Repacketization code (untested)

2025-06-03 09:07:42 +00:00 · 2011-08-10 08:54:49 -04:00 · 2011-08-10 08:54:49 -04:00 · 369553f151
commit 369553f151
parent 4154dad41e
3 changed files with 197 additions and 1 deletions
--- a/src/repacketizer.c
+++ b/src/repacketizer.c
@ -0,0 +1,182 @@
+/* Copyright (c) 2011 Xiph.Org Foundation
+   Written by Jean-Marc Valin */
+/*
+   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 FOUNDATION 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 "string.h"
+#include "opus.h"
+
+struct OpusRepacketizer {
+   unsigned char toc;
+   int nb_frames;
+   const unsigned char *frames[48];
+   short len[48];
+   int framesize;
+};
+
+static 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;
+   }
+}
+
+int opus_repacketizer_get_size(void)
+{
+   return sizeof(OpusRepacketizer);
+}
+
+OpusRepacketizer *opus_repacketizer_init(OpusRepacketizer *rp)
+{
+   rp->nb_frames = 0;
+   return rp;
+}
+
+OpusRepacketizer *opus_repacketizer_create(void)
+{
+   return opus_repacketizer_init(malloc(opus_repacketizer_get_size()));
+}
+
+int opus_repacketizer_cat(OpusRepacketizer *rp, const unsigned char *data, int len)
+{
+   unsigned char tmp_toc;
+   int curr_nb_frames;
+   /* Set of check ToC */
+   if (rp->nb_frames == 0)
+   {
+      rp->toc = data[0];
+      rp->framesize = opus_packet_get_samples_per_frame(data, 48000);
+   } else if (rp->toc != data[0])
+      return 0;
+
+   curr_nb_frames = opus_packet_get_nb_frames(data, len);
+   /* Check the 120 ms maximum packet size */
+   if ((curr_nb_frames+rp->nb_frames)*rp->framesize > 5760)
+      return 0;
+
+   opus_packet_parse(data, len, &tmp_toc, &rp->frames[rp->nb_frames], &rp->len[rp->nb_frames], NULL);
+
+   return 1;
+}
+
+int opus_repacketizer_out_range(OpusRepacketizer *rp, int begin, int end, unsigned char *data, int maxlen)
+{
+   int i, count, tot_size;
+
+   if (begin<0 || begin>=end || end>=rp->nb_frames)
+      return OPUS_BAD_ARG;
+
+   count = end-begin;
+
+   switch (count)
+   {
+   case 1:
+   {
+      /* Code 0 */
+      tot_size = rp->len[0]+1;
+      if (tot_size > maxlen)
+         return OPUS_BUFFER_TOO_SMALL;
+      *data++ = rp->toc&0xFC;
+   }
+   break;
+   case 2:
+   {
+      if (rp->len[1] == rp->len[0])
+      {
+         /* Code 1 */
+         tot_size = 2*rp->len[0]+1;
+         if (tot_size > maxlen)
+            return OPUS_BUFFER_TOO_SMALL;
+         *data++ = (rp->toc&0xFC) | 0x1;
+      } else {
+         /* Code 2 */
+         tot_size = rp->len[0]+rp->len[0]+2+(rp->len[0]>=252);
+         if (tot_size > maxlen)
+            return OPUS_BUFFER_TOO_SMALL;
+         *data++ = (rp->toc&0xFC) | 0x2;
+         data += encode_size(rp->len[0], data);
+      }
+   }
+   break;
+   default:
+   {
+      /* Code 3 */
+      int vbr;
+
+      vbr = 0;
+      for (i=1;i<rp->nb_frames;i++)
+      {
+         if (rp->len[i] != rp->len[0])
+         {
+            vbr=1;
+            break;
+         }
+      }
+      if (vbr)
+      {
+         tot_size = 2;
+         for (i=0;i<rp->nb_frames;i++)
+            tot_size += 1 + (rp->len[i]>=252) + rp->len[i];
+         if (tot_size > maxlen)
+            return OPUS_BUFFER_TOO_SMALL;
+         *data++ = (rp->toc&0xFC) | 0x3;
+         *data++ = rp->nb_frames | 0x80;
+         for (i=0;i<rp->nb_frames-1;i++)
+            data += encode_size(rp->len[i], data);
+      } else {
+         tot_size = rp->nb_frames*rp->len[0]+2;
+         if (tot_size > maxlen)
+            return OPUS_BUFFER_TOO_SMALL;
+         *data++ = (rp->toc&0xFC) | 0x3;
+         *data++ = rp->nb_frames;
+      }
+   }
+   }
+   /* Copy the actual data */
+   for (i=0;i<rp->nb_frames;i++)
+   {
+      memcpy(data, rp->frames[i], rp->len[i]);
+      data += rp->len[i];
+   }
+   return tot_size;
+}
+
+int opus_repacketizer_out(OpusRepacketizer *rp, unsigned char *data, int maxlen)
+{
+   return opus_repacketizer_out_range(rp, 0, rp->nb_frames, data, maxlen);
+}
+
+