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125 lines
4.1 KiB
125 lines
4.1 KiB
/*
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The mediastreamer library aims at providing modular media processing and I/O
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for linphone, but also for any telephony application.
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Copyright (C) 2001 Simon MORLAT simon.morlat@linphone.org
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This library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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This library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with this library; if not, write to the Free Software
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Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#include "msAlawenc.h"
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#include "g711common.h"
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extern MSCodecInfo ALAWinfo;
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static MSALAWEncoderClass *ms_ALAWencoder_class=NULL;
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MSFilter * ms_ALAWencoder_new(void)
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{
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MSALAWEncoder *r;
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r=g_new(MSALAWEncoder,1);
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ms_ALAWencoder_init(r);
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if (ms_ALAWencoder_class==NULL)
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{
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ms_ALAWencoder_class=g_new(MSALAWEncoderClass,1);
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ms_ALAWencoder_class_init(ms_ALAWencoder_class);
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}
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MS_FILTER(r)->klass=MS_FILTER_CLASS(ms_ALAWencoder_class);
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return(MS_FILTER(r));
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}
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/* FOR INTERNAL USE*/
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void ms_ALAWencoder_init(MSALAWEncoder *r)
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{
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ms_filter_init(MS_FILTER(r));
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MS_FILTER(r)->infifos=r->f_inputs;
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MS_FILTER(r)->outfifos=r->f_outputs;
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MS_FILTER(r)->r_mingran=ALAW_ENCODER_RMAXGRAN; /* the filter can be called as soon as there is
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something to process */
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memset(r->f_inputs,0,sizeof(MSFifo*)*MSALAWENCODER_MAX_INPUTS);
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memset(r->f_outputs,0,sizeof(MSFifo*)*MSALAWENCODER_MAX_INPUTS);
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}
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void ms_ALAWencoder_class_init(MSALAWEncoderClass *klass)
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{
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ms_filter_class_init(MS_FILTER_CLASS(klass));
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ms_filter_class_set_name(MS_FILTER_CLASS(klass),"ALAWEncoder");
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MS_FILTER_CLASS(klass)->info=(MSFilterInfo*)&ALAWinfo;
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MS_FILTER_CLASS(klass)->max_finputs=MSALAWENCODER_MAX_INPUTS;
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MS_FILTER_CLASS(klass)->max_foutputs=MSALAWENCODER_MAX_INPUTS;
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MS_FILTER_CLASS(klass)->r_maxgran=ALAW_ENCODER_RMAXGRAN;
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MS_FILTER_CLASS(klass)->w_maxgran=ALAW_ENCODER_WMAXGRAN;
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MS_FILTER_CLASS(klass)->destroy=(MSFilterDestroyFunc)ms_ALAWencoder_destroy;
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MS_FILTER_CLASS(klass)->process=(MSFilterProcessFunc)ms_ALAWencoder_process;
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}
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void ms_ALAWencoder_process(MSALAWEncoder *r)
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{
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MSFifo *fi,*fo;
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int inlen,outlen;
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gchar *s,*d;
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int i;
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/* process output fifos, but there is only one for this class of filter*/
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/* this is the sophisticated design of the process function:
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Here the filter declares that it can be called as soon as there is something
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to read on the input fifo by setting r_mingran=0.
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Then it ask for the fifo to get as many data as possible by calling:
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inlen=ms_fifo_get_read_ptr(fi,0,(void**)&s);
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This avoid multiple call to the process function to process all data available
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on the input fifo... but the writing of the process function is a bit
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more difficult, because althoug ms_fifo_get_read_ptr() returns N bytes,
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we cannot ask ms_fifo_get_write_ptr to return N bytes if
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N>MS_FILTER_CLASS(klass)->w_maxgran. This is forbidden by the MSFifo
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mechanism.
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This is an open issue.
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For the moment what is done here is that ms_fifo_get_write_ptr() is called
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several time with its maximum granularity in order to try to write the output.
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...
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One solution:
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-create a new function ms_fifo_get_rw_ptr(fifo1,p1, fifo2,p2) to
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return the number of bytes able to being processed according to the input
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and output fifo, and their respective data pointers
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*/
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fi=r->f_inputs[0];
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fo=r->f_outputs[0];
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inlen=ms_fifo_get_read_ptr(fi,ALAW_ENCODER_RMAXGRAN,(void**)&s);
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if (s==NULL) return;
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outlen=ms_fifo_get_write_ptr(fo,ALAW_ENCODER_WMAXGRAN,(void**)&d);
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if (d!=NULL)
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{
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for(i=0;i<ALAW_ENCODER_WMAXGRAN;i++)
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{
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d[i]=s16_to_alaw( *((gint16*)s) );
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s+=2;
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}
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}
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else g_warning("MSALAWDecoder: Discarding samples !!");
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}
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void ms_ALAWencoder_destroy( MSALAWEncoder *obj)
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{
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g_free(obj);
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}
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