Re: [FFmpeg-user] Thumbnail tile slow on big video files

[trash]

 Thanks Gyan! The file is exactly 3600 seconds long and I take 4  
frames (20%,40%,60% and 80%).
Adding /-t 2900 -skip_frame nokey/ would be the right thing to do?  
Will that be fast even with a 10Gig video file?


Quoting Gyan :


On Thu, May 18, 2017 at 5:53 PM,  wrote:


Hi,

I run the code below to produce a tile thumnail from video files. That
seems to be very slow on big video files. Anything that I do wrong, or I
could improve to speed up processing?

ffmpeg -ss 720 -i $input_path -f image2 -vframes 1 -aspect 4:3 -filter:vf
select='isnan(prev_selected_t)+gte(t-prev_selected_t\,720)',
scale="'if(gt(a,4/3),128,-1)\':'if(gt(a,4/3),-1,96)\'",pad="
w=128:h=97:x=(ow-iw)/2:y=(oh-ih)/2:color=black",tile=4x1 -y
$output_filename
 


Since your command produces exactly (or upto) 4 frames at an interval of
720 seconds, you can add    -t 2900 -skip_frame nokey    before  -i
$input_path. Only keyframes are passed to the filters, so that should hurry
things up. Also, there's no need to keep the command running after 4 frames
have been found.
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Re: [FFmpeg-user] Thumbnail tile slow on big video files

[Gyan]

On Thu, May 18, 2017 at 5:53 PM,  wrote:

> Hi,
>
> I run the code below to produce a tile thumnail from video files. That
> seems to be very slow on big video files. Anything that I do wrong, or I
> could improve to speed up processing?
>
> ffmpeg -ss 720 -i $input_path -f image2 -vframes 1 -aspect 4:3 -filter:vf
> select='isnan(prev_selected_t)+gte(t-prev_selected_t\,720)',
> scale="'if(gt(a,4/3),128,-1)\':'if(gt(a,4/3),-1,96)\'",pad="
> w=128:h=97:x=(ow-iw)/2:y=(oh-ih)/2:color=black",tile=4x1 -y
> $output_filename
>
>
Since your command produces exactly (or upto) 4 frames at an interval of
720 seconds, you can add-t 2900 -skip_frame nokeybefore  -i
$input_path. Only keyframes are passed to the filters, so that should hurry
things up. Also, there's no need to keep the command running after 4 frames
have been found.
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[FFmpeg-user] Thumbnail tile slow on big video files

[trash]

Hi,

I run the code below to produce a tile thumnail from video files. That  
seems to be very slow on big video files. Anything that I do wrong, or  
I could improve to speed up processing?


ffmpeg -ss 720 -i $input_path -f image2 -vframes 1 -aspect 4:3  
-filter:vf  
select='isnan(prev_selected_t)+gte(t-prev_selected_t\,720)',scale="'if(gt(a,4/3),128,-1)\':'if(gt(a,4/3),-1,96)\'",pad="w=128:h=97:x=(ow-iw)/2:y=(oh-ih)/2:color=black",tile=4x1 -y  
$output_filename


Thanks!
--- Begin Message ---
ffmpeg -ss 720 -i $input_path -f image2 -vframes 1 -aspect 4:3  
-filter:vf  
select='isnan(prev_selected_t)+gte(t-prev_selected_t\,720)',scale="'if(gt(a,4/3),128,-1)\':'if(gt(a,4/3),-1,96)\'",pad="w=128:h=97:x=(ow-iw)/2:y=(oh-ih)/2:color=black",tile=4x1 -y  
$output_filename


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Description: PGP Public Key
--- End Message ---


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