不久前我們已經在RTMP推送端擴展支持了HEVC(H.265 後文統稱H265)編碼格式,但是,由於RTMP官方指定的協議格式已經不再更新,官方的播放器的Flash播放器並不支持H265格式的編碼數據進行解碼播放;現在,我們需要在播放器端解析RTMP流時對H265編碼格式進行擴展支持。
首先,我們可以通過擴展ffmpeg,讓其支持拉H265封裝的RTMP流進行解碼播放,我們可以通過金山雲對FFmepg的擴展支持H265來解決。
然後,我們通過修改EasyRTMPClient的代碼實現對H265 的支持,因爲我們已經實現了推送端的擴展支持,所以,播放端支持則相對比較簡單;不過依然有幾個方面我們需要注意;下面將對整個擴展流程進行介紹。
1. 擴展編碼ID
和推送端一樣,需要先擴展支持H265的編碼ID,我們定義爲12,如下代碼所示:
enum FlvVideoCodecId
{
e_FlvVideoCodecId_None = 0,
e_FlvVideoCodecId_Jpeg = 1,
e_FlvVideoCodecId_H263 = 2,
e_FlvVideoCodecId_Screen = 3,
e_FlvVideoCodecId_Vp6 = 4,
e_FlvVideoCodecId_Vp6Alpha = 5,
e_FlvVideoCodecId_ScreenV2 = 6,
e_FlvVideoCodecId_Avc = 7,
// RTMP擴展支持HEVC(H.265)
e_FlvVideoCodecId_Hevc = 12,
};
enum FlvCodeId
{
FlvCodeId_Jpeg = 1,
FlvCodeId_Sorenson = 2,
FlvCodeId_ScreenVideo = 3,
FlvCodeId_On2Vp6 = 4,
FlvCodeId_On2Vp6Alpha = 5,
FlvCodeId_ScreenVideoV2 = 6,
FlvCodeId_AVC = 7,
// RTMP擴展支持HEVC(H.265)
FlvCodeId_Hevc = 12,
};
2. 擴展H265特有頭部數據結構VPS
因爲H264只有SPS和PPS,所以在兼容H265的時候,我們需要定義其特有的頭VPS:
char vps_buf_[MAX_VPS_LEN];//256
int vps_len_;
3. MetaData解析擴展支持H265
在推送端,我們擴展H265發送的MetaData結構定義如下:
typedef struct HVCCNALUnitArray {
uint8_t array_completeness;
uint8_t NAL_unit_type;
uint16_t numNalus;
uint16_t *nalUnitLength;
uint8_t **nalUnit;
} HVCCNALUnitArray;
typedef struct HEVCDecoderConfigurationRecord {
uint8_t configurationVersion;
uint8_t general_profile_space;
uint8_t general_tier_flag;
uint8_t general_profile_idc;
uint32_t general_profile_compatibility_flags;
uint64_t general_constraint_indicator_flags;
uint8_t general_level_idc;
uint16_t min_spatial_segmentation_idc;
uint8_t parallelismType;
uint8_t chromaFormat;
uint8_t bitDepthLumaMinus8;
uint8_t bitDepthChromaMinus8;
uint16_t avgFrameRate;
uint8_t constantFrameRate;
uint8_t numTemporalLayers;
uint8_t temporalIdNested;
uint8_t lengthSizeMinusOne;
uint8_t numOfArrays;
HVCCNALUnitArray *array;
} HEVCDecoderConfigurationRecord;
現在我們需要從MetaData裏面講VPS,SPS和PPS解析出來,首先,判斷視頻編碼格式:
parser_VideoTag *video_tag = (parser_VideoTag*)(buf+parser_offset);
FlvCodeId video_code_id = (FlvCodeId)(video_tag->code_id&0x0f);
if (video_code_id == FlvCodeId_Hevc)
{
av_frame.u32AVFrameFlag = EASY_SDK_VIDEO_CODEC_H265;// HEVC;
}
else
{
av_frame.u32AVFrameFlag = EASY_SDK_VIDEO_CODEC_H264;// 默認h264, 其他類型是否需要判斷?!;
}
然後,判斷視頻幀格式爲H265後,我們從MetaData中獲取VPS,SPS和PPS,如下代碼所示:
char *parser_config = buf;
Parser_HEVCDecoderConfigurationRecord *decoder_header = (Parser_HEVCDecoderConfigurationRecord*)((char*)parser_config);
parser_offset += sizeof(Parser_HEVCDecoderConfigurationRecord);
int nNumOfArrays = decoder_header->numOfArrays;
for (int i=0; i<nNumOfArrays; i++)
{
Parser_HVCCNALUnitArray* pNALUnit = (Parser_HVCCNALUnitArray*)((char *)parser_config+parser_offset);
parser_offset += sizeof(Parser_HVCCNALUnitArray);
int numNalus = ntohs(*(unsigned short *)((char *)parser_config + parser_offset));
parser_offset += 2;
for (int nI=0; nI<numNalus; nI++)
{
// uint16_t *nalUnitLength;
// uint8_t **nalUnit;
ps_len = *pNALUnit[i]->nalUnitLength;
if (pNALUnit[nI]->NAL_unit_type == 0x20)
{
//獲取VPS
memcpy(vps_buf_, *pNALUnit[i]->nalUnit, ps_len);
vps_len_ = ps_len;
}
else if (pNALUnit[nI]->NAL_unit_type == 0x021)
{
//獲取SPS
memcpy(sps_buf_,*pNALUnit[i]->nalUnit, ps_len);
sps_len_ = ps_len;
}
else if (pNALUnit[nI]->NAL_unit_type == 0x22)
{
//獲取PPS
memcpy(pps_buf_,*pNALUnit[i]->nalUnit, ps_len);
pps_len_ = ps_len;
}
parser_offset += ps_len;
}
}
//從H265的SPS頭部結構中取得視頻長寬
rtmpclient_h265_decode_sps((unsigned char *)sps_buf_, sps_len_, width_, height_);
4. 視頻數據幀Nalu解析擴展支持H265
首先,判斷如果是H265視頻幀,則需要解析視頻幀是否攜帶VPS:
if(av_frame.u32AVFrameFlag == EASY_SDK_VIDEO_CODEC_H265)
{
nalu_type = (buf[parse_offset] >> 1) & 0x3F;
if(nalu_type == e_H265_NAL_UNIT_VPS)
{
memcpy(vps_buf_,buf + parse_offset,nalu_len);
vps_len_ = nalu_len;
parse_offset += nalu_len;
continue;
}
}else{
nalu_type = buf[parse_offset]&0x1F;
}
然後,對於SPS和PPS,以及Idr幀、P幀的nalu數據單元的解析,該部分解析和H264解析方法一致,就不做過多贅述。
下面我們通過EasyScreenLive來推H265編碼格式的RTMP流到EasyDSS,通過EasyPlayerPro(ffmpeg拉流)和EasyPlayer-RTMP(EasyRTMPClient拉流)播放,如下圖所示:
我們發現通過網頁播放我們推送的基於H265編碼的RTMP是播放不了的,而通過EasyPlayer則成功播放了出來,說明我們通過EasyRTMPClient拉取RTMP流擴展支持H265的方案已經完美解決。
歡迎大家下載EasyPlayer測試播放支持H265的RTMP流:
https://github.com/EasyDSS/EasyPlayer-RTMP-Win
https://github.com/EasyDSS/EasyPlayerPro-Win
有任何技術問題,歡迎大家和我進行技術交流:
[email protected]
大家也可以加入EasyPlayer流媒體播放器 QQ羣進行討論:
544917793