Quote:
Originally Posted by pojke
Are any those things important enough to require corrections?
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No, I don't think so...
Later FFmpeg versions got into the habit to introduce more and more warnings which largely can be ignored.
The first "Past duration too large" is very common for MP4 or FLV files from the Internet. I never saw any adverse effects.
The rc buffer underflow warning is something I have never seen so far, but if it was really a serious buffer underflow you would not be able to author the streams, the authoring application would refuse to author them.
The next warning "max bitrate possibly too small..." makes no sense at all. The max bitrate for both passes is set to 8500 kbps which is already a little high for FFmpeg (FFmpeg tends to overshoot the specified max bitrate). And the recommendation to use trellis or increase qmax is nonsense.
Trellis has a severe bug in the MPEG2 encoder which can totally screw up the result. And qmax is at the default of 31, it should not be set to a higher value.
The DVDLab message about open GOPs is also BS. The preferred and best way to encode for DVDs is to use open GOPs. It is true that chapter points could be shifted slightly to the next I-Frame during authoring, but this is rarely a problem. The only valid reason to use closed GOPs is if you are dealing with streams which have several angles.
Looks like you are not familiar with batch files...
I can't give you a complete tutorial, but the use of the % sign is easy to explain.
At the top of the script some variables are set. This is done with the SET command:
SET my_var= blablabla
Later in the script you can reference this variable by using the variable name enclosed in % characters.
She said: %my_var% would be resolved to
She said: blablabla
Quotation marks in batch files must be used for strings which contain special characters like spaces. In this batch file we need to use it for file names with the full path like
c:\program files (x86)\ffmpeg\my file.mp4
The ~ character is a little more complicated, if you are curious there are quite a few batch file tutorials on the Internet.
Cheers
manolito