[FFmpeg-cvslog] lavfi/delogo: avoid propagation of rounding errors in chroma planes

Jean Delvare git at videolan.org
Wed Jul 3 23:19:19 CEST 2013


ffmpeg | branch: master | Jean Delvare <khali at linux-fr.org> | Tue Jul  2 13:50:02 2013 +0200| [f0bcb13aedcff8b4a454347c634ac41aefab9e86] | committer: Michael Niedermayer

lavfi/delogo: avoid propagation of rounding errors in chroma planes

When operating on subsampled chroma planes, some rounding is taking
place. The left and top borders are rounded down while the width and
height are rounded up, so all rounding is done outward to guarantee the
logo area is fully covered.

The problem is that the width and height are counted from the
unrounded left and top borders, respectively. So if the left or top
border position has indeed been rounded down, and the width or height
needs no rounding (up), the position of the the right or bottom border
will be effectively rounded down, i.e. inward.

The issue can easily be seen with a yuv240p input and
  -vf delogo=45:45:60:40:show=1 -vframes 1 delogo-bug.png
(or virtually any logo area with odd x and y and even width and
height.) The right and bottom chroma borders (in green) are clearly
off.

In order to fix this, the width and height must be adjusted to include
the bits lost in the rounding of the left and top border positions,
respectively, prior to being themselves rounded up.

Signed-off-by: Jean Delvare <khali at linux-fr.org>
Signed-off-by: Michael Niedermayer <michaelni at gmx.at>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=f0bcb13aedcff8b4a454347c634ac41aefab9e86
---

 libavfilter/vf_delogo.c      |    6 +-
 tests/ref/fate/filter-delogo |  218 +++++++++++++++++++++---------------------
 2 files changed, 113 insertions(+), 111 deletions(-)

diff --git a/libavfilter/vf_delogo.c b/libavfilter/vf_delogo.c
index ba35cf5..e882dd5 100644
--- a/libavfilter/vf_delogo.c
+++ b/libavfilter/vf_delogo.c
@@ -246,8 +246,10 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *in)
                      FF_CEIL_RSHIFT(inlink->w, hsub),
                      FF_CEIL_RSHIFT(inlink->h, vsub),
                      sar, s->x>>hsub, s->y>>vsub,
-                     FF_CEIL_RSHIFT(s->w, hsub),
-                     FF_CEIL_RSHIFT(s->h, vsub),
+                     /* Up and left borders were rounded down, inject lost bits
+                      * into width and height to avoid error accumulation */
+                     FF_CEIL_RSHIFT(s->w + (s->x & ((1<<hsub)-1)), hsub),
+                     FF_CEIL_RSHIFT(s->h + (s->y & ((1<<vsub)-1)), vsub),
                      s->band>>FFMIN(hsub, vsub),
                      s->show, direct);
     }
diff --git a/tests/ref/fate/filter-delogo b/tests/ref/fate/filter-delogo
index fc31ce5..80342ee 100644
--- a/tests/ref/fate/filter-delogo
+++ b/tests/ref/fate/filter-delogo
@@ -1,110 +1,110 @@
 #tb 0: 32768/982057
-0,          0,          0,        1,   126720, 0x41c3ebfc
-0,          1,          1,        1,   126720, 0x16dfec9a
-0,          2,          2,        1,   126720, 0x16dfec9a
-0,          3,          3,        1,   126720, 0x16dfec9a
-0,          4,          4,        1,   126720, 0xd390ecdc
-0,          5,          5,        1,   126720, 0xf2eaf468
-0,          6,          6,        1,   126720, 0x2bcef4a8
-0,          7,          7,        1,   126720, 0x996ff488
-0,          8,          8,        1,   126720, 0x5adbb7e4
-0,          9,          9,        1,   126720, 0xce00b8a4
-0,         10,         10,        1,   126720, 0xc752b8e4
-0,         11,         11,        1,   126720, 0xd8c9b8b0
-0,         12,         12,        1,   126720, 0x3003b914
-0,         13,         13,        1,   126720, 0xaf93bb84
-0,         14,         14,        1,   126720, 0x0df4bc04
-0,         15,         15,        1,   126720, 0xe4f7bb90
-0,         16,         16,        1,   126720, 0xf4f0b8f4
-0,         17,         17,        1,   126720, 0x6bbbae4c
-0,         18,         18,        1,   126720, 0x189799b5
-0,         19,         19,        1,   126720, 0xb3aba7b9
-0,         20,         20,        1,   126720, 0xaa58ba49
-0,         21,         21,        1,   126720, 0xd458a85d
-0,         22,         22,        1,   126720, 0xe2f7ab39
-0,         23,         23,        1,   126720, 0xda46aa66
-0,         24,         24,        1,   126720, 0x5a87bca9
-0,         25,         25,        1,   126720, 0x30aea71a
-0,         26,         26,        1,   126720, 0xe7f2eafc
-0,         27,         27,        1,   126720, 0xb181b566
-0,         28,         28,        1,   126720, 0x06fc036b
-0,         29,         29,        1,   126720, 0x5b1184d0
-0,         30,         30,        1,   126720, 0xe0dd0159
-0,         31,         31,        1,   126720, 0x984eb9c2
-0,         32,         32,        1,   126720, 0x18de046e
-0,         33,         33,        1,   126720, 0x7739d63b
-0,         34,         34,        1,   126720, 0xa8aedbe1
-0,         35,         35,        1,   126720, 0x3a8bad65
-0,         36,         36,        1,   126720, 0xa0d879dd
-0,         37,         37,        1,   126720, 0x9880c604
-0,         38,         38,        1,   126720, 0xad34b4e2
-0,         39,         39,        1,   126720, 0x62ece114
-0,         40,         40,        1,   126720, 0x06321e84
-0,         41,         41,        1,   126720, 0xb8a278f7
-0,         42,         42,        1,   126720, 0xf3794872
-0,         43,         43,        1,   126720, 0x40228bd8
-0,         44,         44,        1,   126720, 0xd9eb99be
-0,         45,         45,        1,   126720, 0xcd71085c
-0,         46,         46,        1,   126720, 0x53b50e7d
-0,         47,         47,        1,   126720, 0x115825d5
-0,         48,         48,        1,   126720, 0xadb2d397
-0,         49,         49,        1,   126720, 0xd8c9e7b3
-0,         50,         50,        1,   126720, 0xb8b1e4c6
-0,         51,         51,        1,   126720, 0xcf7102d2
-0,         52,         52,        1,   126720, 0x9458eab9
-0,         53,         53,        1,   126720, 0x9654ee85
-0,         54,         54,        1,   126720, 0xf9c8f16b
-0,         55,         55,        1,   126720, 0x37bb27c6
-0,         56,         56,        1,   126720, 0x01f29e29
-0,         57,         57,        1,   126720, 0x2090dc6b
-0,         58,         58,        1,   126720, 0x3f6fd6cb
-0,         59,         59,        1,   126720, 0x16110602
-0,         60,         60,        1,   126720, 0x8f56b840
-0,         61,         61,        1,   126720, 0x12f44aa7
-0,         62,         62,        1,   126720, 0x8a3b2db5
-0,         63,         63,        1,   126720, 0xea6e4b48
-0,         64,         64,        1,   126720, 0xf72e3057
-0,         65,         65,        1,   126720, 0xbcb28cb0
-0,         66,         66,        1,   126720, 0xd8d08db4
-0,         67,         67,        1,   126720, 0x93cd8232
-0,         68,         68,        1,   126720, 0x58421200
-0,         69,         69,        1,   126720, 0xb9754164
-0,         70,         70,        1,   126720, 0xeb259b9c
-0,         71,         71,        1,   126720, 0xaa726578
-0,         72,         72,        1,   126720, 0xe66825b1
-0,         73,         73,        1,   126720, 0x9742aa58
-0,         74,         74,        1,   126720, 0x8fa5815e
-0,         75,         75,        1,   126720, 0xbaf341c7
-0,         76,         76,        1,   126720, 0x94ed5495
-0,         77,         77,        1,   126720, 0x0c11685f
-0,         78,         78,        1,   126720, 0x9ba46776
-0,         79,         79,        1,   126720, 0x3ee0921d
-0,         80,         80,        1,   126720, 0x736df713
-0,         81,         81,        1,   126720, 0xed1aa7dc
-0,         82,         82,        1,   126720, 0x916661df
-0,         83,         83,        1,   126720, 0xa4e75cb4
-0,         84,         84,        1,   126720, 0xb341408d
-0,         85,         85,        1,   126720, 0x3dbf5bf7
-0,         86,         86,        1,   126720, 0x03c990aa
-0,         87,         87,        1,   126720, 0x4d598768
-0,         88,         88,        1,   126720, 0xfd953b86
-0,         89,         89,        1,   126720, 0xf9796c69
-0,         90,         90,        1,   126720, 0xe125664e
-0,         91,         91,        1,   126720, 0x7afc671f
-0,         92,         92,        1,   126720, 0x5cb8e0d5
-0,         93,         93,        1,   126720, 0x5d7d2928
-0,         94,         94,        1,   126720, 0xa9f8faa8
-0,         95,         95,        1,   126720, 0x2c767188
-0,         96,         96,        1,   126720, 0x0188e449
-0,         97,         97,        1,   126720, 0x8483812a
-0,         98,         98,        1,   126720, 0x54953eb4
-0,         99,         99,        1,   126720, 0x7980503e
-0,        100,        100,        1,   126720, 0xc6931503
-0,        101,        101,        1,   126720, 0xc15613f4
-0,        102,        102,        1,   126720, 0xd59fe8fd
-0,        103,        103,        1,   126720, 0x71ed62b7
-0,        104,        104,        1,   126720, 0x4c154002
-0,        105,        105,        1,   126720, 0x7219bca5
-0,        106,        106,        1,   126720, 0x3a04a755
-0,        107,        107,        1,   126720, 0x0784ad95
-0,        108,        108,        1,   126720, 0x29575bd4
+0,          0,          0,        1,   126720, 0x77a5ebed
+0,          1,          1,        1,   126720, 0x4cc1ec8b
+0,          2,          2,        1,   126720, 0x4cc1ec8b
+0,          3,          3,        1,   126720, 0x4cc1ec8b
+0,          4,          4,        1,   126720, 0x0981eccd
+0,          5,          5,        1,   126720, 0x04fef463
+0,          6,          6,        1,   126720, 0x3dd3f4a3
+0,          7,          7,        1,   126720, 0xab74f483
+0,          8,          8,        1,   126720, 0x5ed7b7db
+0,          9,          9,        1,   126720, 0xd1fcb89b
+0,         10,         10,        1,   126720, 0xcb4eb8db
+0,         11,         11,        1,   126720, 0xdcc5b8a7
+0,         12,         12,        1,   126720, 0x33ffb90b
+0,         13,         13,        1,   126720, 0xb38fbb7b
+0,         14,         14,        1,   126720, 0x11f0bbfb
+0,         15,         15,        1,   126720, 0xe8f3bb87
+0,         16,         16,        1,   126720, 0xf8ecb8eb
+0,         17,         17,        1,   126720, 0x5db2ae48
+0,         18,         18,        1,   126720, 0x4e7999a6
+0,         19,         19,        1,   126720, 0xdb84a7a6
+0,         20,         20,        1,   126720, 0x9c4fba45
+0,         21,         21,        1,   126720, 0xe635a858
+0,         22,         22,        1,   126720, 0xd4eeab35
+0,         23,         23,        1,   126720, 0xc416aa56
+0,         24,         24,        1,   126720, 0x4c7ebca5
+0,         25,         25,        1,   126720, 0x2887a70e
+0,         26,         26,        1,   126720, 0xc978eaf1
+0,         27,         27,        1,   126720, 0x8a29b563
+0,         28,         28,        1,   126720, 0x275a0352
+0,         29,         29,        1,   126720, 0x446484bb
+0,         30,         30,        1,   126720, 0xdbe00151
+0,         31,         31,        1,   126720, 0x5874b9aa
+0,         32,         32,        1,   126720, 0xdeb30460
+0,         33,         33,        1,   126720, 0xc6d2d62a
+0,         34,         34,        1,   126720, 0x9270dbc7
+0,         35,         35,        1,   126720, 0x30e4ad59
+0,         36,         36,        1,   126720, 0x117479cd
+0,         37,         37,        1,   126720, 0x0567c5d2
+0,         38,         38,        1,   126720, 0x87c8b4a5
+0,         39,         39,        1,   126720, 0xe5c5e0d1
+0,         40,         40,        1,   126720, 0x78d61e3f
+0,         41,         41,        1,   126720, 0xda8d787f
+0,         42,         42,        1,   126720, 0xf32547f7
+0,         43,         43,        1,   126720, 0x70bc8b60
+0,         44,         44,        1,   126720, 0x3ad09927
+0,         45,         45,        1,   126720, 0x5d9607d6
+0,         46,         46,        1,   126720, 0x348a0e02
+0,         47,         47,        1,   126720, 0x7d21255c
+0,         48,         48,        1,   126720, 0x308ed32b
+0,         49,         49,        1,   126720, 0x79fbe734
+0,         50,         50,        1,   126720, 0xdc5de409
+0,         51,         51,        1,   126720, 0x4ee00283
+0,         52,         52,        1,   126720, 0x2697ea2e
+0,         53,         53,        1,   126720, 0x0885edeb
+0,         54,         54,        1,   126720, 0xc041f0d8
+0,         55,         55,        1,   126720, 0xa893272e
+0,         56,         56,        1,   126720, 0x55419d4e
+0,         57,         57,        1,   126720, 0xbc47dbb5
+0,         58,         58,        1,   126720, 0x9666d60b
+0,         59,         59,        1,   126720, 0xac5c054a
+0,         60,         60,        1,   126720, 0x4affb780
+0,         61,         61,        1,   126720, 0x2b7349eb
+0,         62,         62,        1,   126720, 0x75592d02
+0,         63,         63,        1,   126720, 0xdb904a83
+0,         64,         64,        1,   126720, 0xf85e2f93
+0,         65,         65,        1,   126720, 0x632f8be8
+0,         66,         66,        1,   126720, 0x96108ce4
+0,         67,         67,        1,   126720, 0xb68e816b
+0,         68,         68,        1,   126720, 0x89ca112f
+0,         69,         69,        1,   126720, 0x4bed40d3
+0,         70,         70,        1,   126720, 0xe4cb9b12
+0,         71,         71,        1,   126720, 0xa4f164ec
+0,         72,         72,        1,   126720, 0xd1aa2554
+0,         73,         73,        1,   126720, 0x0277aa01
+0,         74,         74,        1,   126720, 0x8ea280fd
+0,         75,         75,        1,   126720, 0xbae64170
+0,         76,         76,        1,   126720, 0xaf9b543b
+0,         77,         77,        1,   126720, 0x1b31680a
+0,         78,         78,        1,   126720, 0x7da4671e
+0,         79,         79,        1,   126720, 0x82b791cb
+0,         80,         80,        1,   126720, 0xd2fff6bb
+0,         81,         81,        1,   126720, 0x2395a793
+0,         82,         82,        1,   126720, 0x66586185
+0,         83,         83,        1,   126720, 0x99c55c63
+0,         84,         84,        1,   126720, 0x7e3f403e
+0,         85,         85,        1,   126720, 0x9eda5b9a
+0,         86,         86,        1,   126720, 0x27469047
+0,         87,         87,        1,   126720, 0xaa5b870e
+0,         88,         88,        1,   126720, 0x70423b2a
+0,         89,         89,        1,   126720, 0x70d86c0a
+0,         90,         90,        1,   126720, 0x4bd065f3
+0,         91,         91,        1,   126720, 0xd71f66bb
+0,         92,         92,        1,   126720, 0x5333e081
+0,         93,         93,        1,   126720, 0xdf0b28d6
+0,         94,         94,        1,   126720, 0x6c48fa53
+0,         95,         95,        1,   126720, 0x9438712d
+0,         96,         96,        1,   126720, 0x9910e3ec
+0,         97,         97,        1,   126720, 0xb0ea80dd
+0,         98,         98,        1,   126720, 0x71983e67
+0,         99,         99,        1,   126720, 0x18924fe6
+0,        100,        100,        1,   126720, 0x9ca014b9
+0,        101,        101,        1,   126720, 0x45f013a0
+0,        102,        102,        1,   126720, 0xf697e8a9
+0,        103,        103,        1,   126720, 0x214a626a
+0,        104,        104,        1,   126720, 0xb2873fb5
+0,        105,        105,        1,   126720, 0xfb47bc52
+0,        106,        106,        1,   126720, 0x63b7a708
+0,        107,        107,        1,   126720, 0x1904ad40
+0,        108,        108,        1,   126720, 0x80015b91



More information about the ffmpeg-cvslog mailing list