雷州手机网站建设公司,宝安龙华积分商城网站建设,前端开发工程师的工作内容,wordpress做查询系统上次使用了python的opencv模块 述说了使用PyNvCodec 模块#xff0c;这个模块本身并没有rtsp的读写#xff0c;那么读写rtsp是可以使用很多方法的#xff0c;我们为了输出到pytorch直接使用AI程序#xff0c;简化rtsp 输入#xff0c;可以直接使用ffmpeg的子进程
方法一 …上次使用了python的opencv模块 述说了使用PyNvCodec 模块这个模块本身并没有rtsp的读写那么读写rtsp是可以使用很多方法的我们为了输出到pytorch直接使用AI程序简化rtsp 输入可以直接使用ffmpeg的子进程
方法一
使用pyav这个下次再讲
方法二
使用pipe方式也就是我们使用任何一种方式都可以如果我们有ffmpeg那么直接使用ffmpeg来读取流也是可行的使用live555 去读取流也是可行的只要把流取过来pipe给python程序就行把ffmpeg的可执行放到py文件的同一文件夹如下图所示 我们为了使用硬件解码安装了nvidia本身的PyNvCodec模块 首先我们要判决本身系统是否安装有cuda
if os.name nt:# Add CUDA_PATH env variablecuda_path os.environ[CUDA_PATH]if cuda_path:os.add_dll_directory(cuda_path)else:print(CUDA_PATH environment variable is not set., filesys.stderr)print(Cant set CUDA DLLs search path., filesys.stderr)exit(1)# Add PATH as well for minor CUDA releasessys_path os.environ[PATH]if sys_path:paths sys_path.split(;)for path in paths:if os.path.isdir(path):os.add_dll_directory(path)else:print(PATH environment variable is not set., filesys.stderr)exit(1)使用ffmpeg来探测
我们可以使用ffprobe来探测我们的rtsp流用来知道流的格式是h264还是h265ok我们使用process来启动子进程来探测
def get_stream_params(url: str) - Dict:cmd [ffprobe,-v,quiet,-print_format,json,-show_format,-show_streams,url,]proc subprocess.Popen(cmd, stdoutsubprocess.PIPE)stdout proc.communicate()[0]bio BytesIO(stdout)json_out json.load(bio)params {}if not streams in json_out:return {}for stream in json_out[streams]:if stream[codec_type] video:params[width] stream[width]params[height] stream[height]params[framerate] float(eval(stream[avg_frame_rate]))codec_name stream[codec_name]is_h264 True if codec_name h264 else Falseis_hevc True if codec_name hevc else Falseif not is_h264 and not is_hevc:raise ValueError(Unsupported codec: codec_name . Only H.264 and HEVC are supported in this sample.)else:params[codec] (nvc.CudaVideoCodec.H264 if is_h264 else nvc.CudaVideoCodec.HEVC)pix_fmt stream[pix_fmt]is_yuv420 pix_fmt yuv420pis_yuv444 pix_fmt yuv444p# YUVJ420P and YUVJ444P are deprecated but still wide spread, so handle# them as well. They also indicate JPEG color range.is_yuvj420 pix_fmt yuvj420pis_yuvj444 pix_fmt yuvj444pif is_yuvj420:is_yuv420 Trueparams[color_range] nvc.ColorRange.JPEGif is_yuvj444:is_yuv444 Trueparams[color_range] nvc.ColorRange.JPEGif not is_yuv420 and not is_yuv444:raise ValueError(Unsupported pixel format: pix_fmt . Only YUV420 and YUV444 are supported in this sample.)else:params[format] (nvc.PixelFormat.NV12 if is_yuv420 else nvc.PixelFormat.YUV444)# Color range default option. We may have set when parsing# pixel format, so check first.if color_range not in params:params[color_range] nvc.ColorRange.MPEG# Check actual value.if color_range in stream:color_range stream[color_range]if color_range pc or color_range jpeg:params[color_range] nvc.ColorRange.JPEG# Color space default option:params[color_space] nvc.ColorSpace.BT_601# Check actual value.if color_space in stream:color_space stream[color_space]if color_space bt709:params[color_space] nvc.ColorSpace.BT_709return paramsreturn {}rtsp client
写一个rtsp client实际上使用了ffmpeg的子进程并且使用管道来获取数据然后使用PyCodec来解码 def rtsp_client(url: str, name: str, gpu_id: int, length_seconds: int) - None:# Get stream parametersparams get_stream_params(url)if not len(params):raise ValueError(Can not get url streams params)w params[width]h params[height]f params[format]c params[codec]g gpu_id# Prepare ffmpeg argumentsif nvc.CudaVideoCodec.H264 c:codec_name h264elif nvc.CudaVideoCodec.HEVC c:codec_name hevcbsf_name codec_name _mp4toannexb,dump_extraallcmd [ffmpeg,-hide_banner,-i,url,-c:v,copy,-bsf:v,bsf_name,-f,codec_name,pipe:1,]# Run ffmpeg in subprocess and redirect its output to pipeproc subprocess.Popen(cmd, stdoutsubprocess.PIPE)# Create HW decoder classnvdec nvc.PyNvDecoder(w, h, f, c, g)# Amount of bytes we read from pipe first time.read_size 4096# Total bytes read and total frames decded to get average data ratert 0fd 0# Main decoding loop, will not flush intentionally because dont know the# amount of frames available via RTSP.t0 time.time()print(running stream)while True:if (time.time() - t0) length_seconds:print(fListend for {length_seconds}seconds)break# Pipe read underflow protectionif not read_size:read_size int(rt / fd)# Counter overflow protectionrt read_sizefd 1# Read data.# Amount doesnt really matter, will be updated later on during decode.bits proc.stdout.read(read_size)if not len(bits):print(Cant read data from pipe)breakelse:rt len(bits)# Decodeenc_packet np.frombuffer(bufferbits, dtypenp.uint8)pkt_data nvc.PacketData()try:surf nvdec.DecodeSurfaceFromPacket(enc_packet, pkt_data)if not surf.Empty():fd 1# Shifts towards underflow to avoid increasing vRAM consumption.if pkt_data.bsl read_size:read_size pkt_data.bsl# Print process ID every second or so.fps int(params[framerate])if not fd % fps:print(name)# Handle HW exceptions in simplest possible way by decoder respawnexcept nvc.HwResetException:nvdec nvc.PyNvDecoder(w, h, f, c, g)continue主流程
if __name__ __main__:gpuID 0 urls []urls.append(rtsp://172.28.176.1/a.264)pool []for url in urls:client Process(targetrtsp_client,args(url, str(uuid.uuid4()), gpuID, 9),)client.start()pool.append(client)for client in pool:client.join()我们的时间为9秒到了9秒退出程序
