mpegvideo: move ff_draw_horiz_band() to mpegutils.c
[libav.git] / libavcodec / mpegutils.c
1 /*
2 * Mpeg video formats-related defines and utility functions
3 *
4 * This file is part of Libav.
5 *
6 * Libav is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
10 *
11 * Libav is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with Libav; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19 */
20
21 #include <stdint.h>
22
23 #include "libavutil/common.h"
24 #include "libavutil/frame.h"
25 #include "libavutil/pixdesc.h"
26
27 #include "avcodec.h"
28 #include "mpegutils.h"
29
30 void ff_draw_horiz_band(AVCodecContext *avctx,
31 AVFrame *cur, AVFrame *last,
32 int y, int h, int picture_structure,
33 int first_field, int low_delay)
34 {
35 const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(avctx->pix_fmt);
36 int vshift = desc->log2_chroma_h;
37 const int field_pic = picture_structure != PICT_FRAME;
38 if (field_pic) {
39 h <<= 1;
40 y <<= 1;
41 }
42
43 h = FFMIN(h, avctx->height - y);
44
45 if (field_pic && first_field &&
46 !(avctx->slice_flags & SLICE_FLAG_ALLOW_FIELD))
47 return;
48
49 if (avctx->draw_horiz_band) {
50 AVFrame *src;
51 int offset[AV_NUM_DATA_POINTERS];
52 int i;
53
54 if (cur->pict_type == AV_PICTURE_TYPE_B || low_delay ||
55 (avctx->slice_flags & SLICE_FLAG_CODED_ORDER))
56 src = cur;
57 else if (last)
58 src = last;
59 else
60 return;
61
62 if (cur->pict_type == AV_PICTURE_TYPE_B &&
63 picture_structure == PICT_FRAME &&
64 avctx->codec_id != AV_CODEC_ID_SVQ3) {
65 for (i = 0; i < AV_NUM_DATA_POINTERS; i++)
66 offset[i] = 0;
67 } else {
68 offset[0]= y * src->linesize[0];
69 offset[1]=
70 offset[2]= (y >> vshift) * src->linesize[1];
71 for (i = 3; i < AV_NUM_DATA_POINTERS; i++)
72 offset[i] = 0;
73 }
74
75 emms_c();
76
77 avctx->draw_horiz_band(avctx, src, offset,
78 y, picture_structure, h);
79 }
80 }