RAM Disk Dataset

Compare the performance of ffmpeg when videos are read and written to RAM, and when they are read and written to the hard drive.

The parameters of this database

Name	Value	Description (link)	Total
video	park_joy	ctc	\(1\)
profile	sd, fhd	video resolution and more	\(2\)
encoder	libsvtav1, libx264	enc_encoder	\(2\)
quality	\(\left\{\frac{k}{17} \mid k \in [1,16] \right\}\)	enc_quality	\(16\)
effort	fast, medium	enc_effort	\(2\)
mode	vbr	enc_mode	\(1\)
thread	\(\left\{ 8 \right\}\)	enc_threads	\(1\)
repeat	\(5\) times	total repetitions	\(5\)
ramdisk	yes, no	shm in enc_cmd	\(2\)
host	paradoxe-26	env_hostname	\(1\)
metrics		Table t_met_metric
total	\(\prod\)	total number of points	\(2560\)

Download

mendevi download ramdisk.db.xz.torrent

• ramdisk.json.xz (481 Ko).

• ramdisk.db.xz.torrent (305 Mo).

Plots

Effect on encoding

mendevi plot ramdisk.db -x rate -y energy -c enc_ram -wx profile -e enc_scenario -s 'sharey="row"' 'sharey=False'

Effect on decoding

mendevi plot ramdisk.db -x rate -y energy -c dec_ram -wx profile -e dec_scenario -s 'sharey="row"' 'sharey=False'

Conclusion

The energy and time required to encode and decode a video does not depend on whether it is read and written from and to an SSD or in RAM.

Reproduce

mendevi prepare park_joy.mkv -p sd
mendevi prepare park_joy.mkv -p fhd

mendevi encode -r5 -c libx264 -c libsvtav1 -e fast -e medium -t8 -t16 --ram yes -d ram_yes.db reference*
mendevi encode -r5 -c libx264 -c libsvtav1 -e fast -e medium -t8 -t16 --ram no -d ram_no.db reference*
mendevi decode -r5 --family cpu --ram yes -d ram_yes.db sample*
mendevi decode -r5 --family cpu --ram no -d ram_no.db sample*
mendevi merge ram_yes.db ram_no.db && mv merge_ram_yes_ram_no.db ramdisk.db

mendevi probe --no-psnr --no-ssim --no-vif --no-vmaf -d ramdisk.db reference* sample*