[Libav-user] mpeg4 encoding with no b-frames

[marcin_ffmpeg]

Dear All

In my application I'm trying to re-encode video from h264 to mpeg4. It is important to have no b-frames in the output file so I set
encoder context to max_b_frames=0, gop_size is fixed to 25.
With this setting I get loads of following warnings
[mpeg4 @ 0xa53f3620] warning, too many b frames in a row

Problem does not exists when encoder gop_size is set to decoder gop_size and max_b_frames is set to 10.

Is there something what can be done about that? Does frame after decoding from h264 have to be somehow converted?

Thanks for any help
Marcin