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add simple linear resampling implementation to be used when libsamplerate

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git-svn-id: svn://svn.code.sf.net/p/rdesktop/code/trunk/rdesktop@1282 423420c4-83ab-492f-b58f-81f9feb106b5
This commit is contained in:
Michael Gernoth 2006-10-01 17:23:30 +00:00
parent de56acd493
commit a8f9e84598
1 changed files with 31 additions and 36 deletions
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67
rdpsnd_dsp.c
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@ -132,11 +132,6 @@ rdpsnd_dsp_resample_set(uint32 device_srate, uint16 device_bitspersample, uint16
int err; int err;
#endif #endif
#ifndef HAVE_LIBSAMPLERATE
if (device_srate != 44100 && device_srate != 22050)
return False;
#endif
if (device_bitspersample != 16 && device_bitspersample != 8) if (device_bitspersample != 16 && device_bitspersample != 8)
return False; return False;
@ -170,10 +165,6 @@ rdpsnd_dsp_resample_supported(WAVEFORMATEX * format)
return False; return False;
if ((format->wBitsPerSample != 8) && (format->wBitsPerSample != 16)) if ((format->wBitsPerSample != 8) && (format->wBitsPerSample != 16))
return False; return False;
#ifndef HAVE_LIBSAMPLERATE
if ((format->nSamplesPerSec != 44100) && (format->nSamplesPerSec != 22050))
return False;
#endif
return True; return True;
} }
@ -185,11 +176,11 @@ rdpsnd_dsp_resample(unsigned char **out, unsigned char *in, unsigned int size,
#ifdef HAVE_LIBSAMPLERATE #ifdef HAVE_LIBSAMPLERATE
SRC_DATA resample_data; SRC_DATA resample_data;
float *infloat, *outfloat; float *infloat, *outfloat;
int innum, outnum;
int err; int err;
#else #else
int offset; int ratio1k = (resample_to_srate * 1000) / format->nSamplesPerSec;
#endif #endif
int innum, outnum;
static BOOL warned = False; static BOOL warned = False;
unsigned char *tmpdata = NULL; unsigned char *tmpdata = NULL;
int samplewidth = format->wBitsPerSample / 8; int samplewidth = format->wBitsPerSample / 8;
@ -232,6 +223,8 @@ rdpsnd_dsp_resample(unsigned char **out, unsigned char *in, unsigned int size,
warned = True; warned = True;
} }
innum = size / samplewidth;
/* Do the resampling */ /* Do the resampling */
#ifdef HAVE_LIBSAMPLERATE #ifdef HAVE_LIBSAMPLERATE
if (src_converter == NULL) if (src_converter == NULL)
@ -240,7 +233,6 @@ rdpsnd_dsp_resample(unsigned char **out, unsigned char *in, unsigned int size,
return 0; return 0;
} }
innum = size / samplewidth;
outnum = ((float) innum * ((float) resample_to_srate / (float) format->nSamplesPerSec)) + 1; outnum = ((float) innum * ((float) resample_to_srate / (float) format->nSamplesPerSec)) + 1;
infloat = xmalloc(sizeof(float) * innum); infloat = xmalloc(sizeof(float) * innum);
@ -263,42 +255,45 @@ rdpsnd_dsp_resample(unsigned char **out, unsigned char *in, unsigned int size,
outsize = resample_data.output_frames_gen * resample_to_channels * samplewidth; outsize = resample_data.output_frames_gen * resample_to_channels * samplewidth;
*out = xmalloc(outsize); *out = xmalloc(outsize);
src_float_to_short_array(outfloat, (short *) *out, resample_data.output_frames_gen * resample_to_channels); src_float_to_short_array(outfloat, (short *) *out,
resample_data.output_frames_gen * resample_to_channels);
xfree(outfloat); xfree(outfloat);
#else #else
if (format->nSamplesPerSec != 22050) /* Michaels simple linear resampler */
if (resample_to_srate < format->nSamplesPerSec)
{ {
if (!warned) warning("downsampling currently not supported!\n");
{
warning("unsupported source samplerate (%u), not resampling!\n",
format->nSamplesPerSec);
warned = True;
}
return 0; return 0;
} }
outsize = size * 2; outnum = (innum * ratio1k) / 1000;
outsize = outnum * samplewidth;
*out = xmalloc(outsize); *out = xmalloc(outsize);
bzero(*out, outsize);
/* Resample from 22050 to 44100 */ for (i = 0; i < outsize / (resample_to_channels * samplewidth); i++)
for (i = 0; i < (size / samplewidth); i++)
{ {
/* On a stereo-channel we must make sure that left and right int source = ((i + ratio1k / 1000 - 1) * 1000) / ratio1k;
does not get mixed up, so we need to expand the sample-
data with channels in mind: 1234 -> 12123434 if (source * resample_to_channels + samplewidth > size)
If we have a mono-channel, we can expand the data by simply break;
doubling the sample-data: 1234 -> 11223344 */
if (resample_to_channels == 2) if (resample_to_channels == 2)
offset = ((i * 2) - (i & 1)) * samplewidth; {
else memcpy(*out + (i * resample_to_channels * samplewidth),
offset = (i * 2) * samplewidth; in + (source * resample_to_channels * samplewidth), samplewidth);
memcpy(*out + (i * resample_to_channels * samplewidth) + samplewidth,
memcpy(*out + offset, in + (i * samplewidth), samplewidth); in + (source * resample_to_channels * samplewidth) + samplewidth,
memcpy(*out + (resample_to_channels * samplewidth + offset), samplewidth);
in + (i * samplewidth), samplewidth);
} }
else
{
memcpy(*out + (i * samplewidth), in + (source * samplewidth), samplewidth);
}
}
outsize = i * resample_to_channels * samplewidth;
#endif #endif
if (tmpdata != NULL) if (tmpdata != NULL)