Recently with COVID-19 and the “Shelter-In-Place” restrictions in full swing I’ve found myself using Virtual Meeting software more and more. At SAP, the main choices now are:
There seem to be some on-line comparisons from the IT department:
However, what might be missing in those comparison chart is that recording quality is very “varied”. After recently reviewing a recorded (social) meeting from Teams in Streams, my curiosity was piqued. So I ran an experience comparing 3x different mechanism to record on-line content:
- A booked “on-line meeting” on Teams with Cloud recording (automatically to Streams)
- A booked “on-line meeting” on Zoom with local recording (personal free account)
- Pre-recorded direct to DSLR recording (older Nikon D7100)
To make it easier to compare the quality of the recording, I recorded myself singing and playing part of a song on my guitar. (The performances admittedly aren’t stellar or 100% consistent among all 3x, but it doesn’t really factor in the comparison as you will see later.)
To ensure the highest input audio quality as possible, I used the following professional grade recording gear:
- Behringer UMC404HD (Audiophile 4×4, 24-Bit/192 kHz USB Audio/MIDI Interface with Midas Mic Preamplifiers)
- Blue en∙core 300 (Premium Vocal Condenser Microphone, 40Hz-20KHz response)
(To put the “hardware” in perspective, the audio hardware I am using is professional grade, recording at 24-bit/192KHz, which is ~250x the resolution of a CD at 16-bit/44.1KHz).
Immediately, when reviewing the samples the range is quality was evident. You can view the links below via Streams – only available to SAP internally. (For best results, play over high-quality speaker or headphones. Lower quality headsets may impact your ability to discern the differences.)
Teams (direct to Streams) – Teams Recording Sample
The quality here is very poor. Almost shockingly so (and that is what started me on this quest/experiment). There must be some intelligent filtering as the guitar intro part is not picked up at all.
Zoom (local) – Zoom Recording Sample
The quality here is much better. While the video isn’t perfect, the audio is actually quite clear. Volume is also much higher, maybe playback much more enjoyable.
DSLR – DSLR Recording Sample
As you can “see” and “hear” the quality in DSLR recording is by far the best. Vocals and guitar come out well reproduced and any motion is captured well. There isn’t any aliasing or artifacts.
Splitting off the audio from the video and then viewing in them size by side in editing software, we can clearly see the drastic different in the wave-form. Note that in Teams and Zoom the values of the Audio-Interface were identical at the time of recording. The audio by Team is almost undetectable.
So why is this? Looking at the technical details after 1st hand visual and audio evaluation, the data seems to match well with my empirical reactions. It’s crucial to note that no matter how “good” the source was, with a low-quality recording, this is wasted effort.
Teams (direct to Streams)
- Bitrate: 49kbps
- Sample Rate: 16 kHz
- Bitrate: 53kbps
- Sample Rate: 32 kHz
- Bitrate: 1540kbps
- Sample Rate: 48 kHz
Note: Both ZOOM and Teams folded down to MONO, which is actually better as stereo in this case was unnecessary and provided no extra value.
Teams (direct to Streams)
- Bitrate: 1049kbps
- Frame Rate: 8 frames/s
- Bitrate: 1633kbps
- Frame Rate: 25 frames/s
- Bitrate: 22413kbps
- Frame Rate: 30 frames/s
Note: To capture “realistic” motion, you need 24 frames/s or higher. For reference YouTube recommends 8Mbps (8000kbps) for HD uploads.
I haven’t tried…
- Skype local recording – My development team has prioritized the use of Skype (to avoid missing chats and calls on the “other” platform) so I rarely log into it.
- Zoom cloud recording – I don’t have Ariba-purchased license, so I can only locally record meetings
Given the choice, my (current) first preference for any media that I thought would be preserved and shared for a long time, locally recording with DSLR or video camera still seems like the best bet. Often these are “dedicated purpose” devices that are optimized for recording quality. However, this doesn’t offer live-audience interaction.
Therefore for live-audience event that would be shared later, I would go with Zoom over Teams due to the ability to locally record at a much higher quality. I would then upload the media to Streams to re-share with colleagues.
Some useful links:
- On-line complaints on TEAMs audio quality – https://microsoftteams.uservoice.com/forums/555103-public/suggestions/34552138-meeting-record-quality-is-low
- ZOOM and security concerns – https://jam4.sapjam.com/blogs/show/RMoCVrXEs0uijKGRwScWwc