This reverts commit 8f9391f6.

(The root cause for this problem was fixed in commit
49482677)

Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

fix natural reading
Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

 * 12 bytes saved on 32-bits platforms,
 * 32 bytes saved on 64-bits platforms.

Now :demuxdump-file=foo works correctly with RTP input.
Signed-off-by: Rémi Denis-Courmont <remi@remlab.net>

Signed-off-by: Rémi Denis-Courmont <remi@remlab.net>

It allows to add callback called before/after a picture is used.

Previously, if the absolute delay dropped by a longer interval than the
packetization time, we could end up repeatedly waiting into the future,
and never dequeue anything.