Plugin JPEG decoder for data in memory, along with test_mem_jpeg.c and bench_mem_jpeg.c plugins to test and benchmark it, and a line-length clean up in jpeg_load.c.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@20871 a1c6a512-1295-4272-9138-f99709370657

7 files changed, 435 insertions, 14 deletions

diff --git a/apps/plugins/bench_mem_jpeg.c b/apps/plugins/bench_mem_jpeg.c
new file mode 100644
index 0000000..958e520
--- /dev/null
+++ b/apps/plugins/bench_mem_jpeg.c
@@ -0,0 +1,150 @@
+/*****************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _// __ \_/ ___\|  |/ /| __ \ / __ \  \/  /
+ *   Jukebox    |    |   ( (__) )  \___|    ( | \_\ ( (__) )    (
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ * $Id$
+ *
+ * Copyright (C) 2009 Andrew Mahone
+ *
+ * In-memory JPEG decode benchmark.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ****************************************************************************/
+
+#include "plugin.h"
+#include "lib/jpeg_mem.h"
+PLUGIN_HEADER
+
+/* a null output plugin to save memory and better isolate decode cost */
+static unsigned int get_size_null(struct bitmap *bm)
+{
+    (void) bm;
+    return 1;
+}
+
+static void output_row_null(uint32_t row, void * row_in,
+                            struct scaler_context *ctx)
+{
+    (void) row;
+    (void) row_in;
+    (void) ctx;
+    return;
+}
+
+const struct custom_format format_null = {
+#ifdef HAVE_LCD_COLOR
+    .output_row = {
+        output_row_null,
+        output_row_null
+    },
+#else
+    .output_row = output_row_null,
+#endif
+    .get_size = get_size_null
+};
+
+static char output_buf[256];
+static int output_y = 0;
+static int font_h;
+
+#define lcd_printf(...) \
+do { \
+    rb->snprintf(output_buf, sizeof(output_buf), __VA_ARGS__); \
+    rb->lcd_putsxy(0, output_y, output_buf); \
+    rb->lcd_update_rect(0, output_y, LCD_WIDTH, font_h); \
+    output_y += font_h; \
+} while (0)
+
+/* this is the plugin entry point */
+enum plugin_status plugin_start(const void* parameter)
+{
+    size_t plugin_buf_len;
+    unsigned char * plugin_buf =
+        (unsigned char *)rb->plugin_get_buffer(&plugin_buf_len);
+    static char filename[MAX_PATH];
+    struct bitmap bm = {
+        .width = LCD_WIDTH,
+        .height = LCD_HEIGHT,
+    };
+    int ret;
+
+    if(!parameter) return PLUGIN_ERROR;
+
+    rb->strcpy(filename, parameter);
+    rb->lcd_set_drawmode(DRMODE_SOLID|DRMODE_INVERSEVID);
+    rb->lcd_fillrect(0, 0, LCD_WIDTH, LCD_HEIGHT);
+    rb->lcd_set_drawmode(DRMODE_SOLID);
+    rb->lcd_getstringsize("A", NULL, &font_h);
+    int fd = rb->open(filename, O_RDONLY);
+    if (fd < 0)
+    {
+        lcd_printf("file open failed: %d", fd);
+        goto wait;
+    }
+    unsigned long filesize = rb->filesize(fd);
+    if (filesize > plugin_buf_len)
+    {
+        lcd_printf("file too large");
+        goto wait;
+    }
+    plugin_buf_len -= filesize;
+    unsigned char *jpeg_buf = plugin_buf;
+    plugin_buf += filesize;
+    rb->read(fd, jpeg_buf, filesize);
+    rb->close(fd);
+    bm.data = plugin_buf;
+    struct dim jpeg_size;
+    get_jpeg_dim_mem(jpeg_buf, filesize, &jpeg_size);
+    lcd_printf("jpeg file size: %dx%d",jpeg_size.width, jpeg_size.height);
+    bm.width = jpeg_size.width;
+    bm.height = jpeg_size.height;
+    char *size_str[] = { "1/1", "1/2", "1/4", "1/8" };
+    int i;
+    for (i = 0; i < 4; i++)
+    {
+        lcd_printf("timing %s decode", size_str[i]);
+        ret = decode_jpeg_mem(jpeg_buf, filesize, &bm, plugin_buf_len,
+                            FORMAT_NATIVE|FORMAT_RESIZE|FORMAT_KEEP_ASPECT,
+                            &format_null);
+        if (ret == 1)
+        {
+            long t1, t2;
+            int count = 0;
+            t2 = *(rb->current_tick);
+            while (t2 != (t1 = *(rb->current_tick)));
+            do {
+                decode_jpeg_mem(jpeg_buf, filesize, &bm, plugin_buf_len,
+                                FORMAT_NATIVE|FORMAT_RESIZE|FORMAT_KEEP_ASPECT,
+                                &format_null);
+                count++;
+                t2 = *(rb->current_tick);
+            } while (t2 - t1 < HZ || count < 10);
+            t2 -= t1;
+            t2 *= 10;
+            t2 += count >> 1;
+            t2 /= count;
+            t1 = t2 / 1000;
+            t2 -= t1 * 1000;
+            lcd_printf("%01d.%03d secs/decode", (int)t1, (int)t2);
+            bm.width >>= 1;
+            bm.height >>= 1;
+            if (!(bm.width && bm.height))
+                break;
+        } else
+            lcd_printf("insufficient memory");
+    }
+
+wait:
+    while (rb->get_action(CONTEXT_STD,1) != ACTION_STD_OK) rb->yield();
+    return PLUGIN_OK;
+}
diff --git a/apps/plugins/lib/SOURCES b/apps/plugins/lib/SOURCES
index 889fb79..21a35d4 100644
--- a/apps/plugins/lib/SOURCES
+++ b/apps/plugins/lib/SOURCES
@@ -27,9 +27,8 @@ playergfx.c
 profile_plugin.c
 #endif
 #ifdef HAVE_LCD_BITMAP
-#if !defined(HAVE_BMP_SCALING) || !defined(HAVE_JPEG)
+pluginlib_jpeg_mem.c
 pluginlib_resize.c
-#endif
 #ifndef HAVE_JPEG
 pluginlib_jpeg_load.c
 #endif
diff --git a/apps/plugins/lib/jpeg_mem.h b/apps/plugins/lib/jpeg_mem.h
new file mode 100644
index 0000000..8636f70
--- /dev/null
+++ b/apps/plugins/lib/jpeg_mem.h
@@ -0,0 +1,41 @@
+/***************************************************************************
+*             __________               __   ___.
+*   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+*   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+*   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+*   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+*                     \/            \/     \/    \/            \/
+* $Id$
+*
+* Copyright (C) 2009 by Andrew Mahone
+*
+* Header for the in-memory JPEG decoder.
+*
+* This program is free software; you can redistribute it and/or
+* modify it under the terms of the GNU General Public License
+* as published by the Free Software Foundation; either version 2
+* of the License, or (at your option) any later version.
+*
+* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+* KIND, either express or implied.
+*
+****************************************************************************/
+
+#include "plugin.h"
+#include "resize.h"
+#include "bmp.h"
+#include "jpeg_common.h"
+
+#ifndef _JPEG_MEM_H
+#define _JPEG_MEM_H
+
+int get_jpeg_dim_mem(unsigned char *data, unsigned long len,
+                     struct dim *size);
+
+int decode_jpeg_mem(unsigned char *data, unsigned long len,
+                    struct bitmap *bm,
+                    int maxsize,
+                    int format,
+                    const struct custom_format *cformat);
+
+#endif /* _JPEG_MEM_H */
diff --git a/apps/plugins/lib/pluginlib_jpeg_mem.c b/apps/plugins/lib/pluginlib_jpeg_mem.c
new file mode 100644
index 0000000..4a6c1bb
--- /dev/null
+++ b/apps/plugins/lib/pluginlib_jpeg_mem.c
@@ -0,0 +1,29 @@
+/***************************************************************************
+*             __________               __   ___.
+*   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+*   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+*   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+*   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+*                     \/            \/     \/    \/            \/
+* $Id$
+*
+* Copyright (C) 2009 by Andrew Mahone
+*
+* This is a wrapper for the core jpeg_load.c, to provide the from-memory
+* version of the decoder.
+*
+* This program is free software; you can redistribute it and/or
+* modify it under the terms of the GNU General Public License
+* as published by the Free Software Foundation; either version 2
+* of the License, or (at your option) any later version.
+*
+* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+* KIND, either express or implied.
+*
+****************************************************************************/
+
+#include <plugin.h>
+#include "wrappers.h"
+#define JPEG_FROM_MEM
+
+#include "../../recorder/jpeg_load.c"
diff --git a/apps/plugins/test_mem_jpeg.c b/apps/plugins/test_mem_jpeg.c
new file mode 100644
index 0000000..50969c3
--- /dev/null
+++ b/apps/plugins/test_mem_jpeg.c
@@ -0,0 +1,103 @@
+/*****************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _// __ \_/ ___\|  |/ /| __ \ / __ \  \/  /
+ *   Jukebox    |    |   ( (__) )  \___|    ( | \_\ ( (__) )    (
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ * $Id$
+ *
+ * Copyright (C) 2009 Andrew Mahone
+ *
+ * In-memory JPEG decode test.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ****************************************************************************/
+
+#include "plugin.h"
+#include "lib/grey.h"
+#include "lib/jpeg_mem.h"
+PLUGIN_HEADER
+
+/* different graphics libraries */
+#if LCD_DEPTH < 8
+#define USEGSLIB
+GREY_INFO_STRUCT
+#define MYLCD(fn) grey_ub_ ## fn
+#define MYLCD_UPDATE()
+#define MYXLCD(fn) grey_ub_ ## fn
+#define CFORMAT &format_grey
+#else
+#define MYLCD(fn) rb->lcd_ ## fn
+#define MYLCD_UPDATE() rb->lcd_update();
+#define MYXLCD(fn) xlcd_ ## fn
+#define CFORMAT &format_native
+#endif
+
+/* this is the plugin entry point */
+enum plugin_status plugin_start(const void* parameter)
+{
+    size_t plugin_buf_len;
+    unsigned char * plugin_buf =
+        (unsigned char *)rb->plugin_get_buffer(&plugin_buf_len);
+    static char filename[MAX_PATH];
+    struct bitmap bm = {
+        .width = LCD_WIDTH,
+        .height = LCD_HEIGHT,
+    };
+    int ret;
+
+    if(!parameter) return PLUGIN_ERROR;
+
+    rb->strcpy(filename, parameter);
+
+#ifdef USEGSLIB
+    long greysize;
+    if (!grey_init(plugin_buf, plugin_buf_len, GREY_ON_COP,
+                   LCD_WIDTH, LCD_HEIGHT, &greysize))
+    {
+        rb->splash(HZ, "grey buf error");
+        return PLUGIN_ERROR;
+    }
+    plugin_buf += greysize;
+    plugin_buf_len -= greysize;
+#endif
+    int fd = rb->open(filename, O_RDONLY);
+    if (fd < 0)
+        return PLUGIN_ERROR;
+    unsigned long filesize = rb->filesize(fd);
+    if (filesize > plugin_buf_len)
+        return PLUGIN_ERROR;
+    plugin_buf_len -= filesize;
+    unsigned char *jpeg_buf = plugin_buf;
+    plugin_buf += filesize;
+    rb->read(fd, jpeg_buf, filesize);
+    rb->close(fd);
+    bm.data = plugin_buf;
+    ret = decode_jpeg_mem(jpeg_buf, filesize, &bm, plugin_buf_len,
+                          FORMAT_NATIVE|FORMAT_RESIZE|FORMAT_KEEP_ASPECT,
+                          CFORMAT);
+    if (ret < 1)
+        return PLUGIN_ERROR;
+#ifdef USEGSLIB
+    grey_show(true);
+    grey_ub_gray_bitmap((fb_data *)bm.data, (LCD_WIDTH - bm.width) >> 1,
+        (LCD_HEIGHT - bm.height) >> 1, bm.width, bm.height);
+#else
+    rb->lcd_bitmap((fb_data *)bm.data, (LCD_WIDTH - bm.width) >> 1,
+        (LCD_HEIGHT - bm.height) >> 1, bm.width, bm.height);
+#endif
+    MYLCD_UPDATE();
+    while (rb->get_action(CONTEXT_STD,1) != ACTION_STD_OK) rb->yield();
+#ifdef USEGSLIB
+    grey_release();
+#endif
+    return PLUGIN_OK;
+}
diff --git a/apps/plugins/viewers.config b/apps/plugins/viewers.config
index 09d0455..939a0a5 100644
--- a/apps/plugins/viewers.config
+++ b/apps/plugins/viewers.config
@@ -30,6 +30,12 @@ bmp,viewers/test_greylib_bitmap_scale,-
 jpeg,viewers/test_core_jpeg,-
 jpe,viewers/test_core_jpeg,-
 jpg,viewers/test_core_jpeg,-
+jpeg,viewers/test_mem_jpeg,-
+jpe,viewers/test_mem_jpeg,-
+jpg,viewers/test_mem_jpeg,-
+jpeg,viewers/bench_mem_jpeg,-
+jpe,viewers/bench_mem_jpeg,-
+jpg,viewers/bench_mem_jpeg,-
 bmp,apps/rockpaint,11
 bmp,games/sliding_puzzle,11
 mpg,viewers/mpegplayer,4
diff --git a/apps/recorder/jpeg_load.c b/apps/recorder/jpeg_load.c
index 1d8c9ed..5b16e6f 100644
--- a/apps/recorder/jpeg_load.c
+++ b/apps/recorder/jpeg_load.c
@@ -36,6 +36,11 @@
 #define MEMCPY(d,s,c) memcpy(d,s,c)
 #define INLINE static inline
 #define ENDIAN_SWAP16(n) n /* only for poor little endian machines */
+#ifdef ROCKBOX_DEBUG_JPEG
+#define JDEBUGF DEBUGF
+#else
+#define JDEBUGF(...)
+#endif
 
 /**************** begin JPEG code ********************/
 
@@ -51,9 +56,14 @@ typedef uint8_t jpeg_pix_t;
  */
 struct jpeg
 {
+#ifdef JPEG_FROM_MEM
+    unsigned char *data;
+    unsigned long len;
+#else
     int fd;
     int buf_left;
     unsigned char *buf_index;
+#endif
     unsigned long int bitbuf;
     int bitbuf_bits;
     int marker_ind;
@@ -103,6 +113,10 @@ struct jpeg
     struct img_part part;
 };
 
+#ifdef JPEG_FROM_MEM
+static struct jpeg jpeg;
+#endif
+
 INLINE unsigned range_limit(int value)
 {
 #if CONFIG_CPU == SH7034
@@ -811,6 +825,37 @@ struct idct_entry idct_tbl[] = {
 
 /* JPEG decoder implementation */
 
+#ifdef JPEG_FROM_MEM
+INLINE unsigned char *getc(struct jpeg* p_jpeg)
+{
+    if (p_jpeg->len)
+    {
+        p_jpeg->len--;
+        return p_jpeg->data++;
+    } else
+        return NULL;
+}
+
+INLINE bool skip_bytes(struct jpeg* p_jpeg, int count)
+{
+    if (p_jpeg->len >= (unsigned)count)
+    {
+        p_jpeg->len -= count;
+        p_jpeg->data += count;
+        return true;
+    } else {
+        p_jpeg->data += p_jpeg->len;
+        p_jpeg->len = 0;
+        return false;
+    }
+}
+
+INLINE void putc(struct jpeg* p_jpeg)
+{
+    p_jpeg->len++;
+    p_jpeg->data--;
+}
+#else
 INLINE void fill_buf(struct jpeg* p_jpeg)
 {
         p_jpeg->buf_left = read(p_jpeg->fd, p_jpeg->buf, JPEG_READ_BUF_SIZE);
@@ -842,6 +887,13 @@ static bool skip_bytes(struct jpeg* p_jpeg, int count)
     return p_jpeg->buf_left >= 0 || skip_bytes_seek(p_jpeg);
 }
 
+static void putc(struct jpeg* p_jpeg)
+{
+    p_jpeg->buf_left++;
+    p_jpeg->buf_index--;
+}
+#endif
+
 #define e_skip_bytes(jpeg, count) \
 do {\
     if (!skip_bytes((jpeg),(count))) \
@@ -863,12 +915,6 @@ do {\
     c; \
 })
 
-static void putc(struct jpeg* p_jpeg)
-{
-    p_jpeg->buf_left++;
-    p_jpeg->buf_index--;
-}
-
 /* Preprocess the JPEG JFIF file */
 static int process_markers(struct jpeg* p_jpeg)
 {
@@ -881,11 +927,13 @@ static int process_markers(struct jpeg* p_jpeg)
     {
         if (c != 0xFF) /* no marker? */
         {
+            JDEBUGF("Non-marker data\n");
             putc(p_jpeg);
             break; /* exit marker processing */
         }
 
         c = e_getc(p_jpeg, -1);
+        JDEBUGF("marker value %X\n",c);
         switch (c)
         {
         case 0xFF: /* Fill byte */
@@ -896,9 +944,11 @@ static int process_markers(struct jpeg* p_jpeg)
 
         case 0xC0: /* SOF Huff  - Baseline DCT */
             {
+                JDEBUGF("SOF marker ");
                 ret |= SOF0;
                 marker_size = e_getc(p_jpeg, -1) << 8; /* Highbyte */
                 marker_size |= e_getc(p_jpeg, -1); /* Lowbyte */
+                JDEBUGF("len: %d\n", marker_size);
                 n = e_getc(p_jpeg, -1); /* sample precision (= 8 or 12) */
                 if (n != 8)
                 {
@@ -908,6 +958,8 @@ static int process_markers(struct jpeg* p_jpeg)
                 p_jpeg->y_size |= e_getc(p_jpeg, -1); /* Lowbyte */
                 p_jpeg->x_size = e_getc(p_jpeg, -1) << 8; /* Highbyte */
                 p_jpeg->x_size |= e_getc(p_jpeg, -1); /* Lowbyte */
+                JDEBUGF("  dimensions: %dx%d\n", p_jpeg->x_size,
+                    p_jpeg->y_size);
 
                 n = (marker_size-2-6)/3;
                 if (e_getc(p_jpeg, -1) != n || (n != 1 && n != 3))
@@ -1013,8 +1065,13 @@ static int process_markers(struct jpeg* p_jpeg)
             return(-6); /* Arithmetic coding not supported */
 
         case 0xD8: /* Start of Image */
+            JDEBUGF("SOI\n");
+            break;
         case 0xD9: /* End of Image */
+            JDEBUGF("EOI\n");
+            break;
         case 0x01: /* for temp private use arith code */
+            JDEBUGF("private\n");
             break; /* skip parameterless marker */
 
 
@@ -1107,6 +1164,7 @@ static int process_markers(struct jpeg* p_jpeg)
                 marker_size = e_getc(p_jpeg, -1) << 8; /* Highbyte */
                 marker_size |= e_getc(p_jpeg, -1); /* Lowbyte */
                 marker_size -= 2;
+                JDEBUGF("unhandled marker len %d\n", marker_size);
                 e_skip_bytes(p_jpeg, marker_size); /* skip segment */
             }
             break;
@@ -1693,8 +1751,10 @@ static struct img_part *store_row_jpeg(void *jpeg_args)
     int mcu_hscale = p_jpeg->h_scale[1];
     int mcu_vscale = p_jpeg->v_scale[1];
 #else
-    int mcu_hscale = (p_jpeg->h_scale[0] + p_jpeg->frameheader[0].horizontal_sampling - 1);
-    int mcu_vscale = (p_jpeg->v_scale[0] + p_jpeg->frameheader[0].vertical_sampling - 1);
+    int mcu_hscale = (p_jpeg->h_scale[0] +
+        p_jpeg->frameheader[0].horizontal_sampling - 1);
+    int mcu_vscale = (p_jpeg->v_scale[0] +
+        p_jpeg->frameheader[0].vertical_sampling - 1);
 #endif
     unsigned int width = p_jpeg->x_mbl << mcu_hscale;
     unsigned int b_width = width * JPEG_PIX_SZ;
@@ -1855,6 +1915,7 @@ static struct img_part *store_row_jpeg(void *jpeg_args)
  * Reads a JPEG file and puts the data in rockbox format in *bitmap.
  *
  *****************************************************************************/
+#ifndef JPEG_FROM_MEM
 int read_jpeg_file(const char* filename,
                    struct bitmap *bm,
                    int maxsize,
@@ -1874,6 +1935,7 @@ int read_jpeg_file(const char* filename,
     close(fd);
     return ret;
 }
+#endif
 
 static int calc_scale(int in_size, int out_size)
 {
@@ -1889,7 +1951,28 @@ static int calc_scale(int in_size, int out_size)
     return scale;
 }
 
+#ifdef JPEG_FROM_MEM
+int get_jpeg_dim_mem(unsigned char *data, unsigned long len,
+                     struct dim *size)
+{
+    struct jpeg *p_jpeg = &jpeg;
+    memset(p_jpeg, 0, sizeof(struct jpeg));
+    p_jpeg->data = data;
+    p_jpeg->len = len;
+    int status = process_markers(p_jpeg);
+    if (status < 0)
+        return status;
+    if ((status & (DQT | SOF0)) != (DQT | SOF0))
+        return -(status * 16);
+    size->width = p_jpeg->x_size;
+    size->height = p_jpeg->y_size;
+    return 0;
+}
+
+int decode_jpeg_mem(unsigned char *data, unsigned long len,
+#else
 int read_jpeg_fd(int fd,
+#endif
                  struct bitmap *bm,
                  int maxsize,
                  int format,
@@ -1898,17 +1981,25 @@ int read_jpeg_fd(int fd,
     bool resize = false, dither = false;
     struct rowset rset;
     struct dim src_dim;
-    struct jpeg *p_jpeg = (struct jpeg*)bm->data;
-    int tmp_size = maxsize;
     int status;
     int bm_size;
+#ifdef JPEG_FROM_MEM
+    struct jpeg *p_jpeg = &jpeg;
+#else
+    struct jpeg *p_jpeg = (struct jpeg*)bm->data;
+    int tmp_size = maxsize;
     ALIGN_BUFFER(p_jpeg, tmp_size, sizeof(int));
     /* not enough memory for our struct jpeg */
     if ((size_t)tmp_size < sizeof(struct jpeg))
         return -1;
-
+#endif
     memset(p_jpeg, 0, sizeof(struct jpeg));
+#ifdef JPEG_FROM_MEM
+    p_jpeg->data = data;
+    p_jpeg->len = len;
+#else
     p_jpeg->fd = fd;
+#endif
     status = process_markers(p_jpeg);
     if (status < 0)
         return status;
@@ -1968,14 +2059,16 @@ int read_jpeg_fd(int fd,
     char *buf_start = (char *)bm->data + bm_size;
     char *buf_end = (char *)bm->data + maxsize;
     maxsize = buf_end - buf_start;
+#ifndef JPEG_FROM_MEM
     ALIGN_BUFFER(buf_start, maxsize, sizeof(uint32_t));
     if (maxsize < (int)sizeof(struct jpeg))
         return -1;
     memmove(buf_start, p_jpeg, sizeof(struct jpeg));
     p_jpeg = (struct jpeg *)buf_start;
-    fix_huff_tables(p_jpeg);
     buf_start += sizeof(struct jpeg);
     maxsize = buf_end - buf_start;
+#endif
+    fix_huff_tables(p_jpeg);
 #ifdef HAVE_LCD_COLOR
     int decode_buf_size = (p_jpeg->x_mbl << p_jpeg->h_scale[1])
         << p_jpeg->v_scale[1];