Initial revision

Originally committed as revision 5 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 205 insertions, 0 deletions

diff --git a/libavcodec/h263dec.c b/libavcodec/h263dec.c
new file mode 100644
index 0000000000..2af76199ab
--- /dev/null
+++ b/libavcodec/h263dec.c
@@ -0,0 +1,205 @@
+/*
+ * H263 decoder
+ * Copyright (c) 2001 Gerard Lantau.
+ *
+ * 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 program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include "dsputil.h"
+#include "avcodec.h"
+#include "mpegvideo.h"
+
+//#define DEBUG
+
+static int h263_decode_init(AVCodecContext *avctx)
+{
+    MpegEncContext *s = avctx->priv_data;
+    
+    s->out_format = FMT_H263;
+
+    s->width = avctx->width;
+    s->height = avctx->height;
+
+    /* select sub codec */
+    switch(avctx->codec->id) {
+    case CODEC_ID_H263:
+        break;
+    case CODEC_ID_OPENDIVX:
+        s->time_increment_bits = 4; /* default value for broken headers */
+        s->h263_pred = 1;
+        break;
+    case CODEC_ID_MSMPEG4:
+        s->h263_msmpeg4 = 1;
+        s->h263_pred = 1;
+        break;
+    case CODEC_ID_H263I:
+        s->h263_intel = 1;
+        break;
+    default:
+        return -1;
+    }
+
+    /* for h263, we allocate the images after having read the header */
+    if (MPV_common_init(s) < 0)
+        return -1;
+
+    if (s->h263_msmpeg4)
+        msmpeg4_decode_init_vlc(s);
+    else
+        h263_decode_init_vlc(s);
+    
+    return 0;
+}
+
+static int h263_decode_end(AVCodecContext *avctx)
+{
+    MpegEncContext *s = avctx->priv_data;
+
+    MPV_common_end(s);
+    return 0;
+}
+
+static int h263_decode_frame(AVCodecContext *avctx, 
+                             void *data, int *data_size,
+                             UINT8 *buf, int buf_size)
+{
+    MpegEncContext *s = avctx->priv_data;
+    int ret;
+    DCTELEM block[6][64];
+    AVPicture *pict = data; 
+
+#ifdef DEBUG
+    printf("*****frame %d size=%d\n", avctx->frame_number, buf_size);
+    printf("bytes=%x %x %x %x\n", buf[0], buf[1], buf[2], buf[3]);
+#endif
+
+    /* no supplementary picture */
+    if (buf_size == 0) {
+        *data_size = 0;
+        return 0;
+    }
+
+    init_get_bits(&s->gb, buf, buf_size);
+
+    /* let's go :-) */
+    if (s->h263_msmpeg4) {
+        ret = msmpeg4_decode_picture_header(s);
+    } else if (s->h263_pred) {
+        ret = mpeg4_decode_picture_header(s);
+    } else if (s->h263_intel) {
+        ret = intel_h263_decode_picture_header(s);
+    } else {
+        ret = h263_decode_picture_header(s);
+    }
+    if (ret < 0)
+        return -1;
+
+    MPV_frame_start(s);
+
+#ifdef DEBUG
+    printf("qscale=%d\n", s->qscale);
+#endif
+
+    /* decode each macroblock */
+    for(s->mb_y=0; s->mb_y < s->mb_height; s->mb_y++) {
+        for(s->mb_x=0; s->mb_x < s->mb_width; s->mb_x++) {
+#ifdef DEBUG
+            printf("**mb x=%d y=%d\n", s->mb_x, s->mb_y);
+#endif
+            /* DCT & quantize */
+            if (s->h263_msmpeg4) {
+                msmpeg4_dc_scale(s);
+            } else if (s->h263_pred) {
+                h263_dc_scale(s);
+            } else {
+                /* default quantization values */
+                s->y_dc_scale = 8;
+                s->c_dc_scale = 8;
+            }
+
+            memset(block, 0, sizeof(block));
+            s->mv_dir = MV_DIR_FORWARD;
+            s->mv_type = MV_TYPE_16X16; 
+            if (s->h263_msmpeg4) {
+                if (msmpeg4_decode_mb(s, block) < 0)
+                    return -1;
+            } else {
+                if (h263_decode_mb(s, block) < 0)
+                    return -1;
+            }
+            MPV_decode_mb(s, block);
+        }
+    }
+
+    MPV_frame_end(s);
+    
+    pict->data[0] = s->current_picture[0];
+    pict->data[1] = s->current_picture[1];
+    pict->data[2] = s->current_picture[2];
+    pict->linesize[0] = s->linesize;
+    pict->linesize[1] = s->linesize / 2;
+    pict->linesize[2] = s->linesize / 2;
+
+    avctx->quality = s->qscale;
+    *data_size = sizeof(AVPicture);
+    return buf_size;
+}
+
+AVCodec opendivx_decoder = {
+    "opendivx",
+    CODEC_TYPE_VIDEO,
+    CODEC_ID_OPENDIVX,
+    sizeof(MpegEncContext),
+    h263_decode_init,
+    NULL,
+    h263_decode_end,
+    h263_decode_frame,
+};
+
+AVCodec h263_decoder = {
+    "h263",
+    CODEC_TYPE_VIDEO,
+    CODEC_ID_H263,
+    sizeof(MpegEncContext),
+    h263_decode_init,
+    NULL,
+    h263_decode_end,
+    h263_decode_frame,
+};
+
+AVCodec msmpeg4_decoder = {
+    "msmpeg4",
+    CODEC_TYPE_VIDEO,
+    CODEC_ID_MSMPEG4,
+    sizeof(MpegEncContext),
+    h263_decode_init,
+    NULL,
+    h263_decode_end,
+    h263_decode_frame,
+};
+
+AVCodec h263i_decoder = {
+    "h263i",
+    CODEC_TYPE_VIDEO,
+    CODEC_ID_H263I,
+    sizeof(MpegEncContext),
+    h263_decode_init,
+    NULL,
+    h263_decode_end,
+    h263_decode_frame,
+};
+