[FFmpeg-devel] [PATCH] png parser
Michael Niedermayer
michaelni
Wed Jun 10 13:38:52 CEST 2009
On Wed, Jun 10, 2009 at 01:27:10PM +0200, Peter Holik wrote:
> > On Wed, Jun 10, 2009 at 11:52:34AM +0200, Peter Holik wrote:
> >> >>> On Thu, Jun 04, 2009 at 10:40:55AM +0200, Peter Holik wrote:
> >> >>>> > On Mon, Jun 01, 2009 at 12:27:52PM +0200, Peter Holik wrote:
> >> >>>> >> Hi!
> >> >>>> >>
> >> >>>> >> I've now reworked my patch to really parse a png for end of frame.
> >> >>>> >>
> >> >>>> >> Now you can filter out png's of any stream like
> >> >>>> >>
> >> >>>> >> cat garbage a.png garbage b.png garbage | ffmpeg -f image2pipe -vcodec png -i - c%d.png
> >> >>>> >>
> >> >>>> >> cu Peter
> >> >>>> >> Makefile | 1
> >> >>>> >> allcodecs.c | 1
> >> >>>> >> png_parser.c | 124 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 3 files
> >> >> changed, 126 insertions(+)
> >> >>>> >> 63f7cd1bb826726f1d2a9e7254410cd7ec98a81c png-parser.patch
> >> >>>> >> diff --git a/libavcodec/Makefile b/libavcodec/Makefile
> >> >>>> >> index 14ef9f4..189231b 100644
> >> >>>> >> --- a/libavcodec/Makefile
> >> >>>> >> +++ b/libavcodec/Makefile
> >> >>>> >> @@ -411,6 +411,7 @@ OBJS-$(CONFIG_MLP_PARSER) += mlp_parser.o mlp.o
> >> >>>> >> OBJS-$(CONFIG_MPEG4VIDEO_PARSER) += mpeg4video_parser.o h263.o mpeg12data.o
> >> >>>> mpegvideo.o
> >> >>>> >> error_resilience.o
> >> >>>> >> OBJS-$(CONFIG_MPEGAUDIO_PARSER) += mpegaudio_parser.o mpegaudiodecheader.o
> >> >>>> >> mpegaudiodata.o
> >> >>>> >> OBJS-$(CONFIG_MPEGVIDEO_PARSER) += mpegvideo_parser.o mpeg12.o mpeg12data.o
> >> >>>> mpegvideo.o
> >> >>>> >> error_resilience.o
> >> >>>> >> +OBJS-$(CONFIG_PNG_PARSER) += png_parser.o
> >> >>>> >> OBJS-$(CONFIG_PNM_PARSER) += pnm_parser.o pnm.o OBJS-$(CONFIG_VC1_PARSER)
> >> >> += vc1_parser.o
> >> >>>> >> OBJS-$(CONFIG_VP3_PARSER) += vp3_parser.o
> >> >>>> >> diff --git a/libavcodec/allcodecs.c b/libavcodec/allcodecs.c index e8d5d27..362021f
> >> 100644
> >> >>>> >> --- a/libavcodec/allcodecs.c
> >> >>>> >> +++ b/libavcodec/allcodecs.c
> >> >>>> >> @@ -334,6 +334,7 @@ void avcodec_register_all(void)
> >> >>>> >> REGISTER_PARSER (MPEG4VIDEO, mpeg4video);
> >> >>>> >> REGISTER_PARSER (MPEGAUDIO, mpegaudio);
> >> >>>> >> REGISTER_PARSER (MPEGVIDEO, mpegvideo);
> >> >>>> >> + REGISTER_PARSER (PNG, png);
> >> >>>> >> REGISTER_PARSER (PNM, pnm);
> >> >>>> >> REGISTER_PARSER (VC1, vc1);
> >> >>>> >> REGISTER_PARSER (VP3, vp3);
> >> >>>> >> diff --git a/libavcodec/png_parser.c b/libavcodec/png_parser.c new file mode 100644
> >> >>>> >> index 0000000..64f2356
> >> >>>> >> --- /dev/null
> >> >>>> >> +++ b/libavcodec/png_parser.c
> >> >>>> >> @@ -0,0 +1,124 @@
> >> >>>> >> +/*
> >> >>>> >> + * PNG parser
> >> >>>> >> + * Copyright (c) 2009 Peter Holik
> >> >>>> >> + *
> >> >>>> >> + * 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 libavcodec/png_parser.c
> >> >>>> >> + * PNG parser
> >> >>>> >> + */
> >> >>>> >> +
> >> >>>> >> +#include "parser.h"
> >> >>>> >> +#include "bytestream.h"
> >> >>>> >> +#include "png.h"
> >> >>>> >> +
> >> >>>> >> +static int png_parse(AVCodecParserContext *s, AVCodecContext *avctx, +
> >> >> const uint8_t **poutbuf, int *poutbuf_size, + const uint8_t *buf, int
> >> >> buf_size)
> >> >>>> >> +{
> >> >>>> >> + ParseContext *pc = s->priv_data;
> >> >>>> >> + uint8_t *bytestream;
> >> >>>> >> + uint8_t *bytestream_start;
> >> >>>> >> + uint8_t *bytestream_end;
> >> >>>> >> +
> >> >>>> >> + /* EOF considered as end of frame */
> >> >>>> >> + if (buf_size == 0)
> >> >>>> >> + goto flush;
> >> >>>> >> +
> >> >>>> >> + *poutbuf = NULL;
> >> >>>> >> + *poutbuf_size = 0;
> >> >>>> >> +
> >> >>>> >> + /* first add new buffer to parsebuffer */
> >> >>>> >> + bytestream_start = av_fast_realloc(pc->buffer, &pc->buffer_size, +
> >> >> pc->index + buf_size + FF_INPUT_BUFFER_PADDING_SIZE); + if(!bytestream_start)
> >> >>>> >> + goto fail;
> >> >>>> >> + pc->buffer = bytestream_start;
> >> >>>> >> + memcpy(&pc->buffer[pc->index], buf, buf_size);
> >> >>>> >
> >> >>>> > mandatory copying is unacceptable
> >> >>>> > the case where each input is exactly a png frame for example should be free of any
> >> >> timeconsuming operation
> >> >>>> >
> >> >>>> > maybe ff_combine_frame() would be usefull
> >> >>>>
> >> >>>> But ff_combine_frame also does memcpy, so there is no difference to my approach.
> >> >>>
> >> >>> ff_combine_frame() does not always memcpy, your code does always
> >> >>
> >> >> change my patch to only memcpy when input is not exactly a png frame.
> >> >>
> >> >> cu Peter
> >>
> >> ping
> >
> > does your code do something else than ff_combine_frame() ?
> > if no its duplicate code
> > if yes its either worse or ff_combine_frame() should be improved
> >
>
> 1. ff_combine_frame is overhead
elaborate
> 2. i use a variable from PasteContext also altered by ff_combine_frame
which variable is how used by you so that it conflicts with ff_combine_frame?
--
Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB
Many that live deserve death. And some that die deserve life. Can you give
it to them? Then do not be too eager to deal out death in judgement. For
even the very wise cannot see all ends. -- Gandalf
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