rollback to 3428, before the mysterious removal of libs/* at 3431/3432

git-svn-id: svn://localhost/ardour2/branches/3.0@3435 d708f5d6-7413-0410-9779-e7cbd77b26cf

1 files changed, 900 insertions, 0 deletions

diff --git a/libs/ardour/sndfilesource.cc b/libs/ardour/sndfilesource.cc
new file mode 100644
index 0000000000..ab090381b4
--- /dev/null
+++ b/libs/ardour/sndfilesource.cc
@@ -0,0 +1,900 @@
+/*
+    Copyright (C) 2006 Paul Davis 
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+*/
+
+#include <cstring>
+#include <cerrno>
+#include <climits>
+
+#include <pwd.h>
+#include <sys/utsname.h>
+#include <sys/stat.h>
+
+#include <glibmm/miscutils.h>
+#include <ardour/sndfilesource.h>
+#include <ardour/sndfile_helpers.h>
+#include <ardour/utils.h>
+
+#include "i18n.h"
+
+using namespace std;
+using namespace ARDOUR;
+using namespace PBD;
+using Glib::ustring;
+
+gain_t* SndFileSource::out_coefficient = 0;
+gain_t* SndFileSource::in_coefficient = 0;
+nframes_t SndFileSource::xfade_frames = 64;
+const AudioFileSource::Flag SndFileSource::default_writable_flags = AudioFileSource::Flag (AudioFileSource::Writable|
+											   AudioFileSource::Removable|
+											   AudioFileSource::RemovableIfEmpty|
+											   AudioFileSource::CanRename);
+SndFileSource::SndFileSource (Session& s, const XMLNode& node)
+	: AudioFileSource (s, node)
+{
+	init ();
+
+	if (open()) {
+		throw failed_constructor ();
+	}
+}
+
+SndFileSource::SndFileSource (Session& s, ustring path, int chn, Flag flags)
+          /* files created this way are never writable or removable */
+	: AudioFileSource (s, path, Flag (flags & ~(Writable|Removable|RemovableIfEmpty|RemoveAtDestroy)))
+{
+	_channel = chn;
+
+	init ();
+
+	if (open()) {
+		throw failed_constructor ();
+	}
+}
+
+SndFileSource::SndFileSource (Session& s, ustring path, SampleFormat sfmt, HeaderFormat hf, nframes_t rate, Flag flags)
+	: AudioFileSource (s, path, flags, sfmt, hf)
+{
+	int fmt = 0;
+
+	init ();
+
+	/* this constructor is used to construct new files, not open
+	   existing ones.
+	*/
+
+	file_is_new = true;
+
+	switch (hf) {
+	case CAF:
+		fmt = SF_FORMAT_CAF;
+		_flags = Flag (_flags & ~Broadcast);
+		break;
+
+	case AIFF:
+		fmt = SF_FORMAT_AIFF;
+		_flags = Flag (_flags & ~Broadcast);
+		break;
+
+	case BWF:
+		fmt = SF_FORMAT_WAV;
+		_flags = Flag (_flags | Broadcast);
+		break;
+
+	case WAVE:
+		fmt = SF_FORMAT_WAV;
+		_flags = Flag (_flags & ~Broadcast);
+		break;
+
+	case WAVE64:
+		fmt = SF_FORMAT_W64;
+		_flags = Flag (_flags & ~Broadcast);
+		break;
+
+	default:
+		fatal << string_compose (_("programming error: %1"), X_("unsupported audio header format requested")) << endmsg;
+		/*NOTREACHED*/
+		break;
+
+	}
+
+	switch (sfmt) {
+	case FormatFloat:
+		fmt |= SF_FORMAT_FLOAT;
+		break;
+
+	case FormatInt24:
+		fmt |= SF_FORMAT_PCM_24;
+		break;
+
+	case FormatInt16:
+		fmt |= SF_FORMAT_PCM_16;
+		break;
+	}
+	
+	_info.channels = 1;
+	_info.samplerate = rate;
+	_info.format = fmt;
+
+	if (open()) {
+		throw failed_constructor();
+	}
+
+	if (writable() && (_flags & Broadcast)) {
+
+		_broadcast_info = new SF_BROADCAST_INFO;
+		memset (_broadcast_info, 0, sizeof (*_broadcast_info));
+		
+		snprintf (_broadcast_info->description, sizeof (_broadcast_info->description), "BWF %s", _name.c_str());
+		
+		struct utsname utsinfo;
+
+		if (uname (&utsinfo)) {
+			error << string_compose(_("FileSource: cannot get host information for BWF header (%1)"), strerror(errno)) << endmsg;
+			return;
+		}
+		
+		snprintf (_broadcast_info->originator, sizeof (_broadcast_info->originator), "ardour:%s:%s:%s:%s:%s)", 
+			  Glib::get_real_name().c_str(),
+			  utsinfo.nodename,
+			  utsinfo.sysname,
+			  utsinfo.release,
+			  utsinfo.version);
+		
+		_broadcast_info->version = 1;  
+		_broadcast_info->time_reference_low = 0;  
+		_broadcast_info->time_reference_high = 0;  
+		
+		/* XXX do something about this field */
+		
+		snprintf (_broadcast_info->umid, sizeof (_broadcast_info->umid), "%s", "fnord");
+		
+		/* coding history is added by libsndfile */
+
+		if (sf_command (sf, SFC_SET_BROADCAST_INFO, _broadcast_info, sizeof (_broadcast_info)) != SF_TRUE) {
+			char errbuf[256];
+			sf_error_str (0, errbuf, sizeof (errbuf) - 1);
+			error << string_compose (_("cannot set broadcast info for audio file %1 (%2); dropping broadcast info for this file"), _path, errbuf) << endmsg;
+			_flags = Flag (_flags & ~Broadcast);
+			delete _broadcast_info;
+			_broadcast_info = 0;
+		} 
+	} 
+}
+
+void 
+SndFileSource::init ()
+{
+	ustring file;
+
+	// lets try to keep the object initalizations here at the top
+	xfade_buf = 0;
+	sf = 0;
+	_broadcast_info = 0;
+
+	if (is_embedded()) {
+		_name = _path;
+	} else {
+		_name = Glib::path_get_basename (_path);
+	}
+
+	/* although libsndfile says we don't need to set this,
+	   valgrind and source code shows us that we do.
+	*/
+
+	memset (&_info, 0, sizeof(_info));
+
+	_capture_start = false;
+	_capture_end = false;
+	file_pos = 0;
+
+	if (destructive()) {	
+		xfade_buf = new Sample[xfade_frames];
+		timeline_position = header_position_offset;
+	}
+
+	AudioFileSource::HeaderPositionOffsetChanged.connect (mem_fun (*this, &SndFileSource::handle_header_position_change));
+}
+
+int
+SndFileSource::open ()
+{
+	if ((sf = sf_open (_path.c_str(), (writable() ? SFM_RDWR : SFM_READ), &_info)) == 0) {
+		char errbuf[256];
+		sf_error_str (0, errbuf, sizeof (errbuf) - 1);
+#ifndef HAVE_COREAUDIO
+		/* if we have CoreAudio, we will be falling back to that if libsndfile fails,
+		   so we don't want to see this message.
+		*/
+
+		error << string_compose(_("SndFileSource: cannot open file \"%1\" for %2 (%3)"), 
+					_path, (writable() ? "read+write" : "reading"), errbuf) << endmsg;
+#endif
+		return -1;
+	}
+
+	if (_channel >= _info.channels) {
+#ifndef HAVE_COREAUDIO
+		error << string_compose(_("SndFileSource: file only contains %1 channels; %2 is invalid as a channel number"), _info.channels, _channel) << endmsg;
+#endif
+		sf_close (sf);
+		sf = 0;
+		return -1;
+	}
+
+	_length = _info.frames;
+
+	_broadcast_info = new SF_BROADCAST_INFO;
+	memset (_broadcast_info, 0, sizeof (*_broadcast_info));
+	
+	bool timecode_info_exists;
+
+	set_timeline_position (get_timecode_info (sf, _broadcast_info, timecode_info_exists));
+
+	if (_length != 0 && !timecode_info_exists) {
+		delete _broadcast_info;
+		_broadcast_info = 0;
+		_flags = Flag (_flags & ~Broadcast);
+	}
+
+	if (writable()) {
+		sf_command (sf, SFC_SET_UPDATE_HEADER_AUTO, 0, SF_FALSE);
+	}
+
+	return 0;
+}
+
+SndFileSource::~SndFileSource ()
+{
+	GoingAway (); /* EMIT SIGNAL */
+
+	if (sf) {
+		sf_close (sf);
+		sf = 0;
+
+		/* stupid libsndfile updated the headers on close,
+		   so touch the peakfile if it exists and has data
+		   to make sure its time is as new as the audio
+		   file.
+		*/
+
+		touch_peakfile ();
+	}
+
+	if (_broadcast_info) {
+		delete _broadcast_info;
+	}
+
+	if (xfade_buf) {
+		delete [] xfade_buf;
+	}
+}
+
+float
+SndFileSource::sample_rate () const 
+{
+	return _info.samplerate;
+}
+
+nframes_t
+SndFileSource::read_unlocked (Sample *dst, nframes_t start, nframes_t cnt) const
+{
+	int32_t nread;
+	float *ptr;
+	uint32_t real_cnt;
+	nframes_t file_cnt;
+
+	if (start > _length) {
+
+		/* read starts beyond end of data, just memset to zero */
+		
+		file_cnt = 0;
+
+	} else if (start + cnt > _length) {
+		
+		/* read ends beyond end of data, read some, memset the rest */
+		
+		file_cnt = _length - start;
+
+	} else {
+		
+		/* read is entirely within data */
+
+		file_cnt = cnt;
+	}
+	
+	if (file_cnt != cnt) {
+		nframes_t delta = cnt - file_cnt;
+		memset (dst+file_cnt, 0, sizeof (Sample) * delta);
+	}
+
+	if (file_cnt) {
+
+		if (sf_seek (sf, (sf_count_t) start, SEEK_SET|SFM_READ) != (sf_count_t) start) {
+			char errbuf[256];
+			sf_error_str (0, errbuf, sizeof (errbuf) - 1);
+			error << string_compose(_("SndFileSource: could not seek to frame %1 within %2 (%3)"), start, _name.substr (1), errbuf) << endmsg;
+			return 0;
+		}
+		
+		if (_info.channels == 1) {
+			nframes_t ret = sf_read_float (sf, dst, file_cnt);
+			_read_data_count = cnt * sizeof(float);
+			return ret;
+		}
+	}
+
+	real_cnt = cnt * _info.channels;
+
+	Sample* interleave_buf = get_interleave_buffer (real_cnt);
+	
+	nread = sf_read_float (sf, interleave_buf, real_cnt);
+	ptr = interleave_buf + _channel;
+	nread /= _info.channels;
+	
+	/* stride through the interleaved data */
+	
+	for (int32_t n = 0; n < nread; ++n) {
+		dst[n] = *ptr;
+		ptr += _info.channels;
+	}
+
+	_read_data_count = cnt * sizeof(float);
+		
+	return nread;
+}
+
+nframes_t 
+SndFileSource::write_unlocked (Sample *data, nframes_t cnt)
+{
+	if (destructive()) {
+		return destructive_write_unlocked (data, cnt);
+	} else {
+		return nondestructive_write_unlocked (data, cnt);
+	}
+}
+
+nframes_t 
+SndFileSource::nondestructive_write_unlocked (Sample *data, nframes_t cnt)
+{
+	if (!writable()) {
+		warning << string_compose (_("attempt to write a non-writable audio file source (%1)"), _path) << endmsg;
+		return 0;
+	}
+
+	if (_info.channels != 1) {
+		fatal << string_compose (_("programming error: %1 %2"), X_("SndFileSource::write called on non-mono file"), _path) << endmsg;
+		/*NOTREACHED*/
+		return 0;
+	}
+	
+	nframes_t oldlen;
+	int32_t frame_pos = _length;
+
+	if (write_float (data, frame_pos, cnt) != cnt) {
+		return 0;
+	}
+
+	oldlen = _length;
+	update_length (oldlen, cnt);
+
+	if (_build_peakfiles) {
+		compute_and_write_peaks (data, frame_pos, cnt, false, true);
+	}
+
+	_write_data_count = cnt;
+	
+	return cnt;
+}
+
+nframes_t
+SndFileSource::destructive_write_unlocked (Sample* data, nframes_t cnt)
+{
+	nframes_t old_file_pos;
+
+	if (!writable()) {
+		warning << string_compose (_("attempt to write a non-writable audio file source (%1)"), _path) << endmsg;
+		return 0;
+	}
+
+	if (_capture_start && _capture_end) {
+
+		/* start and end of capture both occur within the data we are writing,
+		   so do both crossfades.
+		*/
+
+		_capture_start = false;
+		_capture_end = false;
+		
+		/* move to the correct location place */
+		file_pos = capture_start_frame - timeline_position;
+		
+		// split cnt in half
+		nframes_t subcnt = cnt / 2;
+		nframes_t ofilepos = file_pos;
+		
+		// fade in
+		if (crossfade (data, subcnt, 1) != subcnt) {
+			return 0;
+		}
+		
+		file_pos += subcnt;
+		Sample * tmpdata = data + subcnt;
+		
+		// fade out
+		subcnt = cnt - subcnt;
+		if (crossfade (tmpdata, subcnt, 0) != subcnt) {
+			return 0;
+		}
+		
+		file_pos = ofilepos; // adjusted below
+
+	} else if (_capture_start) {
+
+		/* start of capture both occur within the data we are writing,
+		   so do the fade in
+		*/
+
+		_capture_start = false;
+		_capture_end = false;
+		
+		/* move to the correct location place */
+		file_pos = capture_start_frame - timeline_position;
+
+		if (crossfade (data, cnt, 1) != cnt) {
+			return 0;
+		}
+		
+	} else if (_capture_end) {
+
+		/* end of capture both occur within the data we are writing,
+		   so do the fade out
+		*/
+
+		_capture_start = false;
+		_capture_end = false;
+		
+		if (crossfade (data, cnt, 0) != cnt) {
+			return 0;
+		}
+
+	} else {
+
+		/* in the middle of recording */
+
+		if (write_float (data, file_pos, cnt) != cnt) {
+			return 0;
+		}
+	}
+
+	old_file_pos = file_pos;
+	update_length (file_pos, cnt);
+
+	if (_build_peakfiles) {
+		compute_and_write_peaks (data, file_pos, cnt, false, true);
+	}
+
+	file_pos += cnt;
+	
+	return cnt;
+}
+
+int
+SndFileSource::update_header (nframes_t when, struct tm& now, time_t tnow)
+{	
+	set_timeline_position (when);
+
+	if (_flags & Broadcast) {
+		if (setup_broadcast_info (when, now, tnow)) {
+			return -1;
+		}
+	} 
+
+	return flush_header ();
+}
+
+int
+SndFileSource::flush_header ()
+{
+	if (!writable() || (sf == 0)) {
+		warning << string_compose (_("attempt to flush a non-writable audio file source (%1)"), _path) << endmsg;
+		return -1;
+	}
+	return (sf_command (sf, SFC_UPDATE_HEADER_NOW, 0, 0) != SF_TRUE);
+}
+
+int
+SndFileSource::setup_broadcast_info (nframes_t when, struct tm& now, time_t tnow)
+{
+	if (!writable()) {
+		warning << string_compose (_("attempt to store broadcast info in a non-writable audio file source (%1)"), _path) << endmsg;
+		return -1;
+	}
+
+	if (!(_flags & Broadcast)) {
+		return 0;
+	}
+
+	/* random code is 9 digits */
+	
+	int random_code = random() % 999999999;
+	
+	snprintf (_broadcast_info->originator_reference, sizeof (_broadcast_info->originator_reference), "%2s%3s%12s%02d%02d%02d%9d",
+		  Config->get_bwf_country_code().c_str(),
+		  Config->get_bwf_organization_code().c_str(),
+		  bwf_serial_number,
+		  now.tm_hour,
+		  now.tm_min,
+		  now.tm_sec,
+		  random_code);
+	
+	snprintf (_broadcast_info->origination_date, sizeof (_broadcast_info->origination_date), "%4d-%02d-%02d",
+		  1900 + now.tm_year,
+		  now.tm_mon,
+		  now.tm_mday);
+	
+	snprintf (_broadcast_info->origination_time, sizeof (_broadcast_info->origination_time), "%02d:%02d:%02d",
+		  now.tm_hour,
+		  now.tm_min,
+		  now.tm_sec);
+
+	/* now update header position taking header offset into account */
+	
+	set_header_timeline_position ();
+
+	if (sf_command (sf, SFC_SET_BROADCAST_INFO, _broadcast_info, sizeof (*_broadcast_info)) != SF_TRUE) {
+		error << string_compose (_("cannot set broadcast info for audio file %1; Dropping broadcast info for this file"), _path) << endmsg;
+		_flags = Flag (_flags & ~Broadcast);
+		delete _broadcast_info;
+		_broadcast_info = 0;
+		return -1;
+	}
+
+	return 0;
+}
+
+void
+SndFileSource::set_header_timeline_position ()
+{
+	if (!(_flags & Broadcast)) {
+		return;
+	}
+
+	_broadcast_info->time_reference_high = (timeline_position >> 32);
+	_broadcast_info->time_reference_low = (timeline_position & 0xffffffff);
+
+	if (sf_command (sf, SFC_SET_BROADCAST_INFO, _broadcast_info, sizeof (*_broadcast_info)) != SF_TRUE) {
+		error << string_compose (_("cannot set broadcast info for audio file %1; Dropping broadcast info for this file"), _path) << endmsg;
+		_flags = Flag (_flags & ~Broadcast);
+		delete _broadcast_info;
+		_broadcast_info = 0;
+	}
+}
+
+nframes_t
+SndFileSource::write_float (Sample* data, nframes_t frame_pos, nframes_t cnt)
+{
+	if (sf_seek (sf, frame_pos, SEEK_SET|SFM_WRITE) < 0) {
+		char errbuf[256];
+		sf_error_str (0, errbuf, sizeof (errbuf) - 1);
+		error << string_compose (_("%1: cannot seek to %2 (libsndfile error: %3"), _path, frame_pos, errbuf) << endmsg;
+		return 0;
+	}
+	
+	if (sf_writef_float (sf, data, cnt) != (ssize_t) cnt) {
+		return 0;
+	}
+	
+	return cnt;
+}
+
+nframes_t
+SndFileSource::natural_position() const
+{
+	return timeline_position;
+}
+
+bool
+SndFileSource::set_destructive (bool yn)
+{
+	if (yn) {
+		_flags = Flag (_flags | Destructive);
+		if (!xfade_buf) {
+			xfade_buf = new Sample[xfade_frames];
+		}
+		clear_capture_marks ();
+		timeline_position = header_position_offset;
+	} else {
+		_flags = Flag (_flags & ~Destructive);
+		timeline_position = 0;
+		/* leave xfade buf alone in case we need it again later */
+	}
+
+	return true;
+}
+
+void
+SndFileSource::clear_capture_marks ()
+{
+	_capture_start = false;
+	_capture_end = false;
+}	
+
+void
+SndFileSource::mark_capture_start (nframes_t pos)
+{
+	if (destructive()) {
+		if (pos < timeline_position) {
+			_capture_start = false;
+		} else {
+			_capture_start = true;
+			capture_start_frame = pos;
+		}
+	}
+}
+
+void
+SndFileSource::mark_capture_end()
+{
+	if (destructive()) {
+		_capture_end = true;
+	}
+}
+
+nframes_t
+SndFileSource::crossfade (Sample* data, nframes_t cnt, int fade_in)
+{
+	nframes_t xfade = min (xfade_frames, cnt);
+	nframes_t nofade = cnt - xfade;
+	Sample* fade_data = 0;
+	nframes_t fade_position = 0; // in frames
+	ssize_t retval;
+	nframes_t file_cnt;
+
+	if (fade_in) {
+		fade_position = file_pos;
+		fade_data = data;
+	} else {
+		fade_position = file_pos + nofade;
+		fade_data = data + nofade;
+	}
+
+	if (fade_position > _length) {
+		
+		/* read starts beyond end of data, just memset to zero */
+		
+		file_cnt = 0;
+
+	} else if (fade_position + xfade > _length) {
+		
+		/* read ends beyond end of data, read some, memset the rest */
+		
+		file_cnt = _length - fade_position;
+
+	} else {
+		
+		/* read is entirely within data */
+
+		file_cnt = xfade;
+	}
+
+	if (file_cnt) {
+		
+		if ((retval = read_unlocked (xfade_buf, fade_position, file_cnt)) != (ssize_t) file_cnt) {
+			if (retval >= 0 && errno == EAGAIN) {
+				/* XXX - can we really trust that errno is meaningful here?  yes POSIX, i'm talking to you.
+				 * short or no data there */
+				memset (xfade_buf, 0, xfade * sizeof(Sample));
+			} else {
+				error << string_compose(_("SndFileSource: \"%1\" bad read retval: %2 of %5 (%3: %4)"), _path, retval, errno, strerror (errno), xfade) << endmsg;
+				return 0;
+			}
+		}
+	} 
+
+	if (file_cnt != xfade) {
+		nframes_t delta = xfade - file_cnt;
+		memset (xfade_buf+file_cnt, 0, sizeof (Sample) * delta);
+	}
+	
+	if (nofade && !fade_in) {
+		if (write_float (data, file_pos, nofade) != nofade) {
+			error << string_compose(_("SndFileSource: \"%1\" bad write (%2)"), _path, strerror (errno)) << endmsg;
+			return 0;
+		}
+	}
+
+	if (xfade == xfade_frames) {
+
+		nframes_t n;
+
+		/* use the standard xfade curve */
+		
+		if (fade_in) {
+
+			/* fade new material in */
+			
+			for (n = 0; n < xfade; ++n) {
+				xfade_buf[n] = (xfade_buf[n] * out_coefficient[n]) + (fade_data[n] * in_coefficient[n]);
+			}
+
+		} else {
+
+
+			/* fade new material out */
+			
+			for (n = 0; n < xfade; ++n) {
+				xfade_buf[n] = (xfade_buf[n] * in_coefficient[n]) + (fade_data[n] * out_coefficient[n]);
+			}
+		}
+
+	} else if (xfade < xfade_frames) {
+
+		gain_t in[xfade];
+		gain_t out[xfade];
+
+		/* short xfade, compute custom curve */
+
+		compute_equal_power_fades (xfade, in, out);
+
+		for (nframes_t n = 0; n < xfade; ++n) {
+			xfade_buf[n] = (xfade_buf[n] * out[n]) + (fade_data[n] * in[n]);		
+		}
+
+	} else if (xfade) {
+
+		/* long xfade length, has to be computed across several calls */
+
+	}
+
+	if (xfade) {
+		if (write_float (xfade_buf, fade_position, xfade) != xfade) {
+			error << string_compose(_("SndFileSource: \"%1\" bad write (%2)"), _path, strerror (errno)) << endmsg;
+			return 0;
+		}
+	}
+	
+	if (fade_in && nofade) {
+		if (write_float (data + xfade, file_pos + xfade, nofade) != nofade) {
+			error << string_compose(_("SndFileSource: \"%1\" bad write (%2)"), _path, strerror (errno)) << endmsg;
+			return 0;
+		}
+	}
+
+	return cnt;
+}
+
+nframes_t
+SndFileSource::last_capture_start_frame () const
+{
+	if (destructive()) {
+		return capture_start_frame;
+	} else {
+		return 0;
+	}
+}
+
+void
+SndFileSource::handle_header_position_change ()
+{
+	if (destructive()) {
+		if ( _length != 0 ) {
+			error << string_compose(_("Filesource: start time is already set for existing file (%1): Cannot change start time."), _path ) << endmsg;
+			//in the future, pop up a dialog here that allows user to regenerate file with new start offset
+		} else if (writable()) {
+			timeline_position = header_position_offset;
+			set_header_timeline_position ();  //this will get flushed if/when the file is recorded to
+		}
+	}
+}
+
+void
+SndFileSource::setup_standard_crossfades (nframes_t rate)
+{
+	/* This static method is assumed to have been called by the Session
+	   before any DFS's are created.
+	*/
+
+	xfade_frames = (nframes_t) floor ((Config->get_destructive_xfade_msecs () / 1000.0) * rate);
+
+	if (out_coefficient) {
+		delete [] out_coefficient;
+	}
+
+	if (in_coefficient) {
+		delete [] in_coefficient;
+	}
+
+	out_coefficient = new gain_t[xfade_frames];
+	in_coefficient = new gain_t[xfade_frames];
+
+	compute_equal_power_fades (xfade_frames, in_coefficient, out_coefficient);
+}
+
+void
+SndFileSource::set_timeline_position (int64_t pos)
+{
+	// destructive track timeline postion does not change
+	// except at instantion or when header_position_offset 
+	// (session start) changes
+
+	if (!destructive()) {
+		AudioFileSource::set_timeline_position (pos);
+	} 
+}
+
+int
+SndFileSource::get_soundfile_info (const ustring& path, SoundFileInfo& info, string& error_msg)
+{
+	SNDFILE *sf;
+	SF_INFO sf_info;
+	SF_BROADCAST_INFO binfo;
+	bool timecode_exists;
+
+	sf_info.format = 0; // libsndfile says to clear this before sf_open().
+
+	if ((sf = sf_open ((char*) path.c_str(), SFM_READ, &sf_info)) == 0) { 
+		char errbuf[256];
+		error_msg = sf_error_str (0, errbuf, sizeof (errbuf) - 1);
+		return false;
+	}
+
+	info.samplerate  = sf_info.samplerate;
+	info.channels    = sf_info.channels;
+	info.length      = sf_info.frames;
+	info.format_name = string_compose("Format: %1, %2",
+					   sndfile_major_format(sf_info.format),
+					   sndfile_minor_format(sf_info.format));
+
+	memset (&binfo, 0, sizeof (binfo));
+	info.timecode  = get_timecode_info (sf, &binfo, timecode_exists);
+
+	if (!timecode_exists) {
+		info.timecode = 0;
+	}
+	
+	sf_close (sf);
+
+	return true;
+}
+
+int64_t
+SndFileSource::get_timecode_info (SNDFILE* sf, SF_BROADCAST_INFO* binfo, bool& exists)
+{
+	if (sf_command (sf, SFC_GET_BROADCAST_INFO, binfo, sizeof (*binfo)) != SF_TRUE) {
+		exists = false;
+		return (header_position_offset);
+	} 
+	
+	/* XXX 64 bit alert: when JACK switches to a 64 bit frame count, this needs to use the high bits
+	   of the time reference.
+	*/
+	
+	exists = true;
+	int64_t ret = (uint32_t) binfo->time_reference_high;
+	ret <<= 32;
+	ret |= (uint32_t) binfo->time_reference_low;
+	return ret;
+}
+
+bool
+SndFileSource::one_of_several_channels () const
+{
+	return _info.channels > 1;
+}
+