Same settings but encodes way smaller with StaxRip vs FFmpeg/FFmpeg batch converter

[N'Cha]

Hi

How is that possible? I tested with some anime episodes, and encoding with ffmpeg console, then ffmpeg batch covnerter and then Staxrip (with ffvideosource), all of them with the exact same settings (crf 15, preset slower, bframes 12, tskip tskip-fast etc.) and ffmpeg/ffmpeg batch converter roughly have the same output file size but Staxrip gives consistently files that are like 25% smaller... (the file with staxrip is litteraly 90% smaller than the source despite the slower preset mixed with some veryslow and placebo values)

How is that possible as they all use ffmpeg underneath? And more important, does it mean that the smaller (from Staxrip) one is of a lesser quality ?

The only difference I noticed is that in mediainfo, the ones encoded with ffmpeg batch converter or with the ffmpeg console directly shows that the encoding library is "lavf" and staxrip shows ""libebml v1.4.4 + libmatroska v1.7.1" but I do'nt know what it implies quality-wise

[RanmaCanada]

You can always run them through VMAF to see what's up.

[Losko]

Decoding quality (and processing) may have some impacts also.
So in order to better define your scenario, you should feed your encoding programs with an uncompressed source - this way you can be sure decoding step is not introducing any differences.

[benwaggoner]

Originally Posted by N'Cha

Hi

How is that possible? I tested with some anime episodes, and encoding with ffmpeg console, then ffmpeg batch covnerter and then Staxrip (with ffvideosource), all of them with the exact same settings (crf 15, preset slower, bframes 12, tskip tskip-fast etc.) and ffmpeg/ffmpeg batch converter roughly have the same output file size but Staxrip gives consistently files that are like 25% smaller... (the file with staxrip is litteraly 90% smaller than the source despite the slower preset mixed with some veryslow and placebo values)

How is that possible as they all use ffmpeg underneath? And more important, does it mean that the smaller (from Staxrip) one is of a lesser quality ?

The only difference I noticed is that in mediainfo, the ones encoded with ffmpeg batch converter or with the ffmpeg console directly shows that the encoding library is "lavf" and staxrip shows ""libebml v1.4.4 + libmatroska v1.7.1" but I do'nt know what it implies quality-wise

Getting a 90% reduction with anime content is pretty feasible, depending on what you're converting from. HEVC with the right parameter tuning can make anime look great at very low bitrates.

Are you able to get a --csv-log-level 2 output from the different tools? Comparing those would reveal all.