cljr.c
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1 /*
2  * Cirrus Logic AccuPak (CLJR) codec
3  * Copyright (c) 2003 Alex Beregszaszi
4  *
5  * This file is part of Libav.
6  *
7  * Libav 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  * Libav 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 Libav; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
27 #include "avcodec.h"
28 #include "get_bits.h"
29 #include "put_bits.h"
30 
31 typedef struct CLJRContext {
33 } CLJRContext;
34 
36 {
37  CLJRContext * const a = avctx->priv_data;
38 
39  avctx->coded_frame = &a->picture;
40 
41  return 0;
42 }
43 
44 #if CONFIG_CLJR_DECODER
45 static int decode_frame(AVCodecContext *avctx,
46  void *data, int *data_size,
47  AVPacket *avpkt)
48 {
49  const uint8_t *buf = avpkt->data;
50  int buf_size = avpkt->size;
51  CLJRContext * const a = avctx->priv_data;
52  GetBitContext gb;
53  AVFrame *picture = data;
54  AVFrame * const p = &a->picture;
55  int x, y;
56 
57  if (p->data[0])
58  avctx->release_buffer(avctx, p);
59 
60  if (avctx->height <= 0 || avctx->width <= 0) {
61  av_log(avctx, AV_LOG_ERROR, "Invalid width or height\n");
62  return AVERROR_INVALIDDATA;
63  }
64 
65  if (buf_size < avctx->height * avctx->width) {
66  av_log(avctx, AV_LOG_ERROR,
67  "Resolution larger than buffer size. Invalid header?\n");
68  return AVERROR_INVALIDDATA;
69  }
70 
71  p->reference = 0;
72  if (avctx->get_buffer(avctx, p) < 0) {
73  av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
74  return -1;
75  }
77  p->key_frame = 1;
78 
79  init_get_bits(&gb, buf, buf_size * 8);
80 
81  for (y = 0; y < avctx->height; y++) {
82  uint8_t *luma = &a->picture.data[0][y * a->picture.linesize[0]];
83  uint8_t *cb = &a->picture.data[1][y * a->picture.linesize[1]];
84  uint8_t *cr = &a->picture.data[2][y * a->picture.linesize[2]];
85  for (x = 0; x < avctx->width; x += 4) {
86  luma[3] = get_bits(&gb, 5) << 3;
87  luma[2] = get_bits(&gb, 5) << 3;
88  luma[1] = get_bits(&gb, 5) << 3;
89  luma[0] = get_bits(&gb, 5) << 3;
90  luma += 4;
91  *(cb++) = get_bits(&gb, 6) << 2;
92  *(cr++) = get_bits(&gb, 6) << 2;
93  }
94  }
95 
96  *picture = a->picture;
97  *data_size = sizeof(AVPicture);
98 
99  return buf_size;
100 }
101 
102 static av_cold int decode_init(AVCodecContext *avctx)
103 {
104  avctx->pix_fmt = PIX_FMT_YUV411P;
105  return common_init(avctx);
106 }
107 
108 static av_cold int decode_end(AVCodecContext *avctx)
109 {
110  CLJRContext *a = avctx->priv_data;
111 
112  if (a->picture.data[0])
113  avctx->release_buffer(avctx, &a->picture);
114  return 0;
115 }
116 
117 AVCodec ff_cljr_decoder = {
118  .name = "cljr",
119  .type = AVMEDIA_TYPE_VIDEO,
120  .id = CODEC_ID_CLJR,
121  .priv_data_size = sizeof(CLJRContext),
122  .init = decode_init,
123  .close = decode_end,
124  .decode = decode_frame,
125  .capabilities = CODEC_CAP_DR1,
126  .long_name = NULL_IF_CONFIG_SMALL("Cirrus Logic AccuPak"),
127 };
128 #endif
129 
130 #if CONFIG_CLJR_ENCODER
131 static int encode_frame(AVCodecContext *avctx, unsigned char *buf,
132  int buf_size, void *data)
133 {
134  PutBitContext pb;
135  AVFrame *p = data;
136  int x, y;
137 
139  p->key_frame = 1;
140 
141  init_put_bits(&pb, buf, buf_size / 8);
142 
143  for (y = 0; y < avctx->height; y++) {
144  uint8_t *luma = &p->data[0][y * p->linesize[0]];
145  uint8_t *cb = &p->data[1][y * p->linesize[1]];
146  uint8_t *cr = &p->data[2][y * p->linesize[2]];
147  for (x = 0; x < avctx->width; x += 4) {
148  put_bits(&pb, 5, luma[3] >> 3);
149  put_bits(&pb, 5, luma[2] >> 3);
150  put_bits(&pb, 5, luma[1] >> 3);
151  put_bits(&pb, 5, luma[0] >> 3);
152  luma += 4;
153  put_bits(&pb, 6, *(cb++) >> 2);
154  put_bits(&pb, 6, *(cr++) >> 2);
155  }
156  }
157 
158  flush_put_bits(&pb);
159 
160  return put_bits_count(&pb) / 8;
161 }
162 
163 AVCodec ff_cljr_encoder = {
164  .name = "cljr",
165  .type = AVMEDIA_TYPE_VIDEO,
166  .id = CODEC_ID_CLJR,
167  .priv_data_size = sizeof(CLJRContext),
168  .init = common_init,
169  .encode = encode_frame,
170  .pix_fmts = (const enum PixelFormat[]) { PIX_FMT_YUV411P,
171  PIX_FMT_NONE },
172  .long_name = NULL_IF_CONFIG_SMALL("Cirrus Logic AccuPak"),
173 };
174 #endif