python

超轻量级php框架startmvc

利用python读取YUV文件 转RGB 8bit/10bit通用

更新时间:2020-08-13 03:42:01 作者:startmvc
注:本文所指的YUV均为YUV420中的I420格式(最常见的一种),其他格式不能用以下的代码。

注:本文所指的YUV均为YUV420中的I420格式(最常见的一种),其他格式不能用以下的代码。

位深为8bit时,每个像素占用1字节,对应文件指针的fp.read(1);

位深为10bit时,每个像素占用2字节,对应文件指针的fp.read(2);

然后使用 int.from_bytes() 方法将二进制转换为int型数字。

以下程序可以读8bit或10bit位深的YUV,需要指定从第几帧开始读、一共读多少帧。

它返回三个数组,其shape分别为:Y [frame,W,H] U [frame,W/2,H/2] V [frame,W/2,H/2]

当只读1帧时它返回:Y [W,H] U [W/2,H/2] V [W/2,H/2]


# -*- coding: utf-8 -*-
 
import math
from functools import partial
import numpy as np
import matplotlib.pyplot as plt
 
 
def readyuv420(filename, bitdepth, W, H, startframe, totalframe, show=False):
 # 从第startframe(含)开始读(0-based),共读totalframe帧
 
 uv_H = H // 2
 uv_W = W // 2
 
 if bitdepth == 8:
 Y = np.zeros((totalframe, H, W), np.uint8)
 U = np.zeros((totalframe, uv_H, uv_W), np.uint8)
 V = np.zeros((totalframe, uv_H, uv_W), np.uint8)
 elif bitdepth == 10:
 Y = np.zeros((totalframe, H, W), np.uint16)
 U = np.zeros((totalframe, uv_H, uv_W), np.uint16)
 V = np.zeros((totalframe, uv_H, uv_W), np.uint16)
 
 plt.ion()
 
 bytes2num = partial(int.from_bytes, byteorder='little', signed=False)
 
 bytesPerPixel = math.ceil(bitdepth / 8)
 seekPixels = startframe * H * W * 3 // 2
 fp = open(filename, 'rb')
 fp.seek(bytesPerPixel * seekPixels)
 
 for i in range(totalframe):
 
 for m in range(H):
 for n in range(W):
 if bitdepth == 8:
 pel = bytes2num(fp.read(1))
 Y[i, m, n] = np.uint8(pel)
 elif bitdepth == 10:
 pel = bytes2num(fp.read(2))
 Y[i, m, n] = np.uint16(pel)
 
 for m in range(uv_H):
 for n in range(uv_W):
 if bitdepth == 8:
 pel = bytes2num(fp.read(1))
 U[i, m, n] = np.uint8(pel)
 elif bitdepth == 10:
 pel = bytes2num(fp.read(2))
 U[i, m, n] = np.uint16(pel)
 
 for m in range(uv_H):
 for n in range(uv_W):
 if bitdepth == 8:
 pel = bytes2num(fp.read(1))
 V[i, m, n] = np.uint8(pel)
 elif bitdepth == 10:
 pel = bytes2num(fp.read(2))
 V[i, m, n] = np.uint16(pel)
 
 if show:
 print(i)
 plt.subplot(131)
 plt.imshow(Y[i, :, :], cmap='gray')
 plt.subplot(132)
 plt.imshow(U[i, :, :], cmap='gray')
 plt.subplot(133)
 plt.imshow(V[i, :, :], cmap='gray')
 plt.show()
 plt.pause(1)
 #plt.pause(0.001)
 
 if totalframe==1:
 return Y[0], U[0], V[0]
 else:
 return Y,U,V
 
 
if __name__ == '__main__':
 #y, u, v = readyuv420(r'F:\_commondata\video\176x144 qcif\football_qcif.yuv', 8, 176, 144, 1, 5, True)
 y, u, v = readyuv420(r'F:\_commondata\video\1920x1080 B\RitualDance_1920x1080_60fps_10bit_420.yuv', 10, 1920, 1080, 0, 5, True)
 print(y.shape,u.shape,v.shape)

以下程序将YUV转为RGB(只能读8bit位深的YUV),返回1个数组,其shape为: [frame,W,H,3]


# -*- coding: utf-8 -*-
import cv2
import numpy as np
import matplotlib.pyplot as plt
 
 
def yuv2rgb(yuvfilename, W, H, startframe, totalframe, show=False, out=False):
 # 从第startframe(含)开始读(0-based),共读totalframe帧
 arr = np.zeros((totalframe,H,W,3), np.uint8)
 
 plt.ion()
 with open(yuvfilename, 'rb') as fp:
 seekPixels = startframe * H * W * 3 // 2
 fp.seek(8 * seekPixels) #跳过前startframe帧
 for i in range(totalframe):
 print(i)
 oneframe_I420 = np.zeros((H*3//2,W),np.uint8)
 for j in range(H*3//2):
 for k in range(W):
 oneframe_I420[j,k] = int.from_bytes(fp.read(1), byteorder='little', signed=False)
 oneframe_RGB = cv2.cvtColor(oneframe_I420,cv2.COLOR_YUV2RGB_I420)
 if show:
 plt.imshow(oneframe_RGB)
 plt.show()
 plt.pause(0.001)
 if out:
 outname = yuvfilename[:-4]+'_'+str(startframe+i)+'.png'
 cv2.imwrite(outname,oneframe_RGB[:,:,::-1])
 arr[i] = oneframe_RGB
 return arr
 
if __name__ == '__main__':
 video = yuv2rgb(r'D:\_workspace\akiyo_qcif.yuv', 176, 144, 0, 10, False, True)

用ffmpeg也可以,比如你需要将yuv的第8帧输出成一个png:


ffmpeg -s 176x144 -i akiyo_qcif.yuv -filter:v select="between(n\,8\,8)" out.png

以上这篇利用python读取YUV文件 转RGB 8bit/10bit通用就是小编分享给大家的全部内容了,希望能给大家一个参考,也希望大家多多支持脚本之家。

python YUV文件 RGB 8bit 10bit