How to crop Video with FFMPEG without changing bitrate ?

[DonSeenu]

Hi everybody ...

I have a 1920*1080 resolution video (originally 4:3 ratio but not fitted in 16:9)

so i want to Crop this video with this values -- From Right side = 316 Pixels , Top = 110 Pixels, Left = 316 Pixels and Bottom = 0.

I DON'T WANT TO CHANGE ANYTHING MORE (NO SIZE , NO BITRATE AND AUDIO)

NEED FFMPEG COMMAND FOR THIS WORK...

[ProWo]

ffmpeg -i in.mp4 -filter:v "crop=1288:970:316:110" -c:a copy out.mp4
This way your video will be re-encoded. So you have to specify a bitrate or an encoder crf.

You can preview your crop with
ffplay -i in.mp4 -vf "crop=1288:970:316:110"

[DonSeenu]

so.. How can i Keep same Encoders quality as source ,

[ProWo]

Try my clever FFmpeg-GUI. Load your file, set Video stream modify, set Resize, with crop detect, let detect your crop, control with show, and when it's fine click OK, done.
Set H.264 encoder, CRF 20, preset very fast, set Aspect Ratio 4:3, click convert.
When converting is done, click multiplex, set your new created video file as video source, your original video as audio source (the streams are selected automatically), set the audio language, click on multiplex.
Done.

[jagabo]

so.. How can i Keep same Encoders quality as source ,

You can't. Re-encoding with a lossy encoder will always reduce quality. If you encode with good settings and with enough bitrate the reduction may not be very visible.

Another thing you can try, that won't reduce quality, is to use h264info to change the codecs internal cropping flags. But you'll have to demux the video to an elementary stream, make the changes, then remux. But h264info is a very old program and doesn't work well with some video.

And why do you want to crop anyway? If you're watching on a 16:9 display the player or display will put the black borders back when you watch.

[DonSeenu]

so.. How can i Keep same Encoders quality as source ,

You can't. Re-encoding with a lossy encoder will always reduce quality. If you encode with good settings and with enough bitrate the reduction may not be very visible.

Another thing you can try, that won't reduce quality, is to use h264info to change the codecs internal cropping flags. But you'll have to demux the video to an elementary stream, make the changes, then remux. But h264info is a very old program and doesn't work well with some video.

And why do you want to crop anyway? If you're watching on a 16:9 display the player or display will put the black borders back when you watch.

I want to crop because the pictures are not fully fitted in 16:9 , it's originally 4:3 video but stretched inside 16:9.

[jagabo]

I want to crop because the pictures are not fully fitted in 16:9 , it's originally 4:3 video but stretched inside 16:9.

If you have 4:3 video that's stretched to 16:9 you don't want to crop, you want to resize.

[Cornucopia]

You can also just tell your TV to not resize (stretch). DONE.

Scott