ffmpeg frame grab question

[johnp12]

Hello,

I have a question,

If I had an app developed which would allows users to view a video and take frame grabs from the video,
is it possible to have a low res and a hi res version of the video, where the user would view the low res so that it loads quickly, and the frame grabs are grabbed from the hi res version of the video?

If so, would the ffmpefg frame grb from the hi res video file be quick no matter where the frame is in the video? or would it need to load the video up to the point of there the frame lives? meaning, grabbing a frame from the end of the video could take a long time?

I am thinking about performance issues and getting around slow loading.

thanks

John

[poisondeathray]

If I had an app developed which would allows users to view a video and take frame grabs from the video,
is it possible to have a low res and a hi res version of the video, where the user would view the low res so that it loads quickly, and the frame grabs are grabbed from the hi res version of the video?

Yes it's possible , or even the HD screenshot could be scaled using -s

I'm assuming by "load quickly" you mean primarily bandwidth issues (a larger dimension screenshot will take more kb than a smaller dimension screenshot)

If so, would the ffmpefg frame grb from the hi res video file be quick no matter where the frame is in the video? or would it need to load the video up to the point of there the frame lives? meaning, grabbing a frame from the end of the video could take a long time?

I am thinking about performance issues and getting around slow loading.

It depends on the type of compression used , and the keyframe spacing. In general, the more compressed the file, the slower the seeking, and the more far apart the keyframes, the slower the seeking