Libav
jvdec.c
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1 /*
2  * Bitmap Brothers JV video decoder
3  * Copyright (c) 2011 Peter Ross <pross@xvid.org>
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 
28 #include "libavutil/intreadwrite.h"
29 
30 #include "avcodec.h"
31 #include "dsputil.h"
32 #include "get_bits.h"
33 #include "internal.h"
34 
35 typedef struct JvContext {
40 } JvContext;
41 
43 {
44  JvContext *s = avctx->priv_data;
45 
46  if (!avctx->width || !avctx->height ||
47  (avctx->width & 7) || (avctx->height & 7)) {
48  av_log(avctx, AV_LOG_ERROR, "Invalid video dimensions: %dx%d\n",
49  avctx->width, avctx->height);
50  return AVERROR(EINVAL);
51  }
52 
53  s->frame = av_frame_alloc();
54  if (!s->frame)
55  return AVERROR(ENOMEM);
56 
57  avctx->pix_fmt = AV_PIX_FMT_PAL8;
58  ff_dsputil_init(&s->dsp, avctx);
59  return 0;
60 }
61 
65 static inline void decode2x2(GetBitContext *gb, uint8_t *dst, int linesize)
66 {
67  int i, j, v[2];
68 
69  switch (get_bits(gb, 2)) {
70  case 1:
71  v[0] = get_bits(gb, 8);
72  for (j = 0; j < 2; j++)
73  memset(dst + j * linesize, v[0], 2);
74  break;
75  case 2:
76  v[0] = get_bits(gb, 8);
77  v[1] = get_bits(gb, 8);
78  for (j = 0; j < 2; j++)
79  for (i = 0; i < 2; i++)
80  dst[j * linesize + i] = v[get_bits1(gb)];
81  break;
82  case 3:
83  for (j = 0; j < 2; j++)
84  for (i = 0; i < 2; i++)
85  dst[j * linesize + i] = get_bits(gb, 8);
86  }
87 }
88 
92 static inline void decode4x4(GetBitContext *gb, uint8_t *dst, int linesize)
93 {
94  int i, j, v[2];
95 
96  switch (get_bits(gb, 2)) {
97  case 1:
98  v[0] = get_bits(gb, 8);
99  for (j = 0; j < 4; j++)
100  memset(dst + j * linesize, v[0], 4);
101  break;
102  case 2:
103  v[0] = get_bits(gb, 8);
104  v[1] = get_bits(gb, 8);
105  for (j = 2; j >= 0; j -= 2) {
106  for (i = 0; i < 4; i++)
107  dst[j * linesize + i] = v[get_bits1(gb)];
108  for (i = 0; i < 4; i++)
109  dst[(j + 1) * linesize + i] = v[get_bits1(gb)];
110  }
111  break;
112  case 3:
113  for (j = 0; j < 4; j += 2)
114  for (i = 0; i < 4; i += 2)
115  decode2x2(gb, dst + j * linesize + i, linesize);
116  }
117 }
118 
122 static inline void decode8x8(GetBitContext *gb, uint8_t *dst, int linesize,
123  DSPContext *dsp)
124 {
125  int i, j, v[2];
126 
127  switch (get_bits(gb, 2)) {
128  case 1:
129  v[0] = get_bits(gb, 8);
130  dsp->fill_block_tab[1](dst, v[0], linesize, 8);
131  break;
132  case 2:
133  v[0] = get_bits(gb, 8);
134  v[1] = get_bits(gb, 8);
135  for (j = 7; j >= 0; j--)
136  for (i = 0; i < 8; i++)
137  dst[j * linesize + i] = v[get_bits1(gb)];
138  break;
139  case 3:
140  for (j = 0; j < 8; j += 4)
141  for (i = 0; i < 8; i += 4)
142  decode4x4(gb, dst + j * linesize + i, linesize);
143  }
144 }
145 
146 static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
147  AVPacket *avpkt)
148 {
149  JvContext *s = avctx->priv_data;
150  int buf_size = avpkt->size;
151  const uint8_t *buf = avpkt->data;
152  const uint8_t *buf_end = buf + buf_size;
153  int video_size, video_type, i, j, ret;
154 
155  video_size = AV_RL32(buf);
156  video_type = buf[4];
157  buf += 5;
158 
159  if (video_size) {
160  if ((ret = ff_reget_buffer(avctx, s->frame)) < 0) {
161  av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
162  return ret;
163  }
164 
165  if (video_type == 0 || video_type == 1) {
166  GetBitContext gb;
167  init_get_bits(&gb, buf, 8 * FFMIN(video_size, buf_end - buf));
168 
169  for (j = 0; j < avctx->height; j += 8)
170  for (i = 0; i < avctx->width; i += 8)
171  decode8x8(&gb,
172  s->frame->data[0] + j * s->frame->linesize[0] + i,
173  s->frame->linesize[0], &s->dsp);
174 
175  buf += video_size;
176  } else if (video_type == 2) {
177  if (buf + 1 <= buf_end) {
178  int v = *buf++;
179  for (j = 0; j < avctx->height; j++)
180  memset(s->frame->data[0] + j * s->frame->linesize[0],
181  v, avctx->width);
182  }
183  } else {
184  av_log(avctx, AV_LOG_WARNING,
185  "unsupported frame type %i\n", video_type);
186  return AVERROR_INVALIDDATA;
187  }
188  }
189 
190  if (buf < buf_end) {
191  for (i = 0; i < AVPALETTE_COUNT && buf + 3 <= buf_end; i++) {
192  s->palette[i] = AV_RB24(buf) << 2;
193  buf += 3;
194  }
195  s->palette_has_changed = 1;
196  }
197 
198  if (video_size) {
199  s->frame->key_frame = 1;
202  s->palette_has_changed = 0;
203  memcpy(s->frame->data[1], s->palette, AVPALETTE_SIZE);
204 
205  if ((ret = av_frame_ref(data, s->frame)) < 0)
206  return ret;
207  *got_frame = 1;
208  }
209 
210  return buf_size;
211 }
212 
214 {
215  JvContext *s = avctx->priv_data;
216 
217  av_frame_free(&s->frame);
218 
219  return 0;
220 }
221 
223  .name = "jv",
224  .long_name = NULL_IF_CONFIG_SMALL("Bitmap Brothers JV video"),
225  .type = AVMEDIA_TYPE_VIDEO,
226  .id = AV_CODEC_ID_JV,
227  .priv_data_size = sizeof(JvContext),
228  .init = decode_init,
229  .close = decode_close,
230  .decode = decode_frame,
231  .capabilities = CODEC_CAP_DR1,
232 };