gstreamer/gst/siren/decoder.c

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/*
* Siren Encoder/Decoder library
*
* @author: Youness Alaoui <kakaroto@kakaroto.homelinux.net>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library 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
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
#include "siren7.h"
SirenDecoder
Siren7_NewDecoder (int sample_rate)
{
SirenDecoder decoder = (SirenDecoder) malloc (sizeof (struct stSirenDecoder));
decoder->sample_rate = sample_rate;
decoder->WavHeader.riff.RiffId = ME_TO_LE32 (RIFF_ID);
decoder->WavHeader.riff.RiffSize = sizeof (PCMWavHeader) - 2 * sizeof (int);
decoder->WavHeader.riff.RiffSize =
ME_TO_LE32 (decoder->WavHeader.riff.RiffSize);
decoder->WavHeader.WaveId = ME_TO_LE32 (WAVE_ID);
decoder->WavHeader.FmtId = ME_TO_LE32 (FMT__ID);
decoder->WavHeader.FmtSize = ME_TO_LE32 (sizeof (FmtChunk));
decoder->WavHeader.fmt.Format = ME_TO_LE16 (0x01);
decoder->WavHeader.fmt.Channels = ME_TO_LE16 (1);
decoder->WavHeader.fmt.SampleRate = ME_TO_LE32 (16000);
decoder->WavHeader.fmt.ByteRate = ME_TO_LE32 (32000);
decoder->WavHeader.fmt.BlockAlign = ME_TO_LE16 (2);
decoder->WavHeader.fmt.BitsPerSample = ME_TO_LE16 (16);
decoder->WavHeader.FactId = ME_TO_LE32 (FACT_ID);
decoder->WavHeader.FactSize = ME_TO_LE32 (sizeof (int));
decoder->WavHeader.Samples = ME_TO_LE32 (0);
decoder->WavHeader.DataId = ME_TO_LE32 (DATA_ID);
decoder->WavHeader.DataSize = ME_TO_LE32 (0);
memset (decoder->context, 0, sizeof (decoder->context));
memset (decoder->backup_frame, 0, sizeof (decoder->backup_frame));
decoder->dw1 = 1;
decoder->dw2 = 1;
decoder->dw3 = 1;
decoder->dw4 = 1;
siren_init ();
return decoder;
}
void
Siren7_CloseDecoder (SirenDecoder decoder)
{
free (decoder);
}
int
Siren7_DecodeFrame (SirenDecoder decoder, unsigned char *DataIn,
unsigned char *DataOut)
{
int number_of_coefs,
sample_rate_bits,
rate_control_bits,
rate_control_possibilities,
checksum_bits,
esf_adjustment,
scale_factor, number_of_regions, sample_rate_code, bits_per_frame;
int decoded_sample_rate_code;
static int absolute_region_power_index[28] = { 0 };
static float decoder_standard_deviation[28] = { 0 };
static int power_categories[28] = { 0 };
static int category_balance[28] = { 0 };
int ChecksumTable[4] = { 0x7F80, 0x7878, 0x6666, 0x5555 };
int i, j;
int dwRes = 0;
int envelope_bits = 0;
int rate_control = 0;
int number_of_available_bits;
int number_of_valid_coefs;
int frame_error = 0;
int In[20];
float coefs[320];
float BufferOut[320];
int sum;
int checksum;
int calculated_checksum;
int idx;
int temp1;
int temp2;
for (i = 0; i < 20; i++)
#ifdef __BIG_ENDIAN__
In[i] = ((short *) DataIn)[i];
#else
In[i] =
((((short *) DataIn)[i] << 8) & 0xFF00) | ((((short *) DataIn)[i] >> 8)
& 0x00FF);
#endif
dwRes =
GetSirenCodecInfo (1, decoder->sample_rate, &number_of_coefs,
&sample_rate_bits, &rate_control_bits, &rate_control_possibilities,
&checksum_bits, &esf_adjustment, &scale_factor, &number_of_regions,
&sample_rate_code, &bits_per_frame);
if (dwRes != 0)
return dwRes;
set_bitstream (In);
decoded_sample_rate_code = 0;
for (i = 0; i < sample_rate_bits; i++) {
decoded_sample_rate_code <<= 1;
decoded_sample_rate_code |= next_bit ();
}
if (decoded_sample_rate_code != sample_rate_code)
return 7;
number_of_valid_coefs = region_size * number_of_regions;
number_of_available_bits = bits_per_frame - sample_rate_bits - checksum_bits;
envelope_bits =
decode_envelope (number_of_regions, decoder_standard_deviation,
absolute_region_power_index, esf_adjustment);
number_of_available_bits -= envelope_bits;
for (i = 0; i < rate_control_bits; i++) {
rate_control <<= 1;
rate_control |= next_bit ();
}
number_of_available_bits -= rate_control_bits;
categorize_regions (number_of_regions, number_of_available_bits,
absolute_region_power_index, power_categories, category_balance);
for (i = 0; i < rate_control; i++) {
power_categories[category_balance[i]]++;
}
number_of_available_bits =
decode_vector (decoder, number_of_regions, number_of_available_bits,
decoder_standard_deviation, power_categories, coefs, scale_factor);
frame_error = 0;
if (number_of_available_bits > 0) {
for (i = 0; i < number_of_available_bits; i++) {
if (next_bit () == 0)
frame_error = 1;
}
} else if (number_of_available_bits < 0
&& rate_control + 1 < rate_control_possibilities) {
frame_error |= 2;
}
for (i = 0; i < number_of_regions; i++) {
if (absolute_region_power_index[i] > 33
|| absolute_region_power_index[i] < -31)
frame_error |= 4;
}
if (checksum_bits > 0) {
bits_per_frame >>= 4;
checksum = In[bits_per_frame - 1] & ((1 << checksum_bits) - 1);
In[bits_per_frame - 1] &= ~checksum;
sum = 0;
idx = 0;
do {
sum ^= (In[idx] & 0xFFFF) << (idx % 15);
} while (++idx < bits_per_frame);
sum = (sum >> 15) ^ (sum & 0x7FFF);
calculated_checksum = 0;
for (i = 0; i < 4; i++) {
temp1 = ChecksumTable[i] & sum;
for (j = 8; j > 0; j >>= 1) {
temp2 = temp1 >> j;
temp1 ^= temp2;
}
calculated_checksum <<= 1;
calculated_checksum |= temp1 & 1;
}
if (checksum != calculated_checksum)
frame_error |= 8;
}
if (frame_error != 0) {
for (i = 0; i < number_of_valid_coefs; i++) {
coefs[i] = decoder->backup_frame[i];
decoder->backup_frame[i] = 0;
}
} else {
for (i = 0; i < number_of_valid_coefs; i++)
decoder->backup_frame[i] = coefs[i];
}
for (i = number_of_valid_coefs; i < number_of_coefs; i++)
coefs[i] = 0;
dwRes = siren_rmlt_decode_samples (coefs, decoder->context, 320, BufferOut);
for (i = 0; i < 320; i++) {
if (BufferOut[i] > 32767.0)
((short *) DataOut)[i] = (short) ME_TO_LE16 ((short) 32767);
else if (BufferOut[i] <= -32768.0)
((short *) DataOut)[i] = (short) ME_TO_LE16 ((short) 32768);
else
((short *) DataOut)[i] = (short) ME_TO_LE16 ((short) BufferOut[i]);
}
decoder->WavHeader.Samples = ME_FROM_LE32 (decoder->WavHeader.Samples);
decoder->WavHeader.Samples += 320;
decoder->WavHeader.Samples = ME_TO_LE32 (decoder->WavHeader.Samples);
decoder->WavHeader.DataSize = ME_FROM_LE32 (decoder->WavHeader.DataSize);
decoder->WavHeader.DataSize += 640;
decoder->WavHeader.DataSize = ME_TO_LE32 (decoder->WavHeader.DataSize);
decoder->WavHeader.riff.RiffSize =
ME_FROM_LE32 (decoder->WavHeader.riff.RiffSize);
decoder->WavHeader.riff.RiffSize += 640;
decoder->WavHeader.riff.RiffSize =
ME_TO_LE32 (decoder->WavHeader.riff.RiffSize);
return 0;
}