pybind 传递指针

最新推荐文章于 2023-04-29 22:51:58 发布

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最新推荐文章于 2023-04-29 22:51:58 发布

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分类专栏： pybind 文章标签： Python C++ H264编码 AVCodecContext 图像处理

本文链接：https://blog.youkuaiyun.com/jacke121/article/details/110846048

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该博客介绍了如何使用Python调用C++实现H264视频编码。通过预处理函数`pre_save`配置编码参数，然后在Python中逐帧处理图片并调用`save_frame`进行编码保存。涉及的关键技术包括OpenCV、ffmpeg的AVCodecContext以及图像格式转换。

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编码h264可以参考：https://blog.youkuaiyun.com/jacke121/article/details/87484745

python部分：

先接收指针vp，再调用，是可以的。

#-*- coding:utf-8 -*-
import binddemo
b= binddemo.add(3, 4)
print(b)


filepath="0217.h264"

vp= binddemo.pre_save(filepath, 1280, 720, 5)
import os
import cv2
import numpy as np
import time

from PIL import Image #PIL pakage name is Pillow




path=r"D:\data\VOC2007\JPEGImages/"

files=os.listdir(path)

for i,file in enumerate(files):
    img=cv2.imread(path+file)
    if img is None:
        continue
    # im = Image.open(path+file)
    #
    # in_data = np.asarray(im, dtype=np.uint8)
    #
    # in_data = np.rollaxis(in_data, 2, 0)
    time1=time.time()
    binddemo.save_frame(img,i,vp)
    # example.GetImage(img)

    print(i,'time',time.time()-time1,flush=True)
    time.sleep(0.02)

c++部分：

pre_save返回指针

save_frame 接收指针

void* pre_save(char* filepath, int width, int height, int frame_rate) {
	//void* pre_save(std::string & filepath, int width, int height, int frame_rate) {

	av_log_set_level(AV_LOG_ERROR);
	Rtmp_tool *rtmp_tool;
	rtmp_tool = new Rtmp_tool();
	int nLen;
	int fileI;
	rtmp_tool->nWidth = width;
	rtmp_tool->nHeight = height;

	AVCodecContext *c = NULL;
	AVCodecContext *in_c = NULL;
	AVCodec *pCodecH264; //编码器    

	pCodecH264 = avcodec_find_encoder(AV_CODEC_ID_H264);//查找h264编码器    
	c = avcodec_alloc_context3(pCodecH264);
	if (!c)
	{
		printf("Could not allocate video codec context\n");
		exit(1);
	}
	//av_opt_set(c->priv_data, "preset", "slow", 0);
	av_opt_set(c->priv_data, "preset", "superfast", 0);
	av_opt_set(c->priv_data, "tune", "zerolatency", 0);
	c->bit_rate = 1024 * 1024;// put sample parameters     
	c->width = width;
	c->height = height;

	c->time_base.den = frame_rate;//视频每秒帧数
	c->time_base.num = 1;
	c->framerate.den = 1;//视频帧速
	c->framerate.num = frame_rate;
	c->gop_size = 20; // emit one intra frame every ten frames     
	c->max_b_frames = 0;
	c->thread_count = 1;
	c->pix_fmt = AV_PIX_FMT_YUV420P;//PIX_FMT_RGB24; 
									//打开编码器    
	if (avcodec_open2(c, pCodecH264, NULL)<0)
		printf("不能打开编码库");


	int size = c->width * c->height;


	rtmp_tool->yuv_buff = (uint8_t *)malloc((size * 3) / 2); // size for YUV 420     


	rtmp_tool->f = fopen(filepath, "wb");
	//rtmp_tool->f = fopen(filepath.data(), "wb");
	if (!rtmp_tool->f)
	{
		printf("could not open %s\n", filepath);
		exit(1);
	}

	printf("context3 w h %d %d\n", c->width, c->height);

	AVFrame *frame = av_frame_alloc();
	if (!frame) {
		fprintf(stderr, "Could not allocate video frame\n");
		exit(1);
	}
	frame->format = c->pix_fmt;
	frame->width = c->width;
	frame->height = c->height;
	int ret = av_frame_get_buffer(frame, 32);
	if (ret < 0)
	{
		printf("Could not allocate the video frame data\n");
		exit(1);
	}

	//初始化格式转换器SwsContext  
	rtmp_tool->scxt = sws_getContext(c->width, c->height, AV_PIX_FMT_BGR24, c->width, c->height, AV_PIX_FMT_YUV420P, SWS_POINT, NULL, NULL, NULL);

	rtmp_tool->m_pYUVFrame = frame;
	rtmp_tool->c = c;

	return rtmp_tool;
}
int save_frame(py::array_t<uint8_t> input1, int len, void* vp) {//, void* service) {
	Rtmp_tool *rtmp_tool = (Rtmp_tool *)vp;