/* * RTP packetization for H.264 (RFC3984) * RTP packetizer for HEVC/H.265 payload format (draft version 6) * Copyright (c) 2008 Luca Abeni * Copyright (c) 2014 Thomas Volkert * * 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/HEVC packetization * @author Luca Abeni */ #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/AP framing if (s->buffered_nals == 1) { enum AVCodecID codec = s1->streams[0]->codecpar->codec_id; if (codec == AV_CODEC_ID_H264) ff_rtp_send_data(s1, s->buf + 3, s->buf_ptr - s->buf - 3, last); else ff_rtp_send_data(s1, s->buf + 4, s->buf_ptr - s->buf - 4, 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; enum AVCodecID codec = s1->streams[0]->codecpar->codec_id; 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; int header_size; int skip_aggregate = 0; if (codec == AV_CODEC_ID_H264) { header_size = 1; skip_aggregate = s->flags & FF_RTP_FLAG_H264_MODE0; } else { header_size = 2; } // 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 1/2 bytes for the STAP-A/AP marker), // write the unit to the buffer as a STAP-A/AP packet, otherwise flush // and send as single NAL. if (buffered_size + 2 + header_size + size <= s->max_payload_size && !skip_aggregate) { if (buffered_size == 0) { if (codec == AV_CODEC_ID_H264) { *s->buf_ptr++ = 24; } else { *s->buf_ptr++ = 48 << 1; *s->buf_ptr++ = 1; } } 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 { int flag_byte, header_size; flush_buffered(s1, 0); if (codec == AV_CODEC_ID_H264 && (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); if (codec == AV_CODEC_ID_H264) { uint8_t type = buf[0] & 0x1F; uint8_t nri = buf[0] & 0x60; 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; flag_byte = 1; header_size = 2; } else { uint8_t nal_type = (buf[0] >> 1) & 0x3F; /* * create the HEVC payload header and transmit the buffer as fragmentation units (FU) * * 0 1 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * |F| Type | LayerId | TID | * +-------------+-----------------+ * * F = 0 * Type = 49 (fragmentation unit (FU)) * LayerId = 0 * TID = 1 */ s->buf[0] = 49 << 1; s->buf[1] = 1; /* * create the FU header * * 0 1 2 3 4 5 6 7 * +-+-+-+-+-+-+-+-+ * |S|E| FuType | * +---------------+ * * S = variable * E = variable * FuType = NAL unit type */ s->buf[2] = nal_type; /* set the S bit: mark as start fragment */ s->buf[2] |= 1 << 7; /* pass the original NAL header */ buf += 2; size -= 2; flag_byte = 2; header_size = 3; } while (size + header_size > s->max_payload_size) { memcpy(&s->buf[header_size], buf, s->max_payload_size - header_size); ff_rtp_send_data(s1, s->buf, s->max_payload_size, 0); buf += s->max_payload_size - header_size; size -= s->max_payload_size - header_size; s->buf[flag_byte] &= ~(1 << 7); } s->buf[flag_byte] |= 1 << 6; memcpy(&s->buf[header_size], buf, size); ff_rtp_send_data(s1, s->buf, size + header_size, last); } } void ff_rtp_send_h264_hevc(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); }