SndPcm.hxx

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/*
 * Copyright (c) 2001-2004 MUSIC TECHNOLOGY GROUP (MTG)
 *                         UNIVERSITAT POMPEU FABRA
 *
 *
 * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */

/* alsa 0.9 backwards compatibility for alsa 1.0 */
#define ALSA_PCM_OLD_HW_PARAMS_API
#define ALSA_PCM_OLD_SW_PARAMS_API

#include <alsa/asoundlib.h>
#include "Err.hxx"

class SndPcmError : public CLAM::Err
{
public:
        SndPcmError(const char* _str)
        :Err(_str){

        }
};

class SndPcm
{
public:
        snd_pcm_format_t format;
        int rate;
        int channels_in;
        int channels_out;
        int latency;
        int latency_min;                /* in frames / 2 */
        int latency_max;                /* in frames / 2 */
        int block;                                      /* block mode */
        int tick_time;                  /* disabled, otherwise in us */
        int tick_time_ok;

        snd_pcm_t *phandle, *chandle;

        char error_str[1024];
        void cat_error(const char* fmt,...);

        void ReadBuf(short* data)
        {
                int res = readbuf(chandle,(char*) data,latency);
                if (res>=0) return;
                if (res == -EPIPE)
//                      throw(SndPcmError("SndPcm::ReadBuf() Buffer Overrun!\n"));
                        RecoverXRun(data);
        }
        void WriteBuf(short* data)
        {
                int res = writebuf(phandle,(char*) data,latency);
                if (res>=0) return;
                if (res == -EPIPE)
//                      throw(SndPcmError("SndPcm::WriteBuf() Buffer Underrun!\n"));
                        RecoverXRun(data);
        }
        void ReadBuf(short* data,int len)
        {
                int res = readbuf(chandle,(char*) data,len);
                if (res>=0) return;
                if (res == -EPIPE)
//                      throw(SndPcmError("SndPcm::ReadBuf() Buffer Overrun!\n"));
                        RecoverXRun(data);
        }
        void WriteBuf(short* data,int len)
        {
                int res = writebuf(phandle,(char*) data,len);
                if (res>=0) return;
                if (res == -EPIPE)
//                      throw(SndPcmError("SndPcm::WriteBuf() Buffer Underrun!\n"));
                        RecoverXRun(data);
        }
        SndPcm(int irate,int ichannels_in,int ichannels_out,int ilatency,
                const char* pdevice,const char* cdevice);
        ~SndPcm();

        void Start(void);
        void Stop(void);
        void RecoverXRun(short* data);
        
        void Poll(void);

private:
/*
 * The functions which follow are taken from the latency test included
 * in the ALSA source distribution, with the following copyright note:
 *
 *  Latency test program
 *
 *     Author: Jaroslav Kysela <perex@suse.cz>
 *
 *     Author of bandpass filter sweep effect:
 *             Maarten de Boer <mdeboer@iua.upf.es>
 *
 *  This small demo program can be used for measuring latency between
 *  capture and playback. This latency is measured from driver (diff when
 *  playback and capture was started). Scheduler is set to SCHED_RR.
 *
 *
 *   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., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 *
 */
        int setparams_stream(snd_pcm_t *handle,
                             snd_pcm_hw_params_t *params,
                                         int channels,
                             const char *id);
        int setparams_bufsize(snd_pcm_t *handle,
                              snd_pcm_hw_params_t *params,
                              snd_pcm_hw_params_t *tparams,
                              snd_pcm_uframes_t bufsize,
                              const char *id);
        int setparams_set(snd_pcm_t *handle,
                          snd_pcm_hw_params_t *params,
                          snd_pcm_sw_params_t *swparams,
                          const char *id);
        int setparams(snd_pcm_t *phandle, snd_pcm_t *chandle, int *bufsize);
        long readbuf(snd_pcm_t *handle, char *buf, long len);
        long writebuf(snd_pcm_t *handle, char *buf, long len);
};