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flvdec.c
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1 /*
2  * FLV decoding.
3  * This file is part of FFmpeg.
4  *
5  * FFmpeg is free software; you can redistribute it and/or
6  * modify it under the terms of the GNU Lesser General Public
7  * License as published by the Free Software Foundation; either
8  * version 2.1 of the License, or (at your option) any later version.
9  *
10  * FFmpeg is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13  * Lesser General Public License for more details.
14  *
15  * You should have received a copy of the GNU Lesser General Public
16  * License along with FFmpeg; if not, write to the Free Software
17  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
18  */
19 
20 #include "mpegvideo.h"
21 #include "h263.h"
22 #include "flv.h"
23 #include "libavutil/imgutils.h"
24 
25 void ff_flv2_decode_ac_esc(GetBitContext *gb, int *level, int *run, int *last){
26  int is11 = get_bits1(gb);
27  *last = get_bits1(gb);
28  *run = get_bits(gb, 6);
29  if(is11){
30  *level = get_sbits(gb, 11);
31  } else {
32  *level = get_sbits(gb, 7);
33  }
34 }
35 
37 {
38  int format, width, height;
39 
40  /* picture header */
41  if (get_bits_long(&s->gb, 17) != 1) {
42  av_log(s->avctx, AV_LOG_ERROR, "Bad picture start code\n");
43  return AVERROR_INVALIDDATA;
44  }
45  format = get_bits(&s->gb, 5);
46  if (format != 0 && format != 1) {
47  av_log(s->avctx, AV_LOG_ERROR, "Bad picture format\n");
48  return AVERROR_INVALIDDATA;
49  }
50  s->h263_flv = format+1;
51  s->picture_number = get_bits(&s->gb, 8); /* picture timestamp */
52  format = get_bits(&s->gb, 3);
53  switch (format) {
54  case 0:
55  width = get_bits(&s->gb, 8);
56  height = get_bits(&s->gb, 8);
57  break;
58  case 1:
59  width = get_bits(&s->gb, 16);
60  height = get_bits(&s->gb, 16);
61  break;
62  case 2:
63  width = 352;
64  height = 288;
65  break;
66  case 3:
67  width = 176;
68  height = 144;
69  break;
70  case 4:
71  width = 128;
72  height = 96;
73  break;
74  case 5:
75  width = 320;
76  height = 240;
77  break;
78  case 6:
79  width = 160;
80  height = 120;
81  break;
82  default:
83  width = height = 0;
84  break;
85  }
86  if(av_image_check_size(width, height, 0, s->avctx))
87  return AVERROR(EINVAL);
88  s->width = width;
89  s->height = height;
90 
91  s->pict_type = AV_PICTURE_TYPE_I + get_bits(&s->gb, 2);
93  if (s->droppable)
95 
96  skip_bits1(&s->gb); /* deblocking flag */
97  s->chroma_qscale= s->qscale = get_bits(&s->gb, 5);
98 
99  s->h263_plus = 0;
100 
101  s->unrestricted_mv = 1;
102  s->h263_long_vectors = 0;
103 
104  /* PEI */
105  while (get_bits1(&s->gb) != 0) {
106  skip_bits(&s->gb, 8);
107  }
108  s->f_code = 1;
109 
110  if(s->avctx->debug & FF_DEBUG_PICT_INFO){
111  av_log(s->avctx, AV_LOG_DEBUG, "%c esc_type:%d, qp:%d num:%d\n",
113  s->h263_flv - 1, s->qscale, s->picture_number);
114  }
115 
116  s->y_dc_scale_table=
118 
119  return 0;
120 }
121 
123  .name = "flv",
124  .type = AVMEDIA_TYPE_VIDEO,
125  .id = AV_CODEC_ID_FLV1,
126  .priv_data_size = sizeof(MpegEncContext),
130  .capabilities = CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
131  .max_lowres = 3,
132  .long_name = NULL_IF_CONFIG_SMALL("FLV / Sorenson Spark / Sorenson H.263 (Flash Video)"),
133  .pix_fmts = ff_pixfmt_list_420,
134 };