"broken ffmpeg default settings detected" and "use an encoding preset (vpre)"

[Fe++]

Hi,
I try to encoding a YUV420 picture using ffmpeg and x264, but I'cannot open the x264 codec because i have these errors:

[libx264 @ 0x8b7d8b0]broken ffmpeg default settings detected
[libx264 @ 0x8b7d8b0]use an encoding preset (vpre)

If I use the mpeg4 ffmpeg encoder the encoding is ok, the error is only with x264. What is the cause of this error? Thanks in advance.
Best regards

[Dark Shikari]

ffmpeg's defaults are broken and they override x264's encoding settings with completely broken ones. There doesn't seem to be much effort among ffmpeg developers to get this fixed, or for that matter, accept patches that fix them.

As a result, x264 will refuse to encode if it detects that you are using broken ffmpeg default settings and tells you to use -vpre instead with one of the included presets. This guide (http://rob.opendot.cl/index.php/useful-stuff/ffmpeg-x264-encoding-guide/) gives more information.

[Fe++]

Very clear, many thanks, i understand the problem. I ask another advice, I've to call the x264 not by CLI but by using ffmpeg api's, do you know source code file or other resource where i can consult for understand the correct routine for call x264 encoder?

[Dark Shikari]

Very clear, many thanks, i understand the problem. I ask another advice, I've to call the x264 not by CLI but by using ffmpeg api's, do you know source code file or other resource where i can consult for understand the correct routine for call x264 encoder?If you want to call the x264 library, call it directly, not through libavcodec. See x264.h for the API and x264.c for an example encoder made using the API.

[Fe++]

Thanks, it's exactly the information that i'm looking for.