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Open Sound System
The Hitchhiker's Guide to OSS 4.1 Internals

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vmix_core/rec_export_int.inc

Local input buffer to application export routine for vmix (int)

Description

This file is part of Open Sound System.

Copyright (C) 4Front Technologies 1996-2008.

This this source file is released under GPL v2 license (no other versions). See the COPYING file included in the main directory of this source distribution for the license terms and conditions. 


vmix_mixer_t *mixer = portc->mixer;
vmix_engine_t *eng = &mixer->record_engine;

dmap_t *dmap = audio_engines[portc->audio_dev]->dmap_in;

int frame_size;

int outptr, outmax;
int used_channels;
int i, ch;

Initial setup 


frame_size = sizeof (*outp);

outmax = dmap->bytes_in_use / frame_size;
outptr = portc->rec_dma_pointer / frame_size;

outp = (BUFFER_TYPE) dmap->dmabuf;

used_channels = portc->channels;
if (used_channels > eng->channels)
  used_channels = eng->channels;

/* ignored_channels = portc->channels - used_channels; */

Do the mixing 

for (ch = 0; ch < used_channels; ch++)
  {
    int op = outptr + ch;
    int *chbuf = eng->chbufs[ch+portc->rec_choffs];

    for (i = 0; i < nsamples; i++)
      {
	int tmp;

	tmp = *chbuf++;

Convert the sample to right endianess. 

	outp[op] = VMIX_BYTESWAP (INT_EXPORT(tmp));

	op = (op + portc->channels) % outmax;
      }
  }

Finally save the state variables 


portc->rec_dma_pointer =
  (portc->rec_dma_pointer +
   nsamples * frame_size * portc->channels) % dmap->bytes_in_use;
Copyright (C) 4Front Technologies, 2007. All rights reserved.

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Copyright (C) 4Front Technologies, 2007. All rights reserved.
Back to index OSS web site