/*
* RTP parser for HEVC/H.265 payload format (draft version 6)
* Copyright (c) 2014 Thomas Volkert <thomas@homer-conferencing.com>
*
* This file is part of FFmpeg.
*
* FFmpeg 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.
*
* FFmpeg 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 FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*
*/
#include "libavutil/avstring.h"
#include "avformat.h"
#include "rtpdec.h"
#define RTP_HEVC_PAYLOAD_HEADER_SIZE 2
#define RTP_HEVC_FU_HEADER_SIZE 1
#define RTP_HEVC_DONL_FIELD_SIZE 2
#define HEVC_SPECIFIED_NAL_UNIT_TYPES 48
/* SDP out-of-band signaling data */
struct PayloadContext {
int using_donl_field;
int profile_id;
};
static const uint8_t start_sequence[] = { 0x00, 0x00, 0x00, 0x01 };
static av_cold PayloadContext *hevc_new_context(void)
{
return av_mallocz(sizeof(PayloadContext));
}
static av_cold void hevc_free_context(PayloadContext *data)
{
av_free(data);
}
static av_cold int hevc_init(AVFormatContext *ctx, int st_index,
PayloadContext *data)
{
av_dlog(ctx, "hevc_init() for stream %d\n", st_index);
if (st_index < 0)
return 0;
ctx->streams[st_index]->need_parsing = AVSTREAM_PARSE_FULL;
return 0;
}
static av_cold int hevc_sdp_parse_fmtp_config(AVFormatContext *s,
AVStream *stream,
PayloadContext *hevc_data,
char *attr, char *value)
{
/* profile-space: 0-3 */
/* profile-id: 0-31 */
if (!strcmp(attr, "profile-id")) {
hevc_data->profile_id = atoi(value);
av_dlog(s, "SDP: found profile-id: %d\n", hevc_data->profile_id);
}
/* tier-flag: 0-1 */
/* level-id: 0-255 */
/* interop-constraints: [base16] */
/* profile-compatibility-indicator: [base16] */
/* sprop-sub-layer-id: 0-6, defines highest possible value for TID, default: 6 */
/* recv-sub-layer-id: 0-6 */
/* max-recv-level-id: 0-255 */
/* tx-mode: MSM,SSM */
/* sprop-vps: [base64] */
/* sprop-sps: [base64] */
/* sprop-pps: [base64] */
/* sprop-sei: [base64] */
/* max-lsr, max-lps, max-cpb, max-dpb, max-br, max-tr, max-tc */
/* max-fps */
/* sprop-max-don-diff: 0-32767
When the RTP stream depends on one or more other RTP
streams (in this case tx-mode MUST be equal to "MSM" and
MSM is in use), this parameter MUST be present and the
value MUST be greater than 0.
*/
if (!strcmp(attr, "sprop-max-don-diff")) {
if (atoi(value) > 0)
hevc_data->using_donl_field = 1;
av_dlog(s, "Found sprop-max-don-diff in SDP, DON field usage is: %d\n",
hevc_data->using_donl_field);
}
/* sprop-depack-buf-nalus: 0-32767 */
if (!strcmp(attr, "sprop-depack-buf-nalus")) {
if (atoi(value) > 0)
hevc_data->using_donl_field = 1;
av_dlog(s, "Found sprop-depack-buf-nalus in SDP, DON field usage is: %d\n",
hevc_data->using_donl_field);
}
/* sprop-depack-buf-bytes: 0-4294967295 */
/* depack-buf-cap */
/* sprop-segmentation-id: 0-3 */
/* sprop-spatial-segmentation-idc: [base16] */
/* dec-parallel-ca: */
/* include-dph */
return 0;
}
static av_cold int hevc_parse_sdp_line(AVFormatContext *ctx, int st_index,
PayloadContext *hevc_data, const char *line)
{
AVStream *current_stream;
AVCodecContext *codec;
const char *sdp_line_ptr = line;
if (st_index < 0)
return 0;
current_stream = ctx->streams[st_index];
codec = current_stream->codec;
if (av_strstart(sdp_line_ptr, "framesize:", &sdp_line_ptr)) {
char str_video_width[50];
char *str_video_width_ptr = str_video_width;
/*
* parse "a=framesize:96 320-240"
*/
/* ignore spaces */
while (*sdp_line_ptr && *sdp_line_ptr == ' ')
sdp_line_ptr++;
/* ignore RTP payload ID */
while (*sdp_line_ptr && *sdp_line_ptr != ' ')
sdp_line_ptr++;
/* ignore spaces */
while (*sdp_line_ptr && *sdp_line_ptr == ' ')
sdp_line_ptr++;
/* extract the actual video resolution description */
while (*sdp_line_ptr && *sdp_line_ptr != '-' &&
(str_video_width_ptr - str_video_width) < sizeof(str_video_width) - 1)
*str_video_width_ptr++ = *sdp_line_ptr++;
/* add trailing zero byte */
*str_video_width_ptr = '\0';
/* determine the width value */
codec->width = atoi(str_video_width);
/* jump beyond the "-" and determine the height value */
codec->height = atoi(sdp_line_ptr + 1);
} else if (av_strstart(sdp_line_ptr, "fmtp:", &sdp_line_ptr)) {
return ff_parse_fmtp(ctx, current_stream, hevc_data, sdp_line_ptr,
hevc_sdp_parse_fmtp_config);
}
return 0;
}
static int hevc_handle_packet(AVFormatContext *ctx, PayloadContext *rtp_hevc_ctx,
AVStream *st, AVPacket *pkt, uint32_t *timestamp,
const uint8_t *buf, int len, uint16_t seq,
int flags)
{
const uint8_t *rtp_pl = buf;
int tid, lid, nal_type;
int first_fragment, last_fragment, fu_type;
uint8_t new_nal_header[2];
int res = 0;
/* sanity check for size of input packet: 1 byte payload at least */
if (len < RTP_HEVC_PAYLOAD_HEADER_SIZE + 1) {
av_log(ctx, AV_LOG_ERROR, "Too short RTP/HEVC packet, got %d bytes\n", len);
return AVERROR_INVALIDDATA;
}
/*
decode the HEVC payload header according to section 4 of draft version 6:
0 1
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|F| Type | LayerId | TID |
+-------------+-----------------+
Forbidden zero (F): 1 bit
NAL unit type (Type): 6 bits
NUH layer ID (LayerId): 6 bits
NUH temporal ID plus 1 (TID): 3 bits
*/
nal_type = (buf[0] >> 1) & 0x3f;
lid = ((buf[0] << 5) & 0x20) | ((buf[1] >> 3) & 0x1f);
tid = buf[1] & 0x07;
/* sanity check for correct layer ID */
if (lid) {
/* future scalable or 3D video coding extensions */
avpriv_report_missing_feature(ctx, "Multi-layer HEVC coding\n");
return AVERROR_PATCHWELCOME;
}
/* sanity check for correct temporal ID */
if (!tid) {
av_log(ctx, AV_LOG_ERROR, "Illegal temporal ID in RTP/HEVC packet\n");
return AVERROR_INVALIDDATA;
}
/* sanity check for correct NAL unit type */
if (nal_type > 50) {
av_log(ctx, AV_LOG_ERROR, "Unsupported (HEVC) NAL type (%d)\n", nal_type);
return AVERROR_INVALIDDATA;
}
switch (nal_type) {
/* aggregated packets (AP) */
case 48:
/* pass the HEVC payload header */
buf += RTP_HEVC_PAYLOAD_HEADER_SIZE;
len -= RTP_HEVC_PAYLOAD_HEADER_SIZE;
/* pass the HEVC DONL field */
if (rtp_hevc_ctx->using_donl_field) {
buf += RTP_HEVC_DONL_FIELD_SIZE;
len -= RTP_HEVC_DONL_FIELD_SIZE;
}
/* fall-through */
/* video parameter set (VPS) */
case 32:
/* sequence parameter set (SPS) */
case 33:
/* picture parameter set (PPS) */
case 34:
/* supplemental enhancement information (SEI) */
case 39:
/* single NAL unit packet */
default:
/* sanity check for size of input packet: 1 byte payload at least */
if (len < 1) {
av_log(ctx, AV_LOG_ERROR,
"Too short RTP/HEVC packet, got %d bytes of NAL unit type %d\n",
len, nal_type);
return AVERROR_INVALIDDATA;
}
/* create A/V packet */
if ((res = av_new_packet(pkt, sizeof(start_sequence) + len)) < 0)
return res;
/* A/V packet: copy start sequence */
memcpy(pkt->data, start_sequence, sizeof(start_sequence));
/* A/V packet: copy NAL unit data */
memcpy(pkt->data + sizeof(start_sequence), buf, len);
break;
/* fragmentation unit (FU) */
case 49:
/* pass the HEVC payload header */
buf += RTP_HEVC_PAYLOAD_HEADER_SIZE;
len -= RTP_HEVC_PAYLOAD_HEADER_SIZE;
if (len < 1)
return AVERROR_INVALIDDATA;
/*
decode the FU header
0 1 2 3 4 5 6 7
+-+-+-+-+-+-+-+-+
|S|E| FuType |
+---------------+
Start fragment (S): 1 bit
End fragment (E): 1 bit
FuType: 6 bits
*/
first_fragment = buf[0] & 0x80;
last_fragment = buf[0] & 0x40;
fu_type = buf[0] & 0x3f;
/* pass the HEVC FU header */
buf += RTP_HEVC_FU_HEADER_SIZE;
len -= RTP_HEVC_FU_HEADER_SIZE;
/* pass the HEVC DONL field */
if (rtp_hevc_ctx->using_donl_field) {
buf += RTP_HEVC_DONL_FIELD_SIZE;
len -= RTP_HEVC_DONL_FIELD_SIZE;
}
av_dlog(ctx, " FU type %d with %d bytes\n", fu_type, len);
if (len > 0) {
new_nal_header[0] = (rtp_pl[0] & 0x81) | (fu_type << 1);
new_nal_header[1] = rtp_pl[1];
/* start fragment vs. subsequent fragments */
if (first_fragment) {
if (!last_fragment) {
/* create A/V packet which is big enough */
if ((res = av_new_packet(pkt, sizeof(start_sequence) + sizeof(new_nal_header) + len)) < 0)
return res;
/* A/V packet: copy start sequence */
memcpy(pkt->data, start_sequence, sizeof(start_sequence));
/* A/V packet: copy new NAL header */
memcpy(pkt->data + sizeof(start_sequence), new_nal_header, sizeof(new_nal_header));
/* A/V packet: copy NAL unit data */
memcpy(pkt->data + sizeof(start_sequence) + sizeof(new_nal_header), buf, len);
} else {
av_log(ctx, AV_LOG_ERROR, "Illegal combination of S and E bit in RTP/HEVC packet\n");
res = AVERROR_INVALIDDATA;
}
} else {
/* create A/V packet */
if ((res = av_new_packet(pkt, len)) < 0)
return res;
/* A/V packet: copy NAL unit data */
memcpy(pkt->data, buf, len);
}
} else {
/* sanity check for size of input packet: 1 byte payload at least */
av_log(ctx, AV_LOG_ERROR,
"Too short RTP/HEVC packet, got %d bytes of NAL unit type %d\n",
len, nal_type);
res = AVERROR_INVALIDDATA;
}
break;
/* PACI packet */
case 50:
/* Temporal scalability control information (TSCI) */
avpriv_report_missing_feature(ctx, "PACI packets for RTP/HEVC\n");
res = AVERROR_PATCHWELCOME;
break;
}
pkt->stream_index = st->index;
return res;
}
RTPDynamicProtocolHandler ff_hevc_dynamic_handler = {
.enc_name = "HEVC",
.codec_type = AVMEDIA_TYPE_VIDEO,
.codec_id = AV_CODEC_ID_HEVC,
.init = hevc_init,
.parse_sdp_a_line = hevc_parse_sdp_line,
.alloc = hevc_new_context,
.free = hevc_free_context,
.parse_packet = hevc_handle_packet
};
RTPDynamicProtocolHandler ff_h265_dynamic_handler = {
.enc_name = "H265",
.codec_type = AVMEDIA_TYPE_VIDEO,
.codec_id = AV_CODEC_ID_HEVC,
.init = hevc_init,
.parse_sdp_a_line = hevc_parse_sdp_line,
.alloc = hevc_new_context,
.free = hevc_free_context,
.parse_packet = hevc_handle_packet
};