Show all the markers from a JPG file and dump all frames
Build it with "make" and run it like:
$ ./jpeg-markers image.jpg
Offset: 0 - FFD8: SOI
Offset: 2 - FFE0: JFIF [V:1 U:1/1 Xd:72 Yd:72 Xt:0 Yt:0]
Offset: 14 - FFED: APP13
Offset: 223c - FFE1: EXIF
Offset: 2262 - FFE2: APP2
Offset: 2ebc - FFE1: EXIF
Offset: 448f - FFDB: Define Quantization
Offset: 44d4 - FFDB: Define Quantization
Offset: 4519 - FFC2: Start of Frame (progressive) [P:8, Y:522, X:783, Nf:3]
Offset: 452c - FFC4: Define Huffman
Offset: 454b - FFC4: Define Huffman
Offset: 4565 - FFDA: Start of Scan [NC:3] (8184 bytes)
Offset: 656b - FFC4: Define Huffman
Offset: 659f - FFDA: Start of Scan [NC:1] (21274 bytes)
Offset: b8c3 - FFC4: Define Huffman
Offset: b8f8 - FFDA: Start of Scan [NC:1] (1333 bytes)
Offset: be37 - FFC4: Define Huffman
Offset: be6b - FFDA: Start of Scan [NC:1] (1282 bytes)
Offset: c377 - FFC4: Define Huffman
Offset: c3cc - FFDA: Start of Scan [NC:1] (147491 bytes)
Offset: 303f9 - FFC4: Define Huffman
Offset: 30422 - FFDA: Start of Scan [NC:1] (44414 bytes)
Offset: 3b1aa - FFDA: Start of Scan [NC:3] (2426 bytes)
Offset: 3bb32 - FFC4: Define Huffman
Offset: 3bb57 - FFDA: Start of Scan [NC:1] (575 bytes)
Offset: 3bda0 - FFC4: Define Huffman
Offset: 3bdc5 - FFDA: Start of Scan [NC:1] (577 bytes)
Offset: 3c010 - FFC4: Define Huffman
Offset: 3c039 - FFDA: Start of Scan [NC:1] (48374 bytes)
Offset: 47d39 - FFD9: End of Image
Found 10 scans
(Fields gotten from http://www.videotechnology.com/jpeg/j1.html)
To extract the various scans, use the -e option.
$ ./jpeg-markers -e image.jpg
[...]
Found 10 scans
Saving scan 0 to image-0.jpg
[...]
Saving scan 1 to image-1.jpg
[...]
Saving scan 2 to image-2.jpg
[...]
$ ls -al
total 1568
drwxr-xr-x 18 edwin staff 576 2 Aug 15:17 .
drwx------+ 37 edwin staff 1184 2 Aug 15:01 ..
drwxr-xr-x 13 edwin staff 416 2 Aug 15:12 .git
-rw-r--r-- 1 edwin staff 1320 2 Aug 15:01 LICENSE
-rw-r--r-- 1 edwin staff 66 2 Aug 15:02 Makefile
-rw-r--r-- 1 edwin staff 26363 2 Aug 15:17 image-0.jpg
-rw-r--r-- 1 edwin staff 39449 2 Aug 15:17 image-1.jpg
-rw-r--r-- 1 edwin staff 19508 2 Aug 15:17 image-2.jpg
-rw-r--r-- 1 edwin staff 19457 2 Aug 15:17 image-3.jpg
-rw-r--r-- 1 edwin staff 165666 2 Aug 15:17 image-4.jpg
-rw-r--r-- 1 edwin staff 62589 2 Aug 15:17 image-5.jpg
-rw-r--r-- 1 edwin staff 20605 2 Aug 15:17 image-6.jpg
-rw-r--r-- 1 edwin staff 18750 2 Aug 15:17 image-7.jpg
-rw-r--r-- 1 edwin staff 18752 2 Aug 15:17 image-8.jpg
-rw-r--r-- 1 edwin staff 66549 2 Aug 15:17 image-9.jpg
-rw-r--r-- 1 edwin staff 294203 2 Aug 15:13 image.jpg
-rwxr-xr-x 1 edwin staff 13476 2 Aug 15:13 jpeg-markers
-rw-r--r-- 1 edwin staff 3668 2 Aug 15:12 jpeg-markers.c