1
$\begingroup$

I asked here for a solution how single video images can be extracted very fast from avi files.

Piotr Wendykier gave a solution for Mathematica 11.3.

Now I'm using Mathematica 12 and his solution does not work anymore.

Why 

i = MediaTools`Private`$MFReadNextFrame[]

does not read an image out of the video as in version 11.3?

In[1]:= file = URLSave["http://mirrors.standaloneinstaller.com/video-sample/\ Panasonic_HDC_TM_700_P_50i.avi", "c:\\tmp\\sample.avi"] Out[1]= "c:\\tmp\\sample.avi" In[2]:= Needs["MediaTools`"] In[3]:= MediaTools`Private`$MFInitReader[file] Out[3]= MediaTools`Private`$MFInitReader["c:\\tmp\\sample.avi"] In[4]:= AbsoluteTiming[i = MediaTools`Private`$MFReadNextFrame[];] Out[4]= {1.9*10^-6, Null} In[5]:= MediaTools`Private`$MFFinalizeReader[] Out[5]= MediaTools`Private`$MFFinalizeReader[] In[6]:= ImageDimensions[i] During evaluation of In[6]:= ImageDimensions::imginv: Expecting an image or graphics instead of MediaTools`Private`$MFReadNextFrame[]. Out[6]= ImageDimensions[MediaTools`Private`$MFReadNextFrame[]]
Improve this question
$\endgroup$

1 Answer 1

Reset to default
4
$\begingroup$

In Mathematica 12 we have renamed these private functions. The following code works in 12.0:

In[1]:= file = URLSave["http://mirrors.standaloneinstaller.com/video-sample/\ Panasonic_HDC_TM_700_P_50i.avi", "c:\\tmp\\sample.avi"] Out[1]= "c:\\tmp\\sample.avi" In[2]:= Needs["MediaTools`"] In[3]:= MediaTools`Private`$MFInitVideoReader[file] Out[3]= True In[4]:= AbsoluteTiming[i = MediaTools`Private`$MFReadNextVideoFrame[];] Out[4]= {0.0411032, Null} In[5]:= MediaTools`Private`$MFFinalizeVideoReader[] Out[5]= True In[6]:= ImageDimensions[i] Out[6]= {1920, 1080}

These functions have usage documentation:

enter image description here

Improve this answer
$\endgroup$
1
  • $\begingroup$ Thank you very much for your help. $\endgroup$ Commented Sep 9, 2019 at 10:48

Start asking to get answers

Find the answer to your question by asking.

Ask question

Explore related questions

See similar questions with these tags.