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authorChristophe Grenier <grenier@cgsecurity.org>2014-09-17 08:09:21 +0200
committerChristophe Grenier <grenier@cgsecurity.org>2014-09-17 08:09:21 +0200
commit801793d7d36f157a786f7301e303ab9022a1d946 (patch)
tree7a1297f6201f8c13e7463cf671d36af6ab6f893b /src/file_mlv.c
parent30683f6ebb7cf578ac8a96ea2255f7e664ba1800 (diff)
PhotoRec: recover Magic Lantern Video .mlv file
Diffstat (limited to 'src/file_mlv.c')
-rw-r--r--src/file_mlv.c134
1 files changed, 134 insertions, 0 deletions
diff --git a/src/file_mlv.c b/src/file_mlv.c
new file mode 100644
index 0000000..e3bff65
--- /dev/null
+++ b/src/file_mlv.c
@@ -0,0 +1,134 @@
+/*
+
+ File: file_mlv.c
+
+ Copyright (C) 2014 Christophe GRENIER <grenier@cgsecurity.org>
+
+ This software is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2 of the License, or
+ (at your option) any later version.
+
+ This program 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 General Public License for more details.
+
+ You should have received a copy of the GNU General Public License along
+ with this program; if not, write the Free Software Foundation, Inc., 51
+ Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+#ifdef HAVE_STRING_H
+#include <string.h>
+#endif
+#include <stdio.h>
+#include "types.h"
+#include "filegen.h"
+#include "common.h"
+
+static void register_header_check_mlv(file_stat_t *file_stat);
+
+const file_hint_t file_hint_mlv= {
+ .extension="mlv",
+ .description="Magic Lantern Video",
+ .min_header_distance=0,
+ .max_filesize=PHOTOREC_MAX_FILE_SIZE,
+ .recover=1,
+ .enable_by_default=1,
+ .register_header_check=&register_header_check_mlv
+};
+
+/* See https://bitbucket.org/hudson/magic-lantern/src/tip/modules/mlv_rec/mlv.h?at=unified */
+typedef struct {
+ uint8_t fileMagic[4]; /* Magic Lantern Video file header */
+ uint32_t blockSize; /* size of the whole header */
+ uint8_t versionString[8]; /* null-terminated C-string of the exact revision of this format */
+ uint64_t fileGuid; /* UID of the file (group) generated using hw counter, time of day and PRNG */
+ uint16_t fileNum; /* the ID within fileCount this file has (0 to fileCount-1) */
+ uint16_t fileCount; /* how many files belong to this group (splitting or parallel) */
+ uint32_t fileFlags; /* 1=out-of-order data, 2=dropped frames, 4=single image mode, 8=stopped due to error */
+ uint16_t videoClass; /* 0=none, 1=RAW, 2=YUV, 3=JPEG, 4=H.264 */
+ uint16_t audioClass; /* 0=none, 1=WAV */
+ uint32_t videoFrameCount; /* number of video frames in this file. set to 0 on start, updated when finished. */
+ uint32_t audioFrameCount; /* number of audio frames in this file. set to 0 on start, updated when finished. */
+ uint32_t sourceFpsNom; /* configured fps in 1/s multiplied by sourceFpsDenom */
+ uint32_t sourceFpsDenom; /* denominator for fps. usually set to 1000, but may be 1001 for NTSC */
+} __attribute__ ((__packed__)) mlv_file_hdr_t;
+
+typedef struct {
+ uint8_t blockType[4];
+ uint32_t blockSize;
+ uint64_t timestamp;
+} __attribute__ ((__packed__)) mlv_hdr_t;
+
+static int is_valid_type(const mlv_hdr_t *hdr)
+{
+ unsigned int i;
+ for(i=0; i<4; i++)
+ {
+ const uint8_t c=hdr->blockType[i];
+ if(!((c>='0' && c<='9') || (c>='a' && c<='z') || (c>='A' && c<='Z')))
+ return 0;
+ }
+ return 1;
+}
+
+static data_check_t data_check_mlv(const unsigned char *buffer, const unsigned int buffer_size, file_recovery_t *fr)
+{
+ while(fr->calculated_file_size + buffer_size/2 >= fr->file_size &&
+ fr->calculated_file_size + 8 < fr->file_size + buffer_size/2)
+ {
+ const unsigned int i=fr->calculated_file_size - fr->file_size + buffer_size/2;
+ const mlv_hdr_t *hdr=(const mlv_hdr_t *)&buffer[i];
+ if(le32(hdr->blockSize)<0x10 || !is_valid_type(hdr))
+ return DC_STOP;
+ fr->calculated_file_size+=le32(hdr->blockSize);
+ }
+ return DC_CONTINUE;
+}
+
+static void file_check_mlv(file_recovery_t *file_recovery)
+{
+ mlv_hdr_t hdr;
+ uint64_t fs=0;
+ do
+ {
+ if( fseek(file_recovery->handle, fs, SEEK_SET)<0 ||
+ fread(&hdr, sizeof(hdr), 1, file_recovery->handle)!=1 ||
+ le32(hdr.blockSize)<0x10 ||
+ !is_valid_type(&hdr) ||
+ fs + le32(hdr.blockSize) > file_recovery->file_size)
+ {
+ file_recovery->file_size=fs;
+ return;
+ }
+ fs+=le32(hdr.blockSize);
+ } while(1);
+}
+
+static int header_check_mlv(const unsigned char *buffer, const unsigned int buffer_size, const unsigned int safe_header_only, const file_recovery_t *file_recovery, file_recovery_t *file_recovery_new)
+{
+ const mlv_file_hdr_t *hdr=(const mlv_file_hdr_t *)buffer;
+ if(le32(hdr->blockSize) < 0x34)
+ return 0;
+ if(le16(hdr->fileNum) > le16(hdr->fileCount))
+ return 0;
+ if(le16(hdr->fileNum) >= le16(hdr->fileCount) && le16(hdr->fileCount)>0)
+ return 0;
+ reset_file_recovery(file_recovery_new);
+ file_recovery_new->extension=file_hint_mlv.extension;
+ file_recovery_new->file_check=&file_check_mlv;
+ if(file_recovery_new->blocksize > 0x10)
+ file_recovery_new->data_check=&data_check_mlv;
+ return 1;
+}
+
+static void register_header_check_mlv(file_stat_t *file_stat)
+{
+ register_header_check(0, "MLVI", 4, &header_check_mlv, file_stat);
+}