These could be used for reference counting, or for keeping track of
decoding progress in references in multithreaded decoders.

Support is provided by gcc/msvc/suncc intrinsics, with a fallback using
pthread mutexes.
Signed-off-by: Anton Khirnov <anton@khirnov.net>

When parsing the Xing/Info tag, don't set the bit rate if it's an Info tag.

When parsing the stream, don't override the bit rate if it's already set,
otherwise calculate the mean bit rate from parsed frames. This way, the bit
rate will be set correctly both for CBR and VBR streams.

CC:libav-stable@libav.org
Signed-off-by: Anton Khirnov <anton@khirnov.net>

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

This breaks the dependency of mpegvideo on error_resilience allowing
compilation of components that depend on the former w/o the latter.

Make sure the behavior does not change with the locale.
Signed-off-by: Martin Storsjö <martin@martin.st>

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

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

This makes the decoder independent of mpegvideo.

This copy of the draw_horiz_band code is simplified compared to
the "generic" mpegvideo one which still has a number of special
cases for different codecs.
Signed-off-by: Martin Storsjö <martin@martin.st>

Make av_get_codec_tag_string() show codec tag string characters in a more
intelligible ways. For example the ascii char "@" is used as a number, so
should be displayed like "[64]" rather than as a printable character.

Apart alphanumeric chars, only the characters ' ' and '.' are used
literally in codec tags, all the other characters represent numbers.

This also avoids relying on locale-dependent character class functions.
Signed-off-by: Martin Storsjö <martin@martin.st>

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

This fixes crashes when there is no encoder for the default codec of
selected format.
Signed-off-by: Martin Storsjö <martin@martin.st>

This fixes standalone building of this decoder.
Signed-off-by: Martin Storsjö <martin@martin.st>

Not all hwaccels implement all codecs, so using one single list for
multiple such codecs means some codecs will be represented in the list,
even though they don't actually handle that codec. Copying specific
lists in each codec fixes that.
Signed-off-by: Martin Storsjö <martin@martin.st>

get_uint returns an unsigned value, use an unsigned to store
blocksize to make sure the comparison logic is correct and report
correctly the error for the channel count not supported.

Prevent the loop shorten_decode_close from writing and freeing out of
the array boundary.

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Luca Barbato <lu_zero@gentoo.org>

The decoder assumes a single bit depth for all the planes
while the specification allows different bit depths for luma
and chroma.

Avoid the possible problems described in CVE-2013-2277

CC: libav-stable@libav.org

Some hwaccels use name prefixes, some do not, others only use them for
some codecs.  Add prefixes everywhere for consistency.

This is useful in all the places where special characters in
variable names are manually translated to underscores.

The warnings are false positives, older gcc versions (such as 4.5)
think the variables can be used uninitialized while they in
practice can't, while newer (4.6) gets it right.
Signed-off-by: Martin Storsjö <martin@martin.st>

CC:libav-stable@libav.org

Since decode_slice_header() returns before the reference lists are
constructed, there are zero valid references.

CC:libav-stable@libav.org

They are filled in decode_slice_header() anyway.

The callers of this function can't report errors sanely. If this
one malloc fails, don't write the extradata byte, make sure we
try to malloc it the next time we're called instead, and make sure
we still consume the input data byte.

CC: libav-stable@libav.org
Signed-off-by: Martin Storsjö <martin@martin.st>

This header byte is only present when actually reading a VP6 frame,
not when reading the codec type field in the metadata. This
potential bug has been present since 5b54a90c.

CC: libav-stable@libav.org
Signed-off-by: Martin Storsjö <martin@martin.st>