AVFrame.extended_data has to reset to the AVFrame.data of the current
thread context after copying the frame contents.
Fixes crashes with frame-threading after 2bc0de38.

Adds a flag context_reinit to MpegEncContext to relieable keep track
of frame parameter changes which require a context reinitialization.
This is required for broken inputs which change the frame size but
error out before the context can be reinitialized.

Fixes triggering an assert in avcodec_default_release_buffer()
introduced in 1b3439b3.

This is mainly required for frame parameter changes during frame based
multithreading but single threaded usage profits too from avoiding
ff_MPV_common_end()/ff_MPV_common_init() cycles.

This is a preparation for supporting frame size changes during
frame-based multithreading.

Prevents dangling pointers and makes access after free more obvious.
Setting AVFrame.qscale_table to NULL is required for successfully
allocating a previously freed Picture with ff_alloc_picture().

This assert is no longer true since h264 error concealment needs
last_picture_ptr to be set.
Signed-off-by: Martin Storsjö <martin@martin.st>

Signed-off-by: Kostya Shishkov <kostya.shishkov@gmail.com>

This file defines a single, huge function, MPV_motion(), which
although being declared inline is not actually inlined by the
compiler (for good reason).  There is thus no sense in defining
this function in a header file, resulting in multiple copies of
it in the final library.
Signed-off-by: Mans Rullgard <mans@mansr.com>

Signed-off-by: Mans Rullgard <mans@mansr.com>

Signed-off-by: Martin Storsjö <martin@martin.st>

This feature is complex, of questionable utility, and slows down
normal decoding.
Signed-off-by: Mans Rullgard <mans@mansr.com>

If the dummy frame are not created from a reference frame they could
be deleted untimely resulting in multithreaded decoder waiting on
the current frame to finish.
Noticed by Ronald S. Bultje in the RV34 decoder with a broken file.

Prevents hangs on corrupt input.

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC: libav-stable@libav.org

Signed-off-by: Martin Storsjö <martin@martin.st>

Signed-off-by: Martin Storsjö <martin@martin.st>

Signed-off-by: Martin Storsjö <martin@martin.st>

It is obscure, most likely unused and not bit-exact compared to
libavcodec due to a different IDCT transform algorithm.

When either video dimension is only one macroblock, subtractions
based on v_edge_pos and the macroblock size may be negative. In
that situation, an unsigned comparison isn't sufficent to test for
MV overruns, because a limit of (unsigned)-1 will let any other
value pass.
Signed-off-by: Anton Khirnov <anton@khirnov.net>

Under certain conditions pictures could be released before they were
returned with frame-threading. Broken mv computation in the upcoming
rv34 frame-threading patch was caused by this.

To prevent contexts from running out of available pictures the loop
releasing "unused" pictures has to be run for B frames too.

Adds a new member to MpegEncContext to hold the number of used slice
contexts. Fixes segfaults with '-threads 17 -thread_type slice' and
fate-vsynth{1,2}-mpeg{2,4}thread{,_ilace} with --disable-pthreads.

Signed-off-by: Ronald S. Bultje <rsbultje@gmail.com>

This was intended as an optimisation for skipped blocks in MPEG2
P-frames and never used elsewhere.  Removing this "optimisation"
speeds up MPEG2 decoding by 1-2% (ARM Cortex-A9).
Signed-off-by: Mans Rullgard <mans@mansr.com>

Signed-off-by: Luca Barbato <lu_zero@gentoo.org>

Signed-off-by: Anton Khirnov <anton@khirnov.net>

Signed-off-by: Ronald S. Bultje <rsbultje@gmail.com>

Signed-off-by: Ronald S. Bultje <rsbultje@gmail.com>

Add AV_NUM_DATA_POINTERS to simplify the bump transition.
This will allow for supporting more planar audio channels without having to
allocate separate pointer arrays.

A new field, AVCodecContext.internal is used to hold a new struct
AVCodecInternal, which has private fields that are not codec-specific and are
used by general libavcodec functions.

Moved internal_buffer, internal_buffer_count, and is_copy.