From eac141b69aea8840ccd8dfa5285f1cab5b59d5eb Mon Sep 17 00:00:00 2001 From: Francois-Olivier Devaux Date: Mon, 19 Feb 2007 09:59:29 +0000 Subject: [PATCH] Added OPJ_LIMIT_DECODING enabling us to limit the decoding to main header --- ChangeLog | 3 +++ libopenjpeg/j2k.c | 8 ++++++++ libopenjpeg/j2k.h | 2 ++ libopenjpeg/openjpeg.c | 1 + libopenjpeg/openjpeg.h | 16 ++++++++++++++++ 5 files changed, 30 insertions(+) diff --git a/ChangeLog b/ChangeLog index 42e940f0..57b582ab 100644 --- a/ChangeLog +++ b/ChangeLog @@ -5,6 +5,9 @@ What's New for OpenJPEG ! : changed + : added +February 19, 2007 ++ [FOD] Added OPJ_LIMIT_DECODING enabling us to limit the decoding to main header (modified openjpeg.c, openjpeg.h, j2k.c and j2k.h) + February 13, 2007 ! [FOD] David Fries suggestions. In image_to_j2k and j2k_to_image, strncpy() functions: instead of specifying the path size macro, let the compiler read the length out of the array entry. ! [FOD] David Fries suggestions. Makefile modified. -fPIC flag used for 64-bit compilation. Move operation (rather than copy) for the dist library creation, and -p flag added. diff --git a/libopenjpeg/j2k.c b/libopenjpeg/j2k.c index 6e232f27..db291ff2 100644 --- a/libopenjpeg/j2k.c +++ b/libopenjpeg/j2k.c @@ -1522,6 +1522,7 @@ void j2k_setup_decoder(opj_j2k_t *j2k, opj_dparameters_t *parameters) { opj_cp_t *cp = (opj_cp_t*)opj_malloc(sizeof(opj_cp_t)); cp->reduce = parameters->cp_reduce; cp->layer = parameters->cp_layer; + cp->limit_decoding = parameters->cp_limit_decoding; /* UniPG>> */ #ifdef USE_JPWL cp->correct = parameters->jpwl_correct; @@ -1594,11 +1595,18 @@ opj_image_t* j2k_decode(opj_j2k_t *j2k, opj_cio_t *cio) { return 0; } e = j2k_dec_mstab_lookup(id); + // Check if the marker is known if (!(j2k->state & e->states)) { opj_image_destroy(image); opj_event_msg(cinfo, EVT_ERROR, "%.8x: unexpected marker %x\n", cio_tell(cio) - 2, id); return 0; } + // Check if the decoding is limited to the main header + if (e->id == J2K_MS_SOT && j2k->cp->limit_decoding == LIMIT_TO_MAIN_HEADER) { + opj_event_msg(cinfo, EVT_INFO, "Main Header decoded.\n"); + return image; + } + if (e->handler) { (*e->handler)(j2k); } diff --git a/libopenjpeg/j2k.h b/libopenjpeg/j2k.h index 00ccacfc..9738bf85 100644 --- a/libopenjpeg/j2k.h +++ b/libopenjpeg/j2k.h @@ -197,6 +197,8 @@ typedef struct opj_cp { int reduce; /** if != 0, then only the first "layer" layers are decoded; if == 0 or not used, all the quality layers are decoded */ int layer; + /** if == NO_LIMITATION, decode entire codestream; if == LIMIT_TO_MAIN_HEADER then only decode the main header */ + OPJ_LIMIT_DECODING limit_decoding; /** 0 = no index || 1 = index */ int index_on; /** XTOsiz */ diff --git a/libopenjpeg/openjpeg.c b/libopenjpeg/openjpeg.c index e90fbb68..b522939e 100644 --- a/libopenjpeg/openjpeg.c +++ b/libopenjpeg/openjpeg.c @@ -116,6 +116,7 @@ void OPJ_CALLCONV opj_set_default_decoder_parameters(opj_dparameters_t *paramete /* default decoding parameters */ parameters->cp_layer = 0; parameters->cp_reduce = 0; + parameters->cp_limit_decoding = NO_LIMITATION; parameters->decod_format = -1; parameters->cod_format = -1; diff --git a/libopenjpeg/openjpeg.h b/libopenjpeg/openjpeg.h index 39290106..8e9da446 100644 --- a/libopenjpeg/openjpeg.h +++ b/libopenjpeg/openjpeg.h @@ -143,6 +143,14 @@ typedef enum CODEC_FORMAT { CODEC_JP2 = 2 /**< JPEG-2000 file format : read/write */ } OPJ_CODEC_FORMAT; +/** +Limit decoding to certain portions of the codestream. +*/ +typedef enum LIMIT_DECODING { + NO_LIMITATION = 0, /**< No limitation for the decoding. The entire codestream will de decoded */ + LIMIT_TO_MAIN_HEADER = 1 /**< The decoding is limited to the Main Header */ +} OPJ_LIMIT_DECODING; + /* ========================================================== event manager typedef definitions @@ -331,6 +339,14 @@ typedef struct opj_dparameters { */ int cp_layer; + /** + Specify whether the decoding should be done on the entire codestream, or be limited to the main header + Limiting the decoding to the main header makes it possible to extract the characteristics of the codestream + if == NO_LIMITATION, the entire codestream is decoded; + if == LIMIT_TO_MAIN_HEADER, only the main header is decoded; + */ + OPJ_LIMIT_DECODING cp_limit_decoding; + /**@name command line encoder parameters (not used inside the library) */ /*@{*/ /** input file name */