libavformat/rtpenc_amr.c
08e696c0
 /*
  * RTP packetization for AMR audio
  * Copyright (c) 2007 Luca Abeni
  * Copyright (c) 2009 Martin Storsjo
  *
  * This file is part of FFmpeg.
  *
  * FFmpeg is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *
  * FFmpeg 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
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
  * License along with FFmpeg; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
 #include "avformat.h"
 #include "rtpenc.h"
 
 /**
  * Packetize AMR frames into RTP packets according to RFC 3267,
  * in octet-aligned mode.
  */
 void ff_rtp_send_amr(AVFormatContext *s1, const uint8_t *buff, int size)
 {
     RTPMuxContext *s          = s1->priv_data;
     int max_header_toc_size   = 1 + s->max_frames_per_packet;
     uint8_t *p;
     int len;
 
     /* Test if the packet must be sent. */
     len = s->buf_ptr - s->buf;
     if (s->num_frames == s->max_frames_per_packet || (len && len + size - 1 > s->max_payload_size)) {
         int header_size = s->num_frames + 1;
         p = s->buf + max_header_toc_size - header_size;
         if (p != s->buf)
             memmove(p, s->buf, header_size);
 
         ff_rtp_send_data(s1, p, s->buf_ptr - p, 1);
 
         s->num_frames = 0;
     }
 
     if (!s->num_frames) {
         s->buf[0]    = 0xf0;
         s->buf_ptr   = s->buf + max_header_toc_size;
         s->timestamp = s->cur_timestamp;
     } else {
         /* Mark the previous TOC entry as having more entries following. */
         s->buf[1 + s->num_frames - 1] |= 0x80;
     }
 
     /* Copy the frame type and quality bits. */
     s->buf[1 + s->num_frames++] = buff[0] & 0x7C;
     buff++;
     size--;
     memcpy(s->buf_ptr, buff, size);
     s->buf_ptr += size;
 }