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[FFmpeg-devel,v3] fbdetile cpu based detiling of framebuffers v03

Message ID 20200629175831.1019-1-hanishkvc@gmail.com
State Superseded
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Series [FFmpeg-devel,v3] fbdetile cpu based detiling of framebuffers v03
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Commit Message

C Hanish Menon June 29, 2020, 5:58 p.m. UTC
v03-20200629IST2208 fbdetile

Added a generic detiling logic, which can be easily configured to
detile many different tiling schemes.

The same is inturn used to detile Intel Tile-Yf layout.

NOTE: This is a full patch, it contains the previous versions also
in it.

v02-20200627IST2331

Unrolled Intel Legacy Tile-Y detiling logic.

Also a consolidated patch file, instead of the previous development
flow based multiple patch files.

v01-20200627IST1308

Implemented Intel Legacy Tile-X and Tile-Y detiling logic

NOTES:

This video filter allows framebuffers which are tiled to be detiled
using logic running on the cpu, into a linear layout.

Currently it supports Intel Legacy Tile-X and Tile-Y layout detiling,
as well as the newer Intel Tile-Yf layouts.

THis should help one to work with frames captured (say using kmsgrab)
on laptops having Intel GPU. This can be done live while capturing
itself, or it can be applied later as a seperate pass.

Tile-X conversion logic has been explicitly cross checked, with Tile-X
based frames. However Tile-Y and Tile-Yf conv logics havent been tested
with Tile-Y | Tile-Yf based frames, but it should potentially get the
job done, based on my current understanding of these layout formats.

TODO1: At a later time have to generate Tile-Y|Yf based frames, and then
cross check the corresponding logic explicitly.

TODO2: May be use OpenGL or Vulcan buffer helper routines to do the
layout conversion. But some online discussions from sometime back seem
to indicate that this path is not fully bug free currently.
---
 Changelog                 |   1 +
 doc/filters.texi          |  74 ++++++
 libavfilter/Makefile      |   1 +
 libavfilter/allfilters.c  |   1 +
 libavfilter/vf_fbdetile.c | 465 ++++++++++++++++++++++++++++++++++++++
 5 files changed, 542 insertions(+)
 create mode 100644 libavfilter/vf_fbdetile.c

Comments

Lynne July 1, 2020, 10:07 a.m. UTC | #1
Jun 29, 2020, 18:58 by hanishkvc@gmail.com:

> v03-20200629IST2208 fbdetile
>
> Added a generic detiling logic, which can be easily configured to
> detile many different tiling schemes.
>
> The same is inturn used to detile Intel Tile-Yf layout.
>
> NOTE: This is a full patch, it contains the previous versions also
> in it.
>
> v02-20200627IST2331
>
> Unrolled Intel Legacy Tile-Y detiling logic.
>
> Also a consolidated patch file, instead of the previous development
> flow based multiple patch files.
>
> v01-20200627IST1308
>
> Implemented Intel Legacy Tile-X and Tile-Y detiling logic
>
> NOTES:
>
> This video filter allows framebuffers which are tiled to be detiled
> using logic running on the cpu, into a linear layout.
>
> Currently it supports Intel Legacy Tile-X and Tile-Y layout detiling,
> as well as the newer Intel Tile-Yf layouts.
>
> THis should help one to work with frames captured (say using kmsgrab)
> on laptops having Intel GPU. This can be done live while capturing
> itself, or it can be applied later as a seperate pass.
>
> Tile-X conversion logic has been explicitly cross checked, with Tile-X
> based frames. However Tile-Y and Tile-Yf conv logics havent been tested
> with Tile-Y | Tile-Yf based frames, but it should potentially get the
> job done, based on my current understanding of these layout formats.
>
> TODO1: At a later time have to generate Tile-Y|Yf based frames, and then
> cross check the corresponding logic explicitly.
>
> TODO2: May be use OpenGL or Vulcan buffer helper routines to do the
> layout conversion. But some online discussions from sometime back seem
> to indicate that this path is not fully bug free currently.
>

Still not happening, I'd like to see this done properly with hwdownload. While what you
have works as a hack, we're not interested in hacks but something that works universally.
As I said before, it can be easily sped up by a factor of 4 or 8 using SIMD, so its
unjustifiable to have this in the codebase as a filter.
C Hanish Menon July 1, 2020, 4:37 p.m. UTC | #2
Hi Lynne,

On Wed, Jul 1, 2020 at 3:37 PM Lynne <dev@lynne.ee> wrote:

> Jun 29, 2020, 18:58 by hanishkvc@gmail.com:
>
> > v03-20200629IST2208 fbdetile
> >
> > Added a generic detiling logic, which can be easily configured to
> > detile many different tiling schemes.
> >
> > The same is inturn used to detile Intel Tile-Yf layout.
> >
> > NOTE: This is a full patch, it contains the previous versions also
> > in it.
> >
> > v02-20200627IST2331
> >
> > Unrolled Intel Legacy Tile-Y detiling logic.
> >
> > Also a consolidated patch file, instead of the previous development
> > flow based multiple patch files.
> >
> > v01-20200627IST1308
> >
> > Implemented Intel Legacy Tile-X and Tile-Y detiling logic
> >
> > NOTES:
> >
> > This video filter allows framebuffers which are tiled to be detiled
> > using logic running on the cpu, into a linear layout.
> >
> > Currently it supports Intel Legacy Tile-X and Tile-Y layout detiling,
> > as well as the newer Intel Tile-Yf layouts.
> >
> > THis should help one to work with frames captured (say using kmsgrab)
> > on laptops having Intel GPU. This can be done live while capturing
> > itself, or it can be applied later as a seperate pass.
> >
> > Tile-X conversion logic has been explicitly cross checked, with Tile-X
> > based frames. However Tile-Y and Tile-Yf conv logics havent been tested
> > with Tile-Y | Tile-Yf based frames, but it should potentially get the
> > job done, based on my current understanding of these layout formats.
> >
> > TODO1: At a later time have to generate Tile-Y|Yf based frames, and then
> > cross check the corresponding logic explicitly.
> >
> > TODO2: May be use OpenGL or Vulcan buffer helper routines to do the
> > layout conversion. But some online discussions from sometime back seem
> > to indicate that this path is not fully bug free currently.
> >
>
> Still not happening, I'd like to see this done properly with hwdownload.
> While what you
> have works as a hack, we're not interested in hacks but something that
> works universally.
> As I said before, it can be easily sped up by a factor of 4 or 8 using
> SIMD, so its
> unjustifiable to have this in the codebase as a filter.
>
>
Can you tell me how this is not universal. Rather by embedding it within
hwdownload, we
will be making it limited to use from a hwcontext, while keeping it has a
seperate filter,
allows one to use it either with a hw context or from any other source. And
also it gives
the flexibility to do it live or offline. So not sure in what sense you
call my current flow
restricted and a possible embedded within hwdownload one has being
universal?

Also I am assuming that gcc + libc is sensible enough to use a appropriate
fast memcpy
with say rep movs or simd load-stores as the case may be based on which cpu
architecture to
which the code is being built. The overhead with FullHD content is
negligible. Beyond that if
required I have structured the generic detile logic which I have
implemented to do parallel detiling
of multiple tiles in step, which could be easily translated into true
parallel detiling in a hw or
multicore setup.
Lynne July 1, 2020, 6:58 p.m. UTC | #3
Jul 1, 2020, 17:37 by hanishkvc@gmail.com:

> Hi Lynne,
>
> On Wed, Jul 1, 2020 at 3:37 PM Lynne <dev@lynne.ee> wrote:
>
>> Jun 29, 2020, 18:58 by hanishkvc@gmail.com:
>>
>> > v03-20200629IST2208 fbdetile
>> >
>> > Added a generic detiling logic, which can be easily configured to
>> > detile many different tiling schemes.
>> >
>> > The same is inturn used to detile Intel Tile-Yf layout.
>> >
>> > NOTE: This is a full patch, it contains the previous versions also
>> > in it.
>> >
>> > v02-20200627IST2331
>> >
>> > Unrolled Intel Legacy Tile-Y detiling logic.
>> >
>> > Also a consolidated patch file, instead of the previous development
>> > flow based multiple patch files.
>> >
>> > v01-20200627IST1308
>> >
>> > Implemented Intel Legacy Tile-X and Tile-Y detiling logic
>> >
>> > NOTES:
>> >
>> > This video filter allows framebuffers which are tiled to be detiled
>> > using logic running on the cpu, into a linear layout.
>> >
>> > Currently it supports Intel Legacy Tile-X and Tile-Y layout detiling,
>> > as well as the newer Intel Tile-Yf layouts.
>> >
>> > THis should help one to work with frames captured (say using kmsgrab)
>> > on laptops having Intel GPU. This can be done live while capturing
>> > itself, or it can be applied later as a seperate pass.
>> >
>> > Tile-X conversion logic has been explicitly cross checked, with Tile-X
>> > based frames. However Tile-Y and Tile-Yf conv logics havent been tested
>> > with Tile-Y | Tile-Yf based frames, but it should potentially get the
>> > job done, based on my current understanding of these layout formats.
>> >
>> > TODO1: At a later time have to generate Tile-Y|Yf based frames, and then
>> > cross check the corresponding logic explicitly.
>> >
>> > TODO2: May be use OpenGL or Vulcan buffer helper routines to do the
>> > layout conversion. But some online discussions from sometime back seem
>> > to indicate that this path is not fully bug free currently.
>> >
>>
>> Still not happening, I'd like to see this done properly with hwdownload.
>> While what you
>> have works as a hack, we're not interested in hacks but something that
>> works universally.
>> As I said before, it can be easily sped up by a factor of 4 or 8 using
>> SIMD, so its
>> unjustifiable to have this in the codebase as a filter.
>>
> Can you tell me how this is not universal. Rather by embedding it within
> hwdownload, we
> will be making it limited to use from a hwcontext, while keeping it has a
> seperate filter,
> allows one to use it either with a hw context or from any other source. And
> also it gives
> the flexibility to do it live or offline. So not sure in what sense you
> call my current flow
> restricted and a possible embedded within hwdownload one has being
> universal?
>

You have absolutely no idea what tiling is used outside of the hwcontext.
No, you can't be clever and just say "write it in the filename".
To do this properly, you'll need to add pixel formats for each tiling format. Which we're
definitely not doing for very low level device specific layouts. Further still, you'll need to
add support for that in libswscale (good luck), because its swscale that will be doing the
conversions, not a filter. Filters understand pixel formats only. And options are not pixel
formats.
And even if you were to add those pixel formats and support for it in libswscale, an implicit
conversion will take place before encoding anyway since no encoder will understand those
pixel formats. So you'll need to add support for encoding such pixel formats directly
without conversion.
But as I said before, we're definitely not going to accept such pixel formats, let alone
all the rest that would be necessary to do this properly. And its a good thing, because
there's a correct solution which doesn't rely on hacks, is so simple and will work for anyone:
just do the conversion while downloading. We already kind of do something similar for
some hwcontexts, and drm is not special in any way. In fact, I don't think the drm hwcontext
is correct in even allowing downloading or mapping of tiled images. Its just that by chance
it works for linear images and it doesn't check the mapping (because AMD doesn't support
modifiers so you have no idea whether something is linear or not, and the person who wrote
the hwcontext was using AMD at the time).
So really, please integrate this into hwcontext_drm.c.
diff mbox series

Patch

diff --git a/Changelog b/Changelog
index a60e7d2eb8..0e03491f6a 100644
--- a/Changelog
+++ b/Changelog
@@ -2,6 +2,7 @@  Entries are sorted chronologically from oldest to youngest within each release,
 releases are sorted from youngest to oldest.
 
 version <next>:
+- fbdetile cpu based framebuffer layout detiling video filter
 - AudioToolbox output device
 - MacCaption demuxer
 
diff --git a/doc/filters.texi b/doc/filters.texi
index 67892e0afb..f7bcae1685 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -12210,6 +12210,80 @@  It accepts the following optional parameters:
 The number of the CUDA device to use
 @end table
 
+@anchor{fbdetile}
+@section fbdetile
+
+Detiles the Framebuffer tile layout into a linear layout using CPU.
+
+It currently supports conversion from Intel legacy tile-x and tile-y as well
+as the newer Intel tile-yf layouts into a linear layout. This is useful if
+one is using kmsgrab and hwdownload to capture a screen which is using one
+of these non-linear layouts.
+
+NOTE: It also provides a generic detiling logic, which can be easily configured
+to detile many different tiling schemes if required, in future. The same is
+used for detiling the intel tile-yf layout. Also sample configuration to handle
+intel tile-x and tile-y using generic detile logic is also shown for reference,
+in the code.
+
+Currently it expects the data to be a 32bit RGB based pixel format. However
+the logic doesnt do any pixel format conversion or so. Later will be enabling
+16bit RGB data also, as the logic is transparent to it at one level.
+
+One could either insert this into the filter chain while capturing itself,
+or else, if it is slowing things down or so, then one could instead insert
+it into the filter chain during playback or transcoding or so.
+
+It supports the following optional parameters
+
+@table @option
+@item type
+Specify which detiling conversion to apply. The supported values are
+@table @var
+@item 0
+intel tile-x to linear conversion (the default)
+@item 1
+intel tile-y to linear conversion.
+@item 2
+intel tile-yf to linear conversion.
+@end table
+@end table
+
+If one wants to convert during capture itself, one could do
+@example
+ffmpeg -f kmsgrab -i - -vf "hwdownload,format=bgr0,fbdetile" OUTPUT
+@end example
+
+However if one wants to convert after the tiled data has been already captured
+@example
+ffmpeg -i INPUT -vf "fbdetile" OUTPUT
+@end example
+@example
+ffplay -i INPUT -vf "fbdetile"
+@end example
+
+NOTE: While transcoding a test 1080p h264 stream, with 276 frames, below was
+the average times taken by the different detile logics.
+@example
+rm out.mp4; time ./ffmpeg -i input.mp4 out.mp4
+rm out.mp4; time ./ffmpeg -i input.mp4 -vf fbdetile=0 out.mp4
+rm out.mp4; time ./ffmpeg -i input.mp4 -vf fbdetile=1 out.mp4
+rm out.mp4; time ./ffmpeg -i input.mp4 -vf fbdetile=2 out.mp4
+@end example
+@table @option
+@item with no fbdetile filter
+it took ~7.28 secs, i5-8th Gen
+it took ~10.1 secs, i7-7th Gen
+@item with fbdetile=0 filter, Intel Tile-X
+it took ~8.69 secs, i5-8th Gen
+it took ~13.3 secs, i7-7th Gen
+@item with fbdetile=1 filter, Intel Tile-Y
+it took ~9.20 secs. i5-8th Gen
+it took ~13.5 secs. i7-7th Gen
+@item with fbdetile=2 filter, Intel Tile-Yf
+it took ~13.8 secs. i7-7th Gen
+@end table
+
 @section hqx
 
 Apply a high-quality magnification filter designed for pixel art. This filter
diff --git a/libavfilter/Makefile b/libavfilter/Makefile
index 5123540653..bdb0c379ae 100644
--- a/libavfilter/Makefile
+++ b/libavfilter/Makefile
@@ -280,6 +280,7 @@  OBJS-$(CONFIG_HWDOWNLOAD_FILTER)             += vf_hwdownload.o
 OBJS-$(CONFIG_HWMAP_FILTER)                  += vf_hwmap.o
 OBJS-$(CONFIG_HWUPLOAD_CUDA_FILTER)          += vf_hwupload_cuda.o
 OBJS-$(CONFIG_HWUPLOAD_FILTER)               += vf_hwupload.o
+OBJS-$(CONFIG_FBDETILE_FILTER)               += vf_fbdetile.o
 OBJS-$(CONFIG_HYSTERESIS_FILTER)             += vf_hysteresis.o framesync.o
 OBJS-$(CONFIG_IDET_FILTER)                   += vf_idet.o
 OBJS-$(CONFIG_IL_FILTER)                     += vf_il.o
diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
index 1183e40267..f8dceb2a88 100644
--- a/libavfilter/allfilters.c
+++ b/libavfilter/allfilters.c
@@ -265,6 +265,7 @@  extern AVFilter ff_vf_hwdownload;
 extern AVFilter ff_vf_hwmap;
 extern AVFilter ff_vf_hwupload;
 extern AVFilter ff_vf_hwupload_cuda;
+extern AVFilter ff_vf_fbdetile;
 extern AVFilter ff_vf_hysteresis;
 extern AVFilter ff_vf_idet;
 extern AVFilter ff_vf_il;
diff --git a/libavfilter/vf_fbdetile.c b/libavfilter/vf_fbdetile.c
new file mode 100644
index 0000000000..80672bffa6
--- /dev/null
+++ b/libavfilter/vf_fbdetile.c
@@ -0,0 +1,465 @@ 
+/*
+ * Copyright (c) 2020 HanishKVC
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/**
+ * @file
+ * Detile the Frame buffer's tile layout using the cpu
+ * Currently it supports detiling of following layouts
+ *     legacy Intel Tile-X
+ *     legacy Intel Tile-Y
+ *     newer Intel Tile-Yf
+ * More tiling layouts can be easily supported by adding configuration data
+ * for the generic detile logic, wrt the required tiling schemes.
+ *
+ */
+
+/*
+ * ToThink|Check: Optimisations
+ *
+ * Does gcc setting used by ffmpeg allows memcpy | stringops inlining,
+ * loop unrolling, better native matching instructions, additional
+ * optimisations, ...
+ *
+ * Does gcc map to optimal memcpy logic, based on the situation it is
+ * used in i.e like
+ *     based on size of transfer, alignment, architecture, etc
+ *     a suitable combination of inlining and or rep movsb and or
+ *     simd load/store and or unrolling and or ...
+ *
+ * If not, may be look at vector_size or intrinsics or appropriate arch
+ * and cpu specific inline asm or ...
+ *
+ */
+
+/*
+ * Performance check results on i7-7500u
+ * Run Type      : Type   : Seconds Max, Min : TSCCnt Min, Max
+ * Non filter run:        :  10.10s, 09.96s  :
+ * fbdetile=0 run: TileX  :  13.34s, 13.10s  :  05.95M, 06.00M
+ * fbdetile=1 run: TileY  :  13.50s, 13.39s  :  06.22M, 06.32M
+ * fbdetile=2 run: TileYf :  13.75s, 13.64s  :  09.66M, 09.84M // Optimised DirChangeList
+ * fbdetile=2 run: TileYf :  13.92s, 13.70s  :  12.63M, 13.40M // Raw DirChangeList
+ * fbdetile=3 run: TileGX :  13.66s, 13.32s  :  06.16M, 06.33M
+ * fbdetile=4 run: TileGY :  13.73s, 13.51s  :  08.40M, 08.63M
+ */
+
+#include "libavutil/avassert.h"
+#include "libavutil/imgutils.h"
+#include "libavutil/opt.h"
+#include "avfilter.h"
+#include "formats.h"
+#include "internal.h"
+#include "video.h"
+
+#define DEBUG_PERF 1
+#ifdef DEBUG_PERF
+#include <x86intrin.h>
+uint64_t perfTime = 0;
+int perfCnt = 0;
+#endif
+
+enum FilterMode {
+    TYPE_INTELX,
+    TYPE_INTELY,
+    TYPE_INTELYF,
+    TYPE_INTELGX,
+    TYPE_INTELGY,
+    NB_TYPE
+};
+
+typedef struct FBDetileContext {
+    const AVClass *class;
+    int width, height;
+    int type;
+} FBDetileContext;
+
+#define OFFSET(x) offsetof(FBDetileContext, x)
+#define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
+static const AVOption fbdetile_options[] = {
+    { "type", "set framebuffer format_modifier type", OFFSET(type), AV_OPT_TYPE_INT, {.i64=TYPE_INTELX}, 0, NB_TYPE-1, FLAGS, "type" },
+        { "intelx", "Intel Tile-X layout", 0, AV_OPT_TYPE_CONST, {.i64=TYPE_INTELX}, INT_MIN, INT_MAX, FLAGS, "type" },
+        { "intely", "Intel Tile-Y layout", 0, AV_OPT_TYPE_CONST, {.i64=TYPE_INTELY}, INT_MIN, INT_MAX, FLAGS, "type" },
+        { "intelyf", "Intel Tile-Yf layout", 0, AV_OPT_TYPE_CONST, {.i64=TYPE_INTELYF}, INT_MIN, INT_MAX, FLAGS, "type" },
+        { "intelgx", "Intel Tile-X layout, GenericDetile", 0, AV_OPT_TYPE_CONST, {.i64=TYPE_INTELGX}, INT_MIN, INT_MAX, FLAGS, "type" },
+        { "intelgy", "Intel Tile-Y layout, GenericDetile", 0, AV_OPT_TYPE_CONST, {.i64=TYPE_INTELGY}, INT_MIN, INT_MAX, FLAGS, "type" },
+    { NULL }
+};
+
+AVFILTER_DEFINE_CLASS(fbdetile);
+
+static av_cold int init(AVFilterContext *ctx)
+{
+    FBDetileContext *fbdetile = ctx->priv;
+
+    if (fbdetile->type == TYPE_INTELX) {
+        fprintf(stderr,"INFO:fbdetile:init: Intel tile-x to linear\n");
+    } else if (fbdetile->type == TYPE_INTELY) {
+        fprintf(stderr,"INFO:fbdetile:init: Intel tile-y to linear\n");
+    } else if (fbdetile->type == TYPE_INTELYF) {
+        fprintf(stderr,"INFO:fbdetile:init: Intel tile-yf to linear\n");
+    } else if (fbdetile->type == TYPE_INTELGX) {
+        fprintf(stderr,"INFO:fbdetile:init: Intel tile-x to linear, using generic detile\n");
+    } else if (fbdetile->type == TYPE_INTELGY) {
+        fprintf(stderr,"INFO:fbdetile:init: Intel tile-y to linear, using generic detile\n");
+    } else {
+        fprintf(stderr,"DBUG:fbdetile:init: Unknown Tile format specified, shouldnt reach here\n");
+    }
+    fbdetile->width = 1920;
+    fbdetile->height = 1080;
+    return 0;
+}
+
+static int query_formats(AVFilterContext *ctx)
+{
+    // Currently only RGB based 32bit formats are specified
+    // TODO: Technically the logic is transparent to 16bit RGB formats also to a great extent
+    static const enum AVPixelFormat pix_fmts[] = {AV_PIX_FMT_RGB0, AV_PIX_FMT_0RGB, AV_PIX_FMT_BGR0, AV_PIX_FMT_0BGR,
+                                                  AV_PIX_FMT_RGBA, AV_PIX_FMT_ARGB, AV_PIX_FMT_BGRA, AV_PIX_FMT_ABGR,
+                                                  AV_PIX_FMT_NONE};
+    AVFilterFormats *fmts_list;
+
+    fmts_list = ff_make_format_list(pix_fmts);
+    if (!fmts_list)
+        return AVERROR(ENOMEM);
+    return ff_set_common_formats(ctx, fmts_list);
+}
+
+static int config_props(AVFilterLink *inlink)
+{
+    AVFilterContext *ctx = inlink->dst;
+    FBDetileContext *fbdetile = ctx->priv;
+
+    fbdetile->width = inlink->w;
+    fbdetile->height = inlink->h;
+    fprintf(stderr,"DBUG:fbdetile:config_props: %d x %d\n", fbdetile->width, fbdetile->height);
+
+    return 0;
+}
+
+static void detile_intelx(AVFilterContext *ctx, int w, int h,
+                                uint8_t *dst, int dstLineSize,
+                          const uint8_t *src, int srcLineSize)
+{
+    // Offsets and LineSize are in bytes
+    int tileW = 128; // For a 32Bit / Pixel framebuffer, 512/4
+    int tileH = 8;
+
+    if (w*4 != srcLineSize) {
+        fprintf(stderr,"DBUG:fbdetile:intelx: w%dxh%d, dL%d, sL%d\n", w, h, dstLineSize, srcLineSize);
+        fprintf(stderr,"ERRR:fbdetile:intelx: dont support LineSize | Pitch going beyond width\n");
+    }
+    int sO = 0;
+    int dX = 0;
+    int dY = 0;
+    int nTRows = (w*h)/tileW;
+    int cTR = 0;
+    while (cTR < nTRows) {
+        int dO = dY*dstLineSize + dX*4;
+#ifdef DEBUG_FBTILE
+        fprintf(stderr,"DBUG:fbdetile:intelx: dX%d dY%d, sO%d, dO%d\n", dX, dY, sO, dO);
+#endif
+        memcpy(dst+dO+0*dstLineSize, src+sO+0*512, 512);
+        memcpy(dst+dO+1*dstLineSize, src+sO+1*512, 512);
+        memcpy(dst+dO+2*dstLineSize, src+sO+2*512, 512);
+        memcpy(dst+dO+3*dstLineSize, src+sO+3*512, 512);
+        memcpy(dst+dO+4*dstLineSize, src+sO+4*512, 512);
+        memcpy(dst+dO+5*dstLineSize, src+sO+5*512, 512);
+        memcpy(dst+dO+6*dstLineSize, src+sO+6*512, 512);
+        memcpy(dst+dO+7*dstLineSize, src+sO+7*512, 512);
+        dX += tileW;
+        if (dX >= w) {
+            dX = 0;
+            dY += 8;
+        }
+        sO = sO + 8*512;
+        cTR += 8;
+    }
+}
+
+/*
+ * Intel Legacy Tile-Y layout conversion support
+ *
+ * currently done in a simple dumb way. Two low hanging optimisations
+ * that could be readily applied are
+ *
+ * a) unrolling the inner for loop
+ *    --- Given small size memcpy, should help, DONE
+ *
+ * b) using simd based 128bit loading and storing along with prefetch
+ *    hinting.
+ *
+ *    TOTHINK|CHECK: Does memcpy already does this and more if situation
+ *    is right?!
+ *
+ *    As code (or even intrinsics) would be specific to each architecture,
+ *    avoiding for now. Later have to check if vector_size attribute and
+ *    corresponding implementation by gcc can handle different architectures
+ *    properly, such that it wont become worse than memcpy provided for that
+ *    architecture.
+ *
+ * Or maybe I could even merge the two intel detiling logics into one, as
+ * the semantic and flow is almost same for both logics.
+ *
+ */
+static void detile_intely(AVFilterContext *ctx, int w, int h,
+                                uint8_t *dst, int dstLineSize,
+                          const uint8_t *src, int srcLineSize)
+{
+    // Offsets and LineSize are in bytes
+    int tileW = 4; // For a 32Bit / Pixel framebuffer, 16/4
+    int tileH = 32;
+
+    if (w*4 != srcLineSize) {
+        fprintf(stderr,"DBUG:fbdetile:intely: w%dxh%d, dL%d, sL%d\n", w, h, dstLineSize, srcLineSize);
+        fprintf(stderr,"ERRR:fbdetile:intely: dont support LineSize | Pitch going beyond width\n");
+    }
+    int sO = 0;
+    int dX = 0;
+    int dY = 0;
+    int nTRows = (w*h)/tileW;
+    int cTR = 0;
+    while (cTR < nTRows) {
+        int dO = dY*dstLineSize + dX*4;
+#ifdef DEBUG_FBTILE
+        fprintf(stderr,"DBUG:fbdetile:intely: dX%d dY%d, sO%d, dO%d\n", dX, dY, sO, dO);
+#endif
+
+        memcpy(dst+dO+0*dstLineSize, src+sO+0*16, 16);
+        memcpy(dst+dO+1*dstLineSize, src+sO+1*16, 16);
+        memcpy(dst+dO+2*dstLineSize, src+sO+2*16, 16);
+        memcpy(dst+dO+3*dstLineSize, src+sO+3*16, 16);
+        memcpy(dst+dO+4*dstLineSize, src+sO+4*16, 16);
+        memcpy(dst+dO+5*dstLineSize, src+sO+5*16, 16);
+        memcpy(dst+dO+6*dstLineSize, src+sO+6*16, 16);
+        memcpy(dst+dO+7*dstLineSize, src+sO+7*16, 16);
+        memcpy(dst+dO+8*dstLineSize, src+sO+8*16, 16);
+        memcpy(dst+dO+9*dstLineSize, src+sO+9*16, 16);
+        memcpy(dst+dO+10*dstLineSize, src+sO+10*16, 16);
+        memcpy(dst+dO+11*dstLineSize, src+sO+11*16, 16);
+        memcpy(dst+dO+12*dstLineSize, src+sO+12*16, 16);
+        memcpy(dst+dO+13*dstLineSize, src+sO+13*16, 16);
+        memcpy(dst+dO+14*dstLineSize, src+sO+14*16, 16);
+        memcpy(dst+dO+15*dstLineSize, src+sO+15*16, 16);
+        memcpy(dst+dO+16*dstLineSize, src+sO+16*16, 16);
+        memcpy(dst+dO+17*dstLineSize, src+sO+17*16, 16);
+        memcpy(dst+dO+18*dstLineSize, src+sO+18*16, 16);
+        memcpy(dst+dO+19*dstLineSize, src+sO+19*16, 16);
+        memcpy(dst+dO+20*dstLineSize, src+sO+20*16, 16);
+        memcpy(dst+dO+21*dstLineSize, src+sO+21*16, 16);
+        memcpy(dst+dO+22*dstLineSize, src+sO+22*16, 16);
+        memcpy(dst+dO+23*dstLineSize, src+sO+23*16, 16);
+        memcpy(dst+dO+24*dstLineSize, src+sO+24*16, 16);
+        memcpy(dst+dO+25*dstLineSize, src+sO+25*16, 16);
+        memcpy(dst+dO+26*dstLineSize, src+sO+26*16, 16);
+        memcpy(dst+dO+27*dstLineSize, src+sO+27*16, 16);
+        memcpy(dst+dO+28*dstLineSize, src+sO+28*16, 16);
+        memcpy(dst+dO+29*dstLineSize, src+sO+29*16, 16);
+        memcpy(dst+dO+30*dstLineSize, src+sO+30*16, 16);
+        memcpy(dst+dO+31*dstLineSize, src+sO+31*16, 16);
+
+        dX += tileW;
+        if (dX >= w) {
+            dX = 0;
+            dY += 32;
+        }
+        sO = sO + 32*16;
+        cTR += 32;
+    }
+}
+
+/*
+ * Generic detile logic
+ */
+
+struct changeEntry {
+    int posOffset;
+    int xDelta;
+    int yDelta;
+};
+
+// Settings for Intel Tile-Yf framebuffer layout
+// May need to swap the 4 pixel wide subtile, have to check doc bit more
+int yfBytesPerPixel = 4; // Assumes each pixel is 4 bytes
+int yfSubTileWidth = 4;
+#ifdef RAWDIRCHANGELIST_FORREFERENCE
+int yfSubTileHeight = 4;
+struct changeEntry yfChanges[] = { {4, 0, 4}, {8, 4, -4}, {16, -4, 4}, {32, 4, -12} };
+int yfNumChanges = 4;
+#else
+int yfSubTileHeight = 8;
+struct changeEntry yfChanges[] = { {8, 4, 0}, {16, -4, 8}, {32, 4, -8} };
+int yfNumChanges = 3;
+#endif
+int yfSubTileWidthBytes = 16; //subTileWidth*bytesPerPixel
+int yfTileHeight = 16;
+// Setting for Intel Tile-X framebuffer layout
+struct changeEntry txChanges[] = { {8, 128, 0} };
+int txBytesPerPixel = 4; // Assumes each pixel is 4 bytes
+int txSubTileWidth = 128;
+int txSubTileHeight = 8;
+int txSubTileWidthBytes = 512; //subTileWidth*bytesPerPixel
+int txTileHeight = 8;
+int txNumChanges = 1;
+// Setting for Intel Tile-Y framebuffer layout
+struct changeEntry tyChanges[] = { {32, 4, 0} };
+int tyBytesPerPixel = 4; // Assumes each pixel is 4 bytes
+int tySubTileWidth = 4;
+int tySubTileHeight = 32;
+int tySubTileWidthBytes = 16; //subTileWidth*bytesPerPixel
+int tyTileHeight = 32;
+int tyNumChanges = 1;
+
+static void detile_generic(AVFilterContext *ctx, int w, int h,
+                                  uint8_t *dst, int dstLineSize,
+                            const uint8_t *src, int srcLineSize,
+                            int bytesPerPixel,
+                            int subTileWidth, int subTileHeight, int subTileWidthBytes, int tileHeight,
+                            int numChanges, struct changeEntry *changes)
+{
+
+    if (w*bytesPerPixel != srcLineSize) {
+        fprintf(stderr,"DBUG:fbdetile:generic: w%dxh%d, dL%d, sL%d\n", w, h, dstLineSize, srcLineSize);
+        fprintf(stderr,"ERRR:fbdetile:generic: dont support LineSize | Pitch going beyond width\n");
+    }
+    int sO = 0;
+    int dX = 0;
+    int dY = 0;
+    int nSTRows = (w*h)/subTileWidth;
+    int cSTR = 0;
+    while (cSTR < nSTRows) {
+        int dO = dY*dstLineSize + dX*bytesPerPixel;
+#ifdef DEBUG_FBTILE
+        fprintf(stderr,"DBUG:fbdetile:generic: dX%d dY%d, sO%d, dO%d\n", dX, dY, sO, dO);
+#endif
+
+	// As most tiling layouts have a minimum subtile of 4x4, if I remember correctly,
+	// so this loop could be unrolled to be multiples of 4, and speed up a bit.
+	// However if one unrolls to 4 times, then a tiling involving 3x3 or 2x2 wont
+	// be handlable. For now leaving it has fully generic.
+        for (int k = 0; k < subTileHeight; k++) {
+            memcpy(dst+dO+k*dstLineSize, src+sO+k*subTileWidthBytes, subTileWidthBytes);
+        }
+        sO = sO + subTileHeight*subTileWidthBytes;
+
+        cSTR += subTileHeight;
+        for (int i=numChanges-1; i>=0; i--) {
+            if ((cSTR%changes[i].posOffset) == 0) {
+                dX += changes[i].xDelta;
+                dY += changes[i].yDelta;
+		break;
+            }
+        }
+        if (dX >= w) {
+            dX = 0;
+            dY += tileHeight;
+        }
+    }
+}
+
+static int filter_frame(AVFilterLink *inlink, AVFrame *in)
+{
+    AVFilterContext *ctx = inlink->dst;
+    FBDetileContext *fbdetile = ctx->priv;
+    AVFilterLink *outlink = ctx->outputs[0];
+    AVFrame *out;
+
+    out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
+    if (!out) {
+        av_frame_free(&in);
+        return AVERROR(ENOMEM);
+    }
+    av_frame_copy_props(out, in);
+
+#ifdef DEBUG_PERF
+    uint64_t perfStart = __rdtsc();
+#endif
+    if (fbdetile->type == TYPE_INTELX) {
+        detile_intelx(ctx, fbdetile->width, fbdetile->height,
+                      out->data[0], out->linesize[0],
+                      in->data[0], in->linesize[0]);
+    } else if (fbdetile->type == TYPE_INTELY) {
+        detile_intely(ctx, fbdetile->width, fbdetile->height,
+                      out->data[0], out->linesize[0],
+                      in->data[0], in->linesize[0]);
+    } else if (fbdetile->type == TYPE_INTELYF) {
+        detile_generic(ctx, fbdetile->width, fbdetile->height,
+                        out->data[0], out->linesize[0],
+                        in->data[0], in->linesize[0],
+                        yfBytesPerPixel, yfSubTileWidth, yfSubTileHeight, yfSubTileWidthBytes, yfTileHeight,
+                        yfNumChanges, yfChanges);
+    } else if (fbdetile->type == TYPE_INTELGX) {
+        detile_generic(ctx, fbdetile->width, fbdetile->height,
+                        out->data[0], out->linesize[0],
+                        in->data[0], in->linesize[0],
+                        txBytesPerPixel, txSubTileWidth, txSubTileHeight, txSubTileWidthBytes, txTileHeight,
+                        txNumChanges, txChanges);
+    } else if (fbdetile->type == TYPE_INTELGY) {
+        detile_generic(ctx, fbdetile->width, fbdetile->height,
+                        out->data[0], out->linesize[0],
+                        in->data[0], in->linesize[0],
+                        tyBytesPerPixel, tySubTileWidth, tySubTileHeight, tySubTileWidthBytes, tyTileHeight,
+                        tyNumChanges, tyChanges);
+    }
+#ifdef DEBUG_PERF
+    uint64_t perfEnd = __rdtsc();
+    perfTime += (perfEnd - perfStart);
+    perfCnt += 1;
+#endif
+
+    av_frame_free(&in);
+    return ff_filter_frame(outlink, out);
+}
+
+static av_cold void uninit(AVFilterContext *ctx)
+{
+#ifdef DEBUG_PERF
+    fprintf(stderr, "DBUG:fbdetile:uninit:perf: AvgTSCCnt %ld\n", perfTime/perfCnt);
+#endif
+}
+
+static const AVFilterPad fbdetile_inputs[] = {
+    {
+        .name         = "default",
+        .type         = AVMEDIA_TYPE_VIDEO,
+        .config_props = config_props,
+        .filter_frame = filter_frame,
+    },
+    { NULL }
+};
+
+static const AVFilterPad fbdetile_outputs[] = {
+    {
+        .name = "default",
+        .type = AVMEDIA_TYPE_VIDEO,
+    },
+    { NULL }
+};
+
+AVFilter ff_vf_fbdetile = {
+    .name          = "fbdetile",
+    .description   = NULL_IF_CONFIG_SMALL("Detile Framebuffer using CPU"),
+    .priv_size     = sizeof(FBDetileContext),
+    .init          = init,
+    .uninit        = uninit,
+    .query_formats = query_formats,
+    .inputs        = fbdetile_inputs,
+    .outputs       = fbdetile_outputs,
+    .priv_class    = &fbdetile_class,
+};