trimming images according to exif lengths form the 0-padded raw data

extract_images_tiff.php

@@ -25,6 +25,7 @@ Found problem - does not process files that start in one chunk and end in anothe
 */
    define('START_TIFF',     hex2bin('4d4d002a')); // start of a TIFF, JP/JP4 also have this TIFF marker
    define('START_JP',       hex2bin('ffd8ffe1')); // start of JPEG/JP4, TIFF usually does not have JPEG/JP4 markers
+   define('MAX_HEAD_LEN',   0x300);               // maximal header length that includes complete header
 //disable the default time limit for php scripts.
 set_time_limit(0);
 
@@ -205,16 +206,23 @@ function split_file($path,$file,$destination,$add_to_chn=-1){
       fseek($f,$markers[$i]);
       $s = fread($f,$markers[$i+1]-$markers[$i]);
 
-      $tmp_name = "$path/$destination/image.tmp";
-      file_put_contents($tmp_name,$s);
-
-      $result_name = elphel_specific_result_name($tmp_name,$add_to_chn);
+      $tmp_name = "$path/$destination/header.tmp"; // image.tmp";
+//      file_put_contents($tmp_name,$s);
+      file_put_contents($tmp_name,substr($s, 0, MAX_HEAD_LEN)); // only save beginning of the file
+//      printf ("header length = %d\n", strlen(substr($s, 0, MAX_HEAD_LEN)));
+      $image_length=-1;
+      $result_name = elphel_specific_result_name($tmp_name, $image_length, $add_to_chn);
+      if ($image_length < 0){
+          printf ("Wrong image length from Exif header: %d", $image_length);
+          exit(1);
+      }
       $dest_image = "$path/$destination/$result_name"; // $result_name may now include "/"
       $dest_set_dir = dirname($dest_image);
       if (!is_dir($dest_set_dir)){
           mkdir($dest_set_dir,0777);
       }
-      rename($tmp_name, $dest_image); // "$path/$destination/$result_name");
+//      rename($tmp_name, $dest_image); // "$path/$destination/$result_name");
+      file_put_contents($dest_image,substr($s, 0, $image_length));
     }
     
     return 0;
@@ -224,8 +232,7 @@ function split_file($path,$file,$destination,$add_to_chn=-1){
 }
 
 
-function elphel_specific_result_name($file,$add_to_chn=-10){
-
+function elphel_specific_result_name($file, &$image_length, $add_to_chn=-10){
   global $forced_ext;
   // $add_to_chn<0 - do not use it and do not use scene directories
   $use_scene_dirs = $add_to_chn >= 0;
@@ -234,7 +241,8 @@ function elphel_specific_result_name($file,$add_to_chn=-10){
   }
 
   $exif = exif_read_data($file); // gets false find, what is wrong
-  
+  // image size = ([StripOffsets] => 557)+ ([StripByteCounts] => 656640)
+  $image_length = intval($exif['StripOffsets']) + intval($exif['StripByteCounts']);
   $ext = elphel_specific_result_ext($exif,$forced_ext);
   
   //converting GMT a local time GMT+7