ffmpeg/libavformat/rtpenc_h264.c

137 lines
4.6 KiB
C

/*
* RTP packetization for H.264 (RFC3984)
* Copyright (c) 2008 Luca Abeni
*
* This file is part of Libav.
*
* Libav is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* Libav is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* @brief H.264 packetization
* @author Luca Abeni <lucabe72@email.it>
*/
#include "libavutil/intreadwrite.h"
#include "avformat.h"
#include "avc.h"
#include "rtpenc.h"
static void flush_buffered(AVFormatContext *s1, int last)
{
RTPMuxContext *s = s1->priv_data;
if (s->buf_ptr != s->buf) {
// If we're only sending one single NAL unit, send it as such, skip
// the STAP-A framing
if (s->buffered_nals == 1)
ff_rtp_send_data(s1, s->buf + 3, s->buf_ptr - s->buf - 3, last);
else
ff_rtp_send_data(s1, s->buf, s->buf_ptr - s->buf, last);
}
s->buf_ptr = s->buf;
s->buffered_nals = 0;
}
static void nal_send(AVFormatContext *s1, const uint8_t *buf, int size, int last)
{
RTPMuxContext *s = s1->priv_data;
av_log(s1, AV_LOG_DEBUG, "Sending NAL %x of len %d M=%d\n", buf[0] & 0x1F, size, last);
if (size <= s->max_payload_size) {
int buffered_size = s->buf_ptr - s->buf;
// Flush buffered NAL units if the current unit doesn't fit
if (buffered_size + 2 + size > s->max_payload_size) {
flush_buffered(s1, 0);
buffered_size = 0;
}
// If we aren't using mode 0, and the NAL unit fits including the
// framing (2 bytes length, plus 1 byte for the STAP-A marker),
// write the unit to the buffer as a STAP-A packet, otherwise flush
// and send as single NAL.
if (buffered_size + 3 + size <= s->max_payload_size &&
!(s->flags & FF_RTP_FLAG_H264_MODE0)) {
if (buffered_size == 0)
*s->buf_ptr++ = 24;
AV_WB16(s->buf_ptr, size);
s->buf_ptr += 2;
memcpy(s->buf_ptr, buf, size);
s->buf_ptr += size;
s->buffered_nals++;
} else {
flush_buffered(s1, 0);
ff_rtp_send_data(s1, buf, size, last);
}
} else {
uint8_t type = buf[0] & 0x1F;
uint8_t nri = buf[0] & 0x60;
flush_buffered(s1, 0);
if (s->flags & FF_RTP_FLAG_H264_MODE0) {
av_log(s1, AV_LOG_ERROR,
"NAL size %d > %d, try -slice-max-size %d\n", size,
s->max_payload_size, s->max_payload_size);
return;
}
av_log(s1, AV_LOG_DEBUG, "NAL size %d > %d\n", size, s->max_payload_size);
s->buf[0] = 28; /* FU Indicator; Type = 28 ---> FU-A */
s->buf[0] |= nri;
s->buf[1] = type;
s->buf[1] |= 1 << 7;
buf += 1;
size -= 1;
while (size + 2 > s->max_payload_size) {
memcpy(&s->buf[2], buf, s->max_payload_size - 2);
ff_rtp_send_data(s1, s->buf, s->max_payload_size, 0);
buf += s->max_payload_size - 2;
size -= s->max_payload_size - 2;
s->buf[1] &= ~(1 << 7);
}
s->buf[1] |= 1 << 6;
memcpy(&s->buf[2], buf, size);
ff_rtp_send_data(s1, s->buf, size + 2, last);
}
}
void ff_rtp_send_h264(AVFormatContext *s1, const uint8_t *buf1, int size)
{
const uint8_t *r, *end = buf1 + size;
RTPMuxContext *s = s1->priv_data;
s->timestamp = s->cur_timestamp;
s->buf_ptr = s->buf;
if (s->nal_length_size)
r = ff_avc_mp4_find_startcode(buf1, end, s->nal_length_size) ? buf1 : end;
else
r = ff_avc_find_startcode(buf1, end);
while (r < end) {
const uint8_t *r1;
if (s->nal_length_size) {
r1 = ff_avc_mp4_find_startcode(r, end, s->nal_length_size);
if (!r1)
r1 = end;
r += s->nal_length_size;
} else {
while (!*(r++));
r1 = ff_avc_find_startcode(r, end);
}
nal_send(s1, r, r1 - r, r1 == end);
r = r1;
}
flush_buffered(s1, 1);
}