[FFmpeg-devel] [PATCH v3 2/5] avcodec/golomb: Prevent shift by negative number

[Michael Niedermayer]

On Mon, Jul 27, 2020 at 11:08:07AM +0200, Andreas Rheinhardt wrote:
> This happened in get_ue_golomb() if the cached bitstream reader was in
> use, because there was no check to handle the case of the read value
> not being in the supported range.
> For consistency with the uncached bitstream reader and for compliance
> with the documentation, every value not in the 0-8190 range is treated as
> error although the cached bitstream reader could actually read values in
> the range 0..65534 without problems.
> 
> Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at gmail.com>
> ---
> v3: Besides accepting the same range as the uncached version this
> version also consumes bits in case of error like the uncached version.
> Unfortunately it is not possible to always consume the same number of
> bits, because the uncached version will consume 63 bits as soon as all
> valid bits are zero, whereas the cached version will only consume 63
> bits if the next 31 bits are zero.
> 
>  libavcodec/golomb.h | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)

probably ok

thx

[...]
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