[MPlayer-users] [BUG] failure copying a telecined mpeg stream [SOLVED]

[Giacomo Comes]

On Wed, Jul 20, 2005 at 11:42:04PM -0400, Rich Felker wrote:
> On Wed, Jul 20, 2005 at 03:19:01PM -0400, Giacomo Comes wrote:
> > I have verified that the following command line does not
> > work properly all the times:
> > 
> > mencoder -of mpeg -mpegopts format=dvd -ovc copy -oac copy -noskip -mc 0 -o test.mpg source.mpg
> > 
> > When the source mpeg is 24000/1001fps telecined then the output file test.mpg is shorter.
> > Example: 
> 
> Yes, it's known that -ovc copy will not work with soft telecined
> content.
> 

After several try and some opinion exchange with Nico,
I have found a way to copy mpeg telecined streams.

This command line will do it:

mencoder -of mpeg -mpegopts format=dvd -ovc copy -oac copy -noskip -mc 0 -ofps 24000/1001 -o test.mpg source.mpg

It works only if the source stream is telecined.
The important options are:
-noskip -mc 0 -ofps 24000/1001

With these three options the file test.mpg:

1) has proper a/v sync
2) has the same duration as the source stream
3) has his copied streams identical to the source streams

During the copy mencoder can output many many times the message:

  Too many video packets in the buffer: (4096 in 8277718 bytes).
  Maybe you are playing a non-interleaved stream/file or the codec failed?
  For AVI files, try to force non-interleaved mode with the -ni option.
  ds_fill_buffer: EOF reached (stream: audio)

Nico was worried that it could lead to discarded packets, but 
a byte comparison of the dumped video stream from source.mpg and test.mpg
shows that they are identical (except that the second is few kB shorter,
but it is known that mplayer doesn't dump 100% of the source streams).
I have observed the previous messages only with mixed soft/hard telecined
DVD.

I have done tests with big (DVD) telecined mpegs and the results appears
valid so far.

Giacomo