MP4 render options: "Audio Sample Rate" range options seem odd... not sure how to interpret


#1

In the render options for mp4, it has separate fields for audiio sample rate and audio bit rate. The bit rate options make sense with 64-320 range, but the audio sample rate instead of options like 44.1k, 48k has the same 64-320 options.

I don’t get it. Is it referring to something other than samples per second?

Would I just max it for highest audio quality? Some other rule of thumb?

Just not sure how to make sense of the numeric options.


#2

Rule of Thumb N°1 : don’t render in MP4 unless it’s a quick preview.

Render a sequence of stills (JPG, PNG, EXR…) and then pack them up in your editor of choice into a video format(.MP4, MOV, AVI…) with sound.

This way you get not only the best control on quality, but if one frame fails, you don’t have to re-render everything.


#3

While that’s undoubtedly good advice for most situations, it happens not to be practical in this case. I’m rendering LOTS of short videos (15seconds to 2 minutes), so efficiency and time management trump most other concerns , and I’m not particularly concerned about stuck renders. These are just quick one-offs for social media drip.

I’m just not understanding why it’s asking about audio sample rate with options ranging from 64 to 320. AFAIK, those just sound like bitrate options, not sample rate, but audio bitrate is a separate field.


#4

I notice now that if I use one of the presets where audio sample rate is blanked out, then fill in the rest while leaving that blank, then close and reopen the project, the Audio Sample rate has auto-populates with the correct value of 44.1k (the rate of the audio it contains).

This makes sense whereas the dropdown options did not, and seemed to just be mirroring the audio bitrate options, so I am beginning to think those options are perhaps some kind of bug (in R20, at least)