X-Git-Url: http://www.privoxy.org/gitweb/?p=privoxy.git;a=blobdiff_plain;f=deanimate.c;h=f7aead82c1e8c7172be887b60488b9d285b0e68f;hp=07515005e24f2ac64ce5f911321e6db8717b3a3a;hb=3fae4c0f831bf0d681a20ab55e1d082d24cf5522;hpb=b277622f6ab31e2787cb5f72fe47cd3a9c198d63 diff --git a/deanimate.c b/deanimate.c index 07515005..f7aead82 100644 --- a/deanimate.c +++ b/deanimate.c @@ -1,7 +1,7 @@ -const char deanimate_rcs[] = "$Id: $"; +const char deanimate_rcs[] = "$Id: deanimate.c,v 1.4 2001/07/18 12:28:49 oes Exp $"; /********************************************************************* * - * File : $Source: $ + * File : $Source: /cvsroot/ijbswa/current/deanimate.c,v $ * * Purpose : Declares functions to deanimate GIF images on the fly. * @@ -9,8 +9,8 @@ const char deanimate_rcs[] = "$Id: $"; * buf_copy, buf_getbyte, gif_skip_data_block, and * gif_extract_image * - * Copyright : Written by and Copyright (C) 2001 Andreas S. Oesterhelt - * for the SourceForge IJBSWA team. http://ijbswa.sourceforge.net + * Copyright : Written by and Copyright (C) 2001 by the the SourceForge + * IJBSWA team. http://ijbswa.sourceforge.net * * Based on the GIF file format specification (see * http://tronche.com/computer-graphics/gif/gif89a.html) @@ -36,17 +36,33 @@ const char deanimate_rcs[] = "$Id: $"; * Temple Place - Suite 330, Boston, MA 02111-1307, USA. * * Revisions : - * $Log: $ + * $Log: deanimate.c,v $ + * Revision 1.4 2001/07/18 12:28:49 oes + * - Added feature for extracting the first frame + * to gif_deanimate + * - Separated image buffer extension into buf_extend + * - Extended gif deanimation to GIF87a (untested!) + * - Cosmetics + * + * Revision 1.3 2001/07/15 13:57:50 jongfoster + * Adding #includes string.h and miscutil.h + * + * Revision 1.2 2001/07/13 13:46:20 oes + * Introduced GIF deanimation feature + * * **********************************************************************/ #include "config.h" -#include "project.h" -#include "deanimate.h" +#include #include +#include "project.h" +#include "deanimate.h" +#include "miscutil.h" + const char deanimate_h_rcs[] = DEANIMATE_H_VERSION; /********************************************************************* @@ -75,6 +91,48 @@ void buf_free(struct binbuffer *buf) } +/********************************************************************* + * + * Function : buf_extend + * + * Description : Ensure that a given binbuffer can hold a given amount + * of bytes, by reallocating its buffer if necessary. + * Allocate new mem in chunks of 1000 bytes, so we don't + * have to realloc() too often. + * + * Parameters : + * 1 : buf = Pointer to the binbuffer + * 2 : length = Desired minimum size + * + * + * Returns : 0 on success, 1 on failiure. + * + *********************************************************************/ +int buf_extend(struct binbuffer *buf, int length) +{ + char *newbuf; + + if (buf->offset + length > buf->size) + { + buf->size = buf->size + length + 1000 - (buf->size + length) % 1000; + newbuf = (char *)realloc(buf->buffer, buf->size); + + if (newbuf == NULL) + { + freez(buf->buffer); + return 1; + } + else + { + buf->buffer = newbuf; + return 0; + } + } + return 0; + +} + + /********************************************************************* * * Function : buf_copy @@ -93,7 +151,6 @@ void buf_free(struct binbuffer *buf) *********************************************************************/ int buf_copy(struct binbuffer *src, struct binbuffer *dst, int length) { - char *p; /* * Sanity check: Can't copy more data than we have @@ -104,20 +161,11 @@ int buf_copy(struct binbuffer *src, struct binbuffer *dst, int length) } /* - * If dst can't hold the new data, get mem first. (In chunks - * of 1000 bytes, so we don't have to realloc() too often) + * Ensure that dst can hold the new data */ - if (dst->offset + length > dst->size) + if (buf_extend(dst, length)) { - dst->size = dst->size + length + 1000 - (dst->size + length) % 1000; - p = dst->buffer; - dst->buffer = (char *)realloc(dst->buffer, dst->size); - - if (dst->buffer == NULL) - { - free(p); - return 1; - } + return 1; } /* @@ -167,7 +215,7 @@ unsigned char buf_getbyte(struct binbuffer *src, int offset) * * Description : Safely advances the offset of a given struct binbuffer * that contains a GIF image and whose offset is - * positioned at the start of a data block behind + * positioned at the start of a data block, behind * that block. * * Parameters : @@ -185,7 +233,7 @@ int gif_skip_data_block(struct binbuffer *buf) * by a one-byte length field, with the last chunk having * zero length. */ - while(c = buf_getbyte(buf, 0)) + while((c = buf_getbyte(buf, 0))) { if ((buf->offset += c + 1) >= buf->size - 1) { @@ -243,7 +291,7 @@ int gif_extract_image(struct binbuffer *src, struct binbuffer *dst) /* * Copy the image chunk by chunk. */ - while(c = buf_getbyte(src, 0)) + while((c = buf_getbyte(src, 0))) { if (buf_copy(src, dst, c + 1)) return 1; } @@ -252,7 +300,7 @@ int gif_extract_image(struct binbuffer *src, struct binbuffer *dst) /* * Trim and rewind the dst buffer */ - dst->buffer = (char *)realloc(dst->buffer, dst->offset); + if (NULL == (dst->buffer = (char *)realloc(dst->buffer, dst->offset))) return 1; dst->size = dst->offset; dst->offset = 0; @@ -274,11 +322,13 @@ int gif_extract_image(struct binbuffer *src, struct binbuffer *dst) * Parameters : * 1 : src = Pointer to the source binbuffer * 2 : dst = Pointer to the destination binbuffer + * 3 : get_first_image = Flag: If set, get the first image + * If unset (default), get the last * * Returns : 0 on success, or 1 on failiure * *********************************************************************/ -int gif_deanimate(struct binbuffer *src, struct binbuffer *dst) +int gif_deanimate(struct binbuffer *src, struct binbuffer *dst, int get_first_image) { unsigned char c; struct binbuffer *image; @@ -293,9 +343,8 @@ int gif_deanimate(struct binbuffer *src, struct binbuffer *dst) /* * Check & copy GIF header */ - if (strncmp(src->buffer, "GIF89a", 6)) + if (strncmp(src->buffer, "GIF89a", 6) && strncmp(src->buffer, "GIF87a", 6)) { - fprintf(stderr, "This is not a GIF98a!\n"); return 1; } else @@ -337,22 +386,15 @@ int gif_deanimate(struct binbuffer *src, struct binbuffer *dst) * End-of-GIF Marker: Append current image and return */ case 0x3b: - if (buf_copy(image, dst, image->size) || buf_copy(src, dst, 1)) - { - goto failed; - } - buf_free(image); - return(0); + goto write; /* - * Image block: Extract to current image buffer + * Image block: Extract to current image buffer. */ case 0x2c: image->offset = 0; - if (gif_extract_image(src, image)) - { - goto failed; - } + if (gif_extract_image(src, image)) goto failed; + if (get_first_image) goto write; continue; /* @@ -369,6 +411,7 @@ int gif_deanimate(struct binbuffer *src, struct binbuffer *dst) image->offset = 0; if (buf_copy(src, image, 8) || buf_getbyte(src, 0) != 0x2c) goto failed; if (gif_extract_image(src, image)) goto failed; + if (get_first_image) goto write; continue; /* @@ -419,6 +462,17 @@ failed: buf_free(image); return 1; + /* + * Append the current image to dst and return + */ + +write: + if (buf_copy(image, dst, image->size)) goto failed; + if (buf_extend(dst, 1)) goto failed; + *(dst->buffer + dst->offset++) = 0x3b; + buf_free(image); + return 0; + }