summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
Diffstat
-rw-r--r--jhead.h2
-rwxr-xr-xjpgfile.c253
2 files changed, 255 insertions, 0 deletions
diff --git a/jhead.h b/jhead.h
index 59130cf..6a71745 100644
--- a/jhead.h
+++ b/jhead.h
@@ -237,6 +237,8 @@ int WriteJpegFile(const char * FileName);
Section_t * FindSection(int SectionType);
Section_t * CreateSection(int SectionType, unsigned char * Data, int size);
void ResetJpgfile(void);
+int ReadJpegSectionsFromBuffer (unsigned char* buffer, unsigned int buffer_size, ReadMode_t ReadMode);
+int WriteJpegToBuffer(unsigned char* buffer, unsigned int buffer_size);
// Variables from jhead.c used by exif.c
extern ImageInfo_t ImageInfo;
diff --git a/jpgfile.c b/jpgfile.c
index 99d7293..4cfeb1d 100755
--- a/jpgfile.c
+++ b/jpgfile.c
@@ -310,6 +310,195 @@ int ReadJpegSections (FILE * infile, ReadMode_t ReadMode)
}
//--------------------------------------------------------------------------
+// Parse the marker buffer until SOS or EOI is seen;
+//--------------------------------------------------------------------------
+int ReadJpegSectionsFromBuffer (unsigned char* buffer, unsigned int buffer_size, ReadMode_t ReadMode)
+{
+ int a;
+ unsigned int pos = 0;
+ int HaveCom = FALSE;
+
+ if (!buffer) {
+ return FALSE;
+ }
+
+ if (buffer_size < 1) {
+ return FALSE;
+ }
+
+ a = (int) buffer[pos++];
+
+ if (a != 0xff || buffer[pos++] != M_SOI){
+ return FALSE;
+ }
+
+ for(;;){
+ int itemlen;
+ int marker = 0;
+ int ll,lh, got;
+ uchar * Data;
+
+ CheckSectionsAllocated();
+
+ for (a=0;a<=16;a++){
+ marker = buffer[pos++];
+ if (marker != 0xff) break;
+
+ if (a >= 16){
+ fprintf(stderr,"too many padding bytes\n");
+ return FALSE;
+ }
+ }
+
+ Sections[SectionsRead].Type = marker;
+
+ // Read the length of the section.
+ lh = buffer[pos++];
+ ll = buffer[pos++];
+
+ itemlen = (lh << 8) | ll;
+
+ if (itemlen < 2) {
+ LOGE("invalid marker");
+ return FALSE;
+ }
+
+ Sections[SectionsRead].Size = itemlen;
+
+ Data = (uchar *)malloc(itemlen);
+ if (Data == NULL) {
+ LOGE("Could not allocate memory");
+ return 0;
+ }
+ Sections[SectionsRead].Data = Data;
+
+ // Store first two pre-read bytes.
+ Data[0] = (uchar)lh;
+ Data[1] = (uchar)ll;
+
+ if (pos+itemlen-2 > buffer_size) {
+ LOGE("Premature end of file?");
+ return FALSE;
+ }
+
+ memcpy(Data+2, buffer+pos, itemlen-2); // Read the whole section.
+ pos += itemlen-2;
+
+ SectionsRead += 1;
+
+ printf("reading marker %d", marker);
+ switch(marker){
+
+ case M_SOS: // stop before hitting compressed data
+ // If reading entire image is requested, read the rest of the data.
+ if (ReadMode & READ_IMAGE){
+ int size;
+ // Determine how much file is left.
+ size = buffer_size - pos;
+
+ if (size < 1) {
+ LOGE("could not read the rest of the image");
+ return FALSE;
+ }
+ Data = (uchar *)malloc(size);
+ if (Data == NULL) {
+ LOGE("%d: could not allocate data for entire image size: %d", __LINE__, size);
+ return FALSE;
+ }
+
+ memcpy(Data, buffer+pos, size);
+
+ CheckSectionsAllocated();
+ Sections[SectionsRead].Data = Data;
+ Sections[SectionsRead].Size = size;
+ Sections[SectionsRead].Type = PSEUDO_IMAGE_MARKER;
+ SectionsRead ++;
+ HaveAll = 1;
+ }
+ return TRUE;
+
+ case M_EOI: // in case it's a tables-only JPEG stream
+ LOGE("No image in jpeg!\n");
+ return FALSE;
+
+ case M_COM: // Comment section
+ if (HaveCom || ((ReadMode & READ_METADATA) == 0)){
+ // Discard this section.
+ free(Sections[--SectionsRead].Data);
+ }else{
+ process_COM(Data, itemlen);
+ HaveCom = TRUE;
+ }
+ break;
+
+ case M_JFIF:
+ // Regular jpegs always have this tag, exif images have the exif
+ // marker instead, althogh ACDsee will write images with both markers.
+ // this program will re-create this marker on absence of exif marker.
+ // hence no need to keep the copy from the file.
+ free(Sections[--SectionsRead].Data);
+ break;
+
+ case M_EXIF:
+ // There can be different section using the same marker.
+ if (ReadMode & READ_METADATA){
+ if (memcmp(Data+2, "Exif", 4) == 0){
+ process_EXIF(Data, itemlen);
+ break;
+ }else if (memcmp(Data+2, "http:", 5) == 0){
+ Sections[SectionsRead-1].Type = M_XMP; // Change tag for internal purposes.
+ if (ShowTags){
+ LOGD("Image cotains XMP section, %d bytes long\n", itemlen);
+ if (ShowTags){
+ ShowXmp(Sections[SectionsRead-1]);
+ }
+ }
+ break;
+ }
+ }
+ // Oterwise, discard this section.
+ free(Sections[--SectionsRead].Data);
+ break;
+
+ case M_IPTC:
+ if (ReadMode & READ_METADATA){
+ if (ShowTags){
+ LOGD("Image cotains IPTC section, %d bytes long\n", itemlen);
+ }
+ // Note: We just store the IPTC section. Its relatively straightforward
+ // and we don't act on any part of it, so just display it at parse time.
+ }else{
+ free(Sections[--SectionsRead].Data);
+ }
+ break;
+
+ case M_SOF0:
+ case M_SOF1:
+ case M_SOF2:
+ case M_SOF3:
+ case M_SOF5:
+ case M_SOF6:
+ case M_SOF7:
+ case M_SOF9:
+ case M_SOF10:
+ case M_SOF11:
+ case M_SOF13:
+ case M_SOF14:
+ case M_SOF15:
+ process_SOFn(Data, marker);
+ break;
+ default:
+ // Skip any other sections.
+ if (ShowTags){
+ LOGD("Jpeg section marker 0x%02x size %d\n",marker, itemlen);
+ }
+ break;
+ }
+ }
+ return TRUE;
+}
+
+//--------------------------------------------------------------------------
// Discard read data.
//--------------------------------------------------------------------------
void DiscardData(void)
@@ -585,6 +774,70 @@ int WriteJpegFile(const char * FileName)
return writeOk;
}
+//--------------------------------------------------------------------------
+// Write image to a buffer
+//--------------------------------------------------------------------------
+int WriteJpegToBuffer(unsigned char* buffer, unsigned int buffer_size)
+{
+ unsigned int pos = 0;
+ int a;
+
+ if (!buffer) {
+ return FALSE;
+ }
+
+ if (buffer_size < 1) {
+ return FALSE;
+ }
+
+ if (!HaveAll){
+ LOGE("Can't write back - didn't read all");
+ return FALSE;
+ }
+
+ // Initial static jpeg marker.
+ buffer[pos++] = 0xff;
+ buffer[pos++] = 0xd8;
+
+ if (Sections[0].Type != M_EXIF && Sections[0].Type != M_JFIF){
+ // The image must start with an exif or jfif marker. If we threw those away, create one.
+ static uchar JfifHead[18] = {
+ 0xff, M_JFIF,
+ 0x00, 0x10, 'J' , 'F' , 'I' , 'F' , 0x00, 0x01,
+ 0x01, 0x01, 0x01, 0x2C, 0x01, 0x2C, 0x00, 0x00
+ };
+ memcpy(buffer+pos, JfifHead, 18);
+ pos+= 18;
+ }
+
+ int writeOk = FALSE;
+ int nWrite = 0;
+ // Write all the misc sections
+ for (a=0;a<SectionsRead-1;a++){
+ buffer[pos++] = 0xff;
+ buffer[pos++] = (unsigned char) Sections[a].Type;
+ if (pos+Sections[a].Size > buffer_size) {
+ writeOk = FALSE;
+ break;
+ }
+ memcpy(buffer+pos, Sections[a].Data, Sections[a].Size);
+ pos += Sections[a].Size;
+ writeOk = TRUE;
+ }
+
+ // Write the remaining image data.
+ if (writeOk){
+ if (pos+Sections[a].Size > buffer_size) {
+ writeOk = FALSE;
+ } else {
+ memcpy(buffer+pos, Sections[a].Data, Sections[a].Size);
+ pos += Sections[a].Size;
+ writeOk = TRUE;
+ }
+ }
+ return writeOk;
+}
+
//--------------------------------------------------------------------------
// Check if image has exif header.
generated by cgit v1.2.3 (git 2.25.1) at 2024-07-05 12:29:35 +0000