近期 SkeyePlayer（windows）更新已全面反对 H265 的 RTSP 流的解码播放，这里就反对 H265 过程做简要介绍；
一、libSkeyeRTSPClient 库已反对 H265 视频源的 RTSP 流的拉取和解析
二、H265 头解析
H265 和 H264 相似，不过其 NAL type 格局更多样化，除了 SPS，PPS 之外，还减少了 VPS，上面就针对 H265 帧 nal 头做简略剖析；首先，看 X265 源码中的 H265nal 头格局定义：//H265 NAL type
//this enum have been defined in x265.h
typedef enum tagH265NalUnitType
{
NAL_UNIT_CODED_SLICE_TRAIL_N = 0, // 0
NAL_UNIT_CODED_SLICE_TRAIL_R, // 1
NAL_UNIT_CODED_SLICE_TSA_N, // 2
NAL_UNIT_CODED_SLICE_TLA, // 3 // Current name in the spec: TSA_R
NAL_UNIT_CODED_SLICE_STSA_N, // 4
NAL_UNIT_CODED_SLICE_STSA_R, // 5
NAL_UNIT_CODED_SLICE_RADL_N, // 6
NAL_UNIT_CODED_SLICE_DLP, // 7 // Current name in the spec: RADL_R
NAL_UNIT_CODED_SLICE_RASL_N, // 8
NAL_UNIT_CODED_SLICE_TFD, // 9 // Current name in the spec: RASL_R
NAL_UNIT_RESERVED_10,
NAL_UNIT_RESERVED_11,
NAL_UNIT_RESERVED_12,
NAL_UNIT_RESERVED_13,
NAL_UNIT_RESERVED_14,
NAL_UNIT_RESERVED_15,
NAL_UNIT_CODED_SLICE_BLA, // 16 // Current name in the spec: BLA_W_LP
NAL_UNIT_CODED_SLICE_BLANT, // 17 // Current name in the spec: BLA_W_DLP
NAL_UNIT_CODED_SLICE_BLA_N_LP, // 18
NAL_UNIT_CODED_SLICE_IDR, // 19 // Current name in the spec: IDR_W_DLP
NAL_UNIT_CODED_SLICE_IDR_N_LP, // 20
NAL_UNIT_CODED_SLICE_CRA, // 21
NAL_UNIT_RESERVED_22,
NAL_UNIT_RESERVED_23,
NAL_UNIT_RESERVED_24,
NAL_UNIT_RESERVED_25,
NAL_UNIT_RESERVED_26,
NAL_UNIT_RESERVED_27,
NAL_UNIT_RESERVED_28,
NAL_UNIT_RESERVED_29,
NAL_UNIT_RESERVED_30,
NAL_UNIT_RESERVED_31,
NAL_UNIT_VPS, // 32
NAL_UNIT_SPS, // 33
NAL_UNIT_PPS, // 34
NAL_UNIT_ACCESS_UNIT_DELIMITER, // 35
NAL_UNIT_EOS, // 36
NAL_UNIT_EOB, // 37
NAL_UNIT_FILLER_DATA, // 38
NAL_UNIT_SEI, // 39 Prefix SEI
NAL_UNIT_SEI_SUFFIX, // 40 Suffix SEI
NAL_UNIT_RESERVED_41,
NAL_UNIT_RESERVED_42,
NAL_UNIT_RESERVED_43,
NAL_UNIT_RESERVED_44,
NAL_UNIT_RESERVED_45,
NAL_UNIT_RESERVED_46,
NAL_UNIT_RESERVED_47,
NAL_UNIT_UNSPECIFIED_48,
NAL_UNIT_UNSPECIFIED_49,
NAL_UNIT_UNSPECIFIED_50,
NAL_UNIT_UNSPECIFIED_51,
NAL_UNIT_UNSPECIFIED_52,
NAL_UNIT_UNSPECIFIED_53,
NAL_UNIT_UNSPECIFIED_54,
NAL_UNIT_UNSPECIFIED_55,
NAL_UNIT_UNSPECIFIED_56,
NAL_UNIT_UNSPECIFIED_57,
NAL_UNIT_UNSPECIFIED_58,
NAL_UNIT_UNSPECIFIED_59,
NAL_UNIT_UNSPECIFIED_60,
NAL_UNIT_UNSPECIFIED_61,
NAL_UNIT_UNSPECIFIED_62,
NAL_UNIT_UNSPECIFIED_63,
NAL_UNIT_INVALID,
}H265NalUnitType;
#endif咱们能够看到其中 VPS, SPS 和 PPS 的定义：
NAL_UNIT_VPS, // 32
NAL_UNIT_SPS, // 33
NAL_UNIT_PPS, // 34 同样，咱们也很容易晓得 P 帧 NAL type 定义是 0 -9，I 帧定义是 16-21；可见 H265 的 NAL type 定义比 H264 要多样化，判断也不限度于一种类型；
同时，测试发现，理论 H265 帧数据中的 VPS=0x40 , SPS=0x42, PPS=0x44, 通过换算，咱们不难得出：
NALtype*2 = 理论的流中的 NaLType;
具体解析过程如下：
// 输出的 pbuf 必须蕴含 start code(00 00 00 01)
int GetH265VPSandSPSandPPS(char *pbuf, int bufsize, char *_vps, int *_vpslen, char *_sps, int *_spslen, char *_pps, int *_ppslen)
{char vps[512]={0}, sps[512] = {0}, pps[128] = {0};
int vpslen=0, spslen=0, ppslen=0, i=0, iStartPos=0, ret=-1;
int iFoundVPS=0, iFoundSPS=0, iFoundPPS=0, iFoundSEI=0;
if (NULL == pbuf || bufsize<4) return -1;
for (i=0; i<bufsize; i++)
{if ( (unsigned char)pbuf[i] == 0x00 && (unsigned char)pbuf[i+1] == 0x00 &&
(unsigned char)pbuf[i+2] == 0x00 && (unsigned char)pbuf[i+3] == 0x01 )
{printf("0x%X\n", (unsigned char)pbuf[i+4]);
switch ((unsigned char)pbuf[i+4])
{
case 0x40: //VPS
{
iFoundVPS = 1;
iStartPos = i+4;
}
break;
case 0x42: //SPS
{if (iFoundVPS == 0x01 && i>4)
{
vpslen = i-iStartPos;
if (vpslen>256) return -1; //vps 长度超出范围
memset(vps, 0x00, sizeof(vps));
memcpy(vps, pbuf+iStartPos, vpslen);
}
iStartPos = i+4;
iFoundSPS = 1;
}
break;
case 0x44: //PPS
{if (iFoundSPS == 0x01 && i>4)
{
spslen = i-iStartPos;
if (spslen>256) return -1;
memset(sps, 0x0, sizeof(sps));
memcpy(sps, pbuf+iStartPos, spslen);
}
iStartPos = i+4;
iFoundPPS = 1;
}
break;
case 0x4E: //Prefix SEI
case 0x50: //Suffix SEI
case 0x20: //I frame 16
case 0x22: //I frame 17
case 0x24: //I frame 18
case 0x26: //I frame 19
case 0x28: //I frame 20
case 0x2A: //I frame 21(acturally we should find naltype 16-21)
{if (iFoundPPS == 0x01 && i>4)
{
ppslen = i-iStartPos;
if (ppslen>256) return -1;
memset(pps, 0x0, sizeof(pps));
memcpy(pps, pbuf+iStartPos, ppslen);
}
iStartPos = i+4;
iFoundSEI = 1;
}
break;
default:
break;
}
}
if (iFoundSEI == 0x01) break;
}
if (iFoundVPS == 0x01)
{if (vpslen < 1)
{if (bufsize < sizeof(vps))
{
vpslen = bufsize-4;
memset(vps, 0x00, sizeof(vps));
memcpy(vps, pbuf+4, vpslen);
}
}
if (vpslen > 0)
{if (NULL != _vps) memcpy(_vps, vps, vpslen);
if (NULL != _vpslen) *_vpslen = vpslen;
}
ret = 0;
}
if (iFoundSPS == 0x01)
{if (spslen < 1)
{if (bufsize < sizeof(sps))
{
spslen = bufsize-4;
memset(sps, 0x00, sizeof(sps));
memcpy(sps, pbuf+4, spslen);
}
}
if (spslen > 0)
{if (NULL != _sps) memcpy(_sps, sps, spslen);
if (NULL != _spslen) *_spslen = spslen;
}
ret = 0;
}
if (iFoundPPS == 0x01)
{if (ppslen < 1)
{if (bufsize < sizeof(pps))
{
ppslen = bufsize-4;
memset(pps, 0x00, sizeof(pps));
memcpy(pps, pbuf+4, ppslen); //pps
}
}
if (ppslen > 0)
{if (NULL != _pps) memcpy(_pps, pps, ppslen);
if (NULL != _ppslen) *_ppslen = ppslen;
}
ret = 0;
}
return ret;
}三、解码器需反对 H265
解码器间接应用最新的 FFMPEG 库即反对 H265 解码，且软解效率还能够，大家如果不晓得怎么用，能够去看看 ffplay 的源码，这里不做过多赘述；这里就 SkeyePlayer 调用遇到的问题做简略阐明：1> 旧版的 ffmpeg 以及 live555 等对 H265 的定义是对“H265”子串做的字串格局组合，而新版的 FFMPEG 应用的自定义的程序定义的枚举类型，所以在应用过程中可能呈现对应不上的状况，比方，在 libSkeyeRTSPClient 库中对 H265 的定义为：#define Skeye_SDK_VIDEO_CODEC_H265 0x48323635 /* 1211250229 */而 FFMPEG 中定义 H265（HEVC）格局为 174，SkeyePlayer 中进行格局对立代码如下：
//H265 codecID 改成 FFMPEG 新版的
int nCodec = (_frameinfo->codec == Skeye_SDK_VIDEO_CODEC_H265) ? 174 : _frameinfo->codec;
2> SkeyePlayer 中之前对关键帧帧解码失败的解决是将以该 I 帧为关键帧为依靠的所有 P 帧抛弃，当然这从某种程度上是能够防止花屏的，然而测试解码 H265 时发现，H265 的第一个 I 帧会常常解码失败，经调试发现其实是 FFNPEG 的解码函数返回没有解码实现的后果被程序判断为解码失败，而这个时候应该不做任何解决等下一次返回的时候就能获取到正确的返回后果了，SkeyePlayer 解决如下：
nRet = FFD_DecodeVideo3(pDecoderObj->ffDecoder, pbuf, frameinfo.length, pThread->yuvFrame[pThread->decodeYuvIdx].pYuvBuf, frameinfo.width, frameinfo.height, lTimestamp, lTimestamp);
if (0 != nRet)
{if(nRet == -4)//- 4 示意为以后帧尚未解码实现，不作为错误判断
{_TRACE("视频帧解码尚未实现 [%d]... framesize:%d %02X %02X %02X %02X %02X %02X %02X %02X %02X %02X\n", nRet, frameinfo.length,
(unsigned char)pbuf[0], (unsigned char)pbuf[1], (unsigned char)pbuf[2], (unsigned char)pbuf[3], (unsigned char)pbuf[4],
(unsigned char)pbuf[5], (unsigned char)pbuf[6], (unsigned char)pbuf[7], (unsigned char)pbuf[8], (unsigned char)pbuf[9]);
}
else
{_TRACE("视频帧解解码失败 [%d]... framesize:%d %02X %02X %02X %02X %02X %02X %02X %02X %02X %02X\n", nRet, frameinfo.length,
(unsigned char)pbuf[0], (unsigned char)pbuf[1], (unsigned char)pbuf[2], (unsigned char)pbuf[3], (unsigned char)pbuf[4],
(unsigned char)pbuf[5], (unsigned char)pbuf[6], (unsigned char)pbuf[7], (unsigned char)pbuf[8], (unsigned char)pbuf[9]);
if (frameinfo.type == Skeye_SDK_VIDEO_FRAME_I) // 关键帧
{_TRACE("[ch%d] 以后关键帧解码失败...\n", pThread->channelId);
#ifdef _DEBUG
FILE *f = fopen("keyframe.txt", "wb");
if (NULL != f)
{fwrite(pbuf, 1, frameinfo.length, f);
fclose(f);
}
#endif
}
else
{
#ifdef _DEBUG
FILE *f = fopen("pframe.txt", "wb");
if (NULL != f)
{fwrite(pbuf, 1, frameinfo.length, f);
fclose(f);
}
#endif
}
pThread->findKeyframe = 0x01;
} 经测试，通过如上代码 批改就能无效的防止的解码 H265 视频的时候结尾帧总是会部分卡帧或者花屏的状况呈现。四、H265 格局视频写 MP4
这里接着之前 SkeyePlayer 系列的写 MP4 篇讲，将 H265 封装 MP4；
1> 解析 H265 的头，或者 VPS，SPS 和 PPS
从 H265 帧中取出 NAL 头在上文曾经作过解说这里就不做过多赘述；2> 写入 VPS, SPS 和 PPS 等要害解码信息
bool SkeyeMP4Writer::WriteH265VPSSPSandPPS(unsigned char*vps, int vpslen, unsigned char*sps, int spslen,
unsigned char*pps, int ppslen, int width, int height)
{if (m_nCreateFileFlag&ZOUTFILE_FLAG_VIDEO)
{m_videtrackid = gf_isom_new_track(p_file, 0, GF_ISOM_MEDIA_VISUAL, 1000);
gf_isom_set_track_enabled(p_file, m_videtrackid, 1);
}
else
{return false;}
p_videosample = gf_isom_sample_new();
p_videosample->data = (char*)malloc(1024 * 1024);
p_hevc_config = gf_odf_hevc_cfg_new();
p_hevc_config->nal_unit_size = 32 / 8;
//gf_isom_avc_config_new(p_file, m_videtrackid, p_config, NULL, NULL, &i_videodescidx);
//gf_isom_set_visual_info(p_file, m_videtrackid, i_videodescidx, width, height);
// 初始化配置
gf_isom_hevc_config_new(p_file, m_videtrackid, p_hevc_config, NULL, NULL, &i_videodescidx);
gf_isom_set_nalu_extract_mode(p_file, m_videtrackid, GF_ISOM_NALU_EXTRACT_INSPECT);
gf_isom_set_cts_packing(p_file, m_videtrackid, GF_TRUE);
HEVCState hevc = {0};
m_slotsps = {0};
m_slotpps = {0};
m_slotvps = {0};
m_spss = {0};
m_ppss = {0};
m_vpss = {0};
p_hevc_config->configurationVersion = 1;
//Config vps
int idx = gf_media_hevc_read_vps((char*)vps, vpslen, &hevc);
hevc.vps[idx].crc = gf_crc_32((char*)vps, vpslen);
p_hevc_config->avgFrameRate = hevc.vps[idx].rates[0].avg_pic_rate;
p_hevc_config->constantFrameRate = hevc.vps[idx].rates[0].constand_pic_rate_idc;
p_hevc_config->numTemporalLayers = hevc.vps[idx].max_sub_layers;
p_hevc_config->temporalIdNested = hevc.vps[idx].temporal_id_nesting;
m_vpss.nalus = gf_list_new();
gf_list_add(p_hevc_config->param_array, &m_vpss);
m_vpss.array_completeness = 1;
m_vpss.type = GF_HEVC_NALU_VID_PARAM;// naltype = VPS
m_slotvps.id = idx;
m_slotvps.size = vpslen;
m_slotvps.data = (char*)malloc(vpslen);
memcpy(m_slotvps.data, vps, vpslen);
gf_list_add(m_vpss.nalus, &m_slotvps);
//Config sps
idx = gf_media_hevc_read_sps((char*)sps, spslen, &hevc);
hevc.sps[idx].crc = gf_crc_32((char*)sps, spslen);
p_hevc_config->profile_space = hevc.sps[idx].ptl.profile_space;
p_hevc_config->tier_flag = hevc.sps[idx].ptl.tier_flag;
p_hevc_config->profile_idc = hevc.sps[idx].ptl.profile_idc;
m_spss.nalus = gf_list_new();
gf_list_add(p_hevc_config->param_array, &m_spss);
m_spss.array_completeness = 1;
m_spss.type = GF_HEVC_NALU_SEQ_PARAM;// naltype = SPS
m_slotsps.id = idx;
m_slotsps.size = spslen;
m_slotsps.data = (char*)malloc(spslen);
memcpy(m_slotsps.data, sps, spslen);
gf_list_add(m_spss.nalus, &m_slotsps);
int act_width = hevc.sps[idx].width;
int act_height = hevc.sps[idx].height;
//Config pps
idx = gf_media_hevc_read_pps((char*)pps, ppslen, &hevc);
hevc.pps[idx].crc = gf_crc_32((char*)pps, ppslen);
m_ppss.nalus = gf_list_new();
gf_list_add(p_hevc_config->param_array, &m_ppss);
m_ppss.array_completeness = 1;
m_ppss.type = GF_HEVC_NALU_PIC_PARAM;// naltype = PPS
m_slotpps.id = idx;
m_slotpps.size = ppslen;
m_slotpps.data = (char*)malloc(ppslen);
memcpy(m_slotpps.data, pps, ppslen);
gf_list_add(m_ppss.nalus, &m_slotpps);
gf_isom_set_visual_info(p_file, m_videtrackid, i_videodescidx, act_width, act_height);
gf_isom_hevc_config_update(p_file, m_videtrackid, 1, p_hevc_config);
// 销毁申请的内存资源
gf_list_del(m_vpss.nalus);
gf_list_del(m_spss.nalus);
gf_list_del(m_ppss.nalus);
free(m_slotvps.data);
free(m_slotsps.data);
free(m_slotpps.data);
p_hevc_config->param_array = NULL;
return true;
} 联合写 MP4 篇咱们不难看出，MP4BOX 对 H265 专门封装了个结构函数 gf_isom_hevc_config_new（）用以对 H265 参数的设置，设置办法和 H264 类似，不过对 H265 解决更加粗疏，MP4BOX 将 VPS,SPS,PPS 的各个参数拆分进去进行赋值，通过 gf_isom_hevc_config_update 写入解码参数信息。
留神：H265 写 MP4 尚未退出最新的 SkeyePlayer 源码，这里是独家首发哦 –！（次要是忘了，会在近期退出）
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