Re: [FFmpeg-user] why reducing the resolution a percentage doesn't reduce the video the same proportion?
> On 14 Mar 2023, at 14:03, Natalia Molinero Mingorance > wrote: > > what do you mean by " Why is the output size important if you use -preset > ultrafast? “ That will mean quick and dirty encoding, at the cost of a higher bitrate. -preset slow will make the file significant smaller, at the cost of more processing time / cpu use. (And thus energy use, but if you stream too large files a gazillion times, you might want to invest in high quality encoding instead of quick ’n dirty.) It’s a ‘would you like to be bitten by the cat or by the dog’ situation. Bouke ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
Re: [FFmpeg-user] why reducing the resolution a percentage doesn't reduce the video the same proportion?
what do you mean by " Why is the output size important if you use -preset ultrafast? " El mar, 14 mar 2023 a las 13:48, Bouke / edit 'B () escribió: > On 14 Mar 2023, at 13:07, Phil Rhodes via ffmpeg-user < > ffmpeg-user@ffmpeg.org> wrote: > > > > Also, it depends what you mean by 50% of the resolution. If your > original video is 100x100 pixels and you reduce it to 50x50, then you have > half the resolution, but you only have one quarter the pixels. > > But, the image will still have a tree, a house and a dog. > From what I have understood, the resolution in terms of pixels does not > compute to output file size (Unless you work uncompressed of course.) > > > P > >On Tuesday, 14 March 2023 at 09:37:36 GMT, Natalia Molinero > Mingorance eng.nataliamolin...@gmail.com>> wrote: > > > > I'm using this command: > > > > -y -r -i $inVideoUri -movflags faststart -c:v libx265 -s > > $videoResolution -c:a copy -preset ultrafast $outPutUri > > /// > > some headers or metadata added during the process but I would like to > know > > how to estimate the final video size. > > Why is the output size important if you use -preset ultrafast? > > Bouke > > > ___ > ffmpeg-user mailing list > ffmpeg-user@ffmpeg.org > https://ffmpeg.org/mailman/listinfo/ffmpeg-user > > To unsubscribe, visit link above, or email > ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe". > ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
Re: [FFmpeg-user] why reducing the resolution a percentage doesn't reduce the video the same proportion?
yes, I removed the "-r", sorry. but, by reducing the resolution, the size is also reduced somehow proportionally. El mar, 14 mar 2023 a las 13:31, Michael Koch () escribió: > Am 14.03.2023 um 10:37 schrieb Natalia Molinero Mingorance: > > I'm using this command: > > > > -y -r -i $inVideoUri -movflags faststart -c:v libx265 -s > > $videoResolution -c:a copy -preset ultrafast $outPutUri" > > > > > > However, if "videoResolution" is a 50% of the original video resolution, > > the resulting file size is not 50% of the original one. I assume there > are > > some headers or metadata added during the process but I would like to > know > > how to estimate the final video size. > > You can control the size of the output file by either using the -q:v > option or by specifying the video bitrate with the -b:v option. > > By the way, I don't understand the purpose of the -r option in your > command line. Shoudn't that give an error message if it's not folllowed > by a value? > > Michael > > ___ > ffmpeg-user mailing list > ffmpeg-user@ffmpeg.org > https://ffmpeg.org/mailman/listinfo/ffmpeg-user > > To unsubscribe, visit link above, or email > ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe". > ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
Re: [FFmpeg-user] why reducing the resolution a percentage doesn't reduce the video the same proportion?
On 14 Mar 2023, at 13:07, Phil Rhodes via ffmpeg-user wrote: > > Also, it depends what you mean by 50% of the resolution. If your original > video is 100x100 pixels and you reduce it to 50x50, then you have half the > resolution, but you only have one quarter the pixels. But, the image will still have a tree, a house and a dog. >From what I have understood, the resolution in terms of pixels does not >compute to output file size (Unless you work uncompressed of course.) > P >On Tuesday, 14 March 2023 at 09:37:36 GMT, Natalia Molinero Mingorance > mailto:eng.nataliamolin...@gmail.com>> wrote: > > > I'm using this command: > > -y -r -i $inVideoUri -movflags faststart -c:v libx265 -s > $videoResolution -c:a copy -preset ultrafast $outPutUri /// > some headers or metadata added during the process but I would like to know > how to estimate the final video size. Why is the output size important if you use -preset ultrafast? Bouke ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
Re: [FFmpeg-user] why reducing the resolution a percentage doesn't reduce the video the same proportion?
Am 14.03.2023 um 10:37 schrieb Natalia Molinero Mingorance: I'm using this command: -y -r -i $inVideoUri -movflags faststart -c:v libx265 -s $videoResolution -c:a copy -preset ultrafast $outPutUri" However, if "videoResolution" is a 50% of the original video resolution, the resulting file size is not 50% of the original one. I assume there are some headers or metadata added during the process but I would like to know how to estimate the final video size. You can control the size of the output file by either using the -q:v option or by specifying the video bitrate with the -b:v option. By the way, I don't understand the purpose of the -r option in your command line. Shoudn't that give an error message if it's not folllowed by a value? Michael ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
Re: [FFmpeg-user] why reducing the resolution a percentage doesn't reduce the video the same proportion?
Am 14.03.23 um 10:37 schrieb Natalia Molinero Mingorance: but I would like to know how to estimate the final video size you simply can't when it comes to modern multimedia codecs - you underestimate the complexity of H265 trying to optimize quality and size by thousands of variables ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
Re: [FFmpeg-user] why reducing the resolution a percentage doesn't reduce the video the same proportion?
Hi Natalia This gets complicated, but in general it depends on the compression settings. "libx265" is capable of doing many different things. It's probably best if you look up some examples of how that works because it's too much to explain here, and examples will help. Also, it depends what you mean by 50% of the resolution. If your original video is 100x100 pixels and you reduce it to 50x50, then you have half the resolution, but you only have one quarter the pixels. P On Tuesday, 14 March 2023 at 09:37:36 GMT, Natalia Molinero Mingorance wrote: I'm using this command: -y -r -i $inVideoUri -movflags faststart -c:v libx265 -s $videoResolution -c:a copy -preset ultrafast $outPutUri" However, if "videoResolution" is a 50% of the original video resolution, the resulting file size is not 50% of the original one. I assume there are some headers or metadata added during the process but I would like to know how to estimate the final video size. ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe". ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
