using ffmpeg to chop off the end of a video without seeking through the whole damn thing

[babadoctor]

so I have been using the following command to get the last 10 minutes of a very very long livestream

ffmpeg -i "livestream.mp4" -ss 03:00:00 -t 00:10:00 -codec "copy" "output.mp4"

this takes forever if the video is longer than 12 hours.

 

is there really no way to just kind of lob off the end of the video with ffmpeg? why does it need to seek through the entire video to find the end of the video?????

 

it's really stupid and there has to be a better way.

 

This is especially bad when I need to do it over the internet, as it requires downloading the ENTIRE 12 hour video when I can clearly seek to the end of it with my player.

 

Any suggestions?

[Streetguru]

1 minute ago, babadoctor said:

so I have been using the following command to get the last 10 minutes of a very very long livestream

ffmpeg -i "livestream.mp4" -ss 03:00:00 -t 00:10:00 -codec "copy" "output.mp4"

this takes forever if the video is longer than 12 hours.

 

is there really no way to just kind of lob off the end of the video with ffmpeg? why does it need to seek through the entire video to find the end of the video?????

 

it's really stupid and there has to be a better way.

 

This is especially bad when I need to do it over the internet, as it requires downloading the ENTIRE 12 hour video when I can clearly seek to the end of it with my player.

 

Any suggestions?

Why aren't you just using handbrake? Can trim it in there.

[babadoctor]

10 minutes ago, Streetguru said:

Why aren't you just using handbrake? Can trim it in there.

because i don't want to re encode the video

because i don't want to download the entire livestream so I can seek to the end and clip it.

 

handbreak requires a local file, no?

[mariushm]

Does the server support resume, or jumping at some position in the stream?

If it doesn't, then ffmpeg would have no choice but to download the whole stream, and the live server may throttle you to real time speed (ex lets you buffer 1-2 minutes, then slows down connection to ~ 1x speed and keeps it there)

 

I'd suggest searching for some application that dumps streams with option to dump from a particular time.

Then just work with the local file, extracting the chunk you want from a slightly bigger chunk.

[babadoctor]

5 minutes ago, mariushm said:

Does the server support resume, or jumping at some position in the stream?

If it doesn't, then ffmpeg would have no choice but to download the whole stream, and the live server may throttle you to real time speed (ex lets you buffer 1-2 minutes, then slows down connection to ~ 1x speed and keeps it there)

 

I'd suggest searching for some application that dumps streams with option to dump from a particular time.

Then just work with the local file, extracting the chunk you want from a slightly bigger chunk.

Yes, the server does in fact support resume. I use a node js program called http-server, and it has allowed me to seek through to the end with mpv player.

 

(the videos on the video server were also seekable with mpv)

 

Can you specify what you mean by "dumping streams"?

[igormp]

On 12/29/2019 at 10:44 PM, babadoctor said:

so I have been using the following command to get the last 10 minutes of a very very long livestream

ffmpeg -i "livestream.mp4" -ss 03:00:00 -t 00:10:00 -codec "copy" "output.mp4"

this takes forever if the video is longer than 12 hours.

 

is there really no way to just kind of lob off the end of the video with ffmpeg? why does it need to seek through the entire video to find the end of the video?????

 

it's really stupid and there has to be a better way.

 

This is especially bad when I need to do it over the internet, as it requires downloading the ENTIRE 12 hour video when I can clearly seek to the end of it with my player.

 

Any suggestions?

Rookie mistake, I've done that myself since it's really confusing haha

 

You did -ss after the input file, which means that it'll try to seek the output file instead of the input. You can read more about it here.

 

An example of what you want to do is:

ffmpeg -ss 24 -i "http://distribution.bbb3d.renderfarming.net/video/mp4/bbb_sunflower_1080p_30fps_normal.mp4" -to 10 -c:v copy -c:a copy test.mp4

Which seeks the big buck bunny video to second 24 and tries to download 10 seconds of it into the test.mp4 file while coping the media without doing any transcode.

Notice that the actual output duration won't be 10 seconds due to frame splitting. I hack to get around that that I had to do at work was to use ffprobe to check the amount of frames, and then seek through frames instead of seconds.

[babadoctor]

2 hours ago, igormp said:

Rookie mistake, I've done that myself since it's really confusing haha

 

You did -ss after the input file, which means that it'll try to seek the output file instead of the input. You can read more about it here.

 

An example of what you want to do is:

ffmpeg -ss 24 -i "http://distribution.bbb3d.renderfarming.net/video/mp4/bbb_sunflower_1080p_30fps_normal.mp4" -to 10 -c:v copy -c:a copy test.mp4

Which seeks the big buck bunny video to second 24 and tries to download 10 seconds of it into the test.mp4 file while coping the media without doing any transcode.

Notice that the actual output duration won't be 10 seconds due to frame splitting. I hack to get around that that I had to do at work was to use ffprobe to check the amount of frames, and then seek through frames instead of seconds.

Really solving all of my problems today, huh

 

haha, thanks man