Is it recommended to convert or it leave it at their original flv format?

[leandro]

Hey everyone!

I have plenty of flv files downlaoded from internet with average/high/low quality.
As I use smplayer/mplayer it will play any format in the end regardless the codec.

However, I'm willing to stick to a standard and convert all those videos into mp4/mkv format keeping original bitrate from the flv. I made some tests with ffmpeg and the converted file is about the same size as the original and minimal visual difference from each other.

Since its a lossy procedure, is it recommended to do so or it leave it at their original flv format? What you guys recommend?

thanks

[sum_guy]

I suggest keeping them in the format that you have, any re-encoding will usually just make them worse.

[redwudz]

leandro, in the future please use a more descriptive subject title in your posts to allow others to search for similar topics. I will change yours this time. From our rules:

Try to choose a subject that describes your topic.
Please do not use topic subjects like Help me!!! or Problems.

Thanks,

Moderator redwudz

[yoda313]

@leandro - sum_guy is correct don't reencode unless you have to.

The only reason to reencode is to play on a device that will not read the original flv file.

You may be able to remux them into another container without reencoding if you need to play on a bluray player or some other media player that can play some files. Winff should be able to do this. I don't know about ffmpeg and I am not sure if its based on the same framework as winff either.

Basically if its xvid/divx or h264 video inside the flv you should be able to remux to say a mp4 container without reencoding. However your destination device may well have some of its own restrictions such as bitrate, resolution and other internal codec requirements that would force a reencode to its exact specifications.

Now keep in mind reencoding in and by itself won't make it "dramatically worse" than its original source. Its just that it won't look its best manipulating it. Also using a relatively high bitrate in your destination format will help reduce any quality loss - not eliminate just minimize the effects.

One last note - if you are using a high def source and need to convert to a standard def source there will be quality loss in the downconversion. Thats unavoidable. However again using a relatively high bitrate in the new resolution should help minimize the impact of the loss.

Again you only need to convert if your desired playback device can't play the file. If you are, say just playing it on a computer and you can already play it just leave it as it is.

However if you are interested in converting to a smaller file size to save space than you will have to weigh the benefits of the space saved against any potential quality loss. Also note you should backup your original files to a harddrive or dvd/bluray disc if you intend to do conversions. Always keep your original source so you can go back to it if you need to convert again.

[leandro]

redwudz, sorry man. I'll behave next time.

yoda313, thanks.
The majority of those files are all AVC video (codec) in a FLV container.
I'll change the container only then.
MKV or MP4 container? what would be the more suitable for compatibility?
Is it ok to use MKV container for video with short lentgh, say <30min.

forgive my lazyness, would you guys happen to know the ffmpeg.exe command parameters to convert only the container, not the video...?

Thanks everyone.

[leandro]

i found something...

ffmpeg -i somefile.flv -vcodec copy -acodec copy somefile.mkv
mp4box.exe -add "filename.264:fps=23.976" -add "filename.aac" "filename_output.mp4"

Thanks everyone.

[yoda313]

@leandro - Maybe you could enlighten us a little more. Why do you need to change the container? If you are still going to be playing it on the computer and you can already play the files in question in flv format you don't need to do anything.

Edit - if you need to change it because your player won't OPEN flv files thats a different story.

Consider using mpch or vlc instead. They should handle literally just about anything you throw at them - they'll play them just fine.

[leandro]

@leandro - Maybe you could enlighten us a little more. Why do you need to change the container? If you are still going to be playing it on the computer and you can already play the files in question in flv format you don't need to do anything.

Edit - if you need to change it because your player won't OPEN flv files thats a different story.

Consider using mpch or vlc instead. They should handle literally just about anything you throw at them - they'll play them just fine.

Well some of these movies coming in flv format need some editing:
- aspect ratio correction 16:9 / 3:4
- crop "blank" areas on widescreen
- clip unecessary parts of the video

Then i wonder why not transfer them in a more portable container (mkv/mp4) than flv while making those edits.
i did some research and I found that ffmpeg wont do the aspect ration correction without re-encoding the video.
Now I'll have a look into mp4box, x264 and meconder so i can apply a batch job on those files.

Although flv will play on my computer it gives me the odds. i just to make them videos more portable.
have a look: http://en.wikipedia.org/wiki/Comparison_of_container_formats

Which one would be more suitable to edit (crop/aspect ration correct/clip) those files without reencoding the video (and audio) stream?
- mencoder
- x264
- mp4box
- ffmpeg

cheers!

[Gavino]

Which one would be more suitable to edit (crop/aspect ration correct/clip) those files without reencoding the video (and audio) stream?

Cropping always requires re-encoding.

[leandro]

Which one would be more suitable to edit (crop/aspect ration correct/clip) those files without reencoding the video (and audio) stream?

Cropping always requires re-encoding.

dang it!