Fixes for webcams on Linux with MJPEG streams that omit Huffman tables

panda/src/vision/webcamVideoCursorV4L.cxx

@@ -30,12 +30,6 @@ extern "C" {
 #include <setjmp.h>
 #endif
 
-// This is supposed to be defined in jpegint.h,
-// but not all implementations of JPEG provide that file.
-#ifndef DSTATE_READY
-#define DSTATE_READY 202
-#endif
-
 TypeHandle WebcamVideoCursorV4L::_type_handle;
 
 #define clamp(x) min(max(x, 0.0), 255.0)
@@ -121,6 +115,69 @@ static void my_skip_input_data(j_decompress_ptr cinfo, long num_bytes) {
 static void my_term_source(j_decompress_ptr cinfo) {
 }
 
+// Huffman tables used for MJPEG streams that omit them.
+static JHUFF_TBL dc_luminance_tbl = {
+  {0, 0, 1, 5, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0},
+  {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11},
+  FALSE
+};
+
+static JHUFF_TBL dc_chrominance_tbl = {
+  {0, 0, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0},
+  {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11},
+  FALSE
+};
+
+static JHUFF_TBL ac_luminance_tbl = {
+  {0, 0, 2, 1, 3, 3, 2, 4, 3, 5, 5, 4, 4, 0, 0, 1, 0x7d},
+  {
+    0x01, 0x02, 0x03, 0x00, 0x04, 0x11, 0x05, 0x12, 0x21,
+    0x31, 0x41, 0x06, 0x13, 0x51, 0x61, 0x07, 0x22, 0x71,
+    0x14, 0x32, 0x81, 0x91, 0xa1, 0x08, 0x23, 0x42, 0xb1,
+    0xc1, 0x15, 0x52, 0xd1, 0xf0, 0x24, 0x33, 0x62, 0x72,
+    0x82, 0x09, 0x0a, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x25,
+    0x26, 0x27, 0x28, 0x29, 0x2a, 0x34, 0x35, 0x36, 0x37,
+    0x38, 0x39, 0x3a, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48,
+    0x49, 0x4a, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59,
+    0x5a, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x6a,
+    0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7a, 0x83,
+    0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8a, 0x92, 0x93,
+    0x94, 0x95, 0x96, 0x97, 0x98, 0x99, 0x9a, 0xa2, 0xa3,
+    0xa4, 0xa5, 0xa6, 0xa7, 0xa8, 0xa9, 0xaa, 0xb2, 0xb3,
+    0xb4, 0xb5, 0xb6, 0xb7, 0xb8, 0xb9, 0xba, 0xc2, 0xc3,
+    0xc4, 0xc5, 0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xd2, 0xd3,
+    0xd4, 0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda, 0xe1, 0xe2,
+    0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9, 0xea, 0xf1,
+    0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8, 0xf9, 0xfa
+  },
+  FALSE
+};
+
+static JHUFF_TBL ac_chrominance_tbl = {
+  {0, 0, 2, 1, 2, 4, 4, 3, 4, 7, 5, 4, 4, 0, 1, 2, 0x77},
+  {
+    0x00, 0x01, 0x02, 0x03, 0x11, 0x04, 0x05, 0x21, 0x31,
+    0x06, 0x12, 0x41, 0x51, 0x07, 0x61, 0x71, 0x13, 0x22,
+    0x32, 0x81, 0x08, 0x14, 0x42, 0x91, 0xa1, 0xb1, 0xc1,
+    0x09, 0x23, 0x33, 0x52, 0xf0, 0x15, 0x62, 0x72, 0xd1,
+    0x0a, 0x16, 0x24, 0x34, 0xe1, 0x25, 0xf1, 0x17, 0x18,
+    0x19, 0x1a, 0x26, 0x27, 0x28, 0x29, 0x2a, 0x35, 0x36,
+    0x37, 0x38, 0x39, 0x3a, 0x43, 0x44, 0x45, 0x46, 0x47,
+    0x48, 0x49, 0x4a, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58,
+    0x59, 0x5a, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69,
+    0x6a, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7a,
+    0x82, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8a,
+    0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99, 0x9a,
+    0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7, 0xa8, 0xa9, 0xaa,
+    0xb2, 0xb3, 0xb4, 0xb5, 0xb6, 0xb7, 0xb8, 0xb9, 0xba,
+    0xc2, 0xc3, 0xc4, 0xc5, 0xc6, 0xc7, 0xc8, 0xc9, 0xca,
+    0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda,
+    0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9, 0xea,
+    0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8, 0xf9, 0xfa
+  },
+  FALSE
+};
+
 #endif
 
 ////////////////////////////////////////////////////////////////////
@@ -343,18 +400,25 @@ fetch_buffer() {
 
     // Establish the setjmp return context for my_error_exit to use
     if (setjmp(jerr.setjmp_buffer)) {
-      if (_cinfo->global_state > DSTATE_READY) {
-        jpeg_abort_decompress(_cinfo);
-      }
+      jpeg_abort_decompress(_cinfo);
     } else {
       // Set up data pointer
       _cinfo->src->bytes_in_buffer = bufsize;
       _cinfo->src->next_input_byte = buf;
 
       if (jpeg_read_header(_cinfo, TRUE) == JPEG_HEADER_OK) {
+        if (_cinfo->dc_huff_tbl_ptrs[0] == NULL) {
+          // Many MJPEG streams do not include huffman tables.  Remedy this.
+          _cinfo->dc_huff_tbl_ptrs[0] = &dc_luminance_tbl;
+          _cinfo->dc_huff_tbl_ptrs[1] = &dc_chrominance_tbl;
+          _cinfo->ac_huff_tbl_ptrs[0] = &ac_luminance_tbl;
+          _cinfo->ac_huff_tbl_ptrs[1] = &ac_chrominance_tbl;
+        }
+
         _cinfo->scale_num = 1;
         _cinfo->scale_denom = 1;
         _cinfo->out_color_space = JCS_RGB;
+        _cinfo->dct_method = JDCT_IFAST;
 
         if (jpeg_start_decompress(_cinfo) && _cinfo->output_components == 3
           && _size_x == _cinfo->output_width && _size_y == _cinfo->output_height) {
@@ -363,7 +427,7 @@ fetch_buffer() {
           JSAMPLE *rowptr = newbuf;
           while (_cinfo->output_scanline < _cinfo->output_height) {
             nassertd(rowptr + new_bpl <= buffer_end) break;
-            jpeg_read_scanlines(_cinfo, &rowptr, 1);
+            jpeg_read_scanlines(_cinfo, &rowptr, _cinfo->output_height);
             rowptr += new_bpl;
           }