#------------------------------------------------------------------------------
-# $File: jpeg,v 1.19 2013/02/04 15:50:03 christos Exp $
+# $File: jpeg,v 1.20 2014/08/05 07:32:31 christos Exp $
# JPEG images
# SunOS 5.5.1 had
#
>>11 byte x \b %d.
>>12 byte x \b%02d
# Next, the resolution or aspect ratio of the image:
-#>>13 byte 0 \b, aspect ratio
-#>>13 byte 1 \b, resolution (DPI)
-#>>13 byte 2 \b, resolution (DPCM)
-#>>4 beshort x \b, segment length %d
+>>13 byte 0 \b, aspect ratio
+>>13 byte 1 \b, resolution (DPI)
+>>13 byte 2 \b, resolution (DPCM)
+>>14 beshort x \b, density %dx
+>>16 beshort x \b%d
+>>4 beshort x \b, segment length %d
# Next, show thumbnail info, if it exists:
>>18 byte !0 \b, thumbnail %dx
>>>19 byte x \b%d
>>>>>(150.L+59) byte x %c
>>>>>(150.L+60) byte x \b.%c
>>>>>(150.L+61) byte !0x30 \b%c
-# Here things get sticky. We can do ONE MORE marker segment with
-# indirect addressing, and that's all. It would be great if we could
-# do pointer arithemetic like in an assembler language. Christos?
-# And if there was some sort of looping construct to do searches, plus a few
-# named accumulators, it would be even more effective...
-# At least we can show a comment if no other segments got inserted before:
->(4.S+5) byte 0xFE \b, comment:
->>(4.S+6) pstring/HJ x "%s"
-# Or, we can show the encoding type (I've included only the three most common)
-# and image dimensions if we are lucky and the SOFn (image segment) is here:
-# from: http://www.w3.org/Graphics/JPEG/itu-t81.pdf p35
->(4.S+5) byte 0xC0 \b, baseline
->>(4.S+8) byte x \b, precision %d
->>(4.S+9) beshort x \b, %dx
->>(4.S+11) beshort x \b%d
->>(4.S+13) byte x \b, frames %d
->(4.S+5) byte 0xC1 \b, extended sequential
->>(4.S+8) byte x \b, precision %d
->>(4.S+9) beshort x \b, %dx
->>(4.S+11) beshort x \b%d
->>(4.S+13) byte x \b, frames %d
->(4.S+5) byte 0xC2 \b, progressive
->>(4.S+8) byte x \b, precision %d
->>(4.S+9) beshort x \b, %dx
->>(4.S+11) beshort x \b%d
->>(4.S+13) byte x \b, frames %d
-# I've commented-out quantisation table reporting. I doubt anyone cares yet.
-#>(4.S+5) byte 0xDB \b, quantisation table
-#>>(4.S+6) beshort x \b length=%d
-#>14 beshort x \b, %d x
-#>16 beshort x \b %d
+
+# Jump to the first segment
+>(4.S+4) use jpeg_segment
+
+# This uses recursion...
+0 name jpeg_segment
+>0 beshort 0xFFFE
+>>(2.S+2) use jpeg_segment
+>>2 pstring/HJ x \b, comment: "%s"
+
+>0 beshort 0xFFC0
+>>(2.S+2) use jpeg_segment
+>>4 byte x \b, baseline, precision %d
+>>7 beshort x \b, %dx
+>>5 beshort x \b%d
+>>9 byte x \b, frames %d
+
+>0 beshort 0xFFC1
+>>(2.S+2) use jpeg_segment
+>>4 byte x \b, extended sequential, precision %d
+>>7 beshort x \b, %dx
+>>5 beshort x \b%d
+>>9 byte x \b, frames %d
+
+>0 beshort 0xFFC2
+>>(2.S+2) use jpeg_segment
+>>4 byte x \b, progressive, precision %d
+>>7 beshort x \b, %dx
+>>5 beshort x \b%d
+>>9 byte x \b, frames %d
+
+# Define Huffman Tables
+>0 beshort 0xFFC4
+>>(2.S+2) use jpeg_segment
+
+# Application specific markers
+>0 beshort&0xFFE0 =0xFFE0
+>>(2.S+2) use jpeg_segment
+
+# DB: Define Quantization tables
+# DD: Define Restart interval [XXX: wrong here, it is 4 bytes]
+# D8: Start of image
+# D9: End of image
+# Dn: Restart
+>0 beshort&0xFFD0 =0xFFD0
+>>(2.S+2) use jpeg_segment
# HSI is Handmade Software's proprietary JPEG encoding scheme
0 string hsi1 JPEG image data, HSI proprietary
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