tuning lossless ffmpeg command-line with Claude

The ffmpeg command

ffmpeg -y -r 30 -i in_%05d.jpg -i ../NormPeak-6dBENG.wav -c:v hevc_nvenc -preset lossless -global_quality 18 -pix_fmt nv12 -c:a aac -b:a 192k ~/Downloads/4kframes.mp4

gives the following warnings - 

[aist#1:0/pcm_s16le @ 0x59f7e96fbfc0] Guessed Channel Layout: stereo
....

[in#0/image2 @ 0x59f7e96f4e40] Thread message queue blocking; consider raising the thread_queue_size option (current value: 8)

[swscaler @ 0x59f7e97ae500] deprecated pixel format used, make sure you did set range correctly

    Last message repeated 3 times

[hevc_nvenc @ 0x59f7e9701880] The selected preset is deprecated. Use p1 to p7 + -tune or fast/medium/slow.

[hevc_nvenc @ 0x59f7e9701880] Using global_quality with nvenc is deprecated. Use qp instead. 

Claude's suggestion to fix - 

ffmpeg -y -r 30 -i in_%05d.jpg -thread_queue_size 512 -i ../NormPeak-6dBENG.wav -c:v hevc_nvenc -preset p7 -tune lossless -cq 0 -pix_fmt yuv420p -c:a aac -b:a 192k ~/Downloads/4kframes.mp4

MIDI-mapper for OpenSpace (or any javascript API)

With the help of Claude.ai, I've put up a MIDI-mapper for OpenSpace at OpenSpace MIDI mapping.

The readme.txt lists the prompts used, and usage. Copy-pasting from my post on OpenSpace Slack: With this, we can control OpenSpace using any MIDI control surface or MIDI instrument. Interesting effects like speeding up time for one (MIDI) violin string, slowing down for another string, etc can be thought of.

I've used our KORG nanokontrol - earlier version of this product - to do the development and testing.

By adding suitable functions, this could be extended to call any javascript API using a MIDI controller or MIDI instrument.

Bosch Wiper blades for Hyundai Santro

 PB helped me out with the following info:

Attached is the wiper blades size for Santro
List shows 20" on Driver side and 16" on Passenger side

TYPES OF BOSCH WIPERS
Bosch Clear Advantage — a flat-blade / beam-style wiper. Designed to give uniform pressure across the windshield, better contact, smoother wiping, and more streak-free clearing (especially good in heavy rain or at high speeds).

Bosch ECO (conventional / bracket-frame wiper) — a more traditional wiper with a metal (or mixed) frame + rubber blade. Usually more budget-friendly and covers basic everyday wiping needs.

AMAZON LINKS
Bosch Clear Advantage 16"

Bosch Clear Advantage 20"

Bosch ECO 16"

Bosch ECO 20"

I have been using Bosch ECO, and it works well. 

Will try Clear Advantage next time.

And, found that there were video guides on how to fit the blades, in the amazon listings. Also available on youtube, at Bosch ECO and Clear Advantage.

On my (new) Santro, the 20" blade seems a bit short. Perhaps I'll try the 21-inch blade next time.

hardware accelerated video encoding on Intel Iris graphics has issues with jpg frames input - resolved

 From ChatGPT,

ffmpeg -i filename_%05d.jpg -c:v hevc_qsv -preset veryslow -global_quality 0 output_lossless_qsv.mkv

For 4K (4096x4096) files, this was running at around 8 fps on my i5 laptop, as against 2 fps for non-accelerated libx264. The mistake I made earlier was to put the preset before the -c:v.

• -i must come before input options end.
• All encoder options (-c:v, -preset, -global_quality) must be placed after the input and before the output filename.

If you place -preset before -i filename_%05d.jpg, FFmpeg thinks it’s a decoder option, causing the error:

Codec AVOption preset ... is not a decoding option.

With audio, we would need something like

ffmpeg -r 30 -i KG-LS_%05d.jpg -i audio.wav \

  -c:v hevc_qsv -preset veryslow -global_quality 0 \

  -c:a aac -b:a 192k \

  -shortest \

  output_with_audio.mkv

# or on Windows,

ffmpeg -r 30 -i KG-LS_%05d.jpg -i audio.wav ^

  -c:v hevc_qsv -preset veryslow -global_quality 0 ^

  -c:a aac -b:a 192k ^

  -shortest ^

  output_with_audio.mkv

Edit - this produces a low-bitrate video with colour issues on VLC (and perhaps on other players. The python front-end presets, like the command below, might be useful - 

FFmpeg command to copy-paste:

ffmpeg -y -i in_%05d.jpg -i map_x_directp2.pgm -i map_y_directp2.pgm -i weight_alpha_mask.png -filter_complex '[0:v][1:v][2:v]remap[remapped];[3:v]format=gray,scale=4096:4096,colorchannelmixer=rr=1:gg=1:bb=1[mask_rgb];[remapped][mask_rgb]blend=all_mode=multiply[blended];[blended]scale=3840:2160,setsar=1,setdar=16/9,format=yuv420p[out]' -map '[out]' -map '0:a?' -c:v hevc_qsv -preset fast -crf 23 -pix_fmt yuv420p -c:a aac -b:a 128k D:/out-W4K.mp4

So, without warping, that would be - 

ffmpeg -y -i in_%05d.jpg -i audio.wav -c:v hevc_qsv -preset veryslow -crf 1 -pix_fmt yuv420p -c:a aac -b:a 128k out.mp4

But unfortunately, even the warping command produces a low bitrate video with colour issues. Green tinted instead of purple tinted for the earlier videos. Even changing the codec to libx265 did not help. So, some incompatibility in the input frames is suspected. Maybe I'll just use avidemux instead instead of trying to troubleshoot.

From ffmpeg -h

Getting help:

    -h      -- print basic options

    -h long -- print more options

    -h full -- print all options (including all format and codec specific options, very long)

    -h type=name -- print all options for the named decoder/encoder/demuxer/muxer/filter/bsf/protocol

ffmpeg -h encoder=hevc_qsv
....

  -preset            <int>        E..V....... (from 1 to 7) (default medium)

     veryfast        7            E..V.......

     faster          6            E..V.......

     fast            5            E..V.......

     medium          4            E..V.......

     slow            3            E..V.......

     slower          2            E..V.......

     veryslow        1            E..V.......

....

  -profile           <int>        E..V....... (from 0 to INT_MAX) (default unknown)

     unknown         0            E..V.......

     main            1            E..V.......

     main10          2            E..V.......

     mainsp          3            E..V.......

     rext            4            E..V.......

     scc             9            E..V.......

    

Claude.ai pointed out that the colour tint issues are probably due to wrong pixel format, and the low bitrate is probably because "QSV's CRF implementation is unreliable". So, suggestion is to use nv12 pixel format and global_quality instead of CRF, where quality of 15-20 is near lossless. Or force a high bitrate if that doesn't work - -b:v 20M -maxrate 25M

ffmpeg -y -r 30 -i in_%05d.jpg -i audio.wav -c:v hevc_qsv -preset veryslow -global_quality 18 -pix_fmt nv12 -c:a aac -b:a 128k out.mp4

And that solved the problem.

No colour tint, hevc_qsv encoder resulted in a 25 Mbps video, libx265 encoder with the same preset and quality settings but without the -pix_fmt nv12 resulted in a 7 Mbps video, both of good quality.

Send user digests - Moodle task fails - sends hundreds of emails to Admin

On one of our Moodle instances, emails are supposed to go out through Google Workspace using Google SMTP servers. That being the case, we can't send an unlimited number of emails. So, email notifications had been globally - Site Administration > General > Messaging > Notification settings, which is located at server.url/admin/message.php

When there was a request to allow emails of a particular type to particular users, after enabling the email notification plugin at the above page, the next time a forum post was made, there was a cascade of Send user digests failed and Send user notifications failed messages.

For the immediate failure messages to stop, deleted all the adhoc tasks from mod_forum,

delete from prefix_task_adhoc  where prefix_task_adhoc.component = 'mod_forum';

I had previously set emailstop=1 on the database users table, for all users except the handful which should receive emails. Possibly the reason for the failures was that forcesubscribe=1 was set for many forums for many / all users. 

So, now I set it to zero (email disabled) for all forums on this instance, with

update prefix_forum set prefix_forum.forcesubscribe = 0;

and also updated the defaults,

Site administration > plugins > plugins overview > (chose mod_forum) > settings >

site.url/admin/settings.php?section=modsettingforum

and set subscription mode = subscription disabled for both defaults,

forum_announcementsubscription

and

forum_subscription 

Also, went to prefix_forum_subscriptions table and deleted all entries - which I suppose would be various users' subscriptions to various forums.

Hopefully this is sufficient to prevent the hundreds of failed send notification tasks. 

Update 13 Nov - Again received hundreds of task failed messages. Asked Claude.ai, and made the following changes as suggested, in addition to the above.

# Individual discussion subscriptions might still exist
DELETE FROM prefix_forum_digests;
DELETE FROM prefix_forum_discussion_subs;

UPDATE prefix_user SET maildigest = 0 WHERE emailstop = 1;

# Users might be getting auto-subscribed when they post
UPDATE prefix_forum SET trackingtype = 0;

TRUNCATE prefix_forum_track_prefs;

run 'Issue Certificates' task more often

There was a request for setting up email notifications for one Moodle course, a particular user to be notified when any user completes that course. I had earlier set many tasks to run less often due to our server being overloaded. 'Issue Certificates' task was one of them, especially since it needed some optimizations as per this thread. Checking the logs, I could see that issue certificates was taking between 30 and 120 seconds - so, increased the scheduled task cron frequency from once a day to once an hour, for two of our Moodle instances. 

Set to run every hour at the 30th minute (8:30, 9:30 etc) on one instance and at the 45th minute (8:45, 9:45, etc) on the other instance, in Site Administration > Server > Tasks > Scheduled tasks > \mod_customcert\task\issue_certificates_task