Creative YUV (CYUV) decoder by (Mike Melanson <melanson at pcisys dot net>)

Originally committed as revision 1559 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 181 insertions, 0 deletions

diff --git a/libavcodec/cyuv.c b/libavcodec/cyuv.c
new file mode 100644
index 0000000000..8b34eb9e03
--- /dev/null
+++ b/libavcodec/cyuv.c
@@ -0,0 +1,181 @@
+/*
+ *
+ * Copyright (C) 2003 the ffmpeg project
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser 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
+ *
+ * Creative YUV (CYUV) Video Decoder
+ *   by Mike Melanson (melanson@pcisys.net)
+ * based on "Creative YUV (CYUV) stream format for AVI":
+ *   http://www.csse.monash.edu.au/~timf/videocodec/cyuv.txt
+ *
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "common.h"
+#include "avcodec.h"
+#include "dsputil.h"
+#include "mpegvideo.h"
+#include "bswap.h"
+
+
+typedef struct CyuvDecodeContext {
+    AVCodecContext *avctx;
+    int width, height;
+    AVFrame frame;
+} CyuvDecodeContext;
+
+static int cyuv_decode_init(AVCodecContext *avctx)
+{
+    CyuvDecodeContext *s = avctx->priv_data;
+
+    s->avctx = avctx;
+    s->width = avctx->width;
+    s->height = avctx->height;
+    avctx->pix_fmt = PIX_FMT_YUV411P;
+    avctx->has_b_frames = 0;
+
+    return 0;
+}
+
+static int cyuv_decode_frame(AVCodecContext *avctx, 
+                             void *data, int *data_size,
+                             UINT8 *buf, int buf_size)
+{
+    CyuvDecodeContext *s=avctx->priv_data;
+
+    unsigned char *y_plane;
+    unsigned char *u_plane;
+    unsigned char *v_plane;
+    int y_ptr;
+    int u_ptr;
+    int v_ptr;
+
+    /* prediction error tables (make it clear that they are signed values) */
+    signed char *y_table = buf +  0;
+    signed char *u_table = buf + 16;
+    signed char *v_table = buf + 32;
+
+    unsigned char y_pred, u_pred, v_pred;
+    int stream_ptr;
+    unsigned char cur_byte;
+    int pixel_groups;
+
+    *data_size = 0;
+
+    /* sanity check the buffer size: A buffer has 3x16-bytes tables
+     * followed by (height) lines each with 3 bytes to represent groups
+     * of 4 pixels. Thus, the total size of the buffer ought to be:
+     *    (3 * 16) + height * (width * 3 / 4) */
+    if (buf_size != 48 + s->height * (s->width * 3 / 4)) {
+      printf ("ffmpeg: cyuv: got a buffer with %d bytes when %d were expected\n",
+        buf_size,
+        48 + s->height * (s->width * 3 / 4));
+      return -1;
+    }
+
+    /* pixel data starts 48 bytes in, after 3x16-byte tables */
+    stream_ptr = 48;
+
+    s->frame.reference = 0;
+    if(avctx->get_buffer(avctx, &s->frame) < 0) {
+        fprintf(stderr, "get_buffer() failed\n");
+        return -1;
+    }
+
+    y_plane = s->frame.data[0];
+    u_plane = s->frame.data[1];
+    v_plane = s->frame.data[2];
+
+    /* iterate through each line in the height */
+    for (y_ptr = 0, u_ptr = 0, v_ptr = 0;
+         y_ptr < (s->height * s->frame.linesize[0]); 
+         y_ptr += s->frame.linesize[0] - s->width,
+         u_ptr += s->frame.linesize[1] - s->width / 4,
+         v_ptr += s->frame.linesize[2] - s->width / 4) {
+
+        /* reset predictors */
+        cur_byte = buf[stream_ptr++];
+        u_plane[u_ptr++] = u_pred = cur_byte & 0xF0;
+        y_plane[y_ptr++] = y_pred = (cur_byte & 0x0F) << 4;
+
+        cur_byte = buf[stream_ptr++];
+        v_plane[v_ptr++] = v_pred = cur_byte & 0xF0;
+        y_pred += y_table[cur_byte & 0x0F];
+        y_plane[y_ptr++] = y_pred;
+
+        cur_byte = buf[stream_ptr++];
+        y_pred += y_table[cur_byte & 0x0F];
+        y_plane[y_ptr++] = y_pred;
+        y_pred += y_table[(cur_byte & 0xF0) >> 4];
+        y_plane[y_ptr++] = y_pred;
+
+        /* iterate through the remaining pixel groups (4 pixels/group) */
+        pixel_groups = s->width / 4 - 1;
+        while (pixel_groups--) {
+
+            cur_byte = buf[stream_ptr++];
+            u_pred += u_table[(cur_byte & 0xF0) >> 4];
+            u_plane[u_ptr++] = u_pred;
+            y_pred += y_table[cur_byte & 0x0F];
+            y_plane[y_ptr++] = y_pred;
+
+            cur_byte = buf[stream_ptr++];
+            v_pred += v_table[(cur_byte & 0xF0) >> 4];
+            v_plane[v_ptr++] = v_pred;
+            y_pred += y_table[cur_byte & 0x0F];
+            y_plane[y_ptr++] = y_pred;
+
+            cur_byte = buf[stream_ptr++];
+            y_pred += y_table[cur_byte & 0x0F];
+            y_plane[y_ptr++] = y_pred;
+            y_pred += y_table[(cur_byte & 0xF0) >> 4];
+            y_plane[y_ptr++] = y_pred;
+
+        }
+    }
+
+    *data_size=sizeof(AVFrame);
+    *(AVFrame*)data= s->frame;
+
+    avctx->release_buffer(avctx, &s->frame);
+
+    return buf_size;
+}
+
+static int cyuv_decode_end(AVCodecContext *avctx)
+{
+/*    CyuvDecodeContext *s = avctx->priv_data;*/
+
+    return 0;
+}
+
+AVCodec cyuv_decoder = {
+    "cyuv",
+    CODEC_TYPE_VIDEO,
+    CODEC_ID_CYUV,
+    sizeof(CyuvDecodeContext),
+    cyuv_decode_init,
+    NULL,
+    cyuv_decode_end,
+    cyuv_decode_frame,
+    0,
+    NULL
+};
+