On Sat, May 19, 2018 at 08:23:59PM -0300, James Almer wrote: > On 5/19/2018 6:40 PM, Michael Niedermayer wrote: > > On Fri, May 18, 2018 at 05:06:36PM +0200, Jerome Borsboom wrote: > >> Direct prediction for interlace frame B pictures references the mv in the > >> second block in an MB in the backward reference frame for the twomv case. > >> When the backward reference frame is an I frame, this value may be unset. > >> > >> Signed-off-by: Jerome Borsboom <jerome.borsb...@carpalis.nl> > >> --- > >> libavcodec/vc1_block.c | 6 ++++-- > >> 1 file changed, 4 insertions(+), 2 deletions(-) > >> > >> diff --git a/libavcodec/vc1_block.c b/libavcodec/vc1_block.c > >> index 74935ec9e9..9c170a1e3c 100644 > >> --- a/libavcodec/vc1_block.c > >> +++ b/libavcodec/vc1_block.c > >> @@ -2678,8 +2678,10 @@ static void vc1_decode_i_blocks_adv(VC1Context *v) > >> s->bdsp.clear_blocks(block[0]); > >> mb_pos = s->mb_x + s->mb_y * s->mb_stride; > >> s->current_picture.mb_type[mb_pos + v->mb_off] > >> = MB_TYPE_INTRA; > >> - s->current_picture.motion_val[1][s->block_index[0] + > >> v->blocks_off][0] = 0; > >> - s->current_picture.motion_val[1][s->block_index[0] + > >> v->blocks_off][1] = 0; > >> + for (int i = 0; i < 4; i++) { > >> + s->current_picture.motion_val[1][s->block_index[i] + > >> v->blocks_off][0] = 0; > >> + s->current_picture.motion_val[1][s->block_index[i] + > >> v->blocks_off][1] = 0; > >> + } > > > > see AV_ZERO* > > Those may use mmx instructions, which may require calling emms_c() after > the loop. > memset() may be a better choice here. For a small amount of bytes the > compiler should be able to optimize it into an inlined mov/xor on its own.
This calls clear_blocks() a few lines before which can use mmx too unless iam missing something [...] -- Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB Why not whip the teacher when the pupil misbehaves? -- Diogenes of Sinope
signature.asc
Description: PGP signature
_______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel