如何使用 matlab 从 yuv 420 视频剪辑中提取帧并将它们存储为不同的图像？

发布于 2024-09-16 23:41:18 字数 44 浏览 4 评论 0原文

如何从 yuv 420 视频中提取帧？假设我想将它们存储为静态图像。如何？

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烟若柳尘 2024-09-23 23:41:18

这是来自 MathWorks File Exchange 的提交，它应该可以满足您的要求：

转换 YUV CIF 4:2:0视频文件转图像文件 by Da Yu

函数loadFileYuv 将加载 YUV 文件并返回电影帧数组。每个电影帧都是一个具有以下字段的结构：

cdata：uint8 值的矩阵。尺寸为高 x 宽 x 3。
colormap：N×3 双精度矩阵。在真彩色系统上它是空的。

因此，您可以从数组中的每个影片帧中提取 cdata 字段，并将其保存/用作 RGB 图像。

您的代码可能如下所示：

nFrames = 115;     %# The number of frames
vidHeight = 352;   %# The image height
vidWidth = 240;    %# The image width
mov = loadFileYuv('myVideo.yuv',vidHeight,vidWidth,1:nFrames);  %# Read the file
for k = 1:nFrames  %# Loop over the movie frames
  imwrite(mov(k).cdata,['myImage' int2str(k) '.bmp']);  %# Save each frame to
                                                        %#   a bitmap image file
end

Here's a submission from the MathWorks File Exchange that should do what you want:

Convert YUV CIF 4:2:0 video file to image files by Da Yu

The function loadFileYuv from the above submission will load a YUV file and return an array of movie frames. Each movie frame is a structure with the following fields:

cdata: A matrix of uint8 values. The dimensions are height-by-width-by-3.
colormap: An N-by-3 matrix of doubles. It is empty on true color systems.

You can therefore extract the cdata field from each movie frame in the array and save/use it as an RGB image.

Your code might look something like this:

nFrames = 115;     %# The number of frames
vidHeight = 352;   %# The image height
vidWidth = 240;    %# The image width
mov = loadFileYuv('myVideo.yuv',vidHeight,vidWidth,1:nFrames);  %# Read the file
for k = 1:nFrames  %# Loop over the movie frames
  imwrite(mov(k).cdata,['myImage' int2str(k) '.bmp']);  %# Save each frame to
                                                        %#   a bitmap image file
end

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海风掠过北极光 2024-09-23 23:41:18

抱歉无法帮助您使用 matlab，但在命令行上您可以使用 ffmpeg

ffmpeg -i input.yuv -r 1 -f image2 images%05d.png

-r 1 表示速率 = 每帧

sorry can't help with matlab but on the command line you can do it with ffmpeg

ffmpeg -i input.yuv -r 1 -f image2 images%05d.png

-r 1 means rate = every frame

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靑春怀旧 2024-09-23 23:41:18

您可以使用下面的代码：

vidObj1 = mmreader('testballroom_0.avi');  %# Create a video file object
nFrames = vidObj1.NumberOfFrames;   %# Get the number of frames
vidHeight1 = vidObj1.Height;         %# Get the image height
vidWidth1 = vidObj1.Width;           %# Get the image width

%# Preallocate the structure array of movie frames:

mov1(1:nFrames) = struct('cdata',zeros(vidHeight1,vidWidth1,3,'uint8'),...
                    'colormap',[]);  %# Note that colormap is empty!

您可以访问矩阵 mov1 中的每一帧:)

You can use this code below:

vidObj1 = mmreader('testballroom_0.avi');  %# Create a video file object
nFrames = vidObj1.NumberOfFrames;   %# Get the number of frames
vidHeight1 = vidObj1.Height;         %# Get the image height
vidWidth1 = vidObj1.Width;           %# Get the image width

%# Preallocate the structure array of movie frames:

mov1(1:nFrames) = struct('cdata',zeros(vidHeight1,vidWidth1,3,'uint8'),...
                    'colormap',[]);  %# Note that colormap is empty!

You can access each frame from the matrix mov1 :)

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