yading@11: /*
yading@11:  * RTP packetization for H.264 (RFC3984)
yading@11:  * Copyright (c) 2008 Luca Abeni
yading@11:  *
yading@11:  * This file is part of FFmpeg.
yading@11:  *
yading@11:  * FFmpeg is free software; you can redistribute it and/or
yading@11:  * modify it under the terms of the GNU Lesser General Public
yading@11:  * License as published by the Free Software Foundation; either
yading@11:  * version 2.1 of the License, or (at your option) any later version.
yading@11:  *
yading@11:  * FFmpeg is distributed in the hope that it will be useful,
yading@11:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@11:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@11:  * Lesser General Public License for more details.
yading@11:  *
yading@11:  * You should have received a copy of the GNU Lesser General Public
yading@11:  * License along with FFmpeg; if not, write to the Free Software
yading@11:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@11:  */
yading@11: 
yading@11: /**
yading@11:  * @file
yading@11:  * @brief H.264 packetization
yading@11:  * @author Luca Abeni <lucabe72@email.it>
yading@11:  */
yading@11: 
yading@11: #include "avformat.h"
yading@11: #include "avc.h"
yading@11: #include "rtpenc.h"
yading@11: 
yading@11: static const uint8_t *avc_mp4_find_startcode(const uint8_t *start, const uint8_t *end, int nal_length_size)
yading@11: {
yading@11:     unsigned int res = 0;
yading@11: 
yading@11:     if (end - start < nal_length_size)
yading@11:         return NULL;
yading@11:     while (nal_length_size--)
yading@11:         res = (res << 8) | *start++;
yading@11: 
yading@11:     if (res > end - start)
yading@11:         return NULL;
yading@11: 
yading@11:     return start + res;
yading@11: }
yading@11: 
yading@11: static void nal_send(AVFormatContext *s1, const uint8_t *buf, int size, int last)
yading@11: {
yading@11:     RTPMuxContext *s = s1->priv_data;
yading@11: 
yading@11:     av_log(s1, AV_LOG_DEBUG, "Sending NAL %x of len %d M=%d\n", buf[0] & 0x1F, size, last);
yading@11:     if (size <= s->max_payload_size) {
yading@11:         ff_rtp_send_data(s1, buf, size, last);
yading@11:     } else {
yading@11:         uint8_t type = buf[0] & 0x1F;
yading@11:         uint8_t nri = buf[0] & 0x60;
yading@11: 
yading@11:         if (s->flags & FF_RTP_FLAG_H264_MODE0) {
yading@11:             av_log(s1, AV_LOG_ERROR,
yading@11:                    "NAL size %d > %d, try -slice-max-size %d\n", size,
yading@11:                    s->max_payload_size, s->max_payload_size);
yading@11:             return;
yading@11:         }
yading@11:         av_log(s1, AV_LOG_DEBUG, "NAL size %d > %d\n", size, s->max_payload_size);
yading@11:         s->buf[0] = 28;        /* FU Indicator; Type = 28 ---> FU-A */
yading@11:         s->buf[0] |= nri;
yading@11:         s->buf[1] = type;
yading@11:         s->buf[1] |= 1 << 7;
yading@11:         buf += 1;
yading@11:         size -= 1;
yading@11:         while (size + 2 > s->max_payload_size) {
yading@11:             memcpy(&s->buf[2], buf, s->max_payload_size - 2);
yading@11:             ff_rtp_send_data(s1, s->buf, s->max_payload_size, 0);
yading@11:             buf += s->max_payload_size - 2;
yading@11:             size -= s->max_payload_size - 2;
yading@11:             s->buf[1] &= ~(1 << 7);
yading@11:         }
yading@11:         s->buf[1] |= 1 << 6;
yading@11:         memcpy(&s->buf[2], buf, size);
yading@11:         ff_rtp_send_data(s1, s->buf, size + 2, last);
yading@11:     }
yading@11: }
yading@11: 
yading@11: void ff_rtp_send_h264(AVFormatContext *s1, const uint8_t *buf1, int size)
yading@11: {
yading@11:     const uint8_t *r, *end = buf1 + size;
yading@11:     RTPMuxContext *s = s1->priv_data;
yading@11: 
yading@11:     s->timestamp = s->cur_timestamp;
yading@11:     if (s->nal_length_size)
yading@11:         r = avc_mp4_find_startcode(buf1, end, s->nal_length_size) ? buf1 : end;
yading@11:     else
yading@11:         r = ff_avc_find_startcode(buf1, end);
yading@11:     while (r < end) {
yading@11:         const uint8_t *r1;
yading@11: 
yading@11:         if (s->nal_length_size) {
yading@11:             r1 = avc_mp4_find_startcode(r, end, s->nal_length_size);
yading@11:             if (!r1)
yading@11:                 r1 = end;
yading@11:             r += s->nal_length_size;
yading@11:         } else {
yading@11:             while (!*(r++));
yading@11:             r1 = ff_avc_find_startcode(r, end);
yading@11:         }
yading@11:         nal_send(s1, r, r1 - r, r1 == end);
yading@11:         r = r1;
yading@11:     }
yading@11: }