Autodesk Animator Studio Codec (AASC) video decoder, courtesy of

Konstantin Shishkov

Originally committed as revision 4099 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 174 insertions, 0 deletions

diff --git a/libavcodec/aasc.c b/libavcodec/aasc.c
new file mode 100644
index 0000000000..d2419e98ce
--- /dev/null
+++ b/libavcodec/aasc.c
@@ -0,0 +1,174 @@
+/*
+ * Autodesc RLE Decoder
+ * Copyright (C) 2005 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
+ */
+
+/**
+ * @file aasc.c
+ * Autodesc RLE Video Decoder by Konstantin Shishkov
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "common.h"
+#include "avcodec.h"
+#include "dsputil.h"
+
+typedef struct AascContext {
+    AVCodecContext *avctx;
+    AVFrame frame;
+} AascContext;
+
+#define FETCH_NEXT_STREAM_BYTE() \
+    if (stream_ptr >= buf_size) \
+    { \
+      av_log(s->avctx, AV_LOG_ERROR, " AASC: stream ptr just went out of bounds (fetch)\n"); \
+      break; \
+    } \
+    stream_byte = buf[stream_ptr++];
+
+static int aasc_decode_init(AVCodecContext *avctx)
+{
+    AascContext *s = (AascContext *)avctx->priv_data;
+
+    s->avctx = avctx;
+
+    avctx->pix_fmt = PIX_FMT_BGR24;
+    avctx->has_b_frames = 0;
+    s->frame.data[0] = NULL;
+
+    return 0;
+}
+
+static int aasc_decode_frame(AVCodecContext *avctx,
+                              void *data, int *data_size,
+                              uint8_t *buf, int buf_size)
+{
+    AascContext *s = (AascContext *)avctx->priv_data;
+    int stream_ptr = 4;
+    unsigned char rle_code;
+    unsigned char stream_byte;
+    int pixel_ptr = 0;
+    int row_dec, row_ptr;
+    int frame_size;
+    int i;
+
+    s->frame.reference = 1;
+    s->frame.buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_PRESERVE | FF_BUFFER_HINTS_REUSABLE;
+    if (avctx->reget_buffer(avctx, &s->frame)) {
+        av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
+        return -1;
+    }
+
+    row_dec = s->frame.linesize[0];
+    row_ptr = (s->avctx->height - 1) * row_dec;
+    frame_size = row_dec * s->avctx->height;
+
+    while (row_ptr >= 0) {
+        FETCH_NEXT_STREAM_BYTE();
+        rle_code = stream_byte;
+        if (rle_code == 0) {
+            /* fetch the next byte to see how to handle escape code */
+            FETCH_NEXT_STREAM_BYTE();
+            if (stream_byte == 0) {
+                /* line is done, goto the next one */
+                row_ptr -= row_dec;
+                pixel_ptr = 0;
+            } else if (stream_byte == 1) {
+                /* decode is done */
+                break;
+            } else if (stream_byte == 2) {
+                /* reposition frame decode coordinates */
+                FETCH_NEXT_STREAM_BYTE();
+                pixel_ptr += stream_byte;
+                FETCH_NEXT_STREAM_BYTE();
+                row_ptr -= stream_byte * row_dec;
+            } else {
+                /* copy pixels from encoded stream */
+                if ((pixel_ptr + stream_byte > avctx->width * 3) ||
+                    (row_ptr < 0)) {
+                    av_log(s->avctx, AV_LOG_ERROR, " AASC: frame ptr just went out of bounds (copy1)\n");
+                    break;
+                }
+
+                rle_code = stream_byte;
+                if (stream_ptr + rle_code > buf_size) {
+                    av_log(s->avctx, AV_LOG_ERROR, " AASC: stream ptr just went out of bounds (copy2)\n");
+                    break;
+                }
+
+                for (i = 0; i < rle_code; i++) {
+                    FETCH_NEXT_STREAM_BYTE();
+                    s->frame.data[0][row_ptr + pixel_ptr] = stream_byte;
+                    pixel_ptr++;
+                }
+                if (rle_code & 1)
+                    stream_ptr++;
+            }
+        } else {
+            /* decode a run of data */
+            if ((pixel_ptr + rle_code > avctx->width * 3) ||
+                (row_ptr < 0)) {
+                av_log(s->avctx, AV_LOG_ERROR, " AASC: frame ptr just went out of bounds (run1)\n");
+                break;
+            }
+
+            FETCH_NEXT_STREAM_BYTE();
+
+            while(rle_code--) {
+                s->frame.data[0][row_ptr + pixel_ptr] = stream_byte;
+                pixel_ptr++;
+            }
+        }
+    }
+
+    /* one last sanity check on the way out */
+    if (stream_ptr < buf_size)
+        av_log(s->avctx, AV_LOG_ERROR, " AASC: ended frame decode with bytes left over (%d < %d)\n",
+            stream_ptr, buf_size);
+
+    *data_size = sizeof(AVFrame);
+    *(AVFrame*)data = s->frame;
+
+    /* report that the buffer was completely consumed */
+    return buf_size;
+}
+
+static int aasc_decode_end(AVCodecContext *avctx)
+{
+    AascContext *s = (AascContext *)avctx->priv_data;
+
+    /* release the last frame */
+    if (s->frame.data[0])
+        avctx->release_buffer(avctx, &s->frame);
+
+    return 0;
+}
+
+AVCodec aasc_decoder = {
+    "aasc",
+    CODEC_TYPE_VIDEO,
+    CODEC_ID_AASC,
+    sizeof(AascContext),
+    aasc_decode_init,
+    NULL,
+    aasc_decode_end,
+    aasc_decode_frame,
+    CODEC_CAP_DR1,
+};