mismatch between calculated and reported Framerate using VideoReader

1 次查看（过去 30 天）
KV
KV 2016-3-22
评论： KV 2016-3-23
I am trying to process video data (wmv format) recorded using a standard consumer grade camera using Matlab (R2014a, on Linux/Ubuntu) using VideoReader
vr = VideoReader('my_movie_file.wmv')
frames = read(vr); % read all frames
size(frames, 4) % gives 4025
vr.NumberOfFrames % gives 4025
vr.Duration % gives 134.7950
vr.FrameRate % gives 15
Now, this does not compute!
I.e,
round(vr.FrameRate*vr.Duration) % gives 2022,
which is half the size of vr.NumberOfFrames -- which means that the reported FrameRate is 1/2 the "calculated" value!
What am I missing?? All help will be appreciated.
  5 个评论
显示 3更早的评论
Walter Roberson
Walter Roberson 2016-3-22
Is the file variable framerate? If so then the reported framerate might be the last one in the file (the one in effect at the time you queried)
KV
KV 2016-3-23
Yes, Walter -- the file does have variable frame rate. Is there any way I can get information about "timestamps" on a per-frame basis?

请先登录，再进行评论。

请先登录，再回答此问题。

回答（0 个）

类别

在 Help Center 和 File Exchange 中查找有关 Video Formats and Interfaces 的更多信息

标签

产品

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by