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1 /*
2  * FLV Encoding specific code.
3  *
4  * This file is part of FFmpeg.
5  *
6  * FFmpeg 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  * FFmpeg 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 FFmpeg; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 #include "flv.h"
22 #include "h263.h"
23 #include "h263data.h"
24 #include "mpegvideo.h"
25 #include "mpegvideodata.h"
26 
ff_flv_encode_picture_header(MpegEncContext * s,int picture_number)27 void ff_flv_encode_picture_header(MpegEncContext *s, int picture_number)
28 {
29     int format;
30 
31     align_put_bits(&s->pb);
32 
33     put_bits(&s->pb, 17, 1);
34     /* 0: H.263 escape codes 1: 11-bit escape codes */
35     put_bits(&s->pb, 5, (s->h263_flv - 1));
36     put_bits(&s->pb, 8,
37              (((int64_t) s->picture_number * 30 * s->avctx->time_base.num) /   // FIXME use timestamp
38               s->avctx->time_base.den) & 0xff);   /* TemporalReference */
39     if (s->width == 352 && s->height == 288)
40         format = 2;
41     else if (s->width == 176 && s->height == 144)
42         format = 3;
43     else if (s->width == 128 && s->height == 96)
44         format = 4;
45     else if (s->width == 320 && s->height == 240)
46         format = 5;
47     else if (s->width == 160 && s->height == 120)
48         format = 6;
49     else if (s->width <= 255 && s->height <= 255)
50         format = 0;   /* use 1 byte width & height */
51     else
52         format = 1;   /* use 2 bytes width & height */
53     put_bits(&s->pb, 3, format);   /* PictureSize */
54     if (format == 0) {
55         put_bits(&s->pb, 8, s->width);
56         put_bits(&s->pb, 8, s->height);
57     } else if (format == 1) {
58         put_bits(&s->pb, 16, s->width);
59         put_bits(&s->pb, 16, s->height);
60     }
61     put_bits(&s->pb, 2, s->pict_type == AV_PICTURE_TYPE_P);   /* PictureType */
62     put_bits(&s->pb, 1, 1);   /* DeblockingFlag: on */
63     put_bits(&s->pb, 5, s->qscale);   /* Quantizer */
64     put_bits(&s->pb, 1, 0);   /* ExtraInformation */
65 
66     if (s->h263_aic) {
67         s->y_dc_scale_table =
68         s->c_dc_scale_table = ff_aic_dc_scale_table;
69     } else {
70         s->y_dc_scale_table =
71         s->c_dc_scale_table = ff_mpeg1_dc_scale_table;
72     }
73 }
74 
ff_flv2_encode_ac_esc(PutBitContext * pb,int slevel,int level,int run,int last)75 void ff_flv2_encode_ac_esc(PutBitContext *pb, int slevel, int level,
76                            int run, int last)
77 {
78     if (level < 64) { // 7-bit level
79         put_bits(pb, 1, 0);
80         put_bits(pb, 1, last);
81         put_bits(pb, 6, run);
82 
83         put_sbits(pb, 7, slevel);
84     } else {
85         /* 11-bit level */
86         put_bits(pb, 1, 1);
87         put_bits(pb, 1, last);
88         put_bits(pb, 6, run);
89 
90         put_sbits(pb, 11, slevel);
91     }
92 }
93 
94 static const AVClass flv_class = {
95     .class_name = "flv encoder",
96     .item_name  = av_default_item_name,
97     .option     = ff_mpv_generic_options,
98     .version    = LIBAVUTIL_VERSION_INT,
99 };
100 
101 AVCodec ff_flv_encoder = {
102     .name           = "flv",
103     .long_name      = NULL_IF_CONFIG_SMALL("FLV / Sorenson Spark / Sorenson H.263 (Flash Video)"),
104     .type           = AVMEDIA_TYPE_VIDEO,
105     .id             = AV_CODEC_ID_FLV1,
106     .priv_data_size = sizeof(MpegEncContext),
107     .init           = ff_mpv_encode_init,
108     .encode2        = ff_mpv_encode_picture,
109     .close          = ff_mpv_encode_end,
110     .caps_internal  = FF_CODEC_CAP_INIT_CLEANUP,
111     .pix_fmts       = (const enum AVPixelFormat[]) { AV_PIX_FMT_YUV420P,
112                                                      AV_PIX_FMT_NONE},
113     .priv_class     = &flv_class,
114 };
115