@@ -96,7 +103,7 @@ void
 SoundAsset::construct (boost::function<string (Channel)> get_path)
 {
        ASDCP::Rational asdcp_fps (_fps, 1);
-       
+
        ASDCP::PCM::WAVParser pcm_parser_channel[_channels];
        if (pcm_parser_channel[0].OpenRead (get_path(LEFT).c_str(), asdcp_fps)) {
                throw FileError ("could not open WAV file for reading", get_path(LEFT));
@@ -153,6 +160,15 @@ SoundAsset::construct (boost::function<string (Channel)> get_path)
                throw FileError ("could not open audio MXF for writing", path().string());
        }
 
+       /* Skip through up to our _start_frame; this is pretty inefficient... */
+       for (int i = 0; i < _start_frame; ++i) {
+               for (int j = 0; j < _channels; ++j) {
+                       if (ASDCP_FAILURE (pcm_parser_channel[j].ReadFrame (frame_buffer_channel[j]))) {
+                               throw MiscError ("could not read audio frame");
+                       }
+               }
+       }
+       
        for (int i = 0; i < _length; ++i) {
 
                for (int j = 0; j < _channels; ++j) {