208 lines
7 KiB
C
208 lines
7 KiB
C
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/*
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* RTP packetization for H.264 (RFC3984)
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* RTP packetizer for HEVC/H.265 payload format (draft version 6)
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* Copyright (c) 2008 Luca Abeni
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* Copyright (c) 2014 Thomas Volkert <thomas@homer-conferencing.com>
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*
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* This file is part of FFmpeg.
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*
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* FFmpeg is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* FFmpeg is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with FFmpeg; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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/**
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* @file
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* @brief H.264/HEVC packetization
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* @author Luca Abeni <lucabe72@email.it>
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*/
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#include "libavutil/intreadwrite.h"
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#include "avformat.h"
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#include "avc.h"
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#include "rtpenc.h"
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static void flush_buffered(AVFormatContext *s1, int last)
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{
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RTPMuxContext *s = s1->priv_data;
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if (s->buf_ptr != s->buf) {
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// If we're only sending one single NAL unit, send it as such, skip
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// the STAP-A/AP framing
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if (s->buffered_nals == 1) {
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enum AVCodecID codec = s1->streams[0]->codecpar->codec_id;
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if (codec == AV_CODEC_ID_H264)
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ff_rtp_send_data(s1, s->buf + 3, s->buf_ptr - s->buf - 3, last);
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else
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ff_rtp_send_data(s1, s->buf + 4, s->buf_ptr - s->buf - 4, last);
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} else
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ff_rtp_send_data(s1, s->buf, s->buf_ptr - s->buf, last);
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}
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s->buf_ptr = s->buf;
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s->buffered_nals = 0;
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}
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static void nal_send(AVFormatContext *s1, const uint8_t *buf, int size, int last)
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{
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RTPMuxContext *s = s1->priv_data;
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enum AVCodecID codec = s1->streams[0]->codecpar->codec_id;
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av_log(s1, AV_LOG_DEBUG, "Sending NAL %x of len %d M=%d\n", buf[0] & 0x1F, size, last);
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if (size <= s->max_payload_size) {
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int buffered_size = s->buf_ptr - s->buf;
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int header_size;
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int skip_aggregate = 0;
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if (codec == AV_CODEC_ID_H264) {
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header_size = 1;
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skip_aggregate = s->flags & FF_RTP_FLAG_H264_MODE0;
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} else {
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header_size = 2;
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}
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// Flush buffered NAL units if the current unit doesn't fit
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if (buffered_size + 2 + size > s->max_payload_size) {
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flush_buffered(s1, 0);
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buffered_size = 0;
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}
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// If we aren't using mode 0, and the NAL unit fits including the
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// framing (2 bytes length, plus 1/2 bytes for the STAP-A/AP marker),
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// write the unit to the buffer as a STAP-A/AP packet, otherwise flush
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// and send as single NAL.
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if (buffered_size + 2 + header_size + size <= s->max_payload_size &&
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!skip_aggregate) {
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if (buffered_size == 0) {
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if (codec == AV_CODEC_ID_H264) {
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*s->buf_ptr++ = 24;
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} else {
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*s->buf_ptr++ = 48 << 1;
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*s->buf_ptr++ = 1;
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}
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}
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AV_WB16(s->buf_ptr, size);
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s->buf_ptr += 2;
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memcpy(s->buf_ptr, buf, size);
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s->buf_ptr += size;
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s->buffered_nals++;
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} else {
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flush_buffered(s1, 0);
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ff_rtp_send_data(s1, buf, size, last);
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}
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} else {
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int flag_byte, header_size;
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flush_buffered(s1, 0);
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if (codec == AV_CODEC_ID_H264 && (s->flags & FF_RTP_FLAG_H264_MODE0)) {
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av_log(s1, AV_LOG_ERROR,
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"NAL size %d > %d, try -slice-max-size %d\n", size,
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s->max_payload_size, s->max_payload_size);
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return;
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}
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av_log(s1, AV_LOG_DEBUG, "NAL size %d > %d\n", size, s->max_payload_size);
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if (codec == AV_CODEC_ID_H264) {
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uint8_t type = buf[0] & 0x1F;
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uint8_t nri = buf[0] & 0x60;
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s->buf[0] = 28; /* FU Indicator; Type = 28 ---> FU-A */
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s->buf[0] |= nri;
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s->buf[1] = type;
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s->buf[1] |= 1 << 7;
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buf += 1;
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size -= 1;
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flag_byte = 1;
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header_size = 2;
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} else {
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uint8_t nal_type = (buf[0] >> 1) & 0x3F;
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/*
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* create the HEVC payload header and transmit the buffer as fragmentation units (FU)
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*
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* 0 1
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* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
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* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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* |F| Type | LayerId | TID |
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* +-------------+-----------------+
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*
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* F = 0
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* Type = 49 (fragmentation unit (FU))
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* LayerId = 0
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* TID = 1
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*/
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s->buf[0] = 49 << 1;
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s->buf[1] = 1;
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/*
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* create the FU header
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*
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* 0 1 2 3 4 5 6 7
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* +-+-+-+-+-+-+-+-+
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* |S|E| FuType |
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* +---------------+
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*
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* S = variable
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* E = variable
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* FuType = NAL unit type
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*/
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s->buf[2] = nal_type;
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/* set the S bit: mark as start fragment */
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s->buf[2] |= 1 << 7;
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/* pass the original NAL header */
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buf += 2;
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size -= 2;
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flag_byte = 2;
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header_size = 3;
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}
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while (size + header_size > s->max_payload_size) {
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memcpy(&s->buf[header_size], buf, s->max_payload_size - header_size);
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ff_rtp_send_data(s1, s->buf, s->max_payload_size, 0);
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buf += s->max_payload_size - header_size;
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size -= s->max_payload_size - header_size;
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s->buf[flag_byte] &= ~(1 << 7);
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}
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s->buf[flag_byte] |= 1 << 6;
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memcpy(&s->buf[header_size], buf, size);
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ff_rtp_send_data(s1, s->buf, size + header_size, last);
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}
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}
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void ff_rtp_send_h264_hevc(AVFormatContext *s1, const uint8_t *buf1, int size)
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{
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const uint8_t *r, *end = buf1 + size;
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RTPMuxContext *s = s1->priv_data;
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s->timestamp = s->cur_timestamp;
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s->buf_ptr = s->buf;
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if (s->nal_length_size)
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r = ff_avc_mp4_find_startcode(buf1, end, s->nal_length_size) ? buf1 : end;
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else
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r = ff_avc_find_startcode(buf1, end);
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while (r < end) {
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const uint8_t *r1;
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if (s->nal_length_size) {
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r1 = ff_avc_mp4_find_startcode(r, end, s->nal_length_size);
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if (!r1)
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r1 = end;
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r += s->nal_length_size;
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} else {
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while (!*(r++));
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r1 = ff_avc_find_startcode(r, end);
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}
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nal_send(s1, r, r1 - r, r1 == end);
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r = r1;
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}
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flush_buffered(s1, 1);
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}
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