Question / Help What´s the best video quality-small files for whatsapp settings ?

Dihelson Mendonca

Dihelson Mendonca

Member
I was doing some tests here for "almost live" broadcasts to my whatsapp group. I record from a C920 and external mic using OBS to mp4 files x264. I´m using CBR and 1000kbps as bandwidth. The files are small 720p for 1 minute ( Around 20Mb ) but could be better. Perhaps there may have some good settings that I could for example have a 3 minutes long video with good quality, resolution and around 10Mbytes size. Are there ?

Thanks !
 
koala

koala

Active Member
You have to balance resolution, quality and file size. Usually, you can have only two.

You want a 3 minute video have 10 MB size. This is 10000 kb in 180 seconds, or 10000 kb/180 s = 111 kb/s or bitrate 111 in OBS.
Now find a resolution that will not show a blurry mess at this low bitrate.
Try 240p, which is 426x240. The next higher is 360p, which is 640x360, but 111 bitrate is probably still too low for this.

Start with 426x240 as output resolution and play with these resolutions and increase the bitrate, if necessary.
 
Dihelson Mendonca

Dihelson Mendonca

Member
koala said:
You have to balance resolution, quality and file size. Usually, you can have only two.

You want a 3 minute video have 10 MB size. This is 10000 kb in 180 seconds, or 10000 kb/180 s = 111 kb/s or bitrate 111 in OBS.
Now find a resolution that will not show a blurry mess at this low bitrate.
Try 240p, which is 426x240. The next higher is 360p, which is 640x360, but 111 bitrate is probably still too low for this.

Start with 426x240 as output resolution and play with these resolutions and increase the bitrate, if necessary.
Click to expand...

Hello, Koala, thanks for the answer. When I said 10MB, I mean, may be a little more for 3 minutes or less. I have received some whatsapp files which I stayed wondering how the guys made some 7 to 8 minutes long with some good quality. Instead of CBR, I tried ABR and got best results, because the videos are more about me talking, so there are few moviments. People who know deep about codecs may have some tips and tricks in order to improve the final quality, perhaps messing with advanced parameters, but I´m not such person, I only understand the basics. Anyway, I think it´s great achievement to get a 360p or even 480p 3 minutes for whatsapp less than 20MB. I run a news group and people receive the latest news as a webTV. I´ll try your suggestions, choose the lowest "good" resolution and a bitrate for that which can be accepted.

Perhaps lowering audio bitrate would decrease the output file size ?
 
koala

koala

Active Member
I just browsed through my Whatsapp video folder and checked the details of the longer videos. (in case you wonder where are they: Internal memory of your smartphone->WhatsApp->Media->WhatsApp Video->Private)
I found some with 10-13 MB.
I found these used a horizontal resolution of about 600-640 (which means in OBS you reproduce this with 640x360).
Surprise, surprise, some use a frame rate of only 15 fps! This is a quarter in comparison to 60 fps or half in comparison to 30 fps - quarters/halves file size.
Bitrate is about 500 kb/s, some less.

I don't know if Whatsapp streams the videos or downloads them completely before playing, so you might try to use a constant quality mode like CRF as rate control instead of one of the bitrate-based rate controls such as CBR, ABR. If you have low or no motion in most parts of your video, CRF is destined for producing perfect quality with lowest bitrates. Tune the CRF parameter so you get your desired file size in the end.

It is a very time-intensive process to learn which CRF parameter produces which file size and which visual quality, so you might create some reference "master" video with OBS and too good quality and use a software like Handbrake afterwards to recode to a smaller file size. This way you don't need to always record a new video - you just encode the same video over and over again and vary the parameters. If you use software encoding with Handbrake, you might even squeeze a bit more quality out of the end product, since it is possible to use a preset such as slow or veryslow that OBS isn't able to use, since you have to encode realtime with OBS but not with Handbrake. So it might be a good idea anyway to recode the master in any case.

Lowering the audio bitrate certainly helps as well. Use the smallest values possible (64k). Audio on a smartphone is pathetic anyway, so nobody would hear it.
 
Dihelson Mendonca

Dihelson Mendonca

Member
koala said:
I just browsed through my Whatsapp video folder and checked the details of the longer videos. (in case you wonder where are they: Internal memory of your smartphone->WhatsApp->Media->WhatsApp Video->Private)
I found some with 10-13 MB.
I found these used a horizontal resolution of about 600-640 (which means in OBS you reproduce this with 640x360).
Surprise, surprise, some use a frame rate of only 15 fps! This is a quarter in comparison to 60 fps or half in comparison to 30 fps - quarters/halves file size.
Bitrate is about 500 kb/s, some less.

I don't know if Whatsapp streams the videos or downloads them completely before playing, so you might try to use a constant quality mode like CRF as rate control instead of one of the bitrate-based rate controls such as CBR, ABR. If you have low or no motion in most parts of your video, CRF is destined for producing perfect quality with lowest bitrates. Tune the CRF parameter so you get your desired file size in the end.

It is a very time-intensive process to learn which CRF parameter produces which file size and which visual quality, so you might create some reference "master" video with OBS and too good quality and use a software like Handbrake afterwards to recode to a smaller file size. This way you don't need to always record a new video - you just encode the same video over and over again and vary the parameters. If you use software encoding with Handbrake, you might even squeeze a bit more quality out of the end product, since it is possible to use a preset such as slow or veryslow that OBS isn't able to use, since you have to encode realtime with OBS but not with Handbrake. So it might be a good idea anyway to recode the master in any case.

Lowering the audio bitrate certainly helps as well. Use the smallest values possible (64k). Audio on a smartphone is pathetic anyway, so nobody would hear it.
Click to expand...

Excellent, excellent !

I was just downloading my big whatsapp videos in order to analyse how they were made, when I discovered your reply. 15fps for some cases may seem interesting for whatsapp, along with CRF, handbrake and lowering audio resolution ( BTW, it was in 160Kbps, which has no sense to whatsapp ). I created a folder specially for this project, and a new profile called whatsapp in OBS just for these experimentations: The best quality vs the minimum size. I position myself in front of the camera with all layers ready. I created hotkeys for starting and stopping recording. My external mic is ready. So, I push the recording key combination and begin to record. When finished, I open the whatsapp web chrome tab which is ready to upload from that folder. It´s instantaneous. Perhaps I should configure one more step for handbrake ( like a batch ) and record with high quality in OBS and let handbrake do the hard work. I´ll try what suits best.

Thanks, Koala, one more time. Excellent ideas as always !
 
Dihelson Mendonca

Dihelson Mendonca

Member
TryHD said:
I think that is the wrong approach for getting quality. You should instead set the whatsapp limits higher. https://wccftech.com/increasing-file-size-limit-whatsapp/
Click to expand...

Hello, TryHD, thanks for answering, but I think this yours is not the right approach for me, because I don´t want to have root access to my phone only to increease the file size. Besides, whatsapp gives a 64MB file size these days ( And I don´t intent to use this size, because people often use data plans fro their telephone companies and imagine all day broadcasting eben small files on the size of 64MB size would mean too overload to these people´s plans. For those connected with wi-fi, no problem, but I guess many could be reached on the streets, on places where there´s no wi-fi, so the minimum size would be logical, not the biggest sizes.

Thanks !
 
Dihelson Mendonca

Dihelson Mendonca

Member
TryHD said:
I never had a non rooted phone, so i never thought about it that it would be a problem for somebody lol
Click to expand...

And I even don´t know know how to root my old Motorola G5s plus, for that matter. Just for increasing whatsapp file sizes are at least too dangerous for me.
 
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