xref: /third_party/ffmpeg/libavcodec/flvenc.c (revision cabdff1a)
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 "codec_internal.h"
22#include "flvenc.h"
23#include "h263data.h"
24#include "mpegvideo.h"
25#include "mpegvideodata.h"
26#include "mpegvideoenc.h"
27
28void ff_flv_encode_picture_header(MpegEncContext *s, int picture_number)
29{
30    int format;
31
32    align_put_bits(&s->pb);
33
34    put_bits(&s->pb, 17, 1);
35    /* 0: H.263 escape codes 1: 11-bit escape codes */
36    put_bits(&s->pb, 5, (s->h263_flv - 1));
37    put_bits(&s->pb, 8,
38             (((int64_t) s->picture_number * 30 * s->avctx->time_base.num) /   // FIXME use timestamp
39              s->avctx->time_base.den) & 0xff);   /* TemporalReference */
40    if (s->width == 352 && s->height == 288)
41        format = 2;
42    else if (s->width == 176 && s->height == 144)
43        format = 3;
44    else if (s->width == 128 && s->height == 96)
45        format = 4;
46    else if (s->width == 320 && s->height == 240)
47        format = 5;
48    else if (s->width == 160 && s->height == 120)
49        format = 6;
50    else if (s->width <= 255 && s->height <= 255)
51        format = 0;   /* use 1 byte width & height */
52    else
53        format = 1;   /* use 2 bytes width & height */
54    put_bits(&s->pb, 3, format);   /* PictureSize */
55    if (format == 0) {
56        put_bits(&s->pb, 8, s->width);
57        put_bits(&s->pb, 8, s->height);
58    } else if (format == 1) {
59        put_bits(&s->pb, 16, s->width);
60        put_bits(&s->pb, 16, s->height);
61    }
62    put_bits(&s->pb, 2, s->pict_type == AV_PICTURE_TYPE_P);   /* PictureType */
63    put_bits(&s->pb, 1, 1);   /* DeblockingFlag: on */
64    put_bits(&s->pb, 5, s->qscale);   /* Quantizer */
65    put_bits(&s->pb, 1, 0);   /* ExtraInformation */
66
67    if (s->h263_aic) {
68        s->y_dc_scale_table =
69        s->c_dc_scale_table = ff_aic_dc_scale_table;
70    } else {
71        s->y_dc_scale_table =
72        s->c_dc_scale_table = ff_mpeg1_dc_scale_table;
73    }
74}
75
76void ff_flv2_encode_ac_esc(PutBitContext *pb, int slevel, int level,
77                           int run, int last)
78{
79    if (level < 64) { // 7-bit level
80        put_bits(pb, 1, 0);
81        put_bits(pb, 1, last);
82        put_bits(pb, 6, run);
83
84        put_sbits(pb, 7, slevel);
85    } else {
86        /* 11-bit level */
87        put_bits(pb, 1, 1);
88        put_bits(pb, 1, last);
89        put_bits(pb, 6, run);
90
91        put_sbits(pb, 11, slevel);
92    }
93}
94
95const FFCodec ff_flv_encoder = {
96    .p.name         = "flv",
97    .p.long_name    = NULL_IF_CONFIG_SMALL("FLV / Sorenson Spark / Sorenson H.263 (Flash Video)"),
98    .p.type         = AVMEDIA_TYPE_VIDEO,
99    .p.id           = AV_CODEC_ID_FLV1,
100    .p.priv_class   = &ff_mpv_enc_class,
101    .priv_data_size = sizeof(MpegEncContext),
102    .init           = ff_mpv_encode_init,
103    FF_CODEC_ENCODE_CB(ff_mpv_encode_picture),
104    .close          = ff_mpv_encode_end,
105    .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE | FF_CODEC_CAP_INIT_CLEANUP,
106    .p.pix_fmts     = (const enum AVPixelFormat[]) { AV_PIX_FMT_YUV420P,
107                                                     AV_PIX_FMT_NONE},
108};
109