1/* 2 * RTP packetization for H.264 (RFC3984) 3 * Copyright (c) 2008 Luca Abeni 4 * 5 * This file is part of Libav. 6 * 7 * Libav is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU Lesser General Public 9 * License as published by the Free Software Foundation; either 10 * version 2.1 of the License, or (at your option) any later version. 11 * 12 * Libav is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 15 * Lesser General Public License for more details. 16 * 17 * You should have received a copy of the GNU Lesser General Public 18 * License along with Libav; if not, write to the Free Software 19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 20 */ 21 22/** 23 * @file 24 * @brief H.264 packetization 25 * @author Luca Abeni <lucabe72@email.it> 26 */ 27 28#include "avformat.h" 29#include "avc.h" 30#include "rtpenc.h" 31 32static const uint8_t *avc_mp4_find_startcode(const uint8_t *start, const uint8_t *end, int nal_length_size) 33{ 34 int res = 0; 35 36 if (end - start < nal_length_size) 37 return NULL; 38 while (nal_length_size--) 39 res = (res << 8) | *start++; 40 41 if (start + res > end || res < 0 || start + res < start) 42 return NULL; 43 44 return start + res; 45} 46 47static void nal_send(AVFormatContext *s1, const uint8_t *buf, int size, int last) 48{ 49 RTPMuxContext *s = s1->priv_data; 50 51 av_log(s1, AV_LOG_DEBUG, "Sending NAL %x of len %d M=%d\n", buf[0] & 0x1F, size, last); 52 if (size <= s->max_payload_size) { 53 ff_rtp_send_data(s1, buf, size, last); 54 } else { 55 uint8_t type = buf[0] & 0x1F; 56 uint8_t nri = buf[0] & 0x60; 57 58 av_log(s1, AV_LOG_DEBUG, "NAL size %d > %d\n", size, s->max_payload_size); 59 s->buf[0] = 28; /* FU Indicator; Type = 28 ---> FU-A */ 60 s->buf[0] |= nri; 61 s->buf[1] = type; 62 s->buf[1] |= 1 << 7; 63 buf += 1; 64 size -= 1; 65 while (size + 2 > s->max_payload_size) { 66 memcpy(&s->buf[2], buf, s->max_payload_size - 2); 67 ff_rtp_send_data(s1, s->buf, s->max_payload_size, 0); 68 buf += s->max_payload_size - 2; 69 size -= s->max_payload_size - 2; 70 s->buf[1] &= ~(1 << 7); 71 } 72 s->buf[1] |= 1 << 6; 73 memcpy(&s->buf[2], buf, size); 74 ff_rtp_send_data(s1, s->buf, size + 2, last); 75 } 76} 77 78void ff_rtp_send_h264(AVFormatContext *s1, const uint8_t *buf1, int size) 79{ 80 const uint8_t *r, *end = buf1 + size; 81 RTPMuxContext *s = s1->priv_data; 82 83 s->timestamp = s->cur_timestamp; 84 if (s->nal_length_size) 85 r = avc_mp4_find_startcode(buf1, end, s->nal_length_size) ? buf1 : end; 86 else 87 r = ff_avc_find_startcode(buf1, end); 88 while (r < end) { 89 const uint8_t *r1; 90 91 if (s->nal_length_size) { 92 r1 = avc_mp4_find_startcode(r, end, s->nal_length_size); 93 if (!r1) 94 r1 = end; 95 r += s->nal_length_size; 96 } else { 97 while (!*(r++)); 98 r1 = ff_avc_find_startcode(r, end); 99 } 100 nal_send(s1, r, r1 - r, r1 == end); 101 r = r1; 102 } 103} 104