1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/media/libopus/src/opus.c Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,329 @@
1.4 +/* Copyright (c) 2011 Xiph.Org Foundation, Skype Limited
1.5 + Written by Jean-Marc Valin and Koen Vos */
1.6 +/*
1.7 + Redistribution and use in source and binary forms, with or without
1.8 + modification, are permitted provided that the following conditions
1.9 + are met:
1.10 +
1.11 + - Redistributions of source code must retain the above copyright
1.12 + notice, this list of conditions and the following disclaimer.
1.13 +
1.14 + - Redistributions in binary form must reproduce the above copyright
1.15 + notice, this list of conditions and the following disclaimer in the
1.16 + documentation and/or other materials provided with the distribution.
1.17 +
1.18 + THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
1.19 + ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
1.20 + LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
1.21 + A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
1.22 + OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
1.23 + EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
1.24 + PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
1.25 + PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
1.26 + LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
1.27 + NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
1.28 + SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.29 +*/
1.30 +
1.31 +#ifdef HAVE_CONFIG_H
1.32 +#include "config.h"
1.33 +#endif
1.34 +
1.35 +#include "opus.h"
1.36 +#include "opus_private.h"
1.37 +
1.38 +#ifndef DISABLE_FLOAT_API
1.39 +OPUS_EXPORT void opus_pcm_soft_clip(float *_x, int N, int C, float *declip_mem)
1.40 +{
1.41 + int c;
1.42 + int i;
1.43 + float *x;
1.44 +
1.45 + if (C<1 || N<1 || !_x || !declip_mem) return;
1.46 +
1.47 + /* First thing: saturate everything to +/- 2 which is the highest level our
1.48 + non-linearity can handle. At the point where the signal reaches +/-2,
1.49 + the derivative will be zero anyway, so this doesn't introduce any
1.50 + discontinuity in the derivative. */
1.51 + for (i=0;i<N*C;i++)
1.52 + _x[i] = MAX16(-2.f, MIN16(2.f, _x[i]));
1.53 + for (c=0;c<C;c++)
1.54 + {
1.55 + float a;
1.56 + float x0;
1.57 + int curr;
1.58 +
1.59 + x = _x+c;
1.60 + a = declip_mem[c];
1.61 + /* Continue applying the non-linearity from the previous frame to avoid
1.62 + any discontinuity. */
1.63 + for (i=0;i<N;i++)
1.64 + {
1.65 + if (x[i*C]*a>=0)
1.66 + break;
1.67 + x[i*C] = x[i*C]+a*x[i*C]*x[i*C];
1.68 + }
1.69 +
1.70 + curr=0;
1.71 + x0 = x[0];
1.72 + while(1)
1.73 + {
1.74 + int start, end;
1.75 + float maxval;
1.76 + int special=0;
1.77 + int peak_pos;
1.78 + for (i=curr;i<N;i++)
1.79 + {
1.80 + if (x[i*C]>1 || x[i*C]<-1)
1.81 + break;
1.82 + }
1.83 + if (i==N)
1.84 + {
1.85 + a=0;
1.86 + break;
1.87 + }
1.88 + peak_pos = i;
1.89 + start=end=i;
1.90 + maxval=ABS16(x[i*C]);
1.91 + /* Look for first zero crossing before clipping */
1.92 + while (start>0 && x[i*C]*x[(start-1)*C]>=0)
1.93 + start--;
1.94 + /* Look for first zero crossing after clipping */
1.95 + while (end<N && x[i*C]*x[end*C]>=0)
1.96 + {
1.97 + /* Look for other peaks until the next zero-crossing. */
1.98 + if (ABS16(x[end*C])>maxval)
1.99 + {
1.100 + maxval = ABS16(x[end*C]);
1.101 + peak_pos = end;
1.102 + }
1.103 + end++;
1.104 + }
1.105 + /* Detect the special case where we clip before the first zero crossing */
1.106 + special = (start==0 && x[i*C]*x[0]>=0);
1.107 +
1.108 + /* Compute a such that maxval + a*maxval^2 = 1 */
1.109 + a=(maxval-1)/(maxval*maxval);
1.110 + if (x[i*C]>0)
1.111 + a = -a;
1.112 + /* Apply soft clipping */
1.113 + for (i=start;i<end;i++)
1.114 + x[i*C] = x[i*C]+a*x[i*C]*x[i*C];
1.115 +
1.116 + if (special && peak_pos>=2)
1.117 + {
1.118 + /* Add a linear ramp from the first sample to the signal peak.
1.119 + This avoids a discontinuity at the beginning of the frame. */
1.120 + float delta;
1.121 + float offset = x0-x[0];
1.122 + delta = offset / peak_pos;
1.123 + for (i=curr;i<peak_pos;i++)
1.124 + {
1.125 + offset -= delta;
1.126 + x[i*C] += offset;
1.127 + x[i*C] = MAX16(-1.f, MIN16(1.f, x[i*C]));
1.128 + }
1.129 + }
1.130 + curr = end;
1.131 + if (curr==N)
1.132 + break;
1.133 + }
1.134 + declip_mem[c] = a;
1.135 + }
1.136 +}
1.137 +#endif
1.138 +
1.139 +int encode_size(int size, unsigned char *data)
1.140 +{
1.141 + if (size < 252)
1.142 + {
1.143 + data[0] = size;
1.144 + return 1;
1.145 + } else {
1.146 + data[0] = 252+(size&0x3);
1.147 + data[1] = (size-(int)data[0])>>2;
1.148 + return 2;
1.149 + }
1.150 +}
1.151 +
1.152 +static int parse_size(const unsigned char *data, opus_int32 len, opus_int16 *size)
1.153 +{
1.154 + if (len<1)
1.155 + {
1.156 + *size = -1;
1.157 + return -1;
1.158 + } else if (data[0]<252)
1.159 + {
1.160 + *size = data[0];
1.161 + return 1;
1.162 + } else if (len<2)
1.163 + {
1.164 + *size = -1;
1.165 + return -1;
1.166 + } else {
1.167 + *size = 4*data[1] + data[0];
1.168 + return 2;
1.169 + }
1.170 +}
1.171 +
1.172 +int opus_packet_parse_impl(const unsigned char *data, opus_int32 len,
1.173 + int self_delimited, unsigned char *out_toc,
1.174 + const unsigned char *frames[48], opus_int16 size[48],
1.175 + int *payload_offset, opus_int32 *packet_offset)
1.176 +{
1.177 + int i, bytes;
1.178 + int count;
1.179 + int cbr;
1.180 + unsigned char ch, toc;
1.181 + int framesize;
1.182 + opus_int32 last_size;
1.183 + opus_int32 pad = 0;
1.184 + const unsigned char *data0 = data;
1.185 +
1.186 + if (size==NULL)
1.187 + return OPUS_BAD_ARG;
1.188 +
1.189 + framesize = opus_packet_get_samples_per_frame(data, 48000);
1.190 +
1.191 + cbr = 0;
1.192 + toc = *data++;
1.193 + len--;
1.194 + last_size = len;
1.195 + switch (toc&0x3)
1.196 + {
1.197 + /* One frame */
1.198 + case 0:
1.199 + count=1;
1.200 + break;
1.201 + /* Two CBR frames */
1.202 + case 1:
1.203 + count=2;
1.204 + cbr = 1;
1.205 + if (!self_delimited)
1.206 + {
1.207 + if (len&0x1)
1.208 + return OPUS_INVALID_PACKET;
1.209 + last_size = len/2;
1.210 + /* If last_size doesn't fit in size[0], we'll catch it later */
1.211 + size[0] = (opus_int16)last_size;
1.212 + }
1.213 + break;
1.214 + /* Two VBR frames */
1.215 + case 2:
1.216 + count = 2;
1.217 + bytes = parse_size(data, len, size);
1.218 + len -= bytes;
1.219 + if (size[0]<0 || size[0] > len)
1.220 + return OPUS_INVALID_PACKET;
1.221 + data += bytes;
1.222 + last_size = len-size[0];
1.223 + break;
1.224 + /* Multiple CBR/VBR frames (from 0 to 120 ms) */
1.225 + default: /*case 3:*/
1.226 + if (len<1)
1.227 + return OPUS_INVALID_PACKET;
1.228 + /* Number of frames encoded in bits 0 to 5 */
1.229 + ch = *data++;
1.230 + count = ch&0x3F;
1.231 + if (count <= 0 || framesize*count > 5760)
1.232 + return OPUS_INVALID_PACKET;
1.233 + len--;
1.234 + /* Padding flag is bit 6 */
1.235 + if (ch&0x40)
1.236 + {
1.237 + int p;
1.238 + do {
1.239 + int tmp;
1.240 + if (len<=0)
1.241 + return OPUS_INVALID_PACKET;
1.242 + p = *data++;
1.243 + len--;
1.244 + tmp = p==255 ? 254: p;
1.245 + len -= tmp;
1.246 + pad += tmp;
1.247 + } while (p==255);
1.248 + }
1.249 + if (len<0)
1.250 + return OPUS_INVALID_PACKET;
1.251 + /* VBR flag is bit 7 */
1.252 + cbr = !(ch&0x80);
1.253 + if (!cbr)
1.254 + {
1.255 + /* VBR case */
1.256 + last_size = len;
1.257 + for (i=0;i<count-1;i++)
1.258 + {
1.259 + bytes = parse_size(data, len, size+i);
1.260 + len -= bytes;
1.261 + if (size[i]<0 || size[i] > len)
1.262 + return OPUS_INVALID_PACKET;
1.263 + data += bytes;
1.264 + last_size -= bytes+size[i];
1.265 + }
1.266 + if (last_size<0)
1.267 + return OPUS_INVALID_PACKET;
1.268 + } else if (!self_delimited)
1.269 + {
1.270 + /* CBR case */
1.271 + last_size = len/count;
1.272 + if (last_size*count!=len)
1.273 + return OPUS_INVALID_PACKET;
1.274 + for (i=0;i<count-1;i++)
1.275 + size[i] = (opus_int16)last_size;
1.276 + }
1.277 + break;
1.278 + }
1.279 + /* Self-delimited framing has an extra size for the last frame. */
1.280 + if (self_delimited)
1.281 + {
1.282 + bytes = parse_size(data, len, size+count-1);
1.283 + len -= bytes;
1.284 + if (size[count-1]<0 || size[count-1] > len)
1.285 + return OPUS_INVALID_PACKET;
1.286 + data += bytes;
1.287 + /* For CBR packets, apply the size to all the frames. */
1.288 + if (cbr)
1.289 + {
1.290 + if (size[count-1]*count > len)
1.291 + return OPUS_INVALID_PACKET;
1.292 + for (i=0;i<count-1;i++)
1.293 + size[i] = size[count-1];
1.294 + } else if (bytes+size[count-1] > last_size)
1.295 + return OPUS_INVALID_PACKET;
1.296 + } else
1.297 + {
1.298 + /* Because it's not encoded explicitly, it's possible the size of the
1.299 + last packet (or all the packets, for the CBR case) is larger than
1.300 + 1275. Reject them here.*/
1.301 + if (last_size > 1275)
1.302 + return OPUS_INVALID_PACKET;
1.303 + size[count-1] = (opus_int16)last_size;
1.304 + }
1.305 +
1.306 + if (payload_offset)
1.307 + *payload_offset = (int)(data-data0);
1.308 +
1.309 + for (i=0;i<count;i++)
1.310 + {
1.311 + if (frames)
1.312 + frames[i] = data;
1.313 + data += size[i];
1.314 + }
1.315 +
1.316 + if (packet_offset)
1.317 + *packet_offset = pad+(opus_int32)(data-data0);
1.318 +
1.319 + if (out_toc)
1.320 + *out_toc = toc;
1.321 +
1.322 + return count;
1.323 +}
1.324 +
1.325 +int opus_packet_parse(const unsigned char *data, opus_int32 len,
1.326 + unsigned char *out_toc, const unsigned char *frames[48],
1.327 + opus_int16 size[48], int *payload_offset)
1.328 +{
1.329 + return opus_packet_parse_impl(data, len, 0, out_toc,
1.330 + frames, size, payload_offset, NULL);
1.331 +}
1.332 +
