Lair Of The Multimedia Guru

January 28, 2014

FFmpegs Huffyuv

In the last few weeks FFmpegs huffyuv codec has grown the ability to encode and decode a much broader list of pixel formats. From planar rgb variants 4:4:4 YUV to 4:1:0 YUV and bit depths up to 16bit and alpha support.
One might ask why anyone cares about all this, the awnser is simple

1 thread YUV420 10bit, matrixbench
FFv1 Huffyuv
encode fps 63fps 281fps
decode fps 82fps 418fps
filesize 478mb 765mb

Encoding parameters used:
-an -threads 1 -pix_fmt yuv420p10le -strict -2 -vcodec ffvhuff -context 1
-an -threads 1 -pix_fmt yuv420p10le -strict -2 -vcodec ffv1

6 threads YUV420 10bit, matrixbench
FFv1 Huffyuv
encode fps 269fps 1173fps
decode fps 386fps 2675fps
filesize 480mb 771mb

Encoding parameters used:
-threads 6 -an -pix_fmt yuv420p10le -strict -2 -vcodec ffvhuff -pass 2 test.nut
-threads 6 -an -pix_fmt yuv420p10le -strict -2 -vcodec ffv1 -level 3 -slices 6 test1.nut

As can be seen above huffyuv while it doesnt even get close to ffv1 in terms of compression even though i used per frame huffman tables and 2pass mode in the 2 tests, its simply much faster.

Filed under: Entropy Coding,FFmpeg,VideoCoding — Michael @ 2:27

January 16, 2014

Rant about gmx

Ive been using gmx since over 12 years for my email. And until recently gmx did a fine job at running a SMTP and a POP3 server. But it appears this is slowly changing. A few month ago their SMTP server stoped accepting mail with the verbose message: “550-Requested action not taken: mailbox unavailable\n550 Reject due to policy restrictions.”. It turned out that gmx refused localhost as domain to the EHLO SMTP command. They require a fully qualified domain name now right? no, not really, any random string seems to work just not localhost. My attempt to contact gmx about this, lead to no reaction.

The next thing was this: “550-Requested action not taken: mailbox unavailable\n550 invalid DNS A/AAAA resource record”, yes thats right, gmx rejected outgoing mail because the poor guy had not set up a webpage on the domain that he used to receive mail on. This one btw affected multiple people i tried to communicate with, not just one.

But hang on it was just starting, next there was “451 Requested action aborted: local error in processing’ errormsg=’recipient address nicolas george normalesup org not accepted by the server”

Also it has to mentioned that gmx at around that time (maybe 1-2 month before or so) started to randomly put “*** GMX Spamverdacht ***” in the subjects of random received mails even though i always had and have all spam filtering disabled at gmx (mainly because their filters never worked).
So yeah another try at complaining to gmx about that, and yes this time there was a reaction, i got a mail from them “GMX Sicherheit: Vorsorgliche Sicherheitssperre Ihres GMX Postfachs!” they locked my account and provided me with a few tips on how i can scan my windows system for viruses. Hello gmx, i dont use windows.

My next attempt to contact them and now find out why they locked my account lead to just a polite (probably automated) mail with a link to their payed and expensive phone support. Seriously, locking someones account and refusing to tell them why unless they pay. And locked btw means SMTP was not working, POP3 still worked and so did the web interface where one is asked to change ones password which then unlocks the account again. Maybe iam just missing the point but what sense does that have.

Was that all? no, it seems gmx also reduced the maximum size of mails as a 21mb mail i tried to send to 3 people could not be sent over gmxs smtp server and with a different smtp server it bounced from reimar who also uses gmx so it also could not be received. Iam pretty sure i did transfer bigger things years ago.
Ahh and i almost forgot: “5.7.1 : Recipient address rejected: Your MTA is listed in too many DNSBLs; check”, Yes thats gmx being in the DNSBL lists at the time that happened. Now just why was i not surprised by that …

Did anyone really read this far down ? Well as gmx slowly goes from well working to something else, iam forced to find alternatives to handle email. So i got this one:, iam still using the gmx addy though, feel free to use either if you want to mail or spam me. I guess if these issues with gmx continue then ill have to start updating my mail address everywhere …

2014-01-26 Update

Heres an example of the random marking of mails as spam, the 2 mails where simple git patches send to ffmpeg-devel, sent by me, at the same time from the same computer and their content should be quite similar and should not have triggered any properly trained bayesian filter.

85260 N 0126 2:11 Ronald S. Bultj (1.3K) [FFmpeg-devel] [PATCH] vp9: disable use_last_frame_mvs on resolution change (scalable).
85261 N 0126 2:30 Ronald S. Bultj (8.9K) [FFmpeg-devel] [PATCH] vp9: fix invalid ref frame w/h on size change.
85262 N F 0126 14:49 To FFmpeg devel (1.2K) [FFmpeg-devel] [PATCH 1/2] avcodec/libfdk-aacenc: change MODE_7_1_REAR_SURROUND to map to AV_CH_LAYOUT_7POINT1
85263 N F 0126 14:49 To FFmpeg devel (0.9K) └─>*** GMX Spamverdacht *** [FFmpeg-devel] [PATCH 2/2] avcodec/libfdk-aacenc: change MODE_7_1_FRONT_CENTER to map to AV_CH_LAYOUT_7POINT1_WIDE_BACK

Also ive sent gmx a link to the blogpost, no reaction from them so far

Filed under: Off Topic — Michael @ 4:33

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