Lines Matching full:markers
45 Special markers
573 This will read the source datastream header markers, up to the beginning
910 To emit restart markers in the JPEG file, set one of these nonzero.
916 NOTE: the overhead of restart markers is higher in grayscale JPEG
948 any JFIF 1.02 extension markers.
1214 The de-facto file format standards (JFIF and Adobe) specify APPn markers that
1218 will set the compression parameters to include or omit the APPn markers
1224 markers", below.
1494 the likely location of restart markers, you may be able to do better.
1579 markers at the beginning and end of the file. This means that:
1581 space in the output buffer to hold the header markers (typically 600 or
1584 this restriction might catch you if you insert large special markers, such
1640 and insert dummy EOI markers just as a non-suspending data source manager
1647 The decompressor does not attempt to suspend within standard JPEG markers;
1650 longest standard marker in the file. Standard JPEG markers should normally
1662 markers, but these are handled specially: they are either saved into allocated
1666 Note that if you provide your own marker handling routine for large markers,
1993 * jpeg_finish_output() will read any markers following the target scan,
2120 input processing, including reading the initial markers; that is, you may
2132 initial markers have been read: it will just return JPEG_SUSPENDED.
2200 containing only SOI, DQT and/or DHT markers, and EOI. All the quantization
2312 Special markers
2318 Unfortunately, the use of these markers is not specified by the standard.
2319 COM markers are fairly widely used to hold user-supplied text. The JFIF file
2320 format spec uses APP0 markers with specified initial strings to hold certain
2321 data. Adobe applications use APP14 markers beginning with the string "Adobe"
2322 for miscellaneous data. Other APPn markers are rarely seen, but might
2325 If you wish to store user-supplied text, we recommend you use COM markers
2329 garbage, including nulls, since some applications generate COM markers
2334 It's probably best to avoid using APP0 or APP14 for any private markers.
2335 (NOTE: the upcoming SPIFF standard will use APP8 markers; we recommend you
2336 not use APP8 markers for any private purposes, either.)
2339 can have as many markers as you like.
2345 Adobe markers and will set the JPEG colorspace properly when one is found.
2348 You can write special markers immediately following the datastream header by
2350 call to jpeg_write_scanlines(). When you do this, the markers appear after
2351 the SOI and the JFIF APP0 and Adobe APP14 markers (if written), but before
2366 any special markers. See "I/O suspension".)
2371 If you are writing JFIF 1.02 extension markers (thumbnail images), don't
2375 markers. (We could probably get away with just defaulting to 1.02, but there
2381 When reading, two methods of handling special markers are available:
2382 1. You can ask the library to save the contents of COM and/or APPn markers
2384 2. You can supply your own routine to process COM and/or APPn markers
2394 markers of interest will typically be near the head of the file and so will
2398 determined separately for COM markers and for each APPn marker code.
2401 To save the contents of special markers in memory, call
2413 After jpeg_read_header() completes, you can examine the special markers by
2414 following the cinfo->marker_list pointer chain. All the special markers in
2416 omitting any markers of types you didn't ask for). Both the original data
2423 It is possible that additional special markers appear in the file beyond the
2429 of later markers.
2435 Note that the library is internally interested in APP0 and APP14 markers;
2458 recognize JFIF and Adobe markers if you want colorspace recognition to occur
2462 with the library's own processing of these markers.)
