1/* 2 * RTP packetization for H.264 (RFC3984) 3 * Copyright (c) 2008 Luca Abeni 4 * 5 * This file is part of FFmpeg. 6 * 7 * FFmpeg 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 * FFmpeg 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 FFmpeg; 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 unsigned 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 (res > end - 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 if (s->flags & FF_RTP_FLAG_H264_MODE0) { 59 av_log(s1, AV_LOG_ERROR, 60 "NAL size %d > %d, try -slice-max-size %d\n", size, 61 s->max_payload_size, s->max_payload_size); 62 return; 63 } 64 av_log(s1, AV_LOG_DEBUG, "NAL size %d > %d\n", size, s->max_payload_size); 65 s->buf[0] = 28; /* FU Indicator; Type = 28 ---> FU-A */ 66 s->buf[0] |= nri; 67 s->buf[1] = type; 68 s->buf[1] |= 1 << 7; 69 buf += 1; 70 size -= 1; 71 while (size + 2 > s->max_payload_size) { 72 memcpy(&s->buf[2], buf, s->max_payload_size - 2); 73 ff_rtp_send_data(s1, s->buf, s->max_payload_size, 0); 74 buf += s->max_payload_size - 2; 75 size -= s->max_payload_size - 2; 76 s->buf[1] &= ~(1 << 7); 77 } 78 s->buf[1] |= 1 << 6; 79 memcpy(&s->buf[2], buf, size); 80 ff_rtp_send_data(s1, s->buf, size + 2, last); 81 } 82} 83 84void ff_rtp_send_h264(AVFormatContext *s1, const uint8_t *buf1, int size) 85{ 86 const uint8_t *r, *end = buf1 + size; 87 RTPMuxContext *s = s1->priv_data; 88 89 s->timestamp = s->cur_timestamp; 90 if (s->nal_length_size) 91 r = avc_mp4_find_startcode(buf1, end, s->nal_length_size) ? buf1 : end; 92 else 93 r = ff_avc_find_startcode(buf1, end); 94 while (r < end) { 95 const uint8_t *r1; 96 97 if (s->nal_length_size) { 98 r1 = avc_mp4_find_startcode(r, end, s->nal_length_size); 99 if (!r1) 100 r1 = end; 101 r += s->nal_length_size; 102 } else { 103 while (!*(r++)); 104 r1 = ff_avc_find_startcode(r, end); 105 } 106 nal_send(s1, r, r1 - r, r1 == end); 107 r = r1; 108 } 109} 110