FFmpeg: libavcodec/jvdec.c Source File

FFmpeg
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 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  * Bitmap Brothers JV video decoder
25  * @author Peter Ross <pross@xvid.org>
26  */
27 
28 #include "avcodec.h"
29 #include "dsputil.h"
30 #include "get_bits.h"
31 #include "internal.h"
32 #include "libavutil/intreadwrite.h"
33 
34  typedef struct JvContext {
35   DSPContext dsp;
36   AVFrame frame;
37   uint32_t palette[AVPALETTE_COUNT];
38   int palette_has_changed;
39 } JvContext;
40 
41  static av_cold int decode_init(AVCodecContext *avctx)
42 {
43  JvContext *s = avctx->priv_data;
44  avctx->pix_fmt = AV_PIX_FMT_PAL8;
45  ff_dsputil_init(&s->dsp, avctx);
46  avcodec_get_frame_defaults(&s->frame);
47  return 0;
48 }
49 
50 /**
51  * Decode 2x2 block
52  */
53  static inline void decode2x2(GetBitContext *gb, uint8_t *dst, int linesize)
54 {
55  int i, j, v[2];
56 
57  switch (get_bits(gb, 2)) {
58  case 1:
59  v[0] = get_bits(gb, 8);
60  for (j = 0; j < 2; j++)
61  memset(dst + j*linesize, v[0], 2);
62  break;
63  case 2:
64  v[0] = get_bits(gb, 8);
65  v[1] = get_bits(gb, 8);
66  for (j = 0; j < 2; j++)
67  for (i = 0; i < 2; i++)
68  dst[j*linesize + i] = v[get_bits1(gb)];
69  break;
70  case 3:
71  for (j = 0; j < 2; j++)
72  for (i = 0; i < 2; i++)
73  dst[j*linesize + i] = get_bits(gb, 8);
74  }
75 }
76 
77 /**
78  * Decode 4x4 block
79  */
80  static inline void decode4x4(GetBitContext *gb, uint8_t *dst, int linesize)
81 {
82  int i, j, v[2];
83 
84  switch (get_bits(gb, 2)) {
85  case 1:
86  v[0] = get_bits(gb, 8);
87  for (j = 0; j < 4; j++)
88  memset(dst + j*linesize, v[0], 4);
89  break;
90  case 2:
91  v[0] = get_bits(gb, 8);
92  v[1] = get_bits(gb, 8);
93  for (j = 2; j >= 0; j -= 2) {
94  for (i = 0; i < 4; i++)
95  dst[j*linesize + i] = v[get_bits1(gb)];
96  for (i = 0; i < 4; i++)
97  dst[(j+1)*linesize + i] = v[get_bits1(gb)];
98  }
99  break;
100  case 3:
101  for (j = 0; j < 4; j += 2)
102  for (i = 0; i < 4; i += 2)
103  decode2x2(gb, dst + j*linesize + i, linesize);
104  }
105 }
106 
107 /**
108  * Decode 8x8 block
109  */
110  static inline void decode8x8(GetBitContext *gb, uint8_t *dst, int linesize, DSPContext *dsp)
111 {
112  int i, j, v[2];
113 
114  switch (get_bits(gb, 2)) {
115  case 1:
116  v[0] = get_bits(gb, 8);
117  dsp->fill_block_tab[1](dst, v[0], linesize, 8);
118  break;
119  case 2:
120  v[0] = get_bits(gb, 8);
121  v[1] = get_bits(gb, 8);
122  for (j = 7; j >= 0; j--)
123  for (i = 0; i < 8; i++)
124  dst[j*linesize + i] = v[get_bits1(gb)];
125  break;
126  case 3:
127  for (j = 0; j < 8; j += 4)
128  for (i = 0; i < 8; i += 4)
129  decode4x4(gb, dst + j*linesize + i, linesize);
130  }
131 }
132 
133  static int decode_frame(AVCodecContext *avctx,
134  void *data, int *got_frame,
135  AVPacket *avpkt)
136 {
137  JvContext *s = avctx->priv_data;
138  const uint8_t *buf = avpkt->data;
139  const uint8_t *buf_end = buf + avpkt->size;
140  int video_size, video_type, i, j, ret;
141 
142  if (avpkt->size < 6)
143  return AVERROR_INVALIDDATA;
144 
145  video_size = AV_RL32(buf);
146  video_type = buf[4];
147  buf += 5;
148 
149  if (video_size) {
150  if (video_size < 0 || video_size > avpkt->size - 5) {
151  av_log(avctx, AV_LOG_ERROR, "video size %d invalid\n", video_size);
152  return AVERROR_INVALIDDATA;
153  }
154  if ((ret = ff_reget_buffer(avctx, &s->frame)) < 0)
155  return ret;
156 
157  if (video_type == 0 || video_type == 1) {
158  GetBitContext gb;
159  init_get_bits(&gb, buf, 8 * video_size);
160 
161  for (j = 0; j < avctx->height; j += 8)
162  for (i = 0; i < avctx->width; i += 8)
163  decode8x8(&gb, s->frame.data[0] + j*s->frame.linesize[0] + i,
164  s->frame.linesize[0], &s->dsp);
165 
166  buf += video_size;
167  } else if (video_type == 2) {
168  int v = *buf++;
169  for (j = 0; j < avctx->height; j++)
170  memset(s->frame.data[0] + j*s->frame.linesize[0], v, avctx->width);
171  } else {
172  av_log(avctx, AV_LOG_WARNING, "unsupported frame type %i\n", video_type);
173  return AVERROR_INVALIDDATA;
174  }
175  }
176 
177  if (buf_end - buf >= AVPALETTE_COUNT * 3) {
178  for (i = 0; i < AVPALETTE_COUNT; i++) {
179  uint32_t pal = AV_RB24(buf);
180  s->palette[i] = 0xFFU << 24 | pal << 2 | ((pal >> 4) & 0x30303);
181  buf += 3;
182  }
183  s->palette_has_changed = 1;
184  }
185 
186  if (video_size) {
187  s->frame.key_frame = 1;
188  s->frame.pict_type = AV_PICTURE_TYPE_I;
189  s->frame.palette_has_changed = s->palette_has_changed;
190  s->palette_has_changed = 0;
191  memcpy(s->frame.data[1], s->palette, AVPALETTE_SIZE);
192 
193  if ((ret = av_frame_ref(data, &s->frame)) < 0)
194  return ret;
195  *got_frame = 1;
196  }
197 
198  return avpkt->size;
199 }
200 
201  static av_cold int decode_close(AVCodecContext *avctx)
202 {
203  JvContext *s = avctx->priv_data;
204 
205  av_frame_unref(&s->frame);
206 
207  return 0;
208 }
209 
210  AVCodec ff_jv_decoder = {
211  .name = "jv",
212  .long_name = NULL_IF_CONFIG_SMALL("Bitmap Brothers JV video"),
213  .type = AVMEDIA_TYPE_VIDEO,
214  .id = AV_CODEC_ID_JV,
215  .priv_data_size = sizeof(JvContext),
216  .init = decode_init,
217  .close = decode_close,
218  .decode = decode_frame,
219  .capabilities = CODEC_CAP_DR1,
220 };
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