Hi, On Tue, Dec 18, 2012 at 8:20 AM, Janne Grunau <[email protected]> wrote: > On 2012-12-18 07:30:03 -0800, Ronald S. Bultje wrote: >> Hi, >> >> On Mon, Dec 17, 2012 at 10:55 PM, Janne Grunau <[email protected]> >> wrote: >> > On 2012-12-17 18:24:37 -0800, Ronald S. Bultje wrote: >> >> Hi, >> >> On Dec 17, 2012 1:02 PM, "Janne Grunau" <[email protected]> wrote: >> >> > >> >> > Compute dist_scale_factor_field only for MBAFF since that is the only >> >> > case in which it is used. >> >> >> >> The patch also increases an array size - why? >> > >> > to handle up to 32 references for field pictures. Alternatively both >> > arrays can probably be merged to the usual 16 + 32 size. >> >> Check the code: > > omitting the important: > + if (FRAME_MBAFF) > >> + for (i = 0; i < 2 * h->ref_count[0]; i++) >> + h->dist_scale_factor_field[field][i^field] = >> + get_scale_factor(h, poc, poc1, i+16); >> + } >> + >> + for (i = 0; i < h->ref_count[0]; i++){ >> h->dist_scale_factor[i] = get_scale_factor(h, poc, poc1, i); >> } >> >> For arrays of size: >> >> - int dist_scale_factor[16]; >> + int dist_scale_factor[32]; >> int dist_scale_factor_field[2][32]; >> >> If i for setting dist_scale_factor_field is [0, ref_count * 2] and >> that's [0, 32], them ref_count is 16, thus the second loop i [0, >> ref_count] is [0, 16], thus dist_scale_factor[] only needs to be of >> size 16. > > dist_scale_factor_field is only used for MBAFF. The max reference count > for MBAFF is 16 (!field_pic_flag). For field_pic_flag maximal reference > count is 32. > > The naming of the variables is unfortunate. In other cases we use arrays > sizes like ...[16 + 32] to handle normal and field references for MBAFF > in the same array. That one would be large enough to 32 field pic > references too.
So, shall we commit this and add a FIXME to that effect so we can do that later? Ronald _______________________________________________ libav-devel mailing list [email protected] https://lists.libav.org/mailman/listinfo/libav-devel
