[FFmpeg-devel] [PATCH 3/5] avformat: Add adler protocol

[Michael Niedermayer]

This is based on md5proto but using adler32 instead

Signed-off-by: Michael Niedermayer <michaelni at gmx.at>
---
 libavformat/Makefile     |    1 +
 libavformat/adlerproto.c |   88 ++++++++++++++++++++++++++++++++++++++++++++++
 libavformat/allformats.c |    1 +
 3 files changed, 90 insertions(+)
 create mode 100644 libavformat/adlerproto.c

diff --git a/libavformat/Makefile b/libavformat/Makefile
index 3679708..770d98c 100644
--- a/libavformat/Makefile
+++ b/libavformat/Makefile
@@ -412,6 +412,7 @@ OBJS-$(CONFIG_LIBQUVI_DEMUXER)           += libquvi.o
 OBJS-$(CONFIG_LIBRTMP)                   += librtmp.o
 
 # protocols I/O
+OBJS-$(CONFIG_ADLER_PROTOCOL)            += adlerproto.o
 OBJS-$(CONFIG_APPLEHTTP_PROTOCOL)        += hlsproto.o
 OBJS-$(CONFIG_BLURAY_PROTOCOL)           += bluray.o
 OBJS-$(CONFIG_CACHE_PROTOCOL)            += cache.o
diff --git a/libavformat/adlerproto.c b/libavformat/adlerproto.c
new file mode 100644
index 0000000..891b6eb
--- /dev/null
+++ b/libavformat/adlerproto.c
@@ -0,0 +1,88 @@
+/*
+ * Copyright (c) 2010 Mans Rullgard
+ * Copyright (c) 2013 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 <stdio.h>
+#include "libavutil/avstring.h"
+#include "libavutil/adler32.h"
+#include "libavutil/mem.h"
+#include "libavutil/error.h"
+#include "avformat.h"
+#include "avio.h"
+#include "url.h"
+
+struct AdlerContext {
+    uint32_t checksum;
+};
+
+static int adler_open(URLContext *h, const char *filename, int flags)
+{
+    struct AdlerContext *c = h->priv_data;
+
+    if (!(flags & AVIO_FLAG_WRITE))
+        return AVERROR(EINVAL);
+
+    c->checksum = 1;
+
+    return 0;
+}
+
+static int adler_write(URLContext *h, const unsigned char *buf, int size)
+{
+    struct AdlerContext *c = h->priv_data;
+    c->checksum = av_adler32_update(c->checksum, buf, size);
+    return size;
+}
+
+static int adler_close(URLContext *h)
+{
+    struct AdlerContext *c = h->priv_data;
+    const char *filename = h->filename;
+    uint8_t buf[64];
+    URLContext *out;
+    int err = 0;
+
+    snprintf(buf, 15, "%08x\n", c->checksum);
+
+    av_strstart(filename, "adler:", &filename);
+
+    if (*filename) {
+        err = ffurl_open(&out, filename, AVIO_FLAG_WRITE,
+                         &h->interrupt_callback, NULL);
+        if (err)
+            return err;
+        err = ffurl_write(out, buf, 9);
+        ffurl_close(out);
+    } else {
+        if (fwrite(buf, 1, 9, stdout) < 9)
+            err = AVERROR(errno);
+    }
+
+    return err;
+}
+
+
+URLProtocol ff_adler_protocol = {
+    .name                = "adler",
+    .url_open            = adler_open,
+    .url_write           = adler_write,
+    .url_close           = adler_close,
+    .priv_data_size      = sizeof(struct AdlerContext),
+};
diff --git a/libavformat/allformats.c b/libavformat/allformats.c
index bca2c40..7ee8096 100644
--- a/libavformat/allformats.c
+++ b/libavformat/allformats.c
@@ -302,6 +302,7 @@ void av_register_all(void)
     REGISTER_MUXDEMUX(YUV4MPEGPIPE,     yuv4mpegpipe);
 
     /* protocols */
+    REGISTER_PROTOCOL(ADLER,            adler);
     REGISTER_PROTOCOL(BLURAY,           bluray);
     REGISTER_PROTOCOL(CACHE,            cache);
     REGISTER_PROTOCOL(CONCAT,           concat);
-- 
1.7.9.5