[Mplayer-advusers] Bugs/problems with JPEG output driver

[D Richard Felker III]

On Mon, Feb 02, 2004 at 12:53:34PM -0500, Doug Reynolds wrote:
> I have found a few relatively minor bugs / problems with the JPEG
> video output driver. My system and hardware information is included
> at the bottom of this message. Three problems are described below.
> 
> Doug
> 
> ----------------------------------------------------------------------------
> 
> Problem 1
> ---------
> 
> When using the "-ss [time]" option, the first output JPEG file is
> always the first frame in the video. Subsequent JPEG files are from
> the correct part of the file. Example:

Yes, this is a bug. :( I'd be hesitant to try to fix it myself since
I'm not sure whether moving the seeking code in the loop would cause
problems elsewhere.

> Problem 2
> ---------
> 
> The output filenames created using the JPEG driver are numbered
> starting at 1. If the decoding does not start with the first frame,
> as in the example used in describing Problem 1 above, it would be
> desireable to use the frame number to construct the file name. The
> example above produced these output files:

Not possible. In general, the frame number is not known. Frame numbers
only exist for fixed-fps files, and are probably only known for avi
files.

> ----------------------------------------------------------------------------
> 
> Problem 3
> ---------
> 
> The "-vf tinterlace" filter appears to be incompatible with the JPEG video
> output driver.  Output from the following command is shown below:

Try -vf tinterlace,scale

Rich