caimportable.cc

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/*
    Copyright (C) 2012 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 "ardour/caimportable.h"
#include <sndfile.h>
#include "pbd/error.h"

#include "i18n.h"

using namespace ARDOUR;
using namespace std;
using namespace PBD;

CAImportableSource::CAImportableSource (const string& path)
{
        try {
                af.Open (path.c_str());

                CAStreamBasicDescription file_format (af.GetFileDataFormat());
                CAStreamBasicDescription client_format (file_format);

                /* set canonial form (PCM, native float packed, 32 bit, with the correct number of channels
                   and interleaved (since we plan to deinterleave ourselves)
                */

                client_format.SetCanonical(client_format.NumberChannels(), true);
                af.SetClientFormat (client_format);

        } catch (CAXException& cax) {
                //Don't report an error here since there is one higher up in import.
                //Since libsndfile gets tried second, any failures here may show as
                //invalid errors in the Error log.
                throw failed_constructor ();
        }

}

CAImportableSource::~CAImportableSource ()
{
}

framecnt_t
CAImportableSource::read (Sample* buffer, framecnt_t nframes)
{
        framecnt_t nread = 0;
        AudioBufferList abl;
        framecnt_t per_channel;
        bool at_end = false;

        abl.mNumberBuffers = 1;
        abl.mBuffers[0].mNumberChannels = channels();

        per_channel = nframes / abl.mBuffers[0].mNumberChannels;

        while (nread < per_channel) {

                UInt32 new_cnt = per_channel - nread;

                abl.mBuffers[0].mDataByteSize = new_cnt * abl.mBuffers[0].mNumberChannels * sizeof(Sample);
                abl.mBuffers[0].mData = buffer + nread;

                try {
                        af.Read (new_cnt, &abl);
                } catch (CAXException& cax) {
                        error << string_compose("CAImportable: %1", cax.mOperation);
                        return -1;
                }

                if (new_cnt == 0) {
                        /* EOF */
                        at_end = true;
                        break;
                }

                nread += new_cnt;
        }

        if (!at_end && nread < per_channel) {
                return 0;
        } else {
                return nread * abl.mBuffers[0].mNumberChannels;
        }
}

uint
CAImportableSource::channels () const
{
        return af.GetFileDataFormat().NumberChannels();
}

framecnt_t
CAImportableSource::length () const
{
        return af.GetNumberFrames();
}

framecnt_t
CAImportableSource::samplerate () const
{
        CAStreamBasicDescription client_asbd;

        try {
                client_asbd = af.GetClientDataFormat ();
        } catch (CAXException& cax) {
                error << string_compose ("CAImportable: %1", cax.mOperation) << endmsg;
                return 0.0;
        }

        return client_asbd.mSampleRate;
}

void
CAImportableSource::seek (framepos_t pos)
{
        try {
                af.Seek (pos);
        } catch (CAXException& cax) {
                error << string_compose ("CAImportable: %1 to %2", cax.mOperation, pos) << endmsg;
        }
}