Seeking compression/export settings for single image with audio

[smoking_anthill]

Hi

I have a lot of audio I wish to convert to video so as to upload to google photos and youtube (to get the transcripts). There is only a single image (white text on black background) for the duration of the audio (between 10 and 45 mins of audio).

I would like to good quality audio (AAC and 384 kbps) but i want just want a low quality image to speed up the export process. The image is for easily distinquishing the recordings in google photos.

can someone recommend some settings to make this a fast process to export. maybe something like:
720 *480. (can i go lower here?)
19:9
GOP 15 fixed
constant bitrate of maybe 2500k

this did make a difference (adjusted from youtube settings) but i was hoping for even greater video compression while keeping the audio quality the same.

does anyone perhaps have some better suggestions?

many thanks

[shotcut]

Increase the GOP a lot, do not make it strict, and reduce the bitrate more.

[smoking_anthill]

Thankyou for your advice Shotcut

I was wondering If I ask the question differently it would lead to a different answer…

What if i wish to export the as fast as possible keeping the audio the same quality but the image can be low quality.

I saw somewhere about changing in ‘other’ tab for export
present=ultrafast

I also read in the forum that VBR tends to make files large…

I have tried tried GOP at 999
fixed and constant bitrate: 256K
with buffer size down to 50

But the speed is still about 1 min for every minute of video.

any thoughts or other suggestions?

many thanks