| /* |
| * RTP packetization for H.263 video |
| * Copyright (c) 2009 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" |
| |
| const uint8_t *ff_h263_find_resync_marker_reverse(const uint8_t *av_restrict start, |
| const uint8_t *av_restrict end) |
| { |
| const uint8_t *p = end - 1; |
| start += 1; /* Make sure we never return the original start. */ |
| for (; p > start; p -= 2) { |
| if (!*p) { |
| if (!p[ 1] && p[2]) return p; |
| else if (!p[-1] && p[1]) return p - 1; |
| } |
| } |
| return end; |
| } |
| |
| /** |
| * Packetize H.263 frames into RTP packets according to RFC 4629 |
| */ |
| void ff_rtp_send_h263(AVFormatContext *s1, const uint8_t *buf1, int size) |
| { |
| RTPMuxContext *s = s1->priv_data; |
| int len, max_packet_size; |
| uint8_t *q; |
| |
| max_packet_size = s->max_payload_size; |
| |
| while (size > 0) { |
| q = s->buf; |
| if (size >= 2 && (buf1[0] == 0) && (buf1[1] == 0)) { |
| *q++ = 0x04; |
| buf1 += 2; |
| size -= 2; |
| } else { |
| *q++ = 0; |
| } |
| *q++ = 0; |
| |
| len = FFMIN(max_packet_size - 2, size); |
| |
| /* Look for a better place to split the frame into packets. */ |
| if (len < size) { |
| const uint8_t *end = ff_h263_find_resync_marker_reverse(buf1, |
| buf1 + len); |
| len = end - buf1; |
| } |
| |
| memcpy(q, buf1, len); |
| q += len; |
| |
| /* 90 KHz time stamp */ |
| s->timestamp = s->cur_timestamp; |
| ff_rtp_send_data(s1, s->buf, q - s->buf, (len == size)); |
| |
| buf1 += len; |
| size -= len; |
| } |
| } |