| 1 | /* |
| 2 | * RTP packetization for MPEG video |
| 3 | * Copyright (c) 2002 Fabrice Bellard |
| 4 | * Copyright (c) 2007 Luca Abeni |
| 5 | * |
| 6 | * This file is part of FFmpeg. |
| 7 | * |
| 8 | * FFmpeg is free software; you can redistribute it and/or |
| 9 | * modify it under the terms of the GNU Lesser General Public |
| 10 | * License as published by the Free Software Foundation; either |
| 11 | * version 2.1 of the License, or (at your option) any later version. |
| 12 | * |
| 13 | * FFmpeg is distributed in the hope that it will be useful, |
| 14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 16 | * Lesser General Public License for more details. |
| 17 | * |
| 18 | * You should have received a copy of the GNU Lesser General Public |
| 19 | * License along with FFmpeg; if not, write to the Free Software |
| 20 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| 21 | */ |
| 22 | |
| 23 | #include "libavcodec/internal.h" |
| 24 | #include "avformat.h" |
| 25 | #include "rtpenc.h" |
| 26 | |
| 27 | /* NOTE: a single frame must be passed with sequence header if |
| 28 | needed. XXX: use slices. */ |
| 29 | void ff_rtp_send_mpegvideo(AVFormatContext *s1, const uint8_t *buf1, int size) |
| 30 | { |
| 31 | RTPMuxContext *s = s1->priv_data; |
| 32 | int len, h, max_packet_size; |
| 33 | uint8_t *q; |
| 34 | const uint8_t *end = buf1 + size; |
| 35 | int begin_of_slice, end_of_slice, frame_type, temporal_reference; |
| 36 | |
| 37 | max_packet_size = s->max_payload_size; |
| 38 | begin_of_slice = 1; |
| 39 | end_of_slice = 0; |
| 40 | frame_type = 0; |
| 41 | temporal_reference = 0; |
| 42 | |
| 43 | while (size > 0) { |
| 44 | int begin_of_sequence; |
| 45 | |
| 46 | begin_of_sequence = 0; |
| 47 | len = max_packet_size - 4; |
| 48 | |
| 49 | if (len >= size) { |
| 50 | len = size; |
| 51 | end_of_slice = 1; |
| 52 | } else { |
| 53 | const uint8_t *r, *r1; |
| 54 | int start_code; |
| 55 | |
| 56 | r1 = buf1; |
| 57 | while (1) { |
| 58 | start_code = -1; |
| 59 | r = avpriv_find_start_code(r1, end, &start_code); |
| 60 | if((start_code & 0xFFFFFF00) == 0x100) { |
| 61 | /* New start code found */ |
| 62 | if (start_code == 0x100) { |
| 63 | frame_type = (r[1] & 0x38) >> 3; |
| 64 | temporal_reference = (int)r[0] << 2 | r[1] >> 6; |
| 65 | } |
| 66 | if (start_code == 0x1B8) { |
| 67 | begin_of_sequence = 1; |
| 68 | } |
| 69 | |
| 70 | if (r - buf1 - 4 <= len) { |
| 71 | /* The current slice fits in the packet */ |
| 72 | if (begin_of_slice == 0) { |
| 73 | /* no slice at the beginning of the packet... */ |
| 74 | end_of_slice = 1; |
| 75 | len = r - buf1 - 4; |
| 76 | break; |
| 77 | } |
| 78 | r1 = r; |
| 79 | } else { |
| 80 | if ((r1 - buf1 > 4) && (r - r1 < max_packet_size)) { |
| 81 | len = r1 - buf1 - 4; |
| 82 | end_of_slice = 1; |
| 83 | } |
| 84 | break; |
| 85 | } |
| 86 | } else { |
| 87 | break; |
| 88 | } |
| 89 | } |
| 90 | } |
| 91 | |
| 92 | h = 0; |
| 93 | h |= temporal_reference << 16; |
| 94 | h |= begin_of_sequence << 13; |
| 95 | h |= begin_of_slice << 12; |
| 96 | h |= end_of_slice << 11; |
| 97 | h |= frame_type << 8; |
| 98 | |
| 99 | q = s->buf; |
| 100 | *q++ = h >> 24; |
| 101 | *q++ = h >> 16; |
| 102 | *q++ = h >> 8; |
| 103 | *q++ = h; |
| 104 | |
| 105 | memcpy(q, buf1, len); |
| 106 | q += len; |
| 107 | |
| 108 | /* 90kHz time stamp */ |
| 109 | s->timestamp = s->cur_timestamp; |
| 110 | ff_rtp_send_data(s1, s->buf, q - s->buf, (len == size)); |
| 111 | |
| 112 | buf1 += len; |
| 113 | size -= len; |
| 114 | begin_of_slice = end_of_slice; |
| 115 | end_of_slice = 0; |
| 116 | } |
| 117 | } |