dvr-recover is an incredible Python-powered project helping you to recover recordings of digital video recorders. In other words: The script is able to find video files on the surface of the device's hard disk drive.
Practically, the process is much more complex. Have a look at the following sections if you want to gain more knowledge about the details.
There are many devices on the market, not all models can be supported. See the list of tested devices to see if your device has been already tested.
Copyright (C) 2010, 2011 Stefan Haller [email protected]
This program 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 3 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, see http:https://www.gnu.org/licenses/.
Currently only Panasonic DMR devices have been tested. If you successfully recovered the content of your drive (completely or partly), please drop me a mail!
Working devices:
- Panasonic DMR-EH55
- Panasonic DMR-EH56
- Panasonic DMR-EH57
- Panasonic DMR-EX77
- Panasonic DMR-EX85
- Panasonic DMR-XW300
- Panasonic DVM-E80H
To run the script you need a Python interpreter (2.x, tested with 2.5 and higher).
If you execute the script without any parameters, the script will print the usage message where all parameters, switches and settings are explained in detail.
Executing the script is very easy: Simply open a terminal (on Windows: [Win] + [R] -> enter "cmd" and press enter). At first you have to switch to the directory where the script is located and then you can fire up the Python interpreter.
Linux:
cd /path/to/script/
python dvr-recover.py [parameters]
Windows:
cd C:\Path\to\script\
python dvr-recover.py [parameters]
This section will guide you through the complete process of recovering the data from you hard disk drive.
Naturally the hard disk drive of the digital video recorder must be plugged into the computer. So you need to open the device and fetch the hdd. You can either attach the disk directly to the IDE ports of your motherboard or you can use a IDE-USB-bridge.
It's recommended that you create an image of your disk, but if you think you're lucky you can even use the hard disk drive directly as input on Linux. Note that direct access to the hard disk drive on Windows is currently not supported by dvr-recover. On Windows you have to use 3rd party programs to create the image. On Linux you can use the standard tools (be sure that you have root permissions):
# (Assuming that your disc is labeled /dev/sdb)
dd if=/dev/sdb of=disk.img bs=10M
This guide assumes that you have an exact bitwise copy of the hdd on your file system. Note that it's also possible to split your image into smaller parts. The script is able to handle this situation correctly. But you have to be sure that you specify all parts in the correct order in the later process. If you want to use the hdd directly, you will need to substitute the filenames in this guide with the device identifier (/dev/sdb, ... on Linux).
The script will automatically create a sqlite3 database to store all settings and gained information. If somethings goes heavily wrong, you will be able to reset the state of the program by deleting the database. To do so delete the file "dvr-recover.sqlite" in the working directory of the script.
Before you the script can analyze your hard disk drive, you have to go through a initial setup first. The script needs at least the information about the input filename(s). But there are many other settings to tweak -- most of them have sensible default values. For more information read the usage message of the script by passing "usage" as parameter.
If you call the script with passing "setup" as parameter, it will print the current values of all settings:
$ python dvr-recover.py setup
input_file: /home/user/disk.img.0001
[...]
input_file: /home/user/disk.img.9999
export_dir: /tmp/export
blocksize: 2048
min_chunk_size: 25600
max_create_gap: 90000
max_sort_gap: 90000
To change a setting you have to pass the "setup" parameter and additionally the setting to change with the new value:
$ python dvr-recover.py setup blocksize 2048
The only exception is the handling of input files:
$ python dvr-recover.py setup input clear
$ python dvr-recover.py setup input add disk.img.0001
$ python dvr-recover.py setup input add disk.img.0002
$ python dvr-recover.py setup input del disk.img.0001
$ [and so on...]
Use the parameter "clear" to clear the list of input files. Also available are the parameters "add" and "del" -- both take a filename as argument.
If you want to reset all settings, you have to use the parameter "reset":
$ python dvr-recover.py setup reset
Now you should be able to start the main feature of the script: recovering your hard disk drive.
At first let the script analyze your hard disk drive. Call the script with passing the parameter "create". This process will take quite a long time to complete. You can interrupt the process at any point by pressing [CTRL] + [C]. On the next call with the parameter "create" the script will automatically resume the process where it was interrupted.
$ python dvr-recover.py create
[ 29.5%] 297457/1006929 blocks (9915.2 bl/s; 19.4 MiB/s): 5 chunks
[ 65.0%] 654794/1006929 blocks (11911.2 bl/s; 23.3 MiB/s): 6 chunks
[ 91.3%] 918841/1006929 blocks (8786.1 bl/s; 17.2 MiB/s): 6 chunks
Finished.
Read 1006929 of 1006929 blocks.
Found 7 chunks.
Took 100.97 seconds.
Average speed was 9972.6 blocks/s (19.5 MiB/s).
(The file used for generating the output above was very very small.)
After finishing the analyze of the hdd the script will forbid all further calls with the parameter "create", because this would cause data loss (all data of the last analyze would be reseted first). You must explicitly reset the information in the database by passing the parameter "clear":
$ python dvr-recover.py clear
(THIS WILL DELETE ALL GATHERED DATA FROM THE DATABASE!)
dvr-recover has the ability to sort the chunks and find chunks of the same recording. To start this process pass the paremter "sort" to the script:
$ python dvr-recover.py sort
To revert the effect of "sort", pass "reset".
$ python dvr-recover.py reset
At every stage you can display the chunk info by passing "show".
$ python dvr-recover.py show
----+--------------+--------------+--------------+--------------+------------
| Block Start | Block Size | Clock Start | Clock End | Concatenate
----+--------------+--------------+--------------+--------------+------------
1 | 391379 | 615548 | 250031969 | 402836926 | False
2 | 223188 | 168189 | 401478251 | 484558534 | False
3 | 107989 | 115197 | 546892241 | 592303341 | False
4 | 80992 | 26995 | 1085209725 | 1100156779 | False
# | 53995 | 26995 | 1100157071 | 1115282776 | True
# | 26998 | 26995 | 1115283069 | 1129877061 | True
# | 0 | 26996 | 1129877208 | 1144930337 | True
In the first column you can see the index of the chunk. A '#' is printed if the chunk is concatenated to the previous one.
The last thing is exporting the recordings. If the scrit has found chunks of the same recording, they will be automatically concatenated. You can either export all recordings in the database or only a single one.
$ python dvr-recover.py export
This will export all recordings. You can also specify a chunk id to export. In this example the script would export only the chunk with the id 4 (including the chunks which should be concatenated to this one).
$ python dvr-recover.py export 4
All the basics are explained -- you should be able to use the script now. Of course, there are a lot of other things that were not mentioned in this guide. For more details have a look at the usage message or the source code.
Is there any possibility to tune the script and recover more files? Yes, it is!
You can tune the process of chunk detection with parameters. The most important parameter is "min_chunk_size". The smaller the value is, the more the script finds. But the problem is that the possibility to find "garbage" is even higher.
The default setting is that the program ignores chunks smaller than 50 MB (25600 blocks). If you set it to 0, the script will find everything, even if it's only one frame of a recording. If you play a bit with this parameter you maybe will recover more recordings completely.
IMPORTANT: After changing the parameters run the complete scan again (parameter "create")!
To change the setting run:
$ python dvr-recover.py setup min_chunk_size [NEW_VALUE]
[NEW_VALUE] must be given in blocks. Blocks * blocks size = size in byte. The default block size is 2048 byte.
I tried to set the default value to a sensible default. If somebody can prove that a smaller value is better, I'll set the default value for later releases to a lower value.
Stefan Haller [email protected]
https://github.com/haliner/dvr-recover
Feel free to contact me if you have any additional suggestions or you've found a bug. Feedback is always welcome! IF YOU THINK THE SCRIPT IS TERRIFIC, I WOULD BE VERY GLAD IF YOU LET ME KNOW THAT.