[FFmpeg-user] Max rtbufsize Via dshow

Carl Eugen Hoyos ceffmpeg at gmail.com
Fri Jan 11 02:37:39 EET 2019

2019-01-11 0:39 GMT+01:00, Gabriel Balaich <roderrooder at gmail.com>:

> [dshow @ 0000024ed4b83580] real-time buffer [AVerMedia HD Capture GC573 1]
> [video input] too full or near too full (93% of size: 2147480000 [rtbufsize
> parameter])! frame dropped!
>     Last message repeated 6 times

What happens at this point?
Do the messages stop or does the system continue to drop frames?

> PS C:\Users\djcim>
> Not sure if it is because I'm recording different sources but I'm
> definitely dropping less frames pre-recording as I was even testing
> previously today, yet I am dropping none the less. I drop a lot more frames
> when ending the recording, I would think this is because the buffer is
> being offloaded to the encoder all at once, but I'm not sure.

What happens in-between? Do the drops stop at some point?

>> As an alternative, simply patch libavdevice/dshow.c to avoid
>> dropping frames so you can test if the parameter is really
>> too small.
> I just wasn't sure if it was as simple as switching the variable being
> passed, I'm having a difficult time understanding the source code. I have
> yet to compile FFmpeg myself but I'm sure I could figure it out one way or
> another.

Ignore the variable, patch the dropping away in shall_we_drop() in

I still find it not very likely that 2G buffer is not enough but a larger
buffer would help.

Carl Eugen

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