[FFmpeg-user] ffmpeg stdout write performance on windows (buffering request)

[Roger Pack]

> I did some benchmarking, and it seems that Windows has a significant
> overhead per write call for stdout / piping. These are my results of two
> processes communicating with stdout --> stdin:
>    writing batches of 16 bytes: 4MB/sec
>    writing batches of 1024 bytes: 170MB/sec
>    writing batches of 4096 bytes: 260MB/sec
>    writing batches of 65536 bytes: 980MB/sec

Oddly, I seem unable to get discrepancies when using different buffer
sizes, at least with Windows 7.

Well, when writing to stdout, with size 1600, I get 268 MB/s, then it
maxes out with a buffer size 16K at 293 MB/s.

For read buffer size, 1600 byte buffer -> 299 MB/s, so now problems there...
Who knows what's really going on, though, maybe you can share your
stdin/out test code.