Mediaextract

Extract media files that are embedded within other files.

Setup

make builddir
make
sudo make install PREFIX=/usr

Cross compile for Windows (uses i686-pc-mingw32-gcc):

make TARGET=win32 builddir
make TARGET=win32

Or (uses x86_64-w64-mingw32-gcc):

make TARGET=win64 builddir
make TARGET=win64

Warning: This program only works correctly on platforms that allow unaligned memory access (e.g. x86 and ARM, although it might be quite slow on the latter).

Note: 32bit binaries can only process 2 GB of a file at once. The rest of bigger files will be ignored. You need to run this program several times with different --offset values to process such a file whole.

This also means that using a 32bit binary extracted files can never be larger than 2 GB.

This is because mediaextract uses mmap to read files, wich maps files to memory. On 32bit platforms the address space of the main memory is simply not big enough. 64bit binaries can read up to 8 EB (8 Exabytes) at once.

Usage

mediaextract [option...] <filename> [<filename> ...]

Examples

Extract .wav, .aif and .ogg (might actually be .ogg, .opus or .ogm) files from the file data.bin and store them in the ~/Music directory.

mediaextract -f riff,aiff,ogg -o ~/Music data.bin

This will then write files like such into ~/Music:

data.bin_00000000.ogg
data.bin_00FFB2E3.wav
data.bin_01F3CD45.aif

The hexadecimal number in the written file names give the offset where in the data file the audio file was found.

Extract .mp3, .mp2 and .mp1 files (with or without ID3v2 tags). The mpg123 option yields a lot of false positives because there is no nice way to unambigiously detect MPEG files. These false positives are however usually very small, so using the --min-size option one can hopefully extract only real MPEG files.

mediaextract -f id3v2,mpg123 --min-size=100k -o ~/Music data.bin

Options

-h, --help             Print this help message.
-q, --quiet            Do not print status messages.
-s, --simulate         Don't write any output files.
-o, --output=DIR       Directory where extracted files should be written. (default: ".")
-i, --offset=OFFSET    Start processing at byte OFFSET. (default: 0)
-n, --length=LENGTH    Only process LENGTH bytes.
                       (default and maximum: 8 EB)
-m, --min-size=SIZE    Minumum size of extracted files (skip smaller). (default: 0)
-x, --max-size=SIZE    Maximum size of extracted files (skip larger).
                       (default and maximum: 16 EB)

                       The last character of OFFSET, LENGTH and SIZE may be one of the
                       following:
                         B (or none)  for Bytes
                         k            for Kilobytes (units of 1024 Bytes)
                         M            for Megabytes (units of 1024 Kilobytes)
                         G            for Gigabytes (units of 1024 Megabytes)
                         T            for Terabytes (units of 1024 Gigabytes)
                         P            for Petabytes (units of 1024 Terabytes)
                         E            for Exabytes  (units of 1024 Petabytes)

                       The special value "max" selects the maximum alowed value.

-f, --formats=FORMATS  Comma separated list of formats (file magics) to extract.

                       Supported formats:
                         all      all supported formats
                         default  the default set of formats (AIFF, ASF, AU, BINK, BMP,
                                  GIF, ID3v2, IT, JEPG, MIDI, MP4, Ogg, PNG, RIFF, S3M,
                                  SMK, XM)
                         audio    all audio files (AIFF, ASF, AU, ID3v2, IT, MIDI, MP4,
                                  Ogg, RIFF, S3M, XM)
                         image    all image files (BMP, PNG, JEPG, GIF)
                         tracker  all tracker files (MOD, S3M, IT, XM)
                         video    all video files (ASF, BINK, MP4, RIFF, SMK)

                         aiff     big-endian (Apple) wave files
                         asf      Advanced Systems Format files (also WMA and WMV)
                         au       Sun Microsystems audio file format (.au or .snd)
                         bink     BINK files
                         bmp      Windows Bitmap files
                         gif      Graphics Interchange Format files
                         id3v2    MPEG layer 1/2/3 files with ID3v2 tags
                         it       ImpulseTracker files
                         jepg     JPEG Interchange Format files
                         midi     MIDI files
                         mod      Noisetracker/Soundtracker/Protracker Module files
                         mpg123   MPEG layer 1/2/3 files (MP1, MP2, MP3)
                         mp4      MP4 files (M4A, M4V, 3GPP etc.)
                         ogg      Ogg files (Vorbis, Opus, Theora, etc.)
                         png      Portable Network Graphics files
                         riff     Resource Interchange File Format files (ANI, AVI, MMM,
                                  PAL, RDI, RMI, WAV)
                         s3m      ScreamTracker III files
                         smk      Smaker files
                         xm       Extended Module files

                       WARNING: Because MP1/2/3 files do not have a nice file magic, using
                       the 'mpg123' format may cause *a lot* of false positives. Nowadays
                       MP3 files usually have an ID3v2 tag at the start, so using the
                       'id3v2' format is the better option anyway.

                       The detection accuracy of MOD files is not much better and thus
                       the 'mpg123' and 'mod' formats are per default disabled.

                       NOTE: When using only the 'mpg123' format but not 'id3v2' any ID3v2
                       tag will be stripped. ID3v1 tags will still be kept.

                       If '-' is written before a format name the format will be
                       removed from the set of formats to extract. E.g. extract
                       everything except tracker files:

                         mediaextract --formats=all,-tracker data.bin