[FFmpeg-cvslog] avcodec: add a WebP parser
James Almer
git at videolan.org
Thu Apr 16 21:06:22 EEST 2020
ffmpeg | branch: master | James Almer <jamrial at gmail.com> | Mon Apr 13 20:44:06 2020 -0300| [fccd6c2be0aa4feb3fe8050769705459a1990e83] | committer: James Almer
avcodec: add a WebP parser
Based on code from the BMP parser.
Addresses ticket #8574
Reviewed-by: James Zern <jzern at google.com>
Signed-off-by: James Almer <jamrial at gmail.com>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=fccd6c2be0aa4feb3fe8050769705459a1990e83
---
Changelog | 1 +
libavcodec/Makefile | 1 +
libavcodec/parsers.c | 1 +
libavcodec/version.h | 2 +-
libavcodec/webp_parser.c | 112 +++++++++++++++++++++++++++++++++++++++++++++++
5 files changed, 116 insertions(+), 1 deletion(-)
diff --git a/Changelog b/Changelog
index 6dfe750d81..d9fcd8bb0a 100644
--- a/Changelog
+++ b/Changelog
@@ -58,6 +58,7 @@ version <next>:
- switch from AvxSynth to AviSynth+ on Linux
- mv30 decoder
- Expanded styling support for 3GPP Timed Text Subtitles (movtext)
+- WebP parser
version 4.2:
diff --git a/libavcodec/Makefile b/libavcodec/Makefile
index 1970ff027f..88944d9a3a 100644
--- a/libavcodec/Makefile
+++ b/libavcodec/Makefile
@@ -1084,6 +1084,7 @@ OBJS-$(CONFIG_VC1_PARSER) += vc1_parser.o vc1.o vc1data.o \
OBJS-$(CONFIG_VP3_PARSER) += vp3_parser.o
OBJS-$(CONFIG_VP8_PARSER) += vp8_parser.o
OBJS-$(CONFIG_VP9_PARSER) += vp9_parser.o
+OBJS-$(CONFIG_WEBP_PARSER) += webp_parser.o
OBJS-$(CONFIG_XMA_PARSER) += xma_parser.o
# bitstream filters
diff --git a/libavcodec/parsers.c b/libavcodec/parsers.c
index 33a71de8a0..9fbf182594 100644
--- a/libavcodec/parsers.c
+++ b/libavcodec/parsers.c
@@ -66,6 +66,7 @@ extern AVCodecParser ff_vorbis_parser;
extern AVCodecParser ff_vp3_parser;
extern AVCodecParser ff_vp8_parser;
extern AVCodecParser ff_vp9_parser;
+extern AVCodecParser ff_webp_parser;
extern AVCodecParser ff_xma_parser;
#include "libavcodec/parser_list.c"
diff --git a/libavcodec/version.h b/libavcodec/version.h
index a4eb83124c..8cff2e855b 100644
--- a/libavcodec/version.h
+++ b/libavcodec/version.h
@@ -28,7 +28,7 @@
#include "libavutil/version.h"
#define LIBAVCODEC_VERSION_MAJOR 58
-#define LIBAVCODEC_VERSION_MINOR 79
+#define LIBAVCODEC_VERSION_MINOR 80
#define LIBAVCODEC_VERSION_MICRO 100
#define LIBAVCODEC_VERSION_INT AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \
diff --git a/libavcodec/webp_parser.c b/libavcodec/webp_parser.c
new file mode 100644
index 0000000000..fdb7c38350
--- /dev/null
+++ b/libavcodec/webp_parser.c
@@ -0,0 +1,112 @@
+/*
+ * WebP parser
+ *
+ * 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
+ * WebP parser
+ */
+
+#include "libavutil/bswap.h"
+#include "libavutil/common.h"
+
+#include "parser.h"
+
+typedef struct WebPParseContext {
+ ParseContext pc;
+ uint32_t fsize;
+ uint32_t remaining_size;
+} WebPParseContext;
+
+static int webp_parse(AVCodecParserContext *s, AVCodecContext *avctx,
+ const uint8_t **poutbuf, int *poutbuf_size,
+ const uint8_t *buf, int buf_size)
+{
+ WebPParseContext *ctx = s->priv_data;
+ uint64_t state = ctx->pc.state64;
+ int next = END_NOT_FOUND;
+ int i = 0;
+
+ *poutbuf = NULL;
+ *poutbuf_size = 0;
+
+restart:
+ if (ctx->pc.frame_start_found <= 8) {
+ for (; i < buf_size; i++) {
+ state = (state << 8) | buf[i];
+ if (ctx->pc.frame_start_found == 0) {
+ if ((state >> 32) == MKBETAG('R', 'I', 'F', 'F')) {
+ ctx->fsize = av_bswap32(state);
+ if (ctx->fsize > 15 && ctx->fsize <= UINT32_MAX - 10) {
+ ctx->pc.frame_start_found = 1;
+ ctx->fsize += 8;
+ }
+ }
+ } else if (ctx->pc.frame_start_found == 8) {
+ if ((state >> 32) != MKBETAG('W', 'E', 'B', 'P')) {
+ ctx->pc.frame_start_found = 0;
+ continue;
+ }
+ ctx->pc.frame_start_found++;
+ ctx->remaining_size = ctx->fsize + i - 15;
+ if (ctx->pc.index + i > 15) {
+ next = i - 15;
+ state = 0;
+ break;
+ } else {
+ ctx->pc.state64 = 0;
+ goto restart;
+ }
+ } else if (ctx->pc.frame_start_found)
+ ctx->pc.frame_start_found++;
+ }
+ ctx->pc.state64 = state;
+ } else {
+ if (ctx->remaining_size) {
+ i = FFMIN(ctx->remaining_size, buf_size);
+ ctx->remaining_size -= i;
+ if (ctx->remaining_size)
+ goto flush;
+
+ ctx->pc.frame_start_found = 0;
+ goto restart;
+ }
+ }
+
+flush:
+ if (ff_combine_frame(&ctx->pc, next, &buf, &buf_size) < 0)
+ return buf_size;
+
+ if (next != END_NOT_FOUND && next < 0)
+ ctx->pc.frame_start_found = FFMAX(ctx->pc.frame_start_found - i - 1, 0);
+ else
+ ctx->pc.frame_start_found = 0;
+
+ *poutbuf = buf;
+ *poutbuf_size = buf_size;
+
+ return next;
+}
+
+AVCodecParser ff_webp_parser = {
+ .codec_ids = { AV_CODEC_ID_WEBP },
+ .priv_data_size = sizeof(WebPParseContext),
+ .parser_parse = webp_parse,
+ .parser_close = ff_parse_close,
+};
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