gst_plugins_good/ext/jpeg/smokecodec.c
changeset 8 4a7fac7dd34a
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gst_plugins_good/ext/jpeg/smokecodec.c	Fri Apr 16 15:15:52 2010 +0300
@@ -0,0 +1,715 @@
+/* Smoke codec
+ * Copyright (C) <2004> Wim Taymans <wim@fluendo.com> 
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <math.h>
+
+/* this is a hack hack hack to get around jpeglib header bugs... */
+#ifdef HAVE_STDLIB_H
+# undef HAVE_STDLIB_H
+#endif
+#include <jpeglib.h>
+
+#include "smokecodec.h"
+#include "smokeformat.h"
+
+#ifdef SYMBIAN
+#define DEBUG(a...)   printf( a );
+#else // SYMBIAN
+#ifndef WIN32
+//#define DEBUG(a...)   printf( a );
+#define DEBUG(a,...)
+#else
+#include <gst/gstinfo.h>
+#define DEBUG GST_DEBUG
+#endif
+#endif // SYMBIAN
+
+
+struct _SmokeCodecInfo
+{
+  unsigned int width;
+  unsigned int height;
+  unsigned int fps_num;
+  unsigned int fps_denom;
+
+  unsigned int minquality;
+  unsigned int maxquality;
+  unsigned int bitrate;
+  unsigned int threshold;
+
+  unsigned int refdec;
+
+  unsigned char **line[3];
+  unsigned char *compbuf[3];
+
+  struct jpeg_error_mgr jerr;
+
+  struct jpeg_compress_struct cinfo;
+  struct jpeg_destination_mgr jdest;
+
+  struct jpeg_decompress_struct dinfo;
+  struct jpeg_source_mgr jsrc;
+
+  int need_keyframe;
+  unsigned char *reference;
+};
+
+static void
+smokecodec_init_destination (j_compress_ptr cinfo)
+{
+}
+
+static int
+smokecodec_flush_destination (j_compress_ptr cinfo)
+{
+  return 1;
+}
+
+static void
+smokecodec_term_destination (j_compress_ptr cinfo)
+{
+}
+
+static void
+smokecodec_init_source (j_decompress_ptr cinfo)
+{
+}
+
+static int
+smokecodec_fill_input_buffer (j_decompress_ptr cinfo)
+{
+  return 1;
+}
+
+static void
+smokecodec_skip_input_data (j_decompress_ptr cinfo, long num_bytes)
+{
+}
+
+static int
+smokecodec_resync_to_restart (j_decompress_ptr cinfo, int desired)
+{
+  return 1;
+}
+
+static void
+smokecodec_term_source (j_decompress_ptr cinfo)
+{
+}
+
+
+int
+smokecodec_encode_new (SmokeCodecInfo ** info,
+    const unsigned int width,
+    const unsigned int height,
+    const unsigned int fps_num, const unsigned int fps_denom)
+{
+  SmokeCodecInfo *newinfo;
+  int i, j;
+  unsigned char *base[3];
+
+  if (!info)
+    return SMOKECODEC_NULLPTR;
+  if ((width & 0xf) || (height & 0xf))
+    return SMOKECODEC_WRONGSIZE;
+
+  newinfo = malloc (sizeof (SmokeCodecInfo));
+  if (!newinfo) {
+    return SMOKECODEC_NOMEM;
+  }
+  newinfo->width = width;
+  newinfo->height = height;
+  newinfo->fps_num = fps_num;
+  newinfo->fps_denom = fps_denom;
+
+  /* setup jpeglib */
+  memset (&newinfo->cinfo, 0, sizeof (newinfo->cinfo));
+  memset (&newinfo->jerr, 0, sizeof (newinfo->jerr));
+  newinfo->cinfo.err = jpeg_std_error (&newinfo->jerr);
+  jpeg_create_compress (&newinfo->cinfo);
+  newinfo->cinfo.input_components = 3;
+  jpeg_set_defaults (&newinfo->cinfo);
+
+  newinfo->cinfo.dct_method = JDCT_FASTEST;
+
+  newinfo->cinfo.raw_data_in = TRUE;
+  newinfo->cinfo.in_color_space = JCS_YCbCr;
+  newinfo->cinfo.comp_info[0].h_samp_factor = 2;
+  newinfo->cinfo.comp_info[0].v_samp_factor = 2;
+  newinfo->cinfo.comp_info[1].h_samp_factor = 1;
+  newinfo->cinfo.comp_info[1].v_samp_factor = 1;
+  newinfo->cinfo.comp_info[2].h_samp_factor = 1;
+  newinfo->cinfo.comp_info[2].v_samp_factor = 1;
+
+  newinfo->line[0] = malloc (DCTSIZE * 2 * sizeof (char *));
+  newinfo->line[1] = malloc (DCTSIZE * sizeof (char *));
+  newinfo->line[2] = malloc (DCTSIZE * sizeof (char *));
+  base[0] = newinfo->compbuf[0] = malloc (256 * 2 * DCTSIZE * 2 * DCTSIZE);
+  base[1] = newinfo->compbuf[1] = malloc (256 * DCTSIZE * DCTSIZE);
+  base[2] = newinfo->compbuf[2] = malloc (256 * DCTSIZE * DCTSIZE);
+
+  for (i = 0, j = 0; i < 2 * DCTSIZE; i += 2, j++) {
+    newinfo->line[0][i] = base[0];
+    base[0] += 2 * DCTSIZE * 256;
+    newinfo->line[0][i + 1] = base[0];
+    base[0] += 2 * DCTSIZE * 256;
+    newinfo->line[1][j] = base[1];
+    base[1] += DCTSIZE * 256;
+    newinfo->line[2][j] = base[2];
+    base[2] += DCTSIZE * 256;
+  }
+
+  newinfo->jdest.init_destination = smokecodec_init_destination;
+  newinfo->jdest.empty_output_buffer = smokecodec_flush_destination;
+  newinfo->jdest.term_destination = smokecodec_term_destination;
+  newinfo->cinfo.dest = &newinfo->jdest;
+
+  jpeg_suppress_tables (&newinfo->cinfo, FALSE);
+
+  memset (&newinfo->dinfo, 0, sizeof (newinfo->dinfo));
+  newinfo->dinfo.err = jpeg_std_error (&newinfo->jerr);
+  jpeg_create_decompress (&newinfo->dinfo);
+
+  newinfo->jsrc.init_source = smokecodec_init_source;
+  newinfo->jsrc.fill_input_buffer = smokecodec_fill_input_buffer;
+  newinfo->jsrc.skip_input_data = smokecodec_skip_input_data;
+  newinfo->jsrc.resync_to_restart = smokecodec_resync_to_restart;
+  newinfo->jsrc.term_source = smokecodec_term_source;
+  newinfo->dinfo.src = &newinfo->jsrc;
+
+  newinfo->need_keyframe = 1;
+  newinfo->threshold = 4000;
+  newinfo->minquality = 10;
+  newinfo->maxquality = 85;
+  newinfo->reference = malloc (3 * (width * height) / 2);
+  newinfo->refdec = 0;
+
+  *info = newinfo;
+
+  return SMOKECODEC_OK;
+}
+
+int
+smokecodec_decode_new (SmokeCodecInfo ** info)
+{
+  return smokecodec_encode_new (info, 16, 16, 1, 1);
+}
+
+int
+smokecodec_info_free (SmokeCodecInfo * info)
+{
+  free (info->line[0]);
+  free (info->line[1]);
+  free (info->line[2]);
+  free (info->compbuf[0]);
+  free (info->compbuf[1]);
+  free (info->compbuf[2]);
+  free (info->reference);
+  jpeg_destroy_compress (&info->cinfo);
+  jpeg_destroy_decompress (&info->dinfo);
+  free (info);
+
+  return SMOKECODEC_OK;
+}
+
+SmokeCodecResult
+smokecodec_set_quality (SmokeCodecInfo * info,
+    const unsigned int min, const unsigned int max)
+{
+  info->minquality = min;
+  info->maxquality = max;
+
+  return SMOKECODEC_OK;
+}
+
+SmokeCodecResult
+smokecodec_get_quality (SmokeCodecInfo * info,
+    unsigned int *min, unsigned int *max)
+{
+  *min = info->minquality;
+  *max = info->maxquality;
+
+  return SMOKECODEC_OK;
+}
+
+SmokeCodecResult
+smokecodec_set_threshold (SmokeCodecInfo * info, const unsigned int threshold)
+{
+  info->threshold = threshold;
+
+  return SMOKECODEC_OK;
+}
+
+SmokeCodecResult
+smokecodec_get_threshold (SmokeCodecInfo * info, unsigned int *threshold)
+{
+  *threshold = info->threshold;
+
+  return SMOKECODEC_OK;
+}
+
+SmokeCodecResult
+smokecodec_set_bitrate (SmokeCodecInfo * info, const unsigned int bitrate)
+{
+  info->bitrate = bitrate;
+
+  return SMOKECODEC_OK;
+}
+
+SmokeCodecResult
+smokecodec_get_bitrate (SmokeCodecInfo * info, unsigned int *bitrate)
+{
+  *bitrate = info->bitrate;
+
+  return SMOKECODEC_OK;
+}
+
+static void
+find_best_size (int blocks, unsigned int *width, unsigned int *height)
+{
+  int sqchng;
+  int w, h;
+  int best, bestw;
+  int free;
+
+  sqchng = ceil (sqrt (blocks));
+  w = sqchng;
+  h = sqchng;
+
+  DEBUG ("guess: %d %d\n", w, h);
+
+  free = w * h - blocks;
+  best = free;
+  bestw = w;
+
+  while (w < 256) {
+    DEBUG ("current: %d %d\n", w, h);
+    if (free < best) {
+      best = free;
+      bestw = w;
+      if (free == 0)
+        break;
+    }
+    // if we cannot reduce the height, increase width
+    if (free < w) {
+      w++;
+      free += h;
+    }
+    // reduce height while possible
+    while (free >= w) {
+      h--;
+      free -= w;
+    }
+  }
+  *width = bestw;
+  *height = (blocks + best) / bestw;
+}
+
+static int
+abs_diff (const unsigned char *in1, const unsigned char *in2, const int stride)
+{
+  int s;
+  int i, j, diff;
+
+  s = 0;
+
+  for (i = 0; i < 2 * DCTSIZE; i++) {
+    for (j = 0; j < 2 * DCTSIZE; j++) {
+      diff = in1[j] - in2[j];
+      s += diff * diff;
+    }
+    in1 += stride;
+    in2 += stride;
+  }
+  return s;
+}
+
+static void
+put (const unsigned char *src, unsigned char *dest,
+    int width, int height, int srcstride, int deststride)
+{
+  int i, j;
+
+  for (i = 0; i < height; i++) {
+    for (j = 0; j < width; j++) {
+      dest[j] = src[j];
+    }
+    src += srcstride;
+    dest += deststride;
+  }
+}
+
+/* encoding */
+SmokeCodecResult
+smokecodec_encode_id (SmokeCodecInfo * info,
+    unsigned char *out, unsigned int *outsize)
+{
+  int i;
+
+  *out++ = SMOKECODEC_TYPE_ID;
+  for (i = 0; i < strlen (SMOKECODEC_ID_STRING); i++) {
+    *out++ = SMOKECODEC_ID_STRING[i];
+  }
+  *out++ = 0;
+  *out++ = 1;
+  *out++ = 0;
+
+  *outsize = 9;
+
+  return SMOKECODEC_OK;
+}
+
+SmokeCodecResult
+smokecodec_encode (SmokeCodecInfo * info,
+    const unsigned char *in,
+    SmokeCodecFlags flags, unsigned char *out, unsigned int *outsize)
+{
+  unsigned int i, j, s;
+  const unsigned char *ip;
+  unsigned char *op;
+  unsigned int blocks, encoding;
+  unsigned int size;
+  unsigned int width, height;
+  unsigned int blocks_w, blocks_h;
+  unsigned int threshold;
+  unsigned int max;
+
+  if (info->need_keyframe) {
+    flags |= SMOKECODEC_KEYFRAME;
+    info->need_keyframe = 0;
+  }
+
+  if (flags & SMOKECODEC_KEYFRAME)
+    threshold = 0;
+  else
+    threshold = info->threshold;
+
+  ip = in;
+  op = info->reference;
+
+  width = info->width;
+  height = info->height;
+
+  blocks_w = width / (DCTSIZE * 2);
+  blocks_h = height / (DCTSIZE * 2);
+
+  max = blocks_w * blocks_h;
+
+  out[IDX_TYPE] = SMOKECODEC_TYPE_DATA;
+
+#define STORE16(var, pos, x) \
+   var[pos]   = (x >> 8); \
+   var[pos+1] = (x & 0xff);
+#define STORE32(var, pos, x) \
+   var[pos]   = ((x >> 24) & 0xff); \
+   var[pos+1] = ((x >> 16) & 0xff); \
+   var[pos+2] = ((x >> 8) & 0xff); \
+   var[pos+3] =  (x & 0xff);
+
+  /* write dimension */
+  STORE16 (out, IDX_WIDTH, width);
+  STORE16 (out, IDX_HEIGHT, height);
+
+  /* write framerate */
+  STORE32 (out, IDX_FPS_NUM, info->fps_num);
+  STORE32 (out, IDX_FPS_DENOM, info->fps_denom);
+
+  if (!(flags & SMOKECODEC_KEYFRAME)) {
+    int block = 0;
+
+    blocks = 0;
+    for (i = 0; i < height; i += 2 * DCTSIZE) {
+      for (j = 0; j < width; j += 2 * DCTSIZE) {
+        s = abs_diff (ip, op, width);
+        if (s >= threshold) {
+          STORE16 (out, blocks * 2 + IDX_BLOCKS, block);
+          blocks++;
+        }
+
+        ip += 2 * DCTSIZE;
+        op += 2 * DCTSIZE;
+        block++;
+      }
+      ip += (2 * DCTSIZE - 1) * width;
+      op += (2 * DCTSIZE - 1) * width;
+    }
+    if (blocks == max) {
+      flags |= SMOKECODEC_KEYFRAME;
+      blocks = 0;
+      encoding = max;
+    } else {
+      encoding = blocks;
+    }
+  } else {
+    blocks = 0;
+    encoding = max;
+  }
+  STORE16 (out, IDX_NUM_BLOCKS, blocks);
+  out[IDX_FLAGS] = (flags & 0xff);
+
+  DEBUG ("blocks %d, encoding %d\n", blocks, encoding);
+
+  info->jdest.next_output_byte = &out[blocks * 2 + OFFS_PICT];
+  info->jdest.free_in_buffer = (*outsize) - OFFS_PICT;
+
+  if (encoding > 0) {
+    int quality;
+
+    if (!(flags & SMOKECODEC_KEYFRAME))
+      find_best_size (encoding, &blocks_w, &blocks_h);
+
+    DEBUG ("best: %d %d\n", blocks_w, blocks_h);
+
+    info->cinfo.image_width = blocks_w * DCTSIZE * 2;
+    info->cinfo.image_height = blocks_h * DCTSIZE * 2;
+
+    if (flags & SMOKECODEC_KEYFRAME) {
+      quality = (info->maxquality * 60) / 100;
+    } else {
+      quality =
+          info->maxquality - ((info->maxquality -
+              info->minquality) * blocks) / max;
+    }
+
+    DEBUG ("set q %d %d %d\n", quality, encoding, max);
+    jpeg_set_quality (&info->cinfo, quality, TRUE);
+    DEBUG ("start\n");
+    jpeg_start_compress (&info->cinfo, TRUE);
+
+    for (i = 0; i < encoding; i++) {
+      int pos;
+      int x, y;
+
+      if (flags & SMOKECODEC_KEYFRAME)
+        pos = i;
+      else
+        pos = (out[i * 2 + IDX_BLOCKS] << 8) | (out[i * 2 + IDX_BLOCKS + 1]);
+
+      x = pos % (width / (DCTSIZE * 2));
+      y = pos / (width / (DCTSIZE * 2));
+
+      ip = in + (x * (DCTSIZE * 2)) + (y * (DCTSIZE * 2) * width);
+      op = info->compbuf[0] + (i % blocks_w) * (DCTSIZE * 2);
+      put (ip, op, 2 * DCTSIZE, 2 * DCTSIZE, width, 256 * (DCTSIZE * 2));
+
+      ip = in + width * height + (x * DCTSIZE) + (y * DCTSIZE * width / 2);
+      op = info->compbuf[1] + (i % blocks_w) * (DCTSIZE);
+      put (ip, op, DCTSIZE, DCTSIZE, width / 2, 256 * DCTSIZE);
+
+      ip = in + 5 * (width * height) / 4 + (x * DCTSIZE) +
+          (y * DCTSIZE * width / 2);
+      op = info->compbuf[2] + (i % blocks_w) * (DCTSIZE);
+      put (ip, op, DCTSIZE, DCTSIZE, width / 2, 256 * DCTSIZE);
+
+      if ((i % blocks_w) == (blocks_w - 1) || (i == encoding - 1)) {
+        DEBUG ("write %d\n", pos);
+        jpeg_write_raw_data (&info->cinfo, info->line, 2 * DCTSIZE);
+      }
+    }
+    DEBUG ("finish\n");
+    jpeg_finish_compress (&info->cinfo);
+  }
+
+  size = ((((*outsize) - OFFS_PICT - info->jdest.free_in_buffer) + 3) & ~3);
+  STORE16 (out, IDX_SIZE, size);
+
+  *outsize = size + blocks * 2 + OFFS_PICT;
+  DEBUG ("outsize %d\n", *outsize);
+
+  // and decode in reference frame again
+  if (info->refdec) {
+    smokecodec_decode (info, out, *outsize, info->reference);
+  } else {
+    memcpy (info->reference, in, 3 * (width * height) / 2);
+  }
+
+  return SMOKECODEC_OK;
+}
+
+SmokeCodecResult
+smokecodec_parse_id (SmokeCodecInfo * info,
+    const unsigned char *in, const unsigned int insize)
+{
+  int i;
+
+  if (insize < 4 + strlen (SMOKECODEC_ID_STRING)) {
+    return SMOKECODEC_WRONGVERSION;
+  }
+
+  if (*in++ != SMOKECODEC_TYPE_ID)
+    return SMOKECODEC_ERROR;
+
+  for (i = 0; i < strlen (SMOKECODEC_ID_STRING); i++) {
+    if (*in++ != SMOKECODEC_ID_STRING[i])
+      return SMOKECODEC_ERROR;
+  }
+  if (*in++ != 0 || *in++ != 1 || *in++ != 0)
+    return SMOKECODEC_ERROR;
+
+  return SMOKECODEC_OK;
+}
+
+#define READ16(var, pos, x) \
+ x = var[pos]<<8 | var[pos+1];
+
+#define READ32(var, pos, x) \
+ x = var[pos]<<24 | var[pos+1]<<16 | \
+     var[pos+2]<<8 | var[pos+3];
+
+/* decoding */
+SmokeCodecResult
+smokecodec_parse_header (SmokeCodecInfo * info,
+    const unsigned char *in,
+    const unsigned int insize,
+    SmokeCodecFlags * flags,
+    unsigned int *width,
+    unsigned int *height, unsigned int *fps_num, unsigned int *fps_denom)
+{
+
+  READ16 (in, IDX_WIDTH, *width);
+  READ16 (in, IDX_HEIGHT, *height);
+  *flags = in[IDX_FLAGS];
+  READ32 (in, IDX_FPS_NUM, *fps_num);
+  READ32 (in, IDX_FPS_DENOM, *fps_denom);
+
+  if (info->width != *width ||
+      info->height != *height ||
+      info->fps_num != *fps_num || info->fps_denom != *fps_denom) {
+    DEBUG ("new width: %d %d\n", *width, *height);
+
+    info->reference = realloc (info->reference, 3 * ((*width) * (*height)) / 2);
+    info->width = *width;
+    info->height = *height;
+    info->fps_num = *fps_num;
+    info->fps_denom = *fps_denom;
+  }
+
+  return SMOKECODEC_OK;
+}
+
+SmokeCodecResult
+smokecodec_decode (SmokeCodecInfo * info,
+    const unsigned char *in, const unsigned int insize, unsigned char *out)
+{
+  unsigned int width, height;
+  unsigned int fps_num, fps_denom;
+  SmokeCodecFlags flags;
+  int i, j;
+  int blocks_w, blocks_h;
+  int blockptr;
+  int blocks, decoding;
+  const unsigned char *ip;
+  unsigned char *op;
+  int res;
+
+  smokecodec_parse_header (info, in, insize, &flags, &width, &height,
+      &fps_num, &fps_denom);
+
+  READ16 (in, IDX_NUM_BLOCKS, blocks);
+  DEBUG ("blocks %d\n", blocks);
+
+  if (flags & SMOKECODEC_KEYFRAME)
+    decoding = width / (DCTSIZE * 2) * height / (DCTSIZE * 2);
+  else
+    decoding = blocks;
+
+  if (decoding > 0) {
+    info->jsrc.next_input_byte = &in[blocks * 2 + OFFS_PICT];
+    info->jsrc.bytes_in_buffer = insize - (blocks * 2 + OFFS_PICT);
+
+    DEBUG ("header %02x %d\n", in[blocks * 2 + OFFS_PICT], insize);
+    res = jpeg_read_header (&info->dinfo, TRUE);
+    DEBUG ("header %d %d %d\n", res, info->dinfo.image_width,
+        info->dinfo.image_height);
+
+    blocks_w = info->dinfo.image_width / (2 * DCTSIZE);
+    blocks_h = info->dinfo.image_height / (2 * DCTSIZE);
+
+    info->dinfo.output_width = info->dinfo.image_width;
+    info->dinfo.output_height = info->dinfo.image_height;
+
+    DEBUG ("start\n");
+    info->dinfo.do_fancy_upsampling = FALSE;
+    info->dinfo.do_block_smoothing = FALSE;
+    info->dinfo.out_color_space = JCS_YCbCr;
+    info->dinfo.dct_method = JDCT_IFAST;
+    info->dinfo.raw_data_out = TRUE;
+    jpeg_start_decompress (&info->dinfo);
+
+    blockptr = 0;
+
+    for (i = 0; i < blocks_h; i++) {
+      DEBUG ("read\n");
+      jpeg_read_raw_data (&info->dinfo, info->line, 2 * DCTSIZE);
+
+      DEBUG ("copy %d\n", blocks_w);
+      for (j = 0; j < blocks_w; j++) {
+        int pos;
+        int x, y;
+
+        if (flags & SMOKECODEC_KEYFRAME)
+          pos = blockptr;
+        else
+          READ16 (in, blockptr * 2 + IDX_BLOCKS, pos);
+
+        x = pos % (width / (DCTSIZE * 2));
+        y = pos / (width / (DCTSIZE * 2));
+
+        DEBUG ("block %d %d %d\n", pos, x, y);
+
+        ip = info->compbuf[0] + j * (DCTSIZE * 2);
+        op = info->reference + (x * (DCTSIZE * 2)) +
+            (y * (DCTSIZE * 2) * width);
+        put (ip, op, 2 * DCTSIZE, 2 * DCTSIZE, 256 * (DCTSIZE * 2), width);
+
+        ip = info->compbuf[1] + j * (DCTSIZE);
+        op = info->reference + width * height + (x * DCTSIZE) +
+            (y * DCTSIZE * width / 2);
+        put (ip, op, DCTSIZE, DCTSIZE, 256 * DCTSIZE, width / 2);
+
+        ip = info->compbuf[2] + j * (DCTSIZE);
+        op = info->reference + 5 * (width * height) / 4 + (x * DCTSIZE) +
+            (y * DCTSIZE * width / 2);
+        put (ip, op, DCTSIZE, DCTSIZE, 256 * DCTSIZE, width / 2);
+
+        DEBUG ("block done %d %d %d\n", pos, x, y);
+        blockptr++;
+        if (blockptr >= decoding)
+          break;
+      }
+    }
+    DEBUG ("finish\n");
+    jpeg_finish_decompress (&info->dinfo);
+  }
+
+  DEBUG ("copy\n");
+  if (out != info->reference)
+    memcpy (out, info->reference, 3 * (width * height) / 2);
+  DEBUG ("copy done\n");
+
+  return SMOKECODEC_OK;
+}