summaryrefslogtreecommitdiffstats
path: root/media/libopus/src/opus.c
diff options
context:
space:
mode:
Diffstat (limited to 'media/libopus/src/opus.c')
-rw-r--r--media/libopus/src/opus.c356
1 files changed, 356 insertions, 0 deletions
diff --git a/media/libopus/src/opus.c b/media/libopus/src/opus.c
new file mode 100644
index 000000000..f76f125cf
--- /dev/null
+++ b/media/libopus/src/opus.c
@@ -0,0 +1,356 @@
+/* Copyright (c) 2011 Xiph.Org Foundation, Skype Limited
+ Written by Jean-Marc Valin and Koen Vos */
+/*
+ Redistribution and use in source and binary forms, with or without
+ modification, are permitted provided that the following conditions
+ are met:
+
+ - Redistributions of source code must retain the above copyright
+ notice, this list of conditions and the following disclaimer.
+
+ - Redistributions in binary form must reproduce the above copyright
+ notice, this list of conditions and the following disclaimer in the
+ documentation and/or other materials provided with the distribution.
+
+ THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
+ OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include "opus.h"
+#include "opus_private.h"
+
+#ifndef DISABLE_FLOAT_API
+OPUS_EXPORT void opus_pcm_soft_clip(float *_x, int N, int C, float *declip_mem)
+{
+ int c;
+ int i;
+ float *x;
+
+ if (C<1 || N<1 || !_x || !declip_mem) return;
+
+ /* First thing: saturate everything to +/- 2 which is the highest level our
+ non-linearity can handle. At the point where the signal reaches +/-2,
+ the derivative will be zero anyway, so this doesn't introduce any
+ discontinuity in the derivative. */
+ for (i=0;i<N*C;i++)
+ _x[i] = MAX16(-2.f, MIN16(2.f, _x[i]));
+ for (c=0;c<C;c++)
+ {
+ float a;
+ float x0;
+ int curr;
+
+ x = _x+c;
+ a = declip_mem[c];
+ /* Continue applying the non-linearity from the previous frame to avoid
+ any discontinuity. */
+ for (i=0;i<N;i++)
+ {
+ if (x[i*C]*a>=0)
+ break;
+ x[i*C] = x[i*C]+a*x[i*C]*x[i*C];
+ }
+
+ curr=0;
+ x0 = x[0];
+ while(1)
+ {
+ int start, end;
+ float maxval;
+ int special=0;
+ int peak_pos;
+ for (i=curr;i<N;i++)
+ {
+ if (x[i*C]>1 || x[i*C]<-1)
+ break;
+ }
+ if (i==N)
+ {
+ a=0;
+ break;
+ }
+ peak_pos = i;
+ start=end=i;
+ maxval=ABS16(x[i*C]);
+ /* Look for first zero crossing before clipping */
+ while (start>0 && x[i*C]*x[(start-1)*C]>=0)
+ start--;
+ /* Look for first zero crossing after clipping */
+ while (end<N && x[i*C]*x[end*C]>=0)
+ {
+ /* Look for other peaks until the next zero-crossing. */
+ if (ABS16(x[end*C])>maxval)
+ {
+ maxval = ABS16(x[end*C]);
+ peak_pos = end;
+ }
+ end++;
+ }
+ /* Detect the special case where we clip before the first zero crossing */
+ special = (start==0 && x[i*C]*x[0]>=0);
+
+ /* Compute a such that maxval + a*maxval^2 = 1 */
+ a=(maxval-1)/(maxval*maxval);
+ /* Slightly boost "a" by 2^-22. This is just enough to ensure -ffast-math
+ does not cause output values larger than +/-1, but small enough not
+ to matter even for 24-bit output. */
+ a += a*2.4e-7;
+ if (x[i*C]>0)
+ a = -a;
+ /* Apply soft clipping */
+ for (i=start;i<end;i++)
+ x[i*C] = x[i*C]+a*x[i*C]*x[i*C];
+
+ if (special && peak_pos>=2)
+ {
+ /* Add a linear ramp from the first sample to the signal peak.
+ This avoids a discontinuity at the beginning of the frame. */
+ float delta;
+ float offset = x0-x[0];
+ delta = offset / peak_pos;
+ for (i=curr;i<peak_pos;i++)
+ {
+ offset -= delta;
+ x[i*C] += offset;
+ x[i*C] = MAX16(-1.f, MIN16(1.f, x[i*C]));
+ }
+ }
+ curr = end;
+ if (curr==N)
+ break;
+ }
+ declip_mem[c] = a;
+ }
+}
+#endif
+
+int encode_size(int size, unsigned char *data)
+{
+ if (size < 252)
+ {
+ data[0] = size;
+ return 1;
+ } else {
+ data[0] = 252+(size&0x3);
+ data[1] = (size-(int)data[0])>>2;
+ return 2;
+ }
+}
+
+static int parse_size(const unsigned char *data, opus_int32 len, opus_int16 *size)
+{
+ if (len<1)
+ {
+ *size = -1;
+ return -1;
+ } else if (data[0]<252)
+ {
+ *size = data[0];
+ return 1;
+ } else if (len<2)
+ {
+ *size = -1;
+ return -1;
+ } else {
+ *size = 4*data[1] + data[0];
+ return 2;
+ }
+}
+
+int opus_packet_get_samples_per_frame(const unsigned char *data,
+ opus_int32 Fs)
+{
+ int audiosize;
+ if (data[0]&0x80)
+ {
+ audiosize = ((data[0]>>3)&0x3);
+ audiosize = (Fs<<audiosize)/400;
+ } else if ((data[0]&0x60) == 0x60)
+ {
+ audiosize = (data[0]&0x08) ? Fs/50 : Fs/100;
+ } else {
+ audiosize = ((data[0]>>3)&0x3);
+ if (audiosize == 3)
+ audiosize = Fs*60/1000;
+ else
+ audiosize = (Fs<<audiosize)/100;
+ }
+ return audiosize;
+}
+
+int opus_packet_parse_impl(const unsigned char *data, opus_int32 len,
+ int self_delimited, unsigned char *out_toc,
+ const unsigned char *frames[48], opus_int16 size[48],
+ int *payload_offset, opus_int32 *packet_offset)
+{
+ int i, bytes;
+ int count;
+ int cbr;
+ unsigned char ch, toc;
+ int framesize;
+ opus_int32 last_size;
+ opus_int32 pad = 0;
+ const unsigned char *data0 = data;
+
+ if (size==NULL || len<0)
+ return OPUS_BAD_ARG;
+ if (len==0)
+ return OPUS_INVALID_PACKET;
+
+ framesize = opus_packet_get_samples_per_frame(data, 48000);
+
+ cbr = 0;
+ toc = *data++;
+ len--;
+ last_size = len;
+ switch (toc&0x3)
+ {
+ /* One frame */
+ case 0:
+ count=1;
+ break;
+ /* Two CBR frames */
+ case 1:
+ count=2;
+ cbr = 1;
+ if (!self_delimited)
+ {
+ if (len&0x1)
+ return OPUS_INVALID_PACKET;
+ last_size = len/2;
+ /* If last_size doesn't fit in size[0], we'll catch it later */
+ size[0] = (opus_int16)last_size;
+ }
+ break;
+ /* Two VBR frames */
+ case 2:
+ count = 2;
+ bytes = parse_size(data, len, size);
+ len -= bytes;
+ if (size[0]<0 || size[0] > len)
+ return OPUS_INVALID_PACKET;
+ data += bytes;
+ last_size = len-size[0];
+ break;
+ /* Multiple CBR/VBR frames (from 0 to 120 ms) */
+ default: /*case 3:*/
+ if (len<1)
+ return OPUS_INVALID_PACKET;
+ /* Number of frames encoded in bits 0 to 5 */
+ ch = *data++;
+ count = ch&0x3F;
+ if (count <= 0 || framesize*count > 5760)
+ return OPUS_INVALID_PACKET;
+ len--;
+ /* Padding flag is bit 6 */
+ if (ch&0x40)
+ {
+ int p;
+ do {
+ int tmp;
+ if (len<=0)
+ return OPUS_INVALID_PACKET;
+ p = *data++;
+ len--;
+ tmp = p==255 ? 254: p;
+ len -= tmp;
+ pad += tmp;
+ } while (p==255);
+ }
+ if (len<0)
+ return OPUS_INVALID_PACKET;
+ /* VBR flag is bit 7 */
+ cbr = !(ch&0x80);
+ if (!cbr)
+ {
+ /* VBR case */
+ last_size = len;
+ for (i=0;i<count-1;i++)
+ {
+ bytes = parse_size(data, len, size+i);
+ len -= bytes;
+ if (size[i]<0 || size[i] > len)
+ return OPUS_INVALID_PACKET;
+ data += bytes;
+ last_size -= bytes+size[i];
+ }
+ if (last_size<0)
+ return OPUS_INVALID_PACKET;
+ } else if (!self_delimited)
+ {
+ /* CBR case */
+ last_size = len/count;
+ if (last_size*count!=len)
+ return OPUS_INVALID_PACKET;
+ for (i=0;i<count-1;i++)
+ size[i] = (opus_int16)last_size;
+ }
+ break;
+ }
+ /* Self-delimited framing has an extra size for the last frame. */
+ if (self_delimited)
+ {
+ bytes = parse_size(data, len, size+count-1);
+ len -= bytes;
+ if (size[count-1]<0 || size[count-1] > len)
+ return OPUS_INVALID_PACKET;
+ data += bytes;
+ /* For CBR packets, apply the size to all the frames. */
+ if (cbr)
+ {
+ if (size[count-1]*count > len)
+ return OPUS_INVALID_PACKET;
+ for (i=0;i<count-1;i++)
+ size[i] = size[count-1];
+ } else if (bytes+size[count-1] > last_size)
+ return OPUS_INVALID_PACKET;
+ } else
+ {
+ /* Because it's not encoded explicitly, it's possible the size of the
+ last packet (or all the packets, for the CBR case) is larger than
+ 1275. Reject them here.*/
+ if (last_size > 1275)
+ return OPUS_INVALID_PACKET;
+ size[count-1] = (opus_int16)last_size;
+ }
+
+ if (payload_offset)
+ *payload_offset = (int)(data-data0);
+
+ for (i=0;i<count;i++)
+ {
+ if (frames)
+ frames[i] = data;
+ data += size[i];
+ }
+
+ if (packet_offset)
+ *packet_offset = pad+(opus_int32)(data-data0);
+
+ if (out_toc)
+ *out_toc = toc;
+
+ return count;
+}
+
+int opus_packet_parse(const unsigned char *data, opus_int32 len,
+ unsigned char *out_toc, const unsigned char *frames[48],
+ opus_int16 size[48], int *payload_offset)
+{
+ return opus_packet_parse_impl(data, len, 0, out_toc,
+ frames, size, payload_offset, NULL);
+}
+