ost->frame_aspect_ratio ? // overridden by the -aspect cli option
av_d2q(ost->frame_aspect_ratio * codec->height/codec->width, 255) :
ost->filter->filter->inputs[0]->sample_aspect_ratio;
+ if (!strncmp(ost->enc->name, "libx264", 7) &&
+ codec->pix_fmt == AV_PIX_FMT_NONE &&
+ ost->filter->filter->inputs[0]->format != AV_PIX_FMT_YUV420P)
+ av_log(NULL, AV_LOG_INFO,
+ "No pixel format specified, %s for H.264 encoding chosen.\n"
+ "Use -pix_fmt yuv420p for compatibility with outdated media players.\n",
+ av_get_pix_fmt_name(ost->filter->filter->inputs[0]->format));
codec->pix_fmt = ost->filter->filter->inputs[0]->format;
if (!icodec ||