Implement lazy initialization of the image resample context, so that
the initialization code does not need to be duplicated.

Also manage the case in which resample/size change mid-stream. For
each packet the code computes if resampling is needed.

Previously the resample check was done only at the initialization, in
case size/format changed and no resample was detected at the init
stage ffmpeg was silently exiting.

avfilter_copy_frame_props() avoids code duplication and increases
robustness.

The added files libavfilter/avcodec.[ch] are used for containing
utilities useful for gluing togheter libavfilter and libavcodec.

The format is a per-frame property, having it in AVFrame simplify the
operation of extraction of that information, since avoids the need to
access the codec/stream context.

width and height are per-frame properties, setting these values in
AVFrame simplify the operation of extraction of that information,
since avoids the need to check the codec/stream context.

recreating the value.

Avoids a memleak, is less code and might be faster.

twice and add a missing "const".

* qatar/master:
  mov: fix composition timestamps on movie fragments.
  wmavoice: Use proper size in memeset().

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

The patch below provides exactly that to the MP3 muxer. A XING header
containing

   * the numer of frames,
   * the size, and
   * a TOC

is generated.

It's based on an idea by Anton Khirnov (restricted to the number of
frames) found at

   http://patches.ffmpeg.org/patch/1891/

The TOC is generated as found in lame's "VbrTag.c".

According to my tests the following reproduces the number of frames, the
size and the TOC in "c.mp3" from "b.mp3" (except a shift due to shorter
XING header generated by FFmpeg):

   lame -V2 a.wav b.mp3
   ffmpeg -i b.mp3 -acodec copy -y c.mp3

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

This fixes, for instance, the case that there is a track that has some samples with composition time offset and has a track run without sample-composition-time-offsets-present.

sizeof(array_functrion_argument) gives the size of the pointer type not
the size of the array to which it points.

* qatar/master:
  configure: warn if pkg-config is missing
Merged-by: Michael Niedermayer <michaelni@gmx.at>

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Signed-off-by: Francesco Cosoleto <cosoleto@gmail.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

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