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
24void ff_flv2_decode_ac_esc(GetBitContext *gb, int *level, int *run, int *last){
25    int is11 = get_bits1(gb);
26    *last = get_bits1(gb);
27    *run = get_bits(gb, 6);
28    if(is11){
29        *level = get_sbits(gb, 11);
30    } else {
31        *level = get_sbits(gb, 7);
32    }
33}
34
35int ff_flv_decode_picture_header(MpegEncContext *s)
36{
37    int format, width, height;
38
39    /* picture header */
40    if (get_bits_long(&s->gb, 17) != 1) {
41        av_log(s->avctx, AV_LOG_ERROR, "Bad picture start code\n");
42        return -1;
43    }
44    format = get_bits(&s->gb, 5);
45    if (format != 0 && format != 1) {
46        av_log(s->avctx, AV_LOG_ERROR, "Bad picture format\n");
47        return -1;
48    }
49    s->h263_flv = format+1;
50    s->picture_number = get_bits(&s->gb, 8); /* picture timestamp */
51    format = get_bits(&s->gb, 3);
52    switch (format) {
53    case 0:
54        width = get_bits(&s->gb, 8);
55        height = get_bits(&s->gb, 8);
56        break;
57    case 1:
58        width = get_bits(&s->gb, 16);
59        height = get_bits(&s->gb, 16);
60        break;
61    case 2:
62        width = 352;
63        height = 288;
64        break;
65    case 3:
66        width = 176;
67        height = 144;
68        break;
69    case 4:
70        width = 128;
71        height = 96;
72        break;
73    case 5:
74        width = 320;
75        height = 240;
76        break;
77    case 6:
78        width = 160;
79        height = 120;
80        break;
81    default:
82        width = height = 0;
83        break;
84    }
85    if(avcodec_check_dimensions(s->avctx, width, height))
86        return -1;
87    s->width = width;
88    s->height = height;
89
90    s->pict_type = FF_I_TYPE + get_bits(&s->gb, 2);
91    s->dropable= s->pict_type > FF_P_TYPE;
92    if (s->dropable)
93        s->pict_type = FF_P_TYPE;
94
95    skip_bits1(&s->gb); /* deblocking flag */
96    s->chroma_qscale= s->qscale = get_bits(&s->gb, 5);
97
98    s->h263_plus = 0;
99
100    s->unrestricted_mv = 1;
101    s->h263_long_vectors = 0;
102
103    /* PEI */
104    while (get_bits1(&s->gb) != 0) {
105        skip_bits(&s->gb, 8);
106    }
107    s->f_code = 1;
108
109    if(s->avctx->debug & FF_DEBUG_PICT_INFO){
110        av_log(s->avctx, AV_LOG_DEBUG, "%c esc_type:%d, qp:%d num:%d\n",
111               s->dropable ? 'D' : av_get_pict_type_char(s->pict_type), s->h263_flv-1, s->qscale, s->picture_number);
112    }
113
114    s->y_dc_scale_table=
115    s->c_dc_scale_table= ff_mpeg1_dc_scale_table;
116
117    return 0;
118}
119
120AVCodec flv_decoder = {
121    "flv",
122    AVMEDIA_TYPE_VIDEO,
123    CODEC_ID_FLV1,
124    sizeof(MpegEncContext),
125    ff_h263_decode_init,
126    NULL,
127    ff_h263_decode_end,
128    ff_h263_decode_frame,
129    CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
130    .long_name= NULL_IF_CONFIG_SMALL("Flash Video (FLV) / Sorenson Spark / Sorenson H.263"),
131    .pix_fmts= ff_pixfmt_list_420,
132};
133