FreeRDP/libfreerdp-utils/dsp.c
2011-08-14 21:46:02 +08:00

337 lines
7.3 KiB
C

/**
* FreeRDP: A Remote Desktop Protocol client.
* Digital Sound Processing
*
* Copyright 2010-2011 Vic Lee
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <freerdp/types.h>
#include <freerdp/utils/memory.h>
#include <freerdp/utils/dsp.h>
uint8* dsp_resample(uint8* src, int bytes_per_sample,
uint32 schan, uint32 srate, int sframes,
uint32 rchan, uint32 rrate, int * prframes)
{
uint8* dst;
uint8* p;
int rframes;
int rsize;
int i, j;
int n1, n2;
int sbytes, rbytes;
sbytes = bytes_per_sample * schan;
rbytes = bytes_per_sample * rchan;
rframes = sframes * rrate / srate;
*prframes = rframes;
rsize = rbytes * rframes;
dst = (uint8*) xzalloc(rsize);
p = dst;
for (i = 0; i < rframes; i++)
{
n1 = i * srate / rrate;
if (n1 >= sframes)
n1 = sframes - 1;
n2 = (n1 * rrate == i * srate || n1 == sframes - 1 ? n1 : n1 + 1);
for (j = 0; j < rbytes; j++)
{
/* Nearest Interpolation, probably the easiest, but works */
*p++ = (i * srate - n1 * rrate > n2 * rrate - i * srate ?
src[n2 * sbytes + (j % sbytes)] :
src[n1 * sbytes + (j % sbytes)]);
}
}
return dst;
}
/**
* Microsoft IMA ADPCM specification:
*
* http://wiki.multimedia.cx/index.php?title=Microsoft_IMA_ADPCM
* http://wiki.multimedia.cx/index.php?title=IMA_ADPCM
*/
static const sint16 ima_step_index_table[] =
{
-1, -1, -1, -1, 2, 4, 6, 8,
-1, -1, -1, -1, 2, 4, 6, 8
};
static const sint16 ima_step_size_table[] =
{
7, 8, 9, 10, 11, 12, 13, 14, 16, 17,
19, 21, 23, 25, 28, 31, 34, 37, 41, 45,
50, 55, 60, 66, 73, 80, 88, 97, 107, 118,
130, 143, 157, 173, 190, 209, 230, 253, 279, 307,
337, 371, 408, 449, 494, 544, 598, 658, 724, 796,
876, 963, 1060, 1166, 1282, 1411, 1552, 1707, 1878, 2066,
2272, 2499, 2749, 3024, 3327, 3660, 4026, 4428, 4871, 5358,
5894, 6484, 7132, 7845, 8630, 9493, 10442, 11487, 12635, 13899,
15289, 16818, 18500, 20350, 22385, 24623, 27086, 29794, 32767
};
static uint16 dsp_decode_ima_adpcm_sample(ADPCM* adpcm,
int channel, uint8 sample)
{
sint32 ss;
sint32 d;
ss = ima_step_size_table[adpcm->last_step[channel]];
d = (ss >> 3);
if (sample & 1)
d += (ss >> 2);
if (sample & 2)
d += (ss >> 1);
if (sample & 4)
d += ss;
if (sample & 8)
d = -d;
d += adpcm->last_sample[channel];
if (d < -32768)
d = -32768;
else if (d > 32767)
d = 32767;
adpcm->last_sample[channel] = (sint16) d;
adpcm->last_step[channel] += ima_step_index_table[sample];
if (adpcm->last_step[channel] < 0)
adpcm->last_step[channel] = 0;
else if (adpcm->last_step[channel] > 88)
adpcm->last_step[channel] = 88;
return (uint16) d;
}
uint8* dsp_decode_ima_adpcm(ADPCM* adpcm,
uint8* src, int size, int channels, int block_size, int* out_size)
{
uint8* out;
uint8* dst;
uint8 sample;
uint16 decoded;
int channel;
int i;
*out_size = size * 4;
out = (uint8 *) xzalloc(*out_size);
dst = out;
while (size > 0)
{
if (size % block_size == 0)
{
adpcm->last_sample[0] = (sint16) (((uint16)(*src)) | (((uint16)(*(src + 1))) << 8));
adpcm->last_step[0] = (sint16) (*(src + 2));
src += 4;
size -= 4;
*out_size -= 16;
if (channels > 1)
{
adpcm->last_sample[1] = (sint16) (((uint16)(*src)) | (((uint16)(*(src + 1))) << 8));
adpcm->last_step[1] = (sint16) (*(src + 2));
src += 4;
size -= 4;
*out_size -= 16;
}
}
if (channels > 1)
{
for (i = 0; i < 8; i++)
{
channel = (i < 4 ? 0 : 1);
sample = ((*src) & 0x0f);
decoded = dsp_decode_ima_adpcm_sample(adpcm, channel, sample);
dst[((i & 3) << 3) + (channel << 1)] = (decoded & 0xff);
dst[((i & 3) << 3) + (channel << 1) + 1] = (decoded >> 8);
sample = ((*src) >> 4);
decoded = dsp_decode_ima_adpcm_sample(adpcm, channel, sample);
dst[((i & 3) << 3) + (channel << 1) + 4] = (decoded & 0xff);
dst[((i & 3) << 3) + (channel << 1) + 5] = (decoded >> 8);
src++;
}
dst += 32;
size -= 8;
}
else
{
sample = ((*src) & 0x0f);
decoded = dsp_decode_ima_adpcm_sample(adpcm, 0, sample);
*dst++ = (decoded & 0xff);
*dst++ = (decoded >> 8);
sample = ((*src) >> 4);
decoded = dsp_decode_ima_adpcm_sample(adpcm, 0, sample);
*dst++ = (decoded & 0xff);
*dst++ = (decoded >> 8);
src++;
size--;
}
}
return out;
}
/**
* 0 1 2 3
* 2 0 6 4 10 8 14 12 <left>
*
* 4 5 6 7
* 3 1 7 5 11 9 15 13 <right>
*/
static const struct
{
uint8 byte_num;
uint8 byte_shift;
} ima_stereo_encode_map[] =
{
{ 0, 0 },
{ 4, 0 },
{ 0, 4 },
{ 4, 4 },
{ 1, 0 },
{ 5, 0 },
{ 1, 4 },
{ 5, 4 },
{ 2, 0 },
{ 6, 0 },
{ 2, 4 },
{ 6, 4 },
{ 3, 0 },
{ 7, 0 },
{ 3, 4 },
{ 7, 4 }
};
static uint8 dsp_encode_ima_adpcm_sample(ADPCM* adpcm,
int channel, sint16 sample)
{
sint32 e;
sint32 d;
sint32 ss;
uint8 enc;
sint32 diff;
ss = ima_step_size_table[adpcm->last_step[channel]];
d = e = sample - adpcm->last_sample[channel];
diff = ss >> 3;
enc = 0;
if (e < 0)
{
enc = 8;
e = -e;
}
if (e >= ss)
{
enc |= 4;
e -= ss;
}
ss >>= 1;
if (e >= ss)
{
enc |= 2;
e -= ss;
}
ss >>= 1;
if (e >= ss)
{
enc |= 1;
e -= ss;
}
if (d < 0)
diff = d + e - diff;
else
diff = d - e + diff;
diff += adpcm->last_sample[channel];
if (diff < -32768)
diff = -32768;
else if (diff > 32767)
diff = 32767;
adpcm->last_sample[channel] = (sint16) diff;
adpcm->last_step[channel] += ima_step_index_table[enc];
if (adpcm->last_step[channel] < 0)
adpcm->last_step[channel] = 0;
else if (adpcm->last_step[channel] > 88)
adpcm->last_step[channel] = 88;
return enc;
}
uint8* dsp_encode_ima_adpcm(ADPCM* adpcm,
uint8* src, int size, int channels, int block_size, int* out_size)
{
uint8* out;
uint8* dst;
sint16 sample;
uint8 encoded;
int i;
out = (uint8*) xzalloc(size / 2);
dst = out;
while (size > 0)
{
if ((dst - out) % block_size == 0)
{
*dst++ = adpcm->last_sample[0] & 0xff;
*dst++ = (adpcm->last_sample[0] >> 8) & 0xff;
*dst++ = adpcm->last_step[0];
*dst++ = 0;
if (channels > 1)
{
*dst++ = adpcm->last_sample[1] & 0xff;
*dst++ = (adpcm->last_sample[1] >> 8) & 0xff;
*dst++ = adpcm->last_step[1];
*dst++ = 0;
}
}
if (channels > 1)
{
memset(dst, 0, 8);
for (i = 0; i < 16; i++)
{
sample = (sint16) (((uint16)(*src)) | (((uint16)(*(src + 1))) << 8));
src += 2;
encoded = dsp_encode_ima_adpcm_sample(adpcm, i % 2, sample);
dst[ima_stereo_encode_map[i].byte_num] |= encoded << ima_stereo_encode_map[i].byte_shift;
}
dst += 8;
size -= 32;
}
else
{
sample = (sint16) (((uint16)(*src)) | (((uint16)(*(src + 1))) << 8));
src += 2;
encoded = dsp_encode_ima_adpcm_sample(adpcm, 0, sample);
sample = (sint16) (((uint16)(*src)) | (((uint16)(*(src + 1))) << 8));
src += 2;
encoded |= dsp_encode_ima_adpcm_sample(adpcm, 0, sample) << 4;
*dst++ = encoded;
size -= 4;
}
}
*out_size = dst - out;
return out;
}