From fb5cf145b6bcfa4f83af94398e5560c1132cc410 Mon Sep 17 00:00:00 2001
From: Paul B Mahol <onemda@gmail.com>
Date: Sun, 5 Aug 2012 23:46:41 +0000
Subject: [PATCH] bmp: add a standalone parser

Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>
---
 Changelog               |  1 +
 libavcodec/Makefile     |  1 +
 libavcodec/allcodecs.c  |  1 +
 libavcodec/bmp_parser.c | 91 +++++++++++++++++++++++++++++++++++++++++
 libavcodec/version.h    |  2 +-
 5 files changed, 95 insertions(+), 1 deletion(-)
 create mode 100644 libavcodec/bmp_parser.c

diff --git a/Changelog b/Changelog
index c7f4ca6331..e8864be1c1 100644
--- a/Changelog
+++ b/Changelog
@@ -9,6 +9,7 @@ version <next>:
 - BRender PIX image decoder
 - Amazing Studio PAF playback support
 - XBM decoder
+- bmp standalone parser
 
 
 version 10:
diff --git a/libavcodec/Makefile b/libavcodec/Makefile
index cb5962330b..cc29cbdd8d 100644
--- a/libavcodec/Makefile
+++ b/libavcodec/Makefile
@@ -621,6 +621,7 @@ OBJS-$(CONFIG_AAC_LATM_PARSER)         += latm_parser.o
 OBJS-$(CONFIG_AC3_PARSER)              += ac3_parser.o ac3tab.o \
                                           aac_ac3_parser.o
 OBJS-$(CONFIG_ADX_PARSER)              += adx_parser.o adx.o
+OBJS-$(CONFIG_BMP_PARSER)              += bmp_parser.o
 OBJS-$(CONFIG_CAVSVIDEO_PARSER)        += cavs_parser.o
 OBJS-$(CONFIG_COOK_PARSER)             += cook_parser.o
 OBJS-$(CONFIG_DCA_PARSER)              += dca_parser.o dca.o
diff --git a/libavcodec/allcodecs.c b/libavcodec/allcodecs.c
index a435b17c78..a069694142 100644
--- a/libavcodec/allcodecs.c
+++ b/libavcodec/allcodecs.c
@@ -454,6 +454,7 @@ void avcodec_register_all(void)
     REGISTER_PARSER(AAC_LATM,           aac_latm);
     REGISTER_PARSER(AC3,                ac3);
     REGISTER_PARSER(ADX,                adx);
+    REGISTER_PARSER(BMP,                bmp);
     REGISTER_PARSER(CAVSVIDEO,          cavsvideo);
     REGISTER_PARSER(COOK,               cook);
     REGISTER_PARSER(DCA,                dca);
diff --git a/libavcodec/bmp_parser.c b/libavcodec/bmp_parser.c
new file mode 100644
index 0000000000..b85dd8bcb5
--- /dev/null
+++ b/libavcodec/bmp_parser.c
@@ -0,0 +1,91 @@
+/*
+ * BMP parser
+ * Copyright (c) 2012 Paul B Mahol
+ *
+ * This file is part of Libav.
+ *
+ * Libav 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.
+ *
+ * Libav 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 Libav; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/**
+ * @file
+ * BMP parser
+ */
+
+#include "libavutil/bswap.h"
+#include "libavutil/common.h"
+
+#include "parser.h"
+
+typedef struct BMPParseContext {
+    ParseContext pc;
+    uint32_t fsize;
+    uint32_t remaining_size;
+} BMPParseContext;
+
+static int bmp_parse(AVCodecParserContext *s, AVCodecContext *avctx,
+                     const uint8_t **poutbuf, int *poutbuf_size,
+                     const uint8_t *buf, int buf_size)
+{
+    BMPParseContext *bpc = s->priv_data;
+    uint64_t state = bpc->pc.state64;
+    int next = END_NOT_FOUND;
+    int i = 0;
+
+    *poutbuf_size = 0;
+    if (buf_size == 0)
+        return 0;
+
+    if (!bpc->pc.frame_start_found) {
+        for (; i < buf_size; i++) {
+            state = (state << 8) | buf[i];
+            if ((state >> 48) == (('B' << 8) | 'M')) {
+                bpc->fsize = av_bswap32(state >> 16);
+                bpc->pc.frame_start_found = 1;
+                if (bpc->fsize > buf_size - i + 7)
+                    bpc->remaining_size = bpc->fsize - buf_size + i - 7;
+                else
+                    next = bpc->fsize + i - 7;
+                break;
+            }
+        }
+        bpc->pc.state64 = state;
+    } else {
+        if (bpc->remaining_size) {
+            i = FFMIN(bpc->remaining_size, buf_size);
+            bpc->remaining_size -= i;
+            if (bpc->remaining_size)
+                goto flush;
+            next = i;
+        }
+    }
+
+flush:
+    if (ff_combine_frame(&bpc->pc, next, &buf, &buf_size) < 0)
+        return buf_size;
+
+    bpc->pc.frame_start_found = 0;
+
+    *poutbuf      = buf;
+    *poutbuf_size = buf_size;
+    return next;
+}
+
+AVCodecParser ff_bmp_parser = {
+    .codec_ids      = { AV_CODEC_ID_BMP },
+    .priv_data_size = sizeof(BMPParseContext),
+    .parser_parse   = bmp_parse,
+    .parser_close   = ff_parse_close,
+};
diff --git a/libavcodec/version.h b/libavcodec/version.h
index dc6e2e903f..3b1f65bd77 100644
--- a/libavcodec/version.h
+++ b/libavcodec/version.h
@@ -29,7 +29,7 @@
 #include "libavutil/version.h"
 
 #define LIBAVCODEC_VERSION_MAJOR 55
-#define LIBAVCODEC_VERSION_MINOR 40
+#define LIBAVCODEC_VERSION_MINOR 41
 #define LIBAVCODEC_VERSION_MICRO  0
 
 #define LIBAVCODEC_VERSION_INT  AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \