利用python读取YUV文件 转RGB 8bit/10bit通用
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
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