It also factorize channel order definitions.
The DTS order for middle channels can be wrong.

Add video output that dumps raw YUV frames in a file, with YUV4MPEG2 compatible header as used by mplayers yuv4mpeg video ouput module.

Add scene filter which provides the same functionality as the vout_output image, but which can be inserted in a playback or stream out chain.

This will help our muxers creating better files.

This function was returning a buffer allocated with the wrong type (alloca)
when a filter returned 0 sample (scaletempo at least).

unmaintained and confuse users.

I forgot that changes in [f351451d]

(access_filter_dump could probably be removed too)

The record module:

- automatically selects the right muxer and filename extension by
looking the ES codec. In case it fails, it probes directly the
muxers and keeps the better one.

- removes all ES packets until the first key frame.

- truncates the ES without key frame to match the start time of
the other tracks.