1 files changed, 102 insertions, 14 deletions

diff --git a/server/mjpeg_encoder.c b/server/mjpeg_encoder.c
index 30f15efb..ae48da53 100644
--- a/server/mjpeg_encoder.c
+++ b/server/mjpeg_encoder.c
@@ -21,6 +21,7 @@
 
 #include "red_common.h"
 #include "mjpeg_encoder.h"
+#include <jerror.h>
 #include <jpeglib.h>
 
 struct MJpegEncoder {
@@ -74,33 +75,120 @@ size_t mjpeg_encoder_get_frame_stride(MJpegEncoder *encoder)
     return encoder->stride;
 }
 
-static void init_destination(j_compress_ptr cinfo)
+
+/* code from libjpeg 8 to handle compression to a memory buffer
+ *
+ * Copyright (C) 1994-1996, Thomas G. Lane.
+ * Modified 2009 by Guido Vollbeding.
+ * This file is part of the Independent JPEG Group's software.
+ */
+typedef struct {
+  struct jpeg_destination_mgr pub; /* public fields */
+
+  unsigned char ** outbuffer;	/* target buffer */
+  unsigned long * outsize;
+  unsigned char * newbuffer;	/* newly allocated buffer */
+  uint8_t * buffer;		/* start of buffer */
+  size_t bufsize;
+} mem_destination_mgr;
+
+static void init_mem_destination(j_compress_ptr cinfo)
 {
 }
 
-static boolean empty_output_buffer(j_compress_ptr cinfo)
+static boolean empty_mem_output_buffer(j_compress_ptr cinfo)
 {
-    return FALSE;
+  size_t nextsize;
+  uint8_t * nextbuffer;
+  mem_destination_mgr *dest = (mem_destination_mgr *) cinfo->dest;
+
+  /* Try to allocate new buffer with double size */
+  nextsize = dest->bufsize * 2;
+  nextbuffer = malloc(nextsize);
+
+  if (nextbuffer == NULL)
+    ERREXIT1(cinfo, JERR_OUT_OF_MEMORY, 10);
+
+  memcpy(nextbuffer, dest->buffer, dest->bufsize);
+
+  if (dest->newbuffer != NULL)
+    free(dest->newbuffer);
+
+  dest->newbuffer = nextbuffer;
+
+  dest->pub.next_output_byte = nextbuffer + dest->bufsize;
+  dest->pub.free_in_buffer = dest->bufsize;
+
+  dest->buffer = nextbuffer;
+  dest->bufsize = nextsize;
+
+  return TRUE;
+}
+
+static void term_mem_destination(j_compress_ptr cinfo)
+{
+  mem_destination_mgr *dest = (mem_destination_mgr *) cinfo->dest;
+
+  *dest->outbuffer = dest->buffer;
+  *dest->outsize = dest->bufsize - dest->pub.free_in_buffer;
 }
 
-static void term_destination(j_compress_ptr cinfo)
+/*
+ * Prepare for output to a memory buffer.
+ * The caller may supply an own initial buffer with appropriate size.
+ * Otherwise, or when the actual data output exceeds the given size,
+ * the library adapts the buffer size as necessary.
+ * The standard library functions malloc/free are used for allocating
+ * larger memory, so the buffer is available to the application after
+ * finishing compression, and then the application is responsible for
+ * freeing the requested memory.
+ */
+
+static void
+jpeg_mem_dest (j_compress_ptr cinfo,
+	       unsigned char ** outbuffer, unsigned long * outsize)
 {
+  mem_destination_mgr *dest;
+#define OUTPUT_BUF_SIZE  4096	/* choose an efficiently fwrite'able size */
+
+  if (outbuffer == NULL || outsize == NULL)	/* sanity check */
+    ERREXIT(cinfo, JERR_BUFFER_SIZE);
+
+  /* The destination object is made permanent so that multiple JPEG images
+   * can be written to the same buffer without re-executing jpeg_mem_dest.
+   */
+  if (cinfo->dest == NULL) {	/* first time for this JPEG object? */
+    cinfo->dest = spice_malloc(sizeof(mem_destination_mgr));
+  }
+
+  dest = (mem_destination_mgr *) cinfo->dest;
+  dest->pub.init_destination = init_mem_destination;
+  dest->pub.empty_output_buffer = empty_mem_output_buffer;
+  dest->pub.term_destination = term_mem_destination;
+  dest->outbuffer = outbuffer;
+  dest->outsize = outsize;
+  dest->newbuffer = NULL;
+
+  if (*outbuffer == NULL || *outsize == 0) {
+    /* Allocate initial buffer */
+    dest->newbuffer = *outbuffer = malloc(OUTPUT_BUF_SIZE);
+    if (dest->newbuffer == NULL)
+      ERREXIT1(cinfo, JERR_OUT_OF_MEMORY, 10);
+    *outsize = OUTPUT_BUF_SIZE;
+  }
+
+  dest->pub.next_output_byte = dest->buffer = *outbuffer;
+  dest->pub.free_in_buffer = dest->bufsize = *outsize;
 }
+/* end of code from libjpeg */
 
 int mjpeg_encoder_encode_frame(MJpegEncoder *encoder,
-                               uint8_t *buffer, size_t buffer_len)
+                               uint8_t **buffer, size_t *buffer_len)
 {
-    struct jpeg_destination_mgr destmgr;
     uint8_t *frame;
     int n;
 
-    destmgr.next_output_byte = buffer;
-    destmgr.free_in_buffer = buffer_len;
-    destmgr.init_destination = init_destination;
-    destmgr.empty_output_buffer = empty_output_buffer;
-    destmgr.term_destination = term_destination;
-
-    encoder->cinfo.dest = &destmgr;
+    jpeg_mem_dest(&encoder->cinfo, buffer, buffer_len);
 
     encoder->cinfo.image_width      = encoder->width;
     encoder->cinfo.image_height     = encoder->height;
@@ -125,5 +213,5 @@ int mjpeg_encoder_encode_frame(MJpegEncoder *encoder,
     jpeg_finish_compress(&encoder->cinfo);
 
     encoder->first_frame = FALSE;
-    return destmgr.next_output_byte - buffer;
+    return encoder->cinfo.dest->next_output_byte - *buffer;
 }