[libav-devel] [PATCH 2/4] h264: correct the check for invalid long term frame index in MMCO decode

[Ronald S. Bultje]

Hi,

On Tue, Aug 16, 2011 at 8:05 AM, Diego Biurrun <diego at biurrun.de> wrote:
> From: Jeff Downs <heydowns at somuchpressure.net>
>
> The current check on MMCO parameters prohibits a "max long term frame index
> plus 1" of 16 (frame idx of 15) for the "set max long term frame index" MMCO.
> Fix this off-by-one error to allow the full range of legal values.
>
> Signed-off-by: Diego Biurrun <diego at biurrun.de>
> ---
>  libavcodec/h264_refs.c |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)
>
> diff --git a/libavcodec/h264_refs.c b/libavcodec/h264_refs.c
> index b7e43e7..12e3b94 100644
> --- a/libavcodec/h264_refs.c
> +++ b/libavcodec/h264_refs.c
> @@ -685,7 +685,7 @@ int ff_h264_decode_ref_pic_marking(H264Context *h, GetBitContext *gb){
>                 }
>                 if(opcode==MMCO_SHORT2LONG || opcode==MMCO_LONG2UNUSED || opcode==MMCO_LONG || opcode==MMCO_SET_MAX_LONG){
>                     unsigned int long_arg= get_ue_golomb_31(gb);
> -                    if(long_arg >= 32 || (long_arg >= 16 && !(opcode == MMCO_LONG2UNUSED && FIELD_PICTURE))){
> +                    if(long_arg >= 32 || (long_arg >= 16 && !(opcode == MMCO_SET_MAX_LONG && long_arg == 16) && !(opcode == MMCO_LONG2UNUSED && FIELD_PICTURE))){

I believe Alexander (Strange) said this change was OK.

Ronald