[FFmpeg-devel] [PATCH] avcodec[/format]/webpenc: use WebPAnimEncoder API to generate animated WebP
Michael Niedermayer
michaelni at gmx.at
Fri May 15 04:20:56 CEST 2015
On Fri, May 15, 2015 at 01:29:19AM +0000, Urvang Joshi wrote:
> On Fri, May 8, 2015 at 8:22 AM Michael Niedermayer <michaelni at gmx.at> wrote:
>
> > On Thu, May 07, 2015 at 09:28:43PM +0000, Urvang Joshi wrote:
> > > On Thu, Apr 30, 2015 at 12:05 PM Michael Niedermayer <michaelni at gmx.at>
> > > wrote:
> > >
> > > > On Wed, Apr 29, 2015 at 11:53:40PM +0000, Urvang Joshi wrote:
> > > > > On Mon, Apr 27, 2015 at 5:03 PM Michael Niedermayer <
> > michaelni at gmx.at>
> > > > > wrote:
> > > > >
> > > > > > On Mon, Apr 27, 2015 at 10:18:52PM +0000, Urvang Joshi wrote:
> > > > > > > On Thu, Apr 23, 2015 at 2:51 PM Michael Niedermayer <
> > > > michaelni at gmx.at>
> > > > > > > wrote:
> > > > > > >
> > > > > > > > On Thu, Apr 16, 2015 at 10:40:14PM +0000, Urvang Joshi wrote:
> > > > > > > > > On Thu, Apr 16, 2015 at 3:09 PM James Almer <
> > jamrial at gmail.com>
> > > > > > wrote:
> > > > > > > > >
> > > > > > > > > > On 16/04/15 4:18 PM, Urvang Joshi wrote:
> > > > > > > > > > > Hi,
> > > > > > > > > > > Here's the patch without whitespace changes.
> > > > > > > > > > >
> > > > > > > > > > > Thanks,
> > > > > > > > > > > Urvang
> > > > > > > > > >
> > > > > > > > > > This patch doesn't apply cleanly. Looks like something
> > weird
> > > > with
> > > > > > the
> > > > > > > > > > indentation still.
> > > > > > > > > > Was this patch handmade? It says the hash for libwebpenc.c
> > is
> > > > > > 95d56ac
> > > > > > > > > > (same as git head),
> > > > > > > > > > but the contents of the patch don't match.
> > > > > > > > > >
> > > > > > > > >
> > > > > > > > > Sorry, I should have mentioned that it was created with
> > > > > > > > > "--ignore-all-space" option, so using the same option when
> > > > applying
> > > > > > the
> > > > > > > > > patch would have worked.
> > > > > > > > >
> > > > > > > > > But to avoid any confusion, here's the re-created patch, that
> > > > should
> > > > > > > > apply
> > > > > > > > > cleanly with just 'git am'.
> > > > > > > > >
> > > > > > > > >
> > > > > > > > > >
> > > > > > > > > > After fixing the conflicts and compiling the patch seems to
> > > > work,
> > > > > > but
> > > > > > > > the
> > > > > > > > > > resulting
> > > > > > > > > > animated webp files are smaller than those using the native
> > > > muxer
> > > > > > using
> > > > > > > > > > the default
> > > > > > > > > > encoding and muxing settings.
> > > > > > > > > > Is this because the muxing done by libwebpmux is
> > different, or
> > > > are
> > > > > > the
> > > > > > > > > > quality defaults
> > > > > > > > > > changed in any way when using this codepath? If the former
> > then
> > > > > > that's
> > > > > > > > > > pretty good, but
> > > > > > > > > > if the latter then it should probably be fixed.
> > > > > > > > > >
> > > > > > > > >
> > > > > > > > > Short answer: muxing done by libwebpmux is different, so it's
> > > > > > expected
> > > > > > > > that
> > > > > > > > > it generates smaller WebP files.
> > > > > > > > >
> > > > > > > > > Detailed answer:
> > > > > > > > > The native muxer is naive, and it always uses X offset and Y
> > > > offset
> > > > > > of 0
> > > > > > > > > for all frames. This means the full width x height of all
> > frames
> > > > are
> > > > > > > > > encoded.
> > > > > > > >
> > > > > > > > > libwebpmux muxer is smart on the other hand: for example, it
> > only
> > > > > > encodes
> > > > > > > > > the part of the frame which has changed from previous frame.
> > > > > > > > > This and other optimizations result in smaller WebP files.
> > > > > > > >
> > > > > > > > can you show some PSNR vs filesize information ?
> > > > > > > >
> > > > > > >
> > > > > > > As explained below, we aren't changing the underlying encoder --
> > > > only the
> > > > > > > muxer is being changed.
> > > > > > >
> > > > > > >
> > > > > > > >
> > > > > > > >
> > > > > > > > >
> > > > > > > > > Thanks,
> > > > > > > > > Urvang
> > > > > > > > >
> > > > > > > > >
> > > > > > > > > > _______________________________________________
> > > > > > > > > > ffmpeg-devel mailing list
> > > > > > > > > > ffmpeg-devel at ffmpeg.org
> > > > > > > > > > http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
> > > > > > > > > >
> > > > > > > >
> > > > > > > > > configure | 5 ++
> > > > > > > > > libavcodec/libwebpenc.c | 93
> > > > > > > > +++++++++++++++++++++++++++++++++++++++++++-----
> > > > > > > > > libavformat/webpenc.c | 44 ++++++++++++++++++++++
> > > > > > > >
> > > > > > > > why are there changes to libavformat in a patch changing an
> > > > encoder?
> > > > > > > >
> > > > > > >
> > > > > > > Note that WebPAnimEncoder API used now internally uses WebP
> > encoder
> > > > and
> > > > > > > WebP muxer.
> > > > > > > Earlier, ffmpeg was using WebP encoder with its native muxer.
> > > > > > >
> > > > > > > So, we are only changing the muxer here, the underlying encoder
> > is
> > > > still
> > > > > > > the WebPEncoder as earlier.
> > > > > >
> > > > > > Ok, so the patch adds many #ifs to both the muxer and
> > > > > > encoder, and there are more changes in the encoder than the muxer
> > > > > > the commit message which is 1 single line only speaks about the
> > encoder
> > > > > > and the patch is only about the muxer.
> > > > > > Did i understand it correctly this time ?
> > > > > >
> > > > > > assuming iam not entirely wrong here.
> > > > > > First question is what does the patch actually try to achive ?
> > > > > > replace a native muxer by a new external dependancy ?
> > > > > > if so, why would we want that ?
> > > > > >
> > > > >
> > > > > In theory, here are some of the optimizations that AnimEncoder API
> > (if
> > > > > available) does to be more efficient than native muxer:
> > > > > - Pick the best dispose/blend method combination for each frame.
> > > > > - Based on the dispose/blend method, encode only a sub-rectangle of
> > the
> > > > > frame that has changed from the previous (disposed) frame.
> > > > > - If some pixels in current frame match the corresponding pixels in
> > the
> > > > > previous frame, possibly turn them into transparent pixels (so that
> > they
> > > > > see through the previous frame's pixel), if that improves
> > compression.
> > > > > - Optionally, it can also insert keyframes at regular intervals (not
> > used
> > > > > in this patch; but I plan to add a command-line option to allow this
> > in
> > > > > future).
> > > >
> > > > lets try to agree on terminology first:
> > > > Code which compresses that rectangular area of pixels called
> > > > a picture or frame into a compressed bitstream is called an encoder
> > > > deciding how to encode a frame, frame area or pixel is all encoder
> > > > side.
> > > > In that light comparing "the native muxer" against AnimEncoder API
> > > > which does all kinds of smart encoder steps is very odd thats like
> > > > comparing debian against the linux kernel aka it makes no sense at all
> > > >
> > >
> > > Sorry if this wasn't clear.
> > > To be precise, I was comparing "WebPEncode + Native muxer" to
> > "AnimEncoder"
> > > (which is nothing but WebPEncode + libwebpmux).
> > >
> > >
> > > >
> > > > 2nd our encoder supports reusing pixels from the previous frame.
> > > > AnimEncoder might be better at it or it might be worse but its not a
> > > > feature that isnt already supported
> > > > the feature is tuned by the cr_threshold / cr_size options as i
> > > > said previously.
> > > >
> > > > now if AnimEncoder is better than what we have ATM, i _do_ want it
> > > > supported but do NOT add this code with #ifdefs in the existing
> > > > encoder.
> > > > create a new file, and move the code into it.
> > >
> > >
> > > I can investigate how feasible the splitting is. My concerns with
> > splitting
> > > into two files are:
> >
> > > - There is some common code which will be duplicated in the two files.
> >
> > common parts could be put in a common file and/or shared
> >
>
> Just split the two encoders as well as muxers in separate files (with
> common code in "_common.[hc]" files).
>
> Please take another look.
its better but you are ignoring several things that where said
[...]
> Changelog | 1
> configure | 5
> libavcodec/Makefile | 3
> libavcodec/libwebpenc.c | 281 +-----------------------------------
> libavcodec/libwebpenc_animencoder.c | 146 ++++++++++++++++++
> libavcodec/libwebpenc_common.c | 261 +++++++++++++++++++++++++++++++++
> libavcodec/libwebpenc_common.h | 98 ++++++++++++
> libavformat/Makefile | 3
> libavformat/webpenc.c | 58 ++-----
> libavformat/webpenc_animencoder.c | 68 ++++++++
> libavformat/webpenc_common.c | 38 ++++
> libavformat/webpenc_common.h | 61 +++++++
> 12 files changed, 710 insertions(+), 313 deletions(-)
> 210cc12f7bd486f8ca4e0ae3a799b27acfc0369f split_files.ffmpeg_animated_webp.patch
> From 745a2735420271b287a0ed3a1d58b06d1bc36749 Mon Sep 17 00:00:00 2001
> From: Urvang Joshi <urvang at google.com>
> Date: Thu, 16 Apr 2015 15:21:59 -0700
> Subject: [PATCH] WebP encoder and muxer: use WebPAnimEncoder API when
> available.
The moving of code needs to be split out into a seperate patch
the changes to libavformat need to be put into a patch seperate
of the libavcodec changes
[...]
> @@ -782,7 +782,8 @@ OBJS-$(CONFIG_LIBVPX_VP8_ENCODER) += libvpxenc.o
> OBJS-$(CONFIG_LIBVPX_VP9_DECODER) += libvpxdec.o libvpx.o
> OBJS-$(CONFIG_LIBVPX_VP9_ENCODER) += libvpxenc.o libvpx.o
> OBJS-$(CONFIG_LIBWAVPACK_ENCODER) += libwavpackenc.o
> -OBJS-$(CONFIG_LIBWEBP_ENCODER) += libwebpenc.o
> +OBJS-$(CONFIG_LIBWEBP_ENCODER) += libwebpenc_common.o
> +OBJS-$(CONFIG_LIBWEBP_ENCODER) += libwebpenc.o libwebpenc_animencoder.o
each encoder should use a seperate CONFIG_ identifer
> OBJS-$(CONFIG_LIBX264_ENCODER) += libx264.o
> OBJS-$(CONFIG_LIBX265_ENCODER) += libx265.o
> OBJS-$(CONFIG_LIBXAVS_ENCODER) += libxavs.o
> diff --git a/libavcodec/libwebpenc.c b/libavcodec/libwebpenc.c
> index 95d56ac..5bfceb9 100644
> --- a/libavcodec/libwebpenc.c
> +++ b/libavcodec/libwebpenc.c
> @@ -21,254 +21,31 @@
>
> /**
> * @file
> - * WebP encoder using libwebp
> + * WebP encoder using libwebp (WebPEncode API)
> */
>
> -#include <webp/encode.h>
> +#include "libwebpenc_common.h"
>
> -#include "libavutil/common.h"
> -#include "libavutil/frame.h"
> -#include "libavutil/imgutils.h"
> -#include "libavutil/opt.h"
> -#include "avcodec.h"
> -#include "internal.h"
> +#ifndef USE_WEBP_ANIMENCODER
[...]
> +
> +#endif // USE_WEBP_ANIMENCODER
> diff --git a/libavcodec/libwebpenc_animencoder.c b/libavcodec/libwebpenc_animencoder.c
conditional compilation of files should be done at the
Makefile/configure level not by wraping the whole file in a ifdef
[...]
> diff --git a/libavformat/webpenc.c b/libavformat/webpenc.c
> index ee110de..29f718e 100644
> --- a/libavformat/webpenc.c
> +++ b/libavformat/webpenc.c
> @@ -1,5 +1,5 @@
> /*
> - * webp muxer
> + * webp muxer (native)
> * Copyright (c) 2014 Michael Niedermayer
> *
> * This file is part of FFmpeg.
> @@ -19,36 +19,24 @@
> * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
> */
>
> -#include "libavutil/intreadwrite.h"
> -#include "libavutil/opt.h"
> -#include "avformat.h"
> -#include "internal.h"
> +#include "webpenc_common.h"
> +
> +#ifndef USE_WEBP_ANIMENCODER
[...]
> +#endif // USE_WEBP_ANIMENCODER
> diff --git a/libavformat/webpenc_animencoder.c b/libavformat/webpenc_animencoder.c
> new file mode 100644
> index 0000000..a3cf856
> --- /dev/null
> +++ b/libavformat/webpenc_animencoder.c
> @@ -0,0 +1,68 @@
> +/*
> + * webp muxer using libwebp (AnimEncoder API)
> + *
> + * Copyright (c) 2014 Michael Niedermayer
> + *
> + * 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
> + */
> +
> +#include "webpenc_common.h"
> +
> +#ifdef USE_WEBP_ANIMENCODER
[...]
> +#endif // USE_WEBP_ANIMENCODER
> diff --git a/libavformat/webpenc_common.c b/libavformat/webpenc_common.c
the code in libavformat needs to identify its input based on the data
it receives not on the environment during build
[...]
--
Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB
Let us carefully observe those good qualities wherein our enemies excel us
and endeavor to excel them, by avoiding what is faulty, and imitating what
is excellent in them. -- Plutarch
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