-
-
-/*
- * SOME FINE POINTS:
- *
- * In the above loop, we ignored the return value of jpeg_write_scanlines,
- * which is the number of scanlines actually written. We could get away
- * with this because we were only relying on the value of cinfo.next_scanline,
- * which will be incremented correctly. If you maintain additional loop
- * variables then you should be careful to increment them properly.
- * Actually, for output to a stdio stream you needn't worry, because
- * then jpeg_write_scanlines will write all the lines passed (or else exit
- * with a fatal error). Partial writes can only occur if you use a data
- * destination module that can demand suspension of the compressor.
- * (If you don't know what that's for, you don't need it.)
- *
- * If the compressor requires full-image buffers (for entropy-coding
- * optimization or a multi-scan JPEG file), it will create temporary
- * files for anything that doesn't fit within the maximum-memory setting.
- * (Note that temp files are NOT needed if you use the default parameters.)
- * On some systems you may need to set up a signal handler to ensure that
- * temporary files are deleted if the program is interrupted. See libjpeg.doc.
- *
- * Scanlines MUST be supplied in top-to-bottom order if you want your JPEG
- * files to be compatible with everyone else's. If you cannot readily read
- * your data in that order, you'll need an intermediate array to hold the
- * image. See rdtarga.c or rdbmp.c for examples of handling bottom-to-top
- * source data using the JPEG code's internal virtual-array mechanisms.
- */
-
-
-
-/******************** JPEG DECOMPRESSION SAMPLE INTERFACE *******************/
-
-/* This half of the example shows how to read data from the JPEG decompressor.
- * It's a bit more refined than the above, in that we show:
- * (a) how to modify the JPEG library's standard error-reporting behavior;
- * (b) how to allocate workspace using the library's memory manager.
- *
- * Just to make this example a little different from the first one, we'll
- * assume that we do not intend to put the whole image into an in-memory
- * buffer, but to send it line-by-line someplace else. We need a one-
- * scanline-high JSAMPLE array as a work buffer, and we will let the JPEG
- * memory manager allocate it for us. This approach is actually quite useful
- * because we don't need to remember to deallocate the buffer separately: it
- * will go away automatically when the JPEG object is cleaned up.
- */
-
-/*
- * ERROR HANDLING:
- *
- * The JPEG library's standard error handler (jerror.c) is divided into
- * several "methods" which you can override individually. This lets you
- * adjust the behavior without duplicating a lot of code, which you might
- * have to update with each future release.
- *
- * Our example here shows how to override the "error_exit" method so that
- * control is returned to the library's caller when a fatal error occurs,
- * rather than calling exit() as the standard error_exit method does.
- *
- * We use C's setjmp/longjmp facility to return control. This means that the
- * routine which calls the JPEG library must first execute a setjmp() call to
- * establish the return point. We want the replacement error_exit to do a
- * longjmp(). But we need to make the setjmp buffer accessible to the
- * error_exit routine. To do this, we make a private extension of the
- * standard JPEG error handler object. (If we were using C++, we'd say we
- * were making a subclass of the regular error handler.)
- *
- * Here's the extended error handler struct:
- */
-