| 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 | |
| 32 | static 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 | |
| 47 | static 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 | |
| 84 | void 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 | } |