1 /*
2 * Cirrus Logic AccuPak (CLJR) encoder
3 * Copyright (c) 2003 Alex Beregszaszi
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22 /**
23 * @file
24 * Cirrus Logic AccuPak encoder.
25 */
26
27 #include "libavutil/opt.h"
28
29 #include "avcodec.h"
30 #include "codec_internal.h"
31 #include "encode.h"
32 #include "put_bits.h"
33
34 typedef struct CLJRContext {
35 AVClass *avclass;
36 int dither_type;
37 } CLJRContext;
38
encode_frame(AVCodecContext * avctx,AVPacket * pkt,const AVFrame * p,int * got_packet)39 static int encode_frame(AVCodecContext *avctx, AVPacket *pkt,
40 const AVFrame *p, int *got_packet)
41 {
42 CLJRContext *a = avctx->priv_data;
43 PutBitContext pb;
44 int x, y, ret;
45 uint32_t dither= avctx->frame_number;
46 static const uint32_t ordered_dither[2][2] =
47 {
48 { 0x10400000, 0x104F0000 },
49 { 0xCB2A0000, 0xCB250000 },
50 };
51
52 if (avctx->width%4 && avctx->strict_std_compliance > FF_COMPLIANCE_UNOFFICIAL) {
53 av_log(avctx, AV_LOG_ERROR,
54 "Widths which are not a multiple of 4 might fail with some decoders, "
55 "use vstrict=-1 / -strict -1 to use %d anyway.\n", avctx->width);
56 return AVERROR_EXPERIMENTAL;
57 }
58
59 ret = ff_get_encode_buffer(avctx, pkt, 4 * avctx->height * ((avctx->width + 3) / 4), 0);
60 if (ret < 0)
61 return ret;
62
63 init_put_bits(&pb, pkt->data, pkt->size);
64
65 for (y = 0; y < avctx->height; y++) {
66 uint8_t *luma = &p->data[0][y * p->linesize[0]];
67 uint8_t *cb = &p->data[1][y * p->linesize[1]];
68 uint8_t *cr = &p->data[2][y * p->linesize[2]];
69 uint8_t luma_tmp[4];
70 for (x = 0; x < avctx->width; x += 4) {
71 switch (a->dither_type) {
72 case 0: dither = 0x492A0000; break;
73 case 1: dither = dither * 1664525 + 1013904223; break;
74 case 2: dither = ordered_dither[ y&1 ][ (x>>2)&1 ];break;
75 }
76 if (x+3 >= avctx->width) {
77 memset(luma_tmp, 0, sizeof(luma_tmp));
78 memcpy(luma_tmp, luma, avctx->width - x);
79 luma = luma_tmp;
80 }
81 put_bits(&pb, 5, (249*(luma[3] + (dither>>29) )) >> 11);
82 put_bits(&pb, 5, (249*(luma[2] + ((dither>>26)&7))) >> 11);
83 put_bits(&pb, 5, (249*(luma[1] + ((dither>>23)&7))) >> 11);
84 put_bits(&pb, 5, (249*(luma[0] + ((dither>>20)&7))) >> 11);
85 luma += 4;
86 put_bits(&pb, 6, (253*(*(cb++) + ((dither>>18)&3))) >> 10);
87 put_bits(&pb, 6, (253*(*(cr++) + ((dither>>16)&3))) >> 10);
88 }
89 }
90
91 flush_put_bits(&pb);
92
93 *got_packet = 1;
94 return 0;
95 }
96
97 #define OFFSET(x) offsetof(CLJRContext, x)
98 #define VE AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_ENCODING_PARAM
99 static const AVOption options[] = {
100 { "dither_type", "Dither type", OFFSET(dither_type), AV_OPT_TYPE_INT, { .i64=1 }, 0, 2, VE},
101 { NULL },
102 };
103
104 static const AVClass cljr_class = {
105 .class_name = "cljr encoder",
106 .item_name = av_default_item_name,
107 .option = options,
108 .version = LIBAVUTIL_VERSION_INT,
109 };
110
111 const FFCodec ff_cljr_encoder = {
112 .p.name = "cljr",
113 .p.long_name = NULL_IF_CONFIG_SMALL("Cirrus Logic AccuPak"),
114 .p.type = AVMEDIA_TYPE_VIDEO,
115 .p.id = AV_CODEC_ID_CLJR,
116 .p.capabilities = AV_CODEC_CAP_DR1,
117 .priv_data_size = sizeof(CLJRContext),
118 FF_CODEC_ENCODE_CB(encode_frame),
119 .p.pix_fmts = (const enum AVPixelFormat[]) { AV_PIX_FMT_YUV411P,
120 AV_PIX_FMT_NONE },
121 .p.priv_class = &cljr_class,
122 };
123