FFmpeg RTMP推HEVC/H265流

    直播流媒体协议中，HLS和RTMP协议是两大主流协议。而众所周知的原因，RTMP在许多年前就已经停止拓展和更新，因此标准一直无法支持HEVC的编码格式。目前国内的CDN还有金山云等已经对RTMP进行了标准扩展，播放器上ijkplayer也扩展了该修改。

    具体FFmpeg的修改代码如下：

  
  
From e40fcb1113cb1c93c48b8ef74b8aec6437f23d84 Mon Sep 17 00: 00: 00 2001
From: Franken Zeng <[email protected]>
Date: Wed, 14 Jun 2017 21: 33: 54 + 0800
Subject: [PATCH] The RTMP protocol extensions for H .265/HEVC

---
libavformat/flv.h | 1 +
libavformat/flvdec.c | 16 +++++++++++++---
libavformat/flvenc.c | 29 ++++++++++++++++++++---------
3 files changed, 34 insertions(+), 12 deletions(-)

diff --git a/libavformat/flv.h b/libavformat/flv.h
index df5ce3d17f8. .089bc76972d 100644
--- a/libavformat/flv.h
+++ b/libavformat/flv.h
@@ -109, 6 + 109, 7 @@ enum {
FLV_CODECID_H264 = 7,
FLV_CODECID_REALH263= 8,
FLV_CODECID_MPEG4 = 9,
+ FLV_CODECID_HEVC = 12,
};

enum {
diff --git a/libavformat/flvdec.c b/libavformat/flvdec.c
index 2d89bef15f2..c8073b88a92 100644
--- a/libavformat/flvdec.c
+++ b/libavformat/flvdec.c
@@ -36, 6 + 36, 7 @@
#include "internal.h"
#include "avio_internal.h"
#include "flv.h"
+ #include "hevc.h"

#define VALIDATE_INDEX_TS_THRESH 2500

@@ -291, 6 + 292, 8 @@ static int flv_same_video_codec(AVCodecParameters *vpar, int flags)
return vpar->codec_id == AV_CODEC_ID_VP6A;
case FLV_CODECID_H264:
return vpar->codec_id == AV_CODEC_ID_H264;
+ case FLV_CODECID_HEVC:
+ return vpar->codec_id == AV_CODEC_ID_HEVC;
default:
return vpar->codec_tag == flv_codecid;
}
@@ -340, 6 + 343, 11 @@ static int flv_set_video_codec(AVFormatContext *s, AVStream *vstream,
par->codec_id = AV_CODEC_ID_MPEG4;
ret = 3;
break;
+ case FLV_CODECID_HEVC:
+ par->codec_id = AV_CODEC_ID_HEVC;
+ vstream->need_parsing = AVSTREAM_PARSE_NONE;
+ ret = 3; // not 4, reading packet type will consume one byte
+ break;
default:
avpriv_request_sample(s, "Video codec (%x)", flv_codecid);
par->codec_tag = flv_codecid;
@@ -1149, 10 + 1157, 12 @@ static int flv_read_packet(AVFormatContext *s, AVPacket *pkt)

if (st->codecpar->codec_id == AV_CODEC_ID_AAC ||
st->codecpar->codec_id == AV_CODEC_ID_H264 ||
- st->codecpar->codec_id == AV_CODEC_ID_MPEG4) {
+ st->codecpar->codec_id == AV_CODEC_ID_MPEG4 ||
+ st->codecpar->codec_id == AV_CODEC_ID_HEVC) {
int type = avio_r8(s->pb);
size--;
- if (st->codecpar->codec_id == AV_CODEC_ID_H264 || st->codecpar->codec_id == AV_CODEC_ID_MPEG4) {
+ if (st->codecpar->codec_id == AV_CODEC_ID_H264 || st->codecpar->codec_id == AV_CODEC_ID_MPEG4
+ || st->codecpar->codec_id == AV_CODEC_ID_HEVC) {
// sign extension
int32_t cts = (avio_rb24(s->pb) + 0xff800000) ^ 0xff800000;
pts = dts + cts;
@@ -1168, 7 + 1178, 7 @@ static int flv_read_packet(AVFormatContext *s, AVPacket *pkt)
}
}
if (type == 0 && (!st->codecpar->extradata || st->codecpar->codec_id == AV_CODEC_ID_AAC ||
- st->codecpar->codec_id == AV_CODEC_ID_H264)) {
+ st->codecpar->codec_id == AV_CODEC_ID_H264 || st->codecpar->codec_id == AV_CODEC_ID_HEVC)) {
AVDictionaryEntry *t;

if (st->codecpar->extradata) {
diff --git a/libavformat/flvenc.c b/libavformat/flvenc.c
index 899b07ea7be..eb955e5b451 100644
--- a/libavformat/flvenc.c
+++ b/libavformat/flvenc.c
@@ -34, 6 + 34, 7 @@
#include "libavutil/opt.h"
#include "libavcodec/put_bits.h"
#include "libavcodec/aacenctab.h"
+ #include "hevc.h"


static const AVCodecTag flv_video_codec_ids[] = {
@@ -46, 6 + 47, 7 @@ static const AVCodecTag flv_video_codec_ids[] = {
{ AV_CODEC_ID_VP6, FLV_CODECID_VP6 },
{ AV_CODEC_ID_VP6A, FLV_CODECID_VP6A },
{ AV_CODEC_ID_H264, FLV_CODECID_H264 },
+ { AV_CODEC_ID_HEVC, FLV_CODECID_HEVC },
{ AV_CODEC_ID_NONE, 0 }
};

@@ -486, 7 + 488, 7 @@ static void flv_write_codec_header(AVFormatContext* s, AVCodecParameters* par) {
FLVContext *flv = s->priv_data;

if (par->codec_id == AV_CODEC_ID_AAC || par->codec_id == AV_CODEC_ID_H264
- || par->codec_id == AV_CODEC_ID_MPEG4) {
+ || par->codec_id == AV_CODEC_ID_MPEG4 || par->codec_id == AV_CODEC_ID_HEVC) {
int64_t pos;
avio_w8(pb,
par->codec_type == AVMEDIA_TYPE_VIDEO ?
@@ -533, 7 + 535, 11 @@ static void flv_write_codec_header(AVFormatContext* s, AVCodecParameters* par) {
avio_w8(pb, par->codec_tag | FLV_FRAME_KEY); // flags
avio_w8(pb, 0); // AVC sequence header
avio_wb24(pb, 0); // composition time
- ff_isom_write_avcc(pb, par->extradata, par->extradata_size);
+ if (par->codec_id == AV_CODEC_ID_HEVC) {
+ ff_isom_write_hvcc(pb, par->extradata, par->extradata_size, 0);
+ } else {
+ ff_isom_write_avcc(pb, par->extradata, par->extradata_size);
+ }
}
data_size = avio_tell(pb) - pos;
avio_seek(pb, -data_size - 10, SEEK_CUR);
@@ -836, 7 + 842, 7 @@ static int flv_write_trailer(AVFormatContext *s)
AVCodecParameters *par = s->streams[i]->codecpar;
FLVStreamContext *sc = s->streams[i]->priv_data;
if (par->codec_type == AVMEDIA_TYPE_VIDEO &&
- (par->codec_id == AV_CODEC_ID_H264 || par->codec_id == AV_CODEC_ID_MPEG4))
+ (par->codec_id == AV_CODEC_ID_H264 || par->codec_id == AV_CODEC_ID_MPEG4 || par->codec_id == AV_CODEC_ID_HEVC))
put_avc_eos_tag(pb, sc->last_ts);
}
}
@@ -880, 15 + 886, 16 @@ static int flv_write_packet(AVFormatContext *s, AVPacket *pkt)
int64_t cur_offset = avio_tell(pb);

if (par->codec_id == AV_CODEC_ID_VP6F || par->codec_id == AV_CODEC_ID_VP6A ||
- par->codec_id == AV_CODEC_ID_VP6 || par->codec_id == AV_CODEC_ID_AAC)
+ par->codec_id == AV_CODEC_ID_VP6 || par->codec_id == AV_CODEC_ID_AAC) {
flags_size = 2;
- else if (par->codec_id == AV_CODEC_ID_H264 || par->codec_id == AV_CODEC_ID_MPEG4)
+ } else if (par->codec_id == AV_CODEC_ID_H264 || par->codec_id == AV_CODEC_ID_MPEG4 || par->codec_id == AV_CODEC_ID_HEVC) {
flags_size = 5;
- else
+ } else {
flags_size = 1;
+ }

if (par->codec_id == AV_CODEC_ID_AAC || par->codec_id == AV_CODEC_ID_H264
- || par->codec_id == AV_CODEC_ID_MPEG4) {
+ || par->codec_id == AV_CODEC_ID_MPEG4 || par->codec_id == AV_CODEC_ID_HEVC) {
int side_size = 0;
uint8_t *side = av_packet_get_side_data(pkt, AV_PKT_DATA_NEW_EXTRADATA, &side_size);
if (side && side_size > 0 && (side_size != par->extradata_size || memcmp(side, par->extradata, side_size))) {
@@ -951, 6 + 958, 10 @@ static int flv_write_packet(AVFormatContext *s, AVPacket *pkt)
if (par->extradata_size > 0 && *(uint8_t*)par->extradata != 1)
if ((ret = ff_avc_parse_nal_units_buf(pkt->data, &data, &size)) < 0)
return ret;
+ } else if (par->codec_id == AV_CODEC_ID_HEVC) {
+ if (par->extradata_size > 0 && *( uint8_t*)par->extradata != 1)
+ if ((ret = ff_hevc_annexb2mp4_buf(pkt->data, &data, &size, 0, NULL)) < 0)
+ return ret;
} else if (par->codec_id == AV_CODEC_ID_AAC && pkt->size > 2 &&
(AV_RB16(pkt->data) & 0xfff0) == 0xfff0) {
if (!s->streams[pkt->stream_index]->nb_frames) {
@@ -1021, 9 + 1032, 9 @@ static int flv_write_packet(AVFormatContext *s, AVPacket *pkt)
else
avio_w8(pb, ((FFALIGN(par->width, 16) - par->width) << 4) |
(FFALIGN(par->height, 16) - par->height));
- } else if (par->codec_id == AV_CODEC_ID_AAC)
+ } else if (par->codec_id == AV_CODEC_ID_AAC) {
avio_w8(pb, 1); // AAC raw
- else if (par->codec_id == AV_CODEC_ID_H264 || par->codec_id == AV_CODEC_ID_MPEG4) {
+ } else if (par->codec_id == AV_CODEC_ID_H264 || par->codec_id == AV_CODEC_ID_MPEG4 || par->codec_id == AV_CODEC_ID_HEVC) {
avio_w8(pb, 1); // AVC NALU
avio_wb24(pb, pkt->pts - pkt->dts);
}
  
  

    通过该项修改即可拓展FFmpeg中RTMP对于HEVC的支持。

    我的上一篇文章，《FFmpeg+Nginx搭建RTMP直播推流服务》记录了FFmpeg+Nginx的RTMP的搭建方式。

    但是由于服务端Nginx并没有添加HEVC下重发flv的header头部，因此播放器端只有在从流的最开始才能够成功的解码，否则会出现缺少解码参数集导致无法成功解码。解决办法有两个：

     1. 在FFmpeg代码中每一包都手动添加解码参数集于flv的header中，修改如下：

     ff_write_packet中

  
  
if (par->codec_id == AV_CODEC_ID_AAC || par->codec_id == AV_CODEC_ID_H264
|| par->codec_id == AV_CODEC_ID_MPEG4 || par->codec_id == AV_CODEC_ID_HEVC) {
int side_size = 0;
uint8_t *side = av_packet_get_side_data(pkt, AV_PKT_DATA_NEW_EXTRADATA, &side_size);
if (side && side_size > 0 && (side_size != par->extradata_size || memcmp(side, par->extradata, side_size))) {
av_free(par->extradata);
par->extradata = av_mallocz(side_size + AV_INPUT_BUFFER_PADDING_SIZE);
if (!par->extradata) {
par->extradata_size = 0;
return AVERROR(ENOMEM);
}
memcpy(par->extradata, side, side_size);
par->extradata_size = side_size;
flv_write_codec_header(s, par, pkt->dts);
} else {
flv_write_codec_header(s, par, pkt->dts);
}
}
  
  

    2. 修改Nginx，添加HEVC的支持。这部分暂无时间修改。

转载自：https://blog.csdn.net/smallhujiu/article/details/81703434

    直播流媒体协议中，HLS和RTMP协议是两大主流协议。而众所周知的原因，RTMP在许多年前就已经停止拓展和更新，因此标准一直无法支持HEVC的编码格式。目前国内的CDN还有金山云等已经对RTMP进行了标准扩展，播放器上ijkplayer也扩展了该修改。