Runnig on /run/shm

[furkanbalikci]

Hello again @iizukanao my fps problem still going on. When I read your usage guide again I saw your suggestion "You can take advantage of RAM drive (/run/shm/) and reduce access to SD card. It also provides better quality of recording." When I googled the folder name, I saw that this path is now used as /dev/shm/. You can check it too if you want. Anyway, what I did was to write /dev/shm/ instead of /run/shm/ in the make_dirs.sh file. Then I copied the picam-1.4.11-binary/picam file into /run/shm/ and I think I can use the advantage of ram. Am I missing something in these steps? Or do you have any other suggestions to use it more effectively? If it helps, I can share the stutters with the fps drops with you.

[iizukanao]

Hello @furkanbalikci, sorry for not replying to the previous issue. If /run/shm does not exist in your filesystem, you can just create a symbolic link with sudo ln -s /dev/shm /run/shm and all scripts should work fine.

[furkanbalikci]

Thank you for your attention. If I can handle the fps problem, a huge load will be lifted from my shoulders. I have a few questions right now, I hope this will help us to make new inferences.

1. When I create a symlink as you suggested, I only see the shm folder under /run/shm. Unfortunately the only place I can use picam is the picam file under /home/pi/picam/. When I ran it this way, I was able to find the recorded video in the folder under /rec/archive, not directly under the archive folder. I'm not sure I can take advantage of ram this way.

2. Even without starting the start_record process, the following is what I see in the terminal output when only picam is running.

.......F.vSPEED_UP(14010)...................... 27.39 fps k=164 a-v=7920 c-a=-503 u=16 d=0 pts=14952720
.............................. 29.06 fps k=165 a-v=7500 c-a=-1283 u=16 d=0 pts= 15054720
...........................vNORMAL... 30.22 fps k=166 a-v=1920 c-a=-3 u=16 d=0 pts =15141120
.............................. 29.25 fps k=167 a-v=6000 c-a=-1093 u=16 d=0 pts= 15231120
.............................. 29.90 fps k=168 a-v=6240 c-a=-704 u=16 d=0 pts= 15321120
.............................. 30.43 fps k=169 a-v=4560 c-a=-10 u=16 d=0 pts= 15411120
...F.vSPEED_UP(9840).......................... 27.40 fps k=170 a-v=10350 c-a=-615 u=17 d=0 pts=15505170
.............................. 28.38 fps k=171 a-v=11850 c-a=-1168 u=17 d=0 pts= 15611520
.............................. 30.33 fps k=172 a-v=5670 c-a=-140 u=17 d=0 pts= 15694170

When I examine the speedup parts here in the source code, I see that it is related to PTS. Does this mean that it is causing fps drops as it tries to match the audio with the video? Is there anything I can do to improve this?

[iizukanao]

@furkanbalikci It seems that picam is not keeping up with 30 fps for some reason. Are you running a desktop on your Pi? Running a GUI may affect performance. Please turn it off with sudo raspi-config > System Options > Boot > Console, then reboot.

Is /rec/archive the absolute path to the archive folder? If so, RAM disk is not being used. Can you provide me the output of ls -lR /dev/shm/?

[furkanbalikci]

I am not using destkop version.

Here, output of ls -lR /dev/shm/

/dev/shm/:
total 0
lrwxrwxrwx 1 root root 9 Jun 28 12:11 shm -> /dev/shm/

I am using Pi with ssh.
sudo raspi-config > System Options > Boot > Console, then reboot.
After this process, I am not sure that I could still connect via ssh. Even though I'm not using the desktop version, Should I still do it.

[iizukanao]

@furkanbalikci That folder structure is incorrect and RAM disk is not used. Please run the following commands to correct the /run/shm.

sudo rm -rf /dev/shm/*
sudo rm -rf /run/shm
sudo ln -s /dev/shm /run/shm

Do not append / at the end of the above commands.

[iizukanao]

If you can confirm that the GUI (graphical login screen) is not running, you don't have to reboot it.

[furkanbalikci]

@furkanbalikci That folder structure is incorrect and RAM disk is not used. Please run the following commands to correct the /run/shm.

sudo rm -rf /dev/shm/*
sudo rm -rf /run/shm
sudo ln -s /dev/shm /run/shm

Do not append / at the end of the above commands.

I tried your recommended steps but now both folders are empty.

[iizukanao]

@furkanbalikci Run ./make_dirs.sh then run picam

[furkanbalikci]

After this my full output is bellow. It's not a smooth video. FPS dropping I can catch easily.

.................disk_usage=3% .start rec to rec/archive/2022-06-28_14-13-54.ts
........... 30.20 fps k=26 a-v=4470 c-a=1123 u=1 d=0 pts=2349450
......caught up........................ 30.10 fps k=27 a-v=4710 c-a=855 u=1 d=0 pts=2439450
.............................. 30.13 fps k=28 a-v=4950 c-a=580 u=1 d=0 pts=2529450
.............................. 30.10 fps k=29 a-v=5190 c-a=389 u=1 d=0 pts=2619450
.............................. 30.16 fps k=30 a-v=5430 c-a=48 u=1 d=0 pts=2714880
............................F.. 29.02 fps k=31 a-v=7590 c-a=1201 u=1 d=0 pts=2799450
.............................. 30.49 fps k=32 a-v=7830 c-a=35 u=1 d=0 pts=2897280
.............................. 30.31 fps k=33 a-v=6150 c-a=1077 u=1 d=0 pts=2979450
.............................. 30.15 fps k=34 a-v=6390 c-a=1088 u=1 d=0 pts=3069450
.............................. 30.02 fps k=35 a-v=6630 c-a=1053 u=1 d=0 pts=3159450
.............................. 30.09 fps k=36 a-v=6870 c-a=811 u=1 d=0 pts=3249450
...........................F.vSPEED_UP(16950).. 27.56 fps k=37 a-v=14340 c-a=1216 u=2 d=0 pts=3339900
.............................. 30.28 fps k=38 a-v=10080 c-a=863 u=2 d=0 pts=3434400
.............................. 30.00 fps k=39 a-v=5820 c-a=983 u=2 d=0 pts=3528900
......................vNORMAL........ 30.13 fps k=40 a-v=2910 c-a=677 u=2 d=0 pts=3622050
.............................. 30.13 fps k=41 a-v=3150 c-a=382 u=2 d=0 pts=3712050
.............................. 30.15 fps k=42 a-v=3390 c-a=-48 u=2 d=0 pts=3802050
.........................FvSPEED_UP(12870)..... 28.20 fps k=43 a-v=8490 c-a=-9 u=3 d=0 pts=3892950
.............................. 30.23 fps k=44 a-v=2310 c-a=1227 u=3 d=0 pts=3987450
.......vNORMAL....................... 30.23 fps k=45 a-v=1650 c-a=1032 u=3 d=0 pts=4078350
.............................. 30.07 fps k=46 a-v=1890 c-a=886 u=3 d=0 pts=4168350
.............................. 30.08 fps k=47 a-v=2130 c-a=703 u=3 d=0 pts=4258350
.............................. 30.10 fps k=48 a-v=2370 c-a=535 u=3 d=0 pts=4348350
.......................FvSPEED_UP(10170)....... 28.23 fps k=49 a-v=7170 c-a=502 u=4 d=0 pts=4439550
............................vNORMAL.. 30.11 fps k=50 a-v=3360 c-a=215 u=4 d=0 pts=4533600
.............................. 30.26 fps k=51 a-v=3600 c-a=-164 u=4 d=0 pts=4627200
.............................. 30.21 fps k=52 a-v=1920 c-a=1181 u=4 d=0 pts=4713600
.............................. 30.23 fps k=53 a-v=2160 c-a=940 u=4 d=0 pts=4803600
.............................. 30.01 fps k=54 a-v=2400 c-a=973 u=4 d=0 pts=4893600
.....................FvSPEED_UP(10440)......... 28.21 fps k=55 a-v=6900 c-a=1030 u=5 d=0 pts=4985100
.............................. 30.12 fps k=56 a-v=2640 c-a=682 u=5 d=0 pts=5079600
.vNORMAL............................. 30.09 fps k=57 a-v=2880 c-a=459 u=5 d=0 pts=5169600
.............................. 30.11 fps k=58 a-v=3120 c-a=172 u=5 d=0 pts=5259600
.............................. 30.27 fps k=59 a-v=3360 c-a=-165 u=5 d=0 pts=5352960
.............................. 30.18 fps k=60 a-v=1680 c-a=1225 u=5 d=0 pts=5439600
...................FvSPEED_UP(9960)........... 28.39 fps k=61 a-v=5880 c-a=1019 u=6 d=0 pts=5531400
.............................. 22.49 fps k=62 a-v=32340 c-a=404 u=6 d=0 pts=5625900
.............................. 30.13 fps k=63 a-v=28080 c-a=56 u=6 d=0 pts=5720400
.............................. 30.06 fps k=64 a-v=23820 c-a=-92 u=6 d=0 pts=5814900
.............................. 30.22 fps k=65 a-v=17640 c-a=1207 u=6 d=0 pts=5909400
.............................. 30.24 fps k=66 a-v=13380 c-a=961 u=6 d=0 pts=6003900
.......F....................... 28.23 fps k=67 a-v=14880 c-a=910 u=6 d=0 pts=6098400
.............................. 30.07 fps k=68 a-v=10620 c-a=798 u=6 d=0 pts=6192900
.............................. 30.06 fps k=69 a-v=6360 c-a=673 u=6 d=0 pts=6287400
........................vNORMAL...... 30.18 fps k=70 a-v=3150 c-a=250 u=6 d=0 pts=6380850
.............................. 30.12 fps k=71 a-v=3390 c-a=-77 u=6 d=0 pts=6470850
.............................. 30.25 fps k=72 a-v=1710 c-a=1108 u=6 d=0 pts=6560850
.....F.vSPEED_UP(12510)........................ 28.30 fps k=73 a-v=3960 c-a=1255 u=7 d=0 pts=6654600
................vNORMAL.............. 30.26 fps k=74 a-v=1950 c-a=940 u=7 d=0 pts=6746850
.............................. 30.08 fps k=75 a-v=2190 c-a=779 u=7 d=0 pts=6836850
.............................. 30.07 fps k=76 a-v=2430 c-a=662 u=7 d=0 pts=6926850
.............................. 30.11 fps k=77 a-v=2670 c-a=385 u=7 d=0 pts=7016850
..........stop rec
copy symlink(archive/2022-06-28_14-13-54.ts, rec/2022-06-28_14-13-54.ts)
unlink.vSPEED_UP(9990)................... 28.23 fps k=78 a-v=5670 c-a=288 u=8 d=0 pts=7109850

maybe I should reinstall everything then additionally use just sudo ln -s /dev/shm /run/shm command ?

What do you think about this topic:

When I examine the speedup parts here in the source code, I see that it is related to PTS. Does this mean that it is causing fps drops as it tries to match the audio with the video? Is there anything I can do to improve this?

[iizukanao]

When I examine the speedup parts here in the source code, I see that it is related to PTS. Does this mean that it is causing fps drops as it tries to match the audio with the video? Is there anything I can do to improve this?

vSPEED_UP appears when the video frame rate is lower than expected (less than 30 fps in your case), and picam is internally skipping some video PTS for the missing video frames to keep the audio and video PTS in sync.

From the picam output log, I think the write speed of the SD card is too slow. Please use a faster SD card.

[furkanbalikci]

I am using now samsung evo plus micro sd card 256gb. What would you suggest instead of this.

[iizukanao]

I'm using a Toshiba Exceria series. I can't guarantee that it will work in your case.
Btw, what is the output of sudo dd if=/dev/zero of=/home/pi/test bs=8k count=50k conv=fsync; sudo rm -f /home/pi/test ?

My result is

51200+0 records in
51200+0 records out
419430400 bytes (419 MB, 400 MiB) copied, 19.5284 s, 21.5 MB/s

[furkanbalikci]

My result is

51200+0 records in
51200+0 records out
419430400 bytes (419 MB, 400 MiB) copied, 24.4507 s, 17.2 MB/s

Can you explain this?

[iizukanao]

I think that write speed is good enough.
What command line arguments are you using in picam?

[furkanbalikci]

./picam --alsadev hw:0 --time --videobitrate 5000000 --verbose

[iizukanao]

The arguments that may affect performance are --time and --videobitrate 5000000, but should normally work fine.
Unfortunately, there is nothing more I can do to help.

[furkanbalikci]

Can you send to me link of your SD card?

[iizukanao]

@furkanbalikci https://www.amazon.co.jp/%E6%9D%B1%E8%8A%9D-Toshiba-microSDHC-UHS-I-EXCERIA%E8%B6%85%E9%AB%98%E9%80%9F95MB/dp/B00C67VPGI

[furkanbalikci]

Hi again @iizukanao, What hardware specs (rpi, camera, mic) and command line arguments are you using in picam?
I am using RPi Zero W and for audio catch ReSpeaker 2-Mics Pi HAT to Raspberry Pi (link:https://wiki.seeedstudio.com/ReSpeaker_2_Mics_Pi_HAT_Raspberry/).

[iizukanao]

@furkanbalikci I'm using pi 4B (4GB) + camera module v2 + microphone listed here.
command line is ./picam --alsadev hw:1,0