[FFmpeg-devel] [PATCH] libavcodec/mpegvideo_enc: Fix a chroma mb size error in sse_mb()

Soft Works softworkz at hotmail.com
Sat Jul 2 00:19:54 EEST 2022



> -----Original Message-----
> From: ffmpeg-devel <ffmpeg-devel-bounces at ffmpeg.org> On Behalf Of
> Wenbin Chen
> Sent: Friday, July 1, 2022 7:35 AM
> To: ffmpeg-devel at ffmpeg.org
> Subject: [FFmpeg-devel] [PATCH] libavcodec/mpegvideo_enc: Fix a
> chroma mb size error in sse_mb()
> 
> For 422 frames we should not use hard coded 8 to calculate mb size
> for
> uv plane. Chroma shift should be taken into consideration to be
> compatiple with different sampling format.
> 
> The error is reported by fate test when av_cpu_max_align() return 64
> on the platform supporting AVX512. This is a hidden error and it is
> exposed after commit 17a59a634c39b00a680c6ebbaea58db95594d13d.
> 
> mpeg2enc has a mechanism to reuse frames. When it computes SSE (sum
> of
> squared error) on current mb, reconstructed mb will be wrote to the
> previous mb space, so that the memory can be saved. However if the
> align
> is 64, the frame is shared in somewhere else, so the frame cannot be
> reused and a new frame to store reconstrued data is created. Because
> the
> height of mb is wrong when compute sse on 422 frame, starting from
> the
> second line of macro block, changed data is read when frame is reused
> (we need to read row 16 rather than row 8 if frame is 422), and
> unchanged
> data is read when frame is not reused (a new frame is created so the
> original frame will not be changed).
> 
> That is why commit 17a59a634c39b00a680c6ebbaea58db95594d13d exposes
> this
> issue, because it add av_cpu_max_align() and this function return 64
> on
> platform supporting AVX512 which lead to creating a frame in
> mpeg2enc,
> and this lead to the different outputs.
> 
> Signed-off-by: Wenbin Chen <wenbin.chen at intel.com>
> ---
>  libavcodec/mpegvideo_enc.c             | 29 +++++++++++++------
>  tests/ref/seek/vsynth_lena-mpeg2-422   | 40 +++++++++++++-----------
> --
>  tests/ref/vsynth/vsynth1-mpeg2-422     |  8 +++---
>  tests/ref/vsynth/vsynth2-mpeg2-422     |  8 +++---
>  tests/ref/vsynth/vsynth3-mpeg2-422     |  8 +++---
>  tests/ref/vsynth/vsynth_lena-mpeg2-422 |  8 +++---
>  6 files changed, 56 insertions(+), 45 deletions(-)
> 
> diff --git a/libavcodec/mpegvideo_enc.c b/libavcodec/mpegvideo_enc.c
> index d6a85a037a..c9d9e2a764 100644
> --- a/libavcodec/mpegvideo_enc.c
> +++ b/libavcodec/mpegvideo_enc.c
> @@ -2558,24 +2558,35 @@ static int sse(MpegEncContext *s, uint8_t
> *src1, uint8_t *src2, int w, int h, in
>  static int sse_mb(MpegEncContext *s){
>      int w= 16;
>      int h= 16;
> +    int chroma_mb_w = w >> s->chroma_x_shift;
> +    int chroma_mb_h = h >> s->chroma_y_shift;
> 
>      if(s->mb_x*16 + 16 > s->width ) w= s->width - s->mb_x*16;
>      if(s->mb_y*16 + 16 > s->height) h= s->height- s->mb_y*16;
> 
>      if(w==16 && h==16)
>        if(s->avctx->mb_cmp == FF_CMP_NSSE){
> -        return s->mecc.nsse[0](s, s->new_picture->data[0] + s->mb_x
> * 16 + s->mb_y * s->linesize   * 16, s->dest[0], s->linesize,   16) +
> -               s->mecc.nsse[1](s, s->new_picture->data[1] + s->mb_x
> *  8 + s->mb_y * s->uvlinesize *  8, s->dest[1], s->uvlinesize,  8) +
> -               s->mecc.nsse[1](s, s->new_picture->data[2] + s->mb_x
> *  8 + s->mb_y * s->uvlinesize *  8, s->dest[2], s->uvlinesize,  8);
> +        return s->mecc.nsse[0](s, s->new_picture->data[0] + s->mb_x
> * 16 + s->mb_y * s->linesize * 16,
> +                               s->dest[0], s->linesize, 16) +
> +               s->mecc.nsse[1](s, s->new_picture->data[1] + s->mb_x
> * chroma_mb_w + s->mb_y * s->uvlinesize * chroma_mb_h,
> +                               s->dest[1], s->uvlinesize,
> chroma_mb_h) +
> +               s->mecc.nsse[1](s, s->new_picture->data[2] + s->mb_x
> * chroma_mb_w + s->mb_y * s->uvlinesize * chroma_mb_h,
> +                               s->dest[2], s->uvlinesize,
> chroma_mb_h);
>        }else{
> -        return s->mecc.sse[0](NULL, s->new_picture->data[0] + s-
> >mb_x * 16 + s->mb_y * s->linesize   * 16, s->dest[0], s->linesize,
> 16) +
> -               s->mecc.sse[1](NULL, s->new_picture->data[1] + s-
> >mb_x *  8 + s->mb_y * s->uvlinesize *  8, s->dest[1], s->uvlinesize,
> 8) +
> -               s->mecc.sse[1](NULL, s->new_picture->data[2] + s-
> >mb_x *  8 + s->mb_y * s->uvlinesize *  8, s->dest[2], s->uvlinesize,
> 8);
> +        return s->mecc.sse[0](NULL, s->new_picture->data[0] + s-
> >mb_x * 16 + s->mb_y * s->linesize * 16,
> +                              s->dest[0], s->linesize, 16) +
> +               s->mecc.sse[1](NULL, s->new_picture->data[1] + s-
> >mb_x * chroma_mb_w + s->mb_y * s->uvlinesize * chroma_mb_h,
> +                              s->dest[1], s->uvlinesize,
> chroma_mb_h) +
> +               s->mecc.sse[1](NULL, s->new_picture->data[2] + s-
> >mb_x * chroma_mb_w + s->mb_y * s->uvlinesize * chroma_mb_h,
> +                              s->dest[2], s->uvlinesize,
> chroma_mb_h);
>        }
>      else
> -        return  sse(s, s->new_picture->data[0] + s->mb_x*16 + s-
> >mb_y*s->linesize*16, s->dest[0], w, h, s->linesize)
> -               +sse(s, s->new_picture->data[1] + s->mb_x*8  + s-
> >mb_y*s->uvlinesize*8,s->dest[1], w>>1, h>>1, s->uvlinesize)
> -               +sse(s, s->new_picture->data[2] + s->mb_x*8  + s-
> >mb_y*s->uvlinesize*8,s->dest[2], w>>1, h>>1, s->uvlinesize);
> +        return  sse(s, s->new_picture->data[0] + s->mb_x * 16 + s-
> >mb_y * s->linesize * 16,
> +                    s->dest[0], w, h, s->linesize) +
> +                sse(s, s->new_picture->data[1] + s->mb_x *
> chroma_mb_w + s->mb_y * s->uvlinesize * chroma_mb_h,
> +                    s->dest[1], w >> s->chroma_x_shift, h >> s-
> >chroma_y_shift, s->uvlinesize) +
> +                sse(s, s->new_picture->data[2] + s->mb_x *
> chroma_mb_w + s->mb_y * s->uvlinesize * chroma_mb_h,
> +                    s->dest[2], w >> s->chroma_x_shift, h >> s-
> >chroma_y_shift, s->uvlinesize);
>  }
> 
>  static int pre_estimate_motion_thread(AVCodecContext *c, void *arg){
> diff --git a/tests/ref/seek/vsynth_lena-mpeg2-422
> b/tests/ref/seek/vsynth_lena-mpeg2-422
> index 06d8f7ac3a..1fc2bf93a0 100644
> --- a/tests/ref/seek/vsynth_lena-mpeg2-422
> +++ b/tests/ref/seek/vsynth_lena-mpeg2-422
> @@ -1,46 +1,46 @@
> -ret: 0         st: 0 flags:1 dts: 0.000000 pts: NOPTS    pos:      0
> size: 17497
> +ret: 0         st: 0 flags:1 dts: 0.000000 pts: NOPTS    pos:      0
> size: 18339
>  ret: 0         st:-1 flags:0  ts:-1.000000
> -ret: 0         st: 0 flags:1 dts: 0.000000 pts: NOPTS    pos:      0
> size: 17497
> +ret: 0         st: 0 flags:1 dts: 0.000000 pts: NOPTS    pos:      0
> size: 18339
>  ret: 0         st:-1 flags:1  ts: 1.894167
> -ret: 0         st: 0 flags:1 dts: 1.840000 pts: NOPTS    pos: 325397
> size: 19967
> +ret: 0         st: 0 flags:1 dts: 1.840000 pts: NOPTS    pos: 329242
> size: 21479
>  ret: 0         st: 0 flags:0  ts: 0.788334
> -ret: 0         st: 0 flags:1 dts: 0.880000 pts: NOPTS    pos: 200747
> size: 22575
> +ret: 0         st: 0 flags:1 dts: 0.880000 pts: NOPTS    pos: 203086
> size: 24774
>  ret:-1         st: 0 flags:1  ts:-0.317499
>  ret:-1         st:-1 flags:0  ts: 2.576668
>  ret: 0         st:-1 flags:1  ts: 1.470835
> -ret: 0         st: 0 flags:1 dts: 1.360000 pts: NOPTS    pos: 265466
> size: 21329
> +ret: 0         st: 0 flags:1 dts: 1.360000 pts: NOPTS    pos: 268154
> size: 22845
>  ret: 0         st: 0 flags:0  ts: 0.365002
> -ret: 0         st: 0 flags:1 dts: 0.400000 pts: NOPTS    pos: 104454
> size: 28984
> +ret: 0         st: 0 flags:1 dts: 0.400000 pts: NOPTS    pos: 108763
> size: 32204
>  ret:-1         st: 0 flags:1  ts:-0.740831
>  ret:-1         st:-1 flags:0  ts: 2.153336
>  ret: 0         st:-1 flags:1  ts: 1.047503
> -ret: 0         st: 0 flags:1 dts: 0.880000 pts: NOPTS    pos: 200747
> size: 22575
> +ret: 0         st: 0 flags:1 dts: 0.880000 pts: NOPTS    pos: 203086
> size: 24774
>  ret: 0         st: 0 flags:0  ts:-0.058330
> -ret: 0         st: 0 flags:1 dts: 0.000000 pts: NOPTS    pos:      0
> size: 17497
> +ret: 0         st: 0 flags:1 dts: 0.000000 pts: NOPTS    pos:      0
> size: 18339
>  ret: 0         st: 0 flags:1  ts: 2.835837
> -ret: 0         st: 0 flags:1 dts: 1.840000 pts: NOPTS    pos: 325397
> size: 19967
> +ret: 0         st: 0 flags:1 dts: 1.840000 pts: NOPTS    pos: 329242
> size: 21479
>  ret: 0         st:-1 flags:0  ts: 1.730004
> -ret: 0         st: 0 flags:1 dts: 1.840000 pts: NOPTS    pos: 325397
> size: 19967
> +ret: 0         st: 0 flags:1 dts: 1.840000 pts: NOPTS    pos: 329242
> size: 21479
>  ret: 0         st:-1 flags:1  ts: 0.624171
> -ret: 0         st: 0 flags:1 dts: 0.400000 pts: NOPTS    pos: 104454
> size: 28984
> +ret: 0         st: 0 flags:1 dts: 0.400000 pts: NOPTS    pos: 108763
> size: 32204
>  ret: 0         st: 0 flags:0  ts:-0.481662
> -ret: 0         st: 0 flags:1 dts: 0.000000 pts: NOPTS    pos:      0
> size: 17497
> +ret: 0         st: 0 flags:1 dts: 0.000000 pts: NOPTS    pos:      0
> size: 18339
>  ret: 0         st: 0 flags:1  ts: 2.412505
> -ret: 0         st: 0 flags:1 dts: 1.840000 pts: NOPTS    pos: 325397
> size: 19967
> +ret: 0         st: 0 flags:1 dts: 1.840000 pts: NOPTS    pos: 329242
> size: 21479
>  ret: 0         st:-1 flags:0  ts: 1.306672
> -ret: 0         st: 0 flags:1 dts: 1.360000 pts: NOPTS    pos: 265466
> size: 21329
> +ret: 0         st: 0 flags:1 dts: 1.360000 pts: NOPTS    pos: 268154
> size: 22845
>  ret: 0         st:-1 flags:1  ts: 0.200839
> -ret: 0         st: 0 flags:1 dts: 0.000000 pts: NOPTS    pos:      0
> size: 17497
> +ret: 0         st: 0 flags:1 dts: 0.000000 pts: NOPTS    pos:      0
> size: 18339
>  ret: 0         st: 0 flags:0  ts:-0.904994
> -ret: 0         st: 0 flags:1 dts: 0.000000 pts: NOPTS    pos:      0
> size: 17497
> +ret: 0         st: 0 flags:1 dts: 0.000000 pts: NOPTS    pos:      0
> size: 18339
>  ret: 0         st: 0 flags:1  ts: 1.989173
> -ret: 0         st: 0 flags:1 dts: 1.840000 pts: NOPTS    pos: 325397
> size: 19967
> +ret: 0         st: 0 flags:1 dts: 1.840000 pts: NOPTS    pos: 329242
> size: 21479
>  ret: 0         st:-1 flags:0  ts: 0.883340
> -ret: 0         st: 0 flags:1 dts: 1.360000 pts: NOPTS    pos: 265466
> size: 21329
> +ret: 0         st: 0 flags:1 dts: 1.360000 pts: NOPTS    pos: 268154
> size: 22845
>  ret:-1         st:-1 flags:1  ts:-0.222493
>  ret:-1         st: 0 flags:0  ts: 2.671674
>  ret: 0         st: 0 flags:1  ts: 1.565841
> -ret: 0         st: 0 flags:1 dts: 1.360000 pts: NOPTS    pos: 265466
> size: 21329
> +ret: 0         st: 0 flags:1 dts: 1.360000 pts: NOPTS    pos: 268154
> size: 22845
>  ret: 0         st:-1 flags:0  ts: 0.460008
> -ret: 0         st: 0 flags:1 dts: 0.880000 pts: NOPTS    pos: 200747
> size: 22575
> +ret: 0         st: 0 flags:1 dts: 0.880000 pts: NOPTS    pos: 203086
> size: 24774
>  ret:-1         st:-1 flags:1  ts:-0.645825
> diff --git a/tests/ref/vsynth/vsynth1-mpeg2-422
> b/tests/ref/vsynth/vsynth1-mpeg2-422
> index e936ba463e..a39b2b4dce 100644
> --- a/tests/ref/vsynth/vsynth1-mpeg2-422
> +++ b/tests/ref/vsynth/vsynth1-mpeg2-422
> @@ -1,4 +1,4 @@
> -6e135a1a27235a320311a932147846b4 *tests/data/fate/vsynth1-mpeg2-
> 422.mpeg2video
> -730780 tests/data/fate/vsynth1-mpeg2-422.mpeg2video
> -0273cd8463d1fc115378748239951560 *tests/data/fate/vsynth1-mpeg2-
> 422.out.rawvideo
> -stddev:   10.27 PSNR: 27.90 MAXDIFF:  162 bytes:  7603200/  7603200
> +651f054730be04257498eeae08b3bdc5 *tests/data/fate/vsynth1-mpeg2-
> 422.mpeg2video
> +855859 tests/data/fate/vsynth1-mpeg2-422.mpeg2video
> +10fd55dbd10b08f9271eb89617766be8 *tests/data/fate/vsynth1-mpeg2-
> 422.out.rawvideo
> +stddev:    9.38 PSNR: 28.68 MAXDIFF:  178 bytes:  7603200/  7603200
> diff --git a/tests/ref/vsynth/vsynth2-mpeg2-422
> b/tests/ref/vsynth/vsynth2-mpeg2-422
> index ec7244f9f9..5da29b4eac 100644
> --- a/tests/ref/vsynth/vsynth2-mpeg2-422
> +++ b/tests/ref/vsynth/vsynth2-mpeg2-422
> @@ -1,4 +1,4 @@
> -b2fa9b73c3547191ecc01b8163abd4e5 *tests/data/fate/vsynth2-mpeg2-
> 422.mpeg2video
> -379164 tests/data/fate/vsynth2-mpeg2-422.mpeg2video
> -704f6a96f93c2409219bd48b74169041 *tests/data/fate/vsynth2-mpeg2-
> 422.out.rawvideo
> -stddev:    4.17 PSNR: 35.73 MAXDIFF:   70 bytes:  7603200/  7603200
> +fcaf6242ca4b706d392e40d9631e3465 *tests/data/fate/vsynth2-mpeg2-
> 422.mpeg2video
> +383946 tests/data/fate/vsynth2-mpeg2-422.mpeg2video
> +474bb259f041bfb971691551f678fd09 *tests/data/fate/vsynth2-mpeg2-
> 422.out.rawvideo
> +stddev:    3.93 PSNR: 36.23 MAXDIFF:   69 bytes:  7603200/  7603200
> diff --git a/tests/ref/vsynth/vsynth3-mpeg2-422
> b/tests/ref/vsynth/vsynth3-mpeg2-422
> index 2247f286e6..e83c23635c 100644
> --- a/tests/ref/vsynth/vsynth3-mpeg2-422
> +++ b/tests/ref/vsynth/vsynth3-mpeg2-422
> @@ -1,4 +1,4 @@
> -4d108b861715f1fa010fd70baea91793 *tests/data/fate/vsynth3-mpeg2-
> 422.mpeg2video
> -68612 tests/data/fate/vsynth3-mpeg2-422.mpeg2video
> -73b16e906d07b6bbccf4b00d4a25302c *tests/data/fate/vsynth3-mpeg2-
> 422.out.rawvideo
> -stddev:    4.02 PSNR: 36.05 MAXDIFF:   46 bytes:    86700/    86700
> +96dc854fc40a6410d4edc387b63ded1a *tests/data/fate/vsynth3-mpeg2-
> 422.mpeg2video
> +75445 tests/data/fate/vsynth3-mpeg2-422.mpeg2video
> +5337fc0bfb789919cb3325a02d48eb82 *tests/data/fate/vsynth3-mpeg2-
> 422.out.rawvideo
> +stddev:    3.24 PSNR: 37.90 MAXDIFF:   27 bytes:    86700/    86700
> diff --git a/tests/ref/vsynth/vsynth_lena-mpeg2-422
> b/tests/ref/vsynth/vsynth_lena-mpeg2-422
> index 5f11d4e7cd..85d598782c 100644
> --- a/tests/ref/vsynth/vsynth_lena-mpeg2-422
> +++ b/tests/ref/vsynth/vsynth_lena-mpeg2-422
> @@ -1,4 +1,4 @@
> -521ec92c0b8672011a43dd13db98c400 *tests/data/fate/vsynth_lena-mpeg2-
> 422.mpeg2video
> -356431 tests/data/fate/vsynth_lena-mpeg2-422.mpeg2video
> -51ca353620f85db8b5b1c56f1a275add *tests/data/fate/vsynth_lena-mpeg2-
> 422.out.rawvideo
> -stddev:    3.15 PSNR: 38.14 MAXDIFF:   49 bytes:  7603200/  7603200
> +87e5c69775b363db649c253050536045 *tests/data/fate/vsynth_lena-mpeg2-
> 422.mpeg2video
> +361341 tests/data/fate/vsynth_lena-mpeg2-422.mpeg2video
> +93cefcf101e6d0814acfaa626a02be90 *tests/data/fate/vsynth_lena-mpeg2-
> 422.out.rawvideo
> +stddev:    2.97 PSNR: 38.67 MAXDIFF:   57 bytes:  7603200/  7603200
> --

LGTM. It fixes the broken FATE tests on new CPUs and it's no longer needed
to run configure with --disable-avx512

Thanks for figuring out the cause of this!

softworkz


More information about the ffmpeg-devel mailing list