FFmpeg
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
cljrenc.c
Go to the documentation of this file.
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/common.h"
28 #include "libavutil/opt.h"
29 
30 #include "avcodec.h"
31 #include "internal.h"
32 #include "put_bits.h"
33 
34 typedef struct CLJRContext {
37 } CLJRContext;
38 
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  if ((ret = ff_alloc_packet2(avctx, pkt, 32*avctx->height*avctx->width/4)) < 0)
60  return ret;
61 
62  init_put_bits(&pb, pkt->data, pkt->size);
63 
64  for (y = 0; y < avctx->height; y++) {
65  uint8_t *luma = &p->data[0][y * p->linesize[0]];
66  uint8_t *cb = &p->data[1][y * p->linesize[1]];
67  uint8_t *cr = &p->data[2][y * p->linesize[2]];
68  uint8_t luma_tmp[4];
69  for (x = 0; x < avctx->width; x += 4) {
70  switch (a->dither_type) {
71  case 0: dither = 0x492A0000; break;
72  case 1: dither = dither * 1664525 + 1013904223; break;
73  case 2: dither = ordered_dither[ y&1 ][ (x>>2)&1 ];break;
74  }
75  if (x+3 >= avctx->width) {
76  memset(luma_tmp, 0, sizeof(luma_tmp));
77  memcpy(luma_tmp, luma, avctx->width - x);
78  luma = luma_tmp;
79  }
80  put_bits(&pb, 5, (249*(luma[3] + (dither>>29) )) >> 11);
81  put_bits(&pb, 5, (249*(luma[2] + ((dither>>26)&7))) >> 11);
82  put_bits(&pb, 5, (249*(luma[1] + ((dither>>23)&7))) >> 11);
83  put_bits(&pb, 5, (249*(luma[0] + ((dither>>20)&7))) >> 11);
84  luma += 4;
85  put_bits(&pb, 6, (253*(*(cb++) + ((dither>>18)&3))) >> 10);
86  put_bits(&pb, 6, (253*(*(cr++) + ((dither>>16)&3))) >> 10);
87  }
88  }
89 
90  flush_put_bits(&pb);
91 
92  pkt->size = put_bits_count(&pb) / 8;
93  pkt->flags |= AV_PKT_FLAG_KEY;
94  *got_packet = 1;
95  return 0;
96 }
97 
98 #define OFFSET(x) offsetof(CLJRContext, x)
99 #define VE AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_ENCODING_PARAM
100 static const AVOption options[] = {
101  { "dither_type", "Dither type", OFFSET(dither_type), AV_OPT_TYPE_INT, { .i64=1 }, 0, 2, VE},
102  { NULL },
103 };
104 
105 static const AVClass cljr_class = {
106  .class_name = "cljr encoder",
107  .item_name = av_default_item_name,
108  .option = options,
109  .version = LIBAVUTIL_VERSION_INT,
110 };
111 
113  .name = "cljr",
114  .long_name = NULL_IF_CONFIG_SMALL("Cirrus Logic AccuPak"),
115  .type = AVMEDIA_TYPE_VIDEO,
116  .id = AV_CODEC_ID_CLJR,
117  .priv_data_size = sizeof(CLJRContext),
118  .encode2 = encode_frame,
119  .pix_fmts = (const enum AVPixelFormat[]) { AV_PIX_FMT_YUV411P,
120  AV_PIX_FMT_NONE },
121  .priv_class = &cljr_class,
122 };